Display options:
Normal
Show Abstracts
Compact
Select/unselect all
Displaying article 1-53
p. 2743-2753
Received: 27 December 2010; in revised form: 11 March 2011 / Accepted: 17 March 2011 / Published: 24 March 2011
Show/Hide Abstract
| Download PDF Full-text (242 KB) Abstract: Arabinoxylans were prepared from different hull-less barley milling fractions (bran, shorts and flour). The yields of hull-less bran arabinoxylan (HBB-AX), shorts arabinoxylan (HBS-AX) and flour arabinoxylan (HBF-AX) were 8.42%, 4.08% and 2.13% respectively. Sugar composition analysis showed that arabinose and xylose were the main sugars. HBF-AX had the highest Ara/Xyl ratio, followed by HBS-AX and HBB-AX. Size exclusion chromatography analysis (HPSEC) showed that HBF-AX had the highest molecular weight, followed by HBS-AX and HBB-AX, which had the lowest molecular weight. Aqueous solutions of HBB-AX, HBS-AX and HBF-AX had higher molecular weight(Mw) than in 0.5 mol/L NaOH and 1.0 mol/L NaOH. Dynamic light scattering analysis (DLS) showed that HBB-AX, HBS-AX and HBF-AX had existed in two states in distilled water, 0.5 mol/LNaOH, 1.0 mol/L NaOH, and DMSO/H2 O (90/10), an unaggregated state and an aggregated state, with the latter predominating.
p. 2754-2765
Received: 10 February 2011; in revised form: 18 March 2011 / Accepted: 22 March 2011 / Published: 24 March 2011
Show/Hide Abstract
| Download PDF Full-text (251 KB) Abstract: The methanolic and aqueous extracts of Garcinia kola seeds were screened for their anti-Vibrio activities against 50 Vibrio isolates obtained from wastewater final effluents in the Eastern Cape Province, South Africa. The crude extracts at 10 mg/mL exhibited appreciable inhibitory activities against most of the test Vibrio isolates, with zones of inhibition ranging from 10–19 mm for methanol extract and 8–15 mm for the aqueous extracts. The minimum inhibitory concentrations (MIC) of the methanol extract varied from 0.313 to 2.5 mg/mL while that for the aqueous extract was 10 mg/mL for all the susceptible Vibrio isolates. Rate of kill assay of the methanolic extracts against three selected Vibrio species showed bacteriostatic activities against all of them achieving 58% and 60% (Vibrio vulnificus AL042); 68% and 69% (Vibrio parahaemolyticus AL049); and 70% and 78% (Vibrio fluvialis AL040) killing of the test bacteria at 3× and 4 ×MIC values, respectively, after 2 h exposure time. We conclude that Garcinia kola seeds hold promise as a potential source of therapeutic compounds of relevance in Vibrio infections management.
p. 2766-2784
Received: 21 January 2011; in revised form: 10 March 2011 / Accepted: 22 March 2011 / Published: 25 March 2011
Show/Hide Abstract
| Download PDF Full-text (208 KB) Abstract: Sheep, cattle and goat are domestic ruminants of significant economic interest in the Mediterranean region. Although sharing the same pasture ranges, they ingest different plants and plant parts and, consequently different levels of tannins. This suggests an ability to detect and adapt ingestion according to animal physiological limits of tolerance for plant secondary metabolites. This review will detail the effects of dietary tannins on feeding behavior, and the role of the oral cavity in this process, with focus on such ruminant species. The role of salivary protein profile in tannin perception in the oral cavity, and as a defense mechanism, will be discussed.
(This article belongs to the Special Issue
Tannins )
p. 2785-2795
Received: 31 December 2010; in revised form: 28 February 2011 / Accepted: 2 March 2011 / Published: 29 March 2011
Show/Hide Abstract
| Download PDF Full-text (301 KB) Abstract: Two tetranortriterpenoids, kokosanolide A (1 ) and C (2 ) were isolated from the seeds and three onoceranoid-type triterpenoids: kokosanolide B (3 ), 8,14-secogammacera-7,14-diene-3,21-dione (4 ) and a 1.5:0.5 mixture of 8,14-secogammacera-7,14(27)-diene-3,21-dione (5) and compound 4 were isolated from the bark of kokossan (Lansium domesticum ). Complete 1 H- and 13 C-NMR data of the triterpenoids 1 -5 are reported. The triterpenoids’ structures were elucidated primarily by means of high field 1D- and 2D-NMR, IR and HRMS spectral data. Triterpenoids 1 -5 exhibited moderate to strong antifeedant activity against the fourth instar larvae of Epilachna vigintioctopunctata .
p. 2796-2801
Received: 28 January 2011; in revised form: 21 March 2011 / Accepted: 23 March 2011 / Published: 30 March 2011
Show/Hide Abstract
| Download PDF Full-text (217 KB) Abstract: A new polyketide compound 1 and a new naturally occurring chromone derivative 2 , along with two known indole alkaloids 3 –4 were characterized from the ethyl acetate extract of a soil-derived fungal strain, Exophiala pisciphila PHF-9. The structures of compounds 1 –4 were established by detailed spectroscopic analysis and comparison with literature data. The absolute configuration of 1 was determined by a modified Mosher’s method. Compound 1 exhibited moderate cytotoxicity against A-549, Hela, PANC-28 and BEL-7402 cell lines.
p. 2802-2816
Received: 1 March 2011; in revised form: 21 March 2011 / Accepted: 28 March 2011 / Published: 30 March 2011
Show/Hide Abstract
| Download PDF Full-text (222 KB) Abstract: Panax ginseng is one of the most commonly used Chinese medicines in China, Asia and Western countries. The beneficial effects of ginseng have been attributed to the biological activities of its constituents, the ginsenosides. In this review, we summarize recent publications on the anti-inflammatory effects of ginseng extracts and ginsenosides on cellular responses triggered by different inducers including endotoxin, tumor necrosis factor-alpha (TNF-α), interferon-gamma and other stimuli. Proinflammatory cytokines, chemokines, adhesion molecules and mediators of inflammation including inducible nitric oxide synthase, cyclooxygenase-2 and nitric oxide orchestrate the inflammatory response. Ginseng extracts and ginsenosides including Rb1 , Rd, Rg1 , Rg3 , Rh1 , Rh2 , Rh3 and Rp1 have been reported to have anti-inflammatory properties in different studies related to inflammation. Ginsenosides inhibit different inducers-activated signaling protein kinases and transcription factor nuclear factor-kappaB leading to decreases in the production of cytokines and mediators of inflammation. The therapeutic potential of ginseng on TNF-α-mediated inflammatory diseases is also discussed. Taken together, this summary provides evidences for the anti-inflammatory effects of ginseng extracts and ginsenosides as well as the underlying mechanisms of their effects on inflammatory diseases.
p. 2817-2832
Received: 15 February 2011; in revised form: 24 March 2011 / Accepted: 28 March 2011 / Published: 30 March 2011
Show/Hide Abstract
| Download PDF Full-text (250 KB) Abstract: A convenient and general method for the synthesis in 26–73% yields of a new series of 7-alkyl(aryl/heteroaryl)-2-amino-5-trifluoromethyl-1,8-naphthyridines from direct cyclocondensation reactions of 4-alkoxy-1,1,1-trifluoroalk-3-en-2-ones [CF3 C(O)CH=C(R1 )OR, where R1 = H, Me, Ph, 4-MePh, 4-OMePh, 4-FPh, 4-BrPh, 4-NO2 Ph, 2-furyl, 2-thienyl and R = Me, Et] with 2,6-diaminopyridine (2,6-DAP), under mild conditions, is described. Another synthetic route also allowed the synthesis of 2-amino-5-trifluoromethyl-cycloalka[b ][1,8]naphthyridines in 33–36% yields, from direct or indirect cyclo-condensation reactions of five-, six- and seven-membered 2-trifluoroacetyl-1-methoxy-cycloalkenes with 2,6-DAP.
p. 2833-2845
Received: 28 February 2011; in revised form: 16 March 2011 / Accepted: 25 March 2011 / Published: 30 March 2011
Show/Hide Abstract
| Download PDF Full-text (250 KB) Abstract: A series of novel 5-(4-hydroxybenzyl)-2-thioxoimidazolidin-4-one esters were synthesized under mild conditions by the reaction of 5-(4-hydroxybenzyl)-2-thioxoimidazolidin-4-one and carboxylic acids with DCC and DMAP as the promoters. Their structures were confirmed by 1 H-NMR, IR, ESI-MS and elemental analysis. The preliminary bioassy results indicated that some of compounds exhibit good herbicidal activity against Zea mays , Triticum aestivum and Arabidopsis thaliana . The further greenhouse test showed that compounds 6 -16 and 6 -28 have 60%, 50% and 50% efficacy against Stellaria media, Echinochloa crus-galli and Setaria viridis at 1,000 g/ha, respectively.
p. 2846-2861
Received: 10 January 2011; in revised form: 7 March 2011 / Accepted: 9 March 2011 / Published: 31 March 2011
Show/Hide Abstract
| Download PDF Full-text (294 KB) Abstract: The concentration of trans -resveratrol in 165 grape cane samples from three major grape production regions and four large distribution centers of Chinese wild Vitis species were determined by reversed-phase high-performance liquid chromatography (HPLC). Among the different genotype groups and purpose of uses, cultivars of V. vinifera had much higher amounts of trans -resveratrol than did the cultivars of both V. labrusca or V. labrusca and V. vinifera hybrids, and within the V. vinifera species, significantly higher amounts of trans -resveratrol were found in wine grapes compared to table ones. No significant differences were observed between V. labrusca and its hybrids from crosses with V. vinifera , and between red cultivars and white ones (P < 0.05 or P < 0.01). The contents of trans -resveratrol, as a normal constituent occurring in grape canes, in Chinese wild species of V. amurensis , V. pentagona , and V. davidii from their native habitats were also relatively high.
p. 2862-2870
Received: 18 February 2011; in revised form: 21 March 2011 / Accepted: 28 March 2011 / Published: 31 March 2011
Show/Hide Abstract
| Download PDF Full-text (299 KB) Abstract: Zinc- and silver-doped mullite ceramic discs were prepared and tested as potentially resistant materials against bacterial adhesion and biofilm formation. Elemental analysis and X-ray diffraction studies showed that zinc ions were incorporated in the structural framework of the mullite, while silver ions remained outside the mullite crystal lattice, which allowed their slow (0.02 ppm/24 hours) leaching into the surrounding aqueous environment. In agreement with this behavior, silver-doped mullite showed potent resistance against surface attachment of Pseudomonas aeruginosa , while on the other hand, zinc-doped mullite failed to stop bacterial attachment.
p. 2871-2883
Received: 17 February 2011; in revised form: 23 March 2011 / Accepted: 25 March 2011 / Published: 4 April 2011
Show/Hide Abstract
| Download PDF Full-text (619 KB) | Abstract: Controlling the ratio of 2,2′-bpy to benzene-1,3,5-tricarboxylic acid produces two interesting complexes, namely [Co(2,2′-bpy)3 ] (SO4 ) 8.5H2 O (1 ) and [Cu2 (BTCA) (2,2′-bpy)4 ] (OH) (2,2′-bpy)0.5 ·14H2 O (2 ) (H3 BTCA = benzene-1,3,5-tricarboxylic acid, 2,2′-bpy = 2,2′-bipyridine). We report the structural evidence in the solid state of discrete lamellar water cluster conformations. These units are found to act as supramolecular glue in the aggregation of cobalt (II) or copper (II) complexes to give three dimensional cage-like networks through hydrogen-bonding. It is interesting that the structure of complex 1 contains a 3D negatively charged cage.
p. 2884-2913
Received: 10 February 2011; in revised form: 14 March 2011 / Accepted: 29 March 2011 / Published: 4 April 2011
Show/Hide Abstract
| Download PDF Full-text (1317 KB) | Abstract: Steroid and terpene chemistry still have a great impact on medicinal chemistry. Therefore, the development of new reactions or “greener” processes in this field is a contemporaneous issue. In this review, the use of bismuth(III) salts, as “ecofriendly” reagents/catalysts, on new chemical processes involving steroids and terpenes as substrates will be focused. Special attention will be given to some mechanistic considerations concerning selected reactions.
p. 2914-2936
Received: 9 March 2011; in revised form: 25 March 2011 / Accepted: 31 March 2011 / Published: 4 April 2011
Show/Hide Abstract
| Download PDF Full-text (858 KB) Abstract: Phenols are broadly distributed in the plant kingdom and are the most abundant secondary metabolites of plants. Plant polyphenols have drawn increasing attention due to their potential antioxidant properties and their marked effects in the prevention of various oxidative stress associated diseases such as cancer. The objective of this study was to investigate a suitable method for determination of protocatechuic acid, 4-aminobenzoic acid, chlorogenic acid, caffeic acid, vanillin, p -coumaric acid, rutin, ferulic acid, quercetin, resveratrol and quercitrin from apricot samples. A high-performance liquid chromatograph with electrochemical and UV detectors was used. The method was optimized in respect to both the separation selectivity of individual phenolic compounds and the maximum sensitivity with the electrochemical detection. The lowest limits of detection (3 S/N) using UV detection were estimated for ferulic acid (3 µM), quercitrin (4 µM) and quercetin (4 µM). Using electrochemical detection values of 27 nM, 40 nM and 37 nM were achieved for ferulic acid, quercitrin and quercetin, respectively. It follows from the acquired results that the coulometric detection under a universal potential of 600 mV is more suitable and sensitive for polyphenols determination than UV detection at a universal wavelength of 260 nm. Subsequently, we tested the influence of solvent composition, vortexing and sonication on separation efficiency. Our results showed that a combination of water, acetone and methanol in 20:20:60 ratio was the most effective for p -aminobenzoic acid, chlorgenic acid, caffeic acid, protocatechuic acid, ferulic acid, rutin, resveratrol and quercetin, in comparison with other solvents. On the other hand, vortexing at 4 °C produced the highest yield. Moreover, we tested the contents of individual polyphenols in the apricot cultivars Mamaria, Mold and LE-1075. The major phenolic compounds were chlorgenic acid and rutin. Chlorgenic acid was found in amounts of 2,302 mg/100 g in cultivar LE-1075, 546 mg/100 g in cultivar Mamaria and 129 mg/100 g in cultivar Mold. Generally, the cultivar LE-1075 produced the highest polyphenol content values, contrary to Mold, which compared to cultivar LE-1075 was quite poor from the point of view of the phenolics content.
p. 2937-2943
Received: 18 February 2011; in revised form: 29 March 2011 / Accepted: 1 April 2011 / Published: 4 April 2011
Show/Hide Abstract
| Download PDF Full-text (221 KB) Abstract: From the commercial extract of the leaves of Stevia rebaudiana , a new diterpene glycoside was isolated besides the known steviol glycosides including stevioside, rebaudiosides A-F, rubusoside and dulcoside A. The new compound was identified as 13-[(2-O -β-D-glucopyranosyl-3-O -β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent -kaur-16-en-19-oic acid-(2-O -α-L-rhamnopyranosyl-β-D-glucopyranosyl) ester (1 ) on the basis of extensive spectroscopic (NMR and MS) and chemical studies.
p. 2944-2959
Received: 17 January 2011; in revised form: 11 March 2011 / Accepted: 17 March 2011 / Published: 6 April 2011
Show/Hide Abstract
| Download PDF Full-text (279 KB) Abstract: Liver cancer has become one of the major types of cancer with high mortality and liver cancer is not responsive to the current cytotoxic agents used in chemotherapy. The purpose of this study was to examine the in vitro cytotoxicity of goniothalamin on human hepatoblastoma HepG2 cells and normal liver Chang cells. The cytotoxicity of goniothalamin against HepG2 and liver Chang cell was tested using MTT cell viability assay, LDH leakage assay, cell cycle flow cytometry PI analysis, BrdU proliferation ELISA assay and trypan blue dye exclusion assay. Goniothalamin selectively inhibited HepG2 cells [IC50 = 4.6 (±0.23) µM in the MTT assay; IC50 = 5.20 (±0.01) µM for LDH assay at 72 hours], with less sensitivity in Chang cells [IC50 = 35.0 (±0.09) µM for MTT assay; IC50 = 32.5 (±0.04) µM for LDH assay at 72 hours]. In the trypan blue dye exclusion assay, the Viability Indexes were 52 ± 1.73% for HepG2 cells and 62 ± 4.36% for Chang cells at IC50 after 72 hours. Cytotoxicity of goniothalamin was related to inhibition of DNA synthesis, as revealed by the reduction of BrdU incorporation. At 72 hours, the lowest concentration of goniothalamin (2.3 µL) retained 97.6% of normal liver Chang cells proliferation while it reduced HepG2 cell proliferation to 19.8% as compared to control. Besides, goniothalamin caused accumulation of hypodiploid apoptosis and different degree of G2/M arrested as shown in cell cycle analysis by flow cytometry. Goniothalamin selectively killed liver cancer cell through suppression of proliferation and induction of apoptosis. These results suggest that goniothalamin shows potential cytotoxicity against hepatoblastoma HepG2 cells.
p. 2960-2970
Received: 22 February 2011; in revised form: 23 March 2011 / Accepted: 31 March 2011 / Published: 6 April 2011
Show/Hide Abstract
| Download PDF Full-text (251 KB) Abstract: A series of substituted tetraphenylporphyrin iron chloride complexes [RTPPFe(III)Cl, R=o /p -NO2 , o /p -Cl, H, o /p -CH3 , o /p -OCH3 ] were synthesized by a novel universal mixed-solvent method and the spectral properties of free base porphyrins and iron porphyrin compounds were compared with each other. The experimental results showed that the one-pot mixed solvent method was superior to the two-step method in the yields, reaction time and workup of reaction mixtures for the synthesis of iron porphyrin compounds. The highest yields (28.7%-40.4%) of RTPPFe(III)Cl were obtained in the mixed solvents propionic acid, glacial acetic acid and m -nitrotoluene under reflux for 2 h. A detailed analysis of ultraviolet-visible (UV-vis), infrared (IR) and far-infrared (FIR) spectra suggested the transformation from free base porphyrins to iron porphyrins. The red shift of the Soret band in ultraviolet-visible spectra due to the presence of p -nitrophenyl substituents and the blue shift of Fe-Cl bond of TPPFeCl in far-infrared spectra were further explained by the electron transfer and molecular planarity in the porphyrin ring.
p. 2971-2981
Received: 24 December 2010; in revised form: 15 March 2011 / Accepted: 16 March 2011 / Published: 6 April 2011
Show/Hide Abstract
| Download PDF Full-text (238 KB) Abstract: Chiral C 2 -symmetric diamines have emerged as versatile auxiliaries or ligands in numerous asymmetric transformations. Chiral 2,2’-bispyrrolidine-based salan ligands were prepared and applied to the asymmetric aryl transfer to aldehydes with arylboronic acids as the source of transferable aryl groups. The corresponding diarylmethanols were obtained in high yields with moderate to good enantioselectivitives of up to 83% ee.
p. 2982-2989
Received: 8 February 2011; in revised form: 31 March 2011 / Accepted: 2 April 2011 / Published: 6 April 2011
Show/Hide Abstract
| Download PDF Full-text (132 KB) Abstract: The compounds 1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl nitrate (C1 ), (1,3-dioxo-1,3-dihydro-2H -isoindol-2-yl)ethyl nitrate (C2 ), 3-(1,3-dioxo-1,3-dihydro-2H -isoindol-2-yl)benzyl nitrate (C3 ), 4-(1,3-dioxo-1,3-dihydro-2H -isoindol-2-yl)-N -hydroxy-benzenesulfonamide (C4 ), 4-(1,3-dioxo-1,3-dihydro-2H -isoindol-2-yl)benzyl nitrate (C5 ), and 2-[4-(1,3-dioxo-1,3-dihydro-2H -isoindol-2-yl)phenyl]ethyl nitrate (C6 ) were evaluated with a micronucleus test using mouse peripheral blood to identify new candidate drugs for the treatment of sickle cell disease (SCD) that are safer than hydroxyurea. The compounds induced an average frequency of micronucleated reticulocytes (MNRET) of less than six per 1,000 cells at 12.5, 25, 50, and 100 mg/kg, whereas hydroxyurea induced an average MNRET frequency of 7.8, 9.8, 15, and 33.7 per 1000 cells respectively, at the same concentrations. Compounds C1–C6 are new non-genotoxic in vivo candidate drugs for the treatment of SCD symptoms.
p. 2990-3000
Received: 10 February 2011; in revised form: 15 March 2011 / Accepted: 1 April 2011 / Published: 6 April 2011
Show/Hide Abstract
| Download PDF Full-text (289 KB) Abstract: Generation of reactive oxygen species plays a pivotal role in the development of cardiovascular diseases. The present study describes the effects of the methanolic extract of Phoebe grandis (MPG) stem bark on reactive oxygen species-induced endothelial dysfunction in vitro . Endothelium-dependent (acetylcholine, ACh) and -independent relaxation (sodium nitroprusside, SNP) was investigated from isolated rat aorta of Sprague-Dawley (SD) in the presence of the β-NADH (enzymatic superoxide inducer) and MPG extract. Superoxide anion production in aortic vessels was measured by lucigen chemiluminesence. Thirty minutes incubation of the rat aorta in vitro with β-NADH increased superoxide radical production and significantly inhibited ACh-induced relaxations. Pretreatment with MPG (0.5, 5 and 50 μg/mL) restored the ACh-induced relaxations (Rmax : 92.29% ± 2.93, 91.02% ± 4.54 and 88.31 ± 2.36, respectively) in the presence of β-NADH. MPG was ineffective in reversing the impaired ACh-induced relaxations caused by pyrogallol, a non-enzymatic superoxide generator. Superoxide dismutase (a superoxide scavenger), however, reversed the impaired ACh relaxations induced by both β-NADH and pyrogallol. MPG also markedly inhibited the β-NADH-induced generation of the superoxide radicals. Furthermore, MPG scavenging peroxyl radicals generated by tBuOOH (10−4 M).These results indicate that MPG may improve the endothelium dependent relaxations to ACh through its scavenging activity as well as by inhibiting the NADH/NADPH oxidase induced generation of superoxide anions.
p. 3001-3009
Received: 7 March 2011; in revised form: 31 March 2011 / Accepted: 1 April 2011 / Published: 7 April 2011
Show/Hide Abstract
| Download PDF Full-text (172 KB) Abstract: Cissampelos capensis , commonly known by the Afrikaans name “dawidjies” or “dawidjieswortel”, is the most important and best known medicinal plant of the family Menispermaceae used by the Khoisan and other rural people in the western region of South Africa. The main alkaloids in the leaves, stems and rhizomes were isolated and identified. Several of the main compounds were previously found in species of the related genus Antizoma and this similarity indicates that the two genera are closely related if not congeneric. Bulbocapnine (an aporphine alkaloid), dicentrine (an aporphine alkaloid) and salutaridine (a morphinane alkaloid) were the main alkaloids in the leaves, while bulbocapnine, cissacapine, cycleanine and insularine (the last three are bisbenzyltetrahydro-isoquinoline alkaloids) are the major compounds in the stems. The rhizome contains mostly bisbenzyltetrahydroisoquinoline alkaloids, with 12-O -methylcurine, cissacapine and cycleanine as the main ones. Alkaloids appear to be quite variable within different plant parts and different provenances, as confirmed by the difference in alkaloid patterns between coastal and inland forms of Cissampelos capensis (the morphinane alkaloid salutaridine, for example, is the major leaf alkaloid along the coast but is practically absent from the inland form of the species). The variety of alkaloids identified may contribute to the medicinal value of this species. The data on alkaloidal variation in the species has potential value and practical applications in chemotaxonomy, toxicology and pharmacognosy.
p. 3010-3017
Received: 2 March 2011; in revised form: 30 March 2011 / Accepted: 1 April 2011 / Published: 7 April 2011
Show/Hide Abstract
| Download PDF Full-text (193 KB) Abstract: The effects of cyclodextrins and derivatives on the activity and structure of pullulanase were investigated in this study. Our results showed that cyclodextrins and derivatives decreased the activity of pullulanase. This decrease was attributed to the interaction between the hydrophobic cavities of cyclodextrins and pullulanase. The hydrophobic cavity was confirmed to encapsulate the groups of pullulanase molecules by the addition of competitive guests. The results obtained from fluorescence spectroscopy analysis showed that β-CD showed more efficient interactions with pullulanase molecules and the side chain groups of cyclodextrin significantly prevented the interaction between the hydrophobic cavities of β-CD and pullulanase molecules. These findings suggest that the geometric dimension of hydrophobic cavities was crucial for matching between cyclodextrins and pullulanase and steric hindrance caused by side chains led to the decrease of the interaction.
p. 3018-3028
Received: 16 March 2011; in revised form: 1 April 2011 / Accepted: 2 April 2011 / Published: 7 April 2011
Show/Hide Abstract
| Download PDF Full-text (218 KB) Abstract: A new abietene diterpene, kaempfolienol (5S ,6S ,7S ,9S ,10S ,11R ,13S -abiet-8(14)-enepenta-6,7,9,11,13-ol, 1 ), was isolated from a rhizome extract of Kaempferia angustifolia Rosc. along with the known compounds crotepoxide, boesenboxide, zeylenol, 2′-hydroxy-4,4′,6′-trimethoxychalcone, (24S )-24-methyl-5α-lanosta-9(11),25-dien-3β-ol, β-sitosterol and β-sitosterol-3-O -β-D-glucopyranoside. The structures of all compounds were elucidated on the basis of mass spectroscopic and NMR data. Zeylenol (2 ), the major constituent of the plant, was derivatized into diacetate, triacetate and epoxide derivatives through standard organic reactions. The cytotoxic activity of compounds 1 , 2 and the zeylenol derivatives was evaluated against the HL-60, MCF-7, HT-29 and HeLa cell lines.
p. 3029-3036
Received: 1 February 2011; in revised form: 31 March 2011 / Accepted: 2 April 2011 / Published: 8 April 2011
Show/Hide Abstract
| Download PDF Full-text (1766 KB) Abstract: Chitin benzoic acid esters were prepared using a phosphoryl mixed anhydride method. The products were characterized by 1 H-NMR and FT-IR spectroscopy. FT-IR analysis revealed that the degree of O -acyl substitution of the products was in a range of 1.17–1.83. Morphological surface changes in the parent molecule due to the introduction of benzoic acid moieties were observed by scanning electron microscopy. The surface of the products was porous, in contrast to the sheet-shape of the parent molecules. The solubility of the products, which improved with increased degree of acid substitution, was tested in various organic solvents.
p. 3037-3047
Received: 18 February 2011; in revised form: 10 March 2011 / Accepted: 10 March 2011 / Published: 8 April 2011
Show/Hide Abstract
| Download PDF Full-text (137 KB) Abstract: This study was designed to investigate the antimicrobial activity of Cinnamomum iners standardized leave methanolic extract (CSLE), its fractions and isolated compounds. CSLE and fractions were subjected to disc diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests using different Gram positive and Gram negative bacteria and yeast. Within the series of fractions tested, the ethyl acetate fraction was the most active, particularly against methicillin resistant Staphylococcus aureus (MRSA) and Escherichia coli , with MIC values of 100 and 200 µg/mL, respectively. The active compound in this fraction was isolated and identified as xanthorrhizol [5-(1, 5-dimethyl-4-hexenyl)-2-methylphenol] by various spectroscopic techniques. The overall results of this study provide evidence that Cinnamomum iners leaves extract as well as the isolated compound xanthorrhizol exhibit antimicrobial activity for both Gram negative and Gram positive pathogens, especially against MRSA strains.
p. 3048-3065
Received: 26 January 2011; in revised form: 31 March 2011 / Accepted: 2 April 2011 / Published: 8 April 2011
Show/Hide Abstract
| Download PDF Full-text (533 KB) Abstract: RuXian-I has traditionally been used as a remedy for breast hyperplasia in the Inner Mongolia Autonomous Region of China. As a first step toward the investigation of biomarkers associated with RuXian-I treatment, a proteome-wide analysis of rat breast tissue was conducted. First, rat breast hyperplasia was induced by injection of estradiol and progesterone. After treatment with RuXian-I, there is a marked decrease in the hyperplasia, as can be shown by decreases in the nipple diameter and the pathological changes in breast. Subsequently, we used an approach that integrates size-based 2D-DIGE, MALDI-TOF/TOF-MS, and bioinformatics to analyze data from the control group, the model group and the RuXian-I treatment group. Using this approach, seventeen affected proteins were identified. Among these, 15 (including annexin A1, annexin A2, superoxide dismutase [Mn], peroxiredoxin-1, translationally-controlled tumor protein and a B-crystallin) were significantly up-regulated in the model group and down-regulated upon treatment with RuXian-I, and two (Tpil protein and myosin-4) have the opposite change trend. The expression of annexin A1 was confirmed using immunohistochemistry. The expression of superoxide dismutase (SOD) activity was confirmed biochemically. These results indicated that RuXian-I treats rat breast hyperplasia through regulation of cell cycle, immune system, metabolic, signal transduction, etc. The differential expressions of these proteins (annexin A1, superoxide dismutase [Mn], alpha B-crystallins and translationally controlled tumor protein, among others) were associated with occurrence and metastasis of breast cancer. These findings might provide not only far-reaching valuable insights into the mechanism of RuXian-I action, but also leads for prognosis and diagnosis of breast hyperplasia and breast cancer.
p. 3066-3076
Received: 28 February 2011; in revised form: 31 March 2011 / Accepted: 2 April 2011 / Published: 11 April 2011
Show/Hide Abstract
| Download PDF Full-text (209 KB) | Abstract: A novel and straightforward solid phase synthesis of distamycin analogues containing benzene units has been developed.
p. 3077-3088
Received: 6 March 2011; in revised form: 5 April 2011 / Accepted: 11 April 2011 / Published: 13 April 2011
Show/Hide Abstract
| Download PDF Full-text (244 KB) Abstract: In our screening program for new agrochemicals from Chinese medicinal herbs and wild plants, Zanthoxylum schinifolium essential oils were found to possess strong insecticidal activity against the maize weevil Sitophilus zeamais . The essential oils of Z. schinifolium fruits and leaves were extracted via hydrodistillation and investigated by GC and GC-MS. Estragole (69.52%) was the major compound of the essential oil of fresh fruits, followed by linalool (8.63%) and limonene (4.34%) and 94.33% of the total components were monoterpenoids. The main components of the essential oil of fresh leaves were linalool (12.94%), ar -tumerone (8.95%), limonene (6.45%) and elixene (5.43%) and only 50.62% were monoterpenoids. However, the essential oil from purchased fruits contained linalool (33.42%), limonene (13.66%) and sabinene (5.72%), followed by estragole (4.67%), nerol (4.56%) and 4-terpineol (4.27%). Estragole, linalool and sabinene were separated and purified by silica gel column chromatography and preparative thin layer chromatography, and further identified by means of physicochemical and spectrometric analysis. The essential oil from the fresh fruits (LD50 = 15.93 μg/adult) possessed two times more toxicity to the insects compared with that of fresh leaves (LD50 = 35.31 μg/adult). Estragole, linalool and sabinene exhibited contact activity against S. zeamais with LD50 values of 17.63, 13.90 and 23.98 μg/adult, respectively. The essential oils of Z . schinifolium possessed strong fumigant toxicity against S. zeamais adults with LC50 values of 13.19 mg/L (fresh fruits), 24.04 mg/L (fresh leaves) and 17.63 mg/L (purchased fruits). Estragole, linalool and sabinene also exhibited strong fumigant toxicity against the maize weevils with LC50 values of 14.10, 10.46 and 9.12 mg/L, respectively.
p. 3089-3105
Received: 12 January 2011; in revised form: 7 April 2011 / Accepted: 12 April 2011 / Published: 13 April 2011
Show/Hide Abstract
| Download PDF Full-text (395 KB) Abstract: Since its introduction in 1985, phage display technology has been successfully used in projects aimed at deciphering biological processes and isolating molecules of practical value in several applications. Bacteriophage lambda, representing a classical molecular cloning and expression system has also been exploited for generating large combinatorial libraries of small peptides and protein domains exposed on its capsid. More recently, lambda display has been consistently and successfully employed for domain mapping, antigen discovery and protein interaction studies or, more generally, in functional genomics. We show here the results obtained by the use of large libraries of cDNA and genomic DNA for the molecular dissection of the human B-cell response against complex pathogens, including protozoan parasites, bacteria and viruses. Moreover, by reviewing the experimental work performed in recent investigations we illustrate the potential of lambda display in the diagnostics field and for identifying antigens useful as targets for vaccine development.
p. 3106-3118
Received: 18 March 2011; in revised form: 8 April 2011 / Accepted: 12 April 2011 / Published: 13 April 2011
Show/Hide Abstract
| Download PDF Full-text (9608 KB) | Abstract: We review fluorescent probes that can be photoswitched or photoactivated and are suited for single-molecule localization based super-resolution microscopy. We exploit the underlying photochemical mechanisms that allow photoswitching of many synthetic organic fluorophores in the presence of reducing agents, and study the impact of these on the photoswitching properties of various photoactivatable or photoconvertible fluorescent proteins. We have identified mEos2 as a fluorescent protein that exhibits reversible photoswitching under various imaging buffer conditions and present strategies to characterize reversible photoswitching. Finally, we discuss opportunities to combine fluorescent proteins with organic fluorophores for dual-color photoswitching microscopy.
p. 3119-3127
Received: 7 January 2011; in revised form: 5 April 2011 / Accepted: 11 April 2011 / Published: 13 April 2011
Show/Hide Abstract
| Download PDF Full-text (262 KB) Abstract: A new bisbenzylisoquinoline, lancifoliaine (1 ), together with seven known alkaloids – N -allyllaurolitsine (2 ), reticuline (3 ), actinodaphnine, norboldine, pallidine, cassythicine and boldine – were isolated from the stem bark of Litsea lancifolia (Lauraceae). In addition to that of lancifoliaine, complete 13 C-NMR data of N -allyl-laurolitsine (2 ) was also reported. The alkaloidal structures were elucidated by means of high field 1D- and 2D-NMR IR, UV, and LCMS-IT-TOF spectral data. N -Allyllaurolitsine (2 ) showed a moderate vasorelaxant activity on isolated rat aorta.
p. 3128-3145
Received: 11 March 2011; in revised form: 13 April 2011 / Accepted: 13 April 2011 / Published: 13 April 2011
Show/Hide Abstract
| Download PDF Full-text (423 KB) Abstract: The conceptual and practical issues regarding the reduction of the Haldane-Radić enzymic mechanism, specific for cholinesterase kinetics, to the consecrated or logistically modified Michaelis-Menten kinetics, specific for some mutant enzymes, are here clarified as due to the limited initial substrate concentration, through detailed initial rate and progress curve analysis, even when other classical conditions for such equivalence are not entirely fulfilled.
p. 3146-3151
Received: 31 March 2011; in revised form: 11 April 2011 / Accepted: 12 April 2011 / Published: 14 April 2011
Show/Hide Abstract
| Download PDF Full-text (270 KB) Abstract: Ten compounds were isolated from the dichloromethane extract of Atractylodes macrocephala and their aromatase inhibiting activities were tested using an in vitro fluorescent-based aromatase assay. The results indicated that atractylenolide I (1 ), atractylenolide II (2 ) and atractylenolide III (3 ) had inhibition ratios of 94.56 ± 0.70%, 90.93 ± 1.41% and 86.31 ± 8.46%, respectively, at a concentration of 10 μM. We conclude from our results that atractylenolide and its derivates may serve as potential aromatase inhibitors (AIs) and thus merit continued study in the future.
p. 3152-3167
Received: 14 March 2011; in revised form: 12 April 2011 / Accepted: 14 April 2011 / Published: 14 April 2011
Show/Hide Abstract
| Download PDF Full-text (250 KB) Abstract: Extracts of Melittis melissophyllum leaves in ether, chloroform, ethyl acetate, n -butanol and water were evaporated to dryness and dissolved in 50% ethanol to make 10% (w/v) solutions. The potential protective action of the extracts was assessed by the corresponding in vitro and in vivo tests. In the in vitro experiments extracts were tested as potential scavengers of free radicals (DPPH, O2 · - , NO, and OH radicals), as well as inhibitors of liposomal peroxidation (LPx). The results obtained show that all extracts (exept n-BuOH extract) are good scavengers of radicals and reduce LPx intensity in liposomes, which points to their protective (antioxidant) activity. In vivo experiments were concerned with antioxidant systems (activities of GSHPx, GSHR, Px, CAT, XOD, GSH content and intensity of LPx) in liver homogenate and blood-hemolysate of experimental animals after their treatment with extracts of M. melis s ophyllum leaves, or in combination with CCl4 . On the basis of the results obtained it can be concluded that the examined extracts have protective (antioxidative) effect and this antioxidative behaviour is more pronounced in liver than in blood-hemolysate. The reason is probably the fact that liver contains other enzymatic systems, which can also participate in the antioxidative mechanism. Of all the extracts the H2 O one showed the highest protective activity.
p. 3168-3178
Received: 25 March 2011; in revised form: 11 April 2011 / Accepted: 12 April 2011 / Published: 15 April 2011
Show/Hide Abstract
| Download PDF Full-text (306 KB) Abstract: The syntheses of four new bis(imino)acenaphthene (BIAN) imidazolium chlorides are reported, three of which have been structurally characterized. The synthesis of a new, structurally authenticated BIAN ligand is also described. We report the results of the use of these BIAN imidazolium salts as antimicrobials against the pathogens S. aureus , B. subtilis , E. coli and P. aeruginosa . The antimicrobial efficacies were particularly high for the N-(2,6-diisopropylphenyl)- and N-(mesityl)- substituted BIAN imidazolium salts (MIC values < 0.6 μg/mL).
p. 3179-3196
Received: 25 January 2011; in revised form: 6 April 2011 / Accepted: 7 April 2011 / Published: 15 April 2011
Show/Hide Abstract
| Download PDF Full-text (703 KB) Abstract: Many studies on intracellular calcium ([Ca2+ ]i ) and intracellular pH (pHi ) have been carried out due to their importance in regulation of different cellular functions. However, most of the previous studies are focused on human or mammalian cells. The purpose of the present study was to characterize the effect of Rhodojaponin-III (R-III) on [Ca2+ ]i and pHi and the proliferation of Sf9 cells. R-III strongly inhibited Sf9 cells proliferation with a time- and dose-dependent manner. Flow cytometry established that R-III interfered with Sf9 cells division and arrested them in G2/M. By using confocal scanning technique, effects of R-III on intracellular free calcium ([Ca2+ ]i ) and intracellular pH (pHi ) in Sf9 cells were determined. R-III induced a significant dose-dependent (1, 10, 100, 200 μg/mL) increase in [Ca2+ ]i and pHi of Sf9 cells in presence of Ca2+ -containing solution (Hanks) and an irreversible decrease in the absence of extra cellular Ca2+ . We also found that both extra cellular Ca2+ and intracellular Ca2+ stores contributed to the increase of [Ca2+ ]i , because completely treating Sf9 cells with CdCl2 (5 mM), a Ca2+ channels blocker, R-III (100 μg/mL) induced a transient elevation of [Ca2+ ]i in case of cells either in presence of Ca2+ containing or Ca2+ free solution. In these conditions, pHi showed similar changes with that of [Ca2+ ]i on the whole. Accordingly, we supposed that there was a certain linkage for change of [Ca2+ ]i , cell cycle arrest, proliferation inhibition in Sf9 cells induced by R-III.
p. 3197-3211
Received: 6 March 2011; in revised form: 4 April 2011 / Accepted: 11 April 2011 / Published: 15 April 2011
Show/Hide Abstract
| Download PDF Full-text (275 KB) Abstract: Grifola frondosa is an edible mushroom currently available in Taiwan. Ethanolic, cold-water and hot-water extracts were prepared and their antioxidant properties were investigated. At 1 mg/mL, G. frondosa T1 and T2 cold-water extracts showed high reducing powers of 1.02 and 0.50, respectively. Chelating abilities on ferrous ions of G. frondosa T1 and T2 were higher for cold-water extracts than for ethanolic and hot-water extracts. For the scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, G. frondosa T1 and T2 extracts were effective in the following order: ethanolic > hot-water > cold-water. The G. frondosa hot-water extract showed high scavenging ability on superoxide anions. Total phenols, flavonoids, ascorbic acid and α-tocopherol are the major antioxidant components found in the various G. frondosa extracts. Based on EC50 values (
p. 3212-3221
Received: 21 February 2011; in revised form: 8 April 2011 / Accepted: 12 April 2011 / Published: 15 April 2011
Show/Hide Abstract
| Download PDF Full-text (267 KB) Abstract: The ability of the flavan kazinol Q (KQ ) to induce DNA breakage in the presence of Cu(II) was examined by agarose gel electrophoresis using supercoiled plasmid DNA. In KQ -mediated DNA breakage reaction, the involvement of reactive oxygen species (ROS), H2 O2 and O2 - was established by the inhibition of DNA breakage by catalase and revealed DNA breakage by superoxide dismutase (SOD). The cell viability of gastric carcinoma SCM-1 cells treated with various concentrations of KQ was significantly decreased by cotreatment with Cu(II). Treatment of SCM-1 cells with 300 μM Cu(II) enhanced the necrosis induced by 100 μM KQ . Treatment of SCM-1 cells with 100 mM KQ in the presence of 300 mM Cu(II) increased the generation of H2 O2 . Taken together, the above finding suggested that KQ cotreatment with Cu(II) produced increased amounts of H2 O2 , thus enhancing subsequent cell death due to necrosis.
p. 3222-3231
Received: 9 February 2011; in revised form: 4 April 2011 / Accepted: 12 April 2011 / Published: 15 April 2011
Show/Hide Abstract
| Download PDF Full-text (386 KB) Abstract: In this article, we have focused on the structure identification of Euphorbia factor L3 belonging to the lathyrane diterpenoids isolated from Caper Euphorbia Seed. Its anticancer activity in vitro against lung cancer A549 cells was also investigated and the IC50 values were 34.04 ± 3.99 μM. Furthermore, Euphorbia factor L3 could induce apoptosis in A549 cells via the mitochondrial pathway including loss of mitochondrial potential and release of cytochrome c .
p. 3232-3251
Received: 1 March 2011; in revised form: 3 April 2011 / Accepted: 12 April 2011 / Published: 18 April 2011
Show/Hide Abstract
| Download PDF Full-text (308 KB) Abstract: The appearance of selenium in organic synthesis is relatively rare, and thus examples in the literature pertaining to the masking of its considerable reactivity are similarly uncommon. Greene's Protecting Groups in Organic Synthesis, the standard reference for the state of the art in this arena, offers no entries for selenium protective methodology, in stark comparison to its mention of the great variety of protecting groups germane to its chalcogen cousin sulfur. This scarcity of Se-protection methods makes it no less interesting and pertinent toward the construction of selenium-containing organic systems which do indeed require the iterative blocking and de-blocking of selenol functionalities. A selenium-containing system which is especially relevant is selenocysteine, as its use in Solid Phase Peptide Synthesis requires extensive protection of its selenol side chain. This review will attempt to summarize the current state of understanding with regard to selenium protection protocol in organic synthesis. Moreover, it will provide a special emphasis on selenocysteine side chain protection, comprising both the breadth of functionality used for this purpose as well as methods of deprotection.
p. 3252-3314
Received: 8 March 2011; in revised form: 28 March 2011 / Accepted: 11 April 2011 / Published: 18 April 2011
Show/Hide Abstract
| Download PDF Full-text (688 KB) Abstract: Since Gomberg’s discovery of radicals as chemical entities, the interest around them has increased through the years. Nowadays, radical chemistry is used in the synthesis of 75% of all polymers, inevitably establishing a close relationship with Solid-Phase Organic Synthesis. More recently, the interest of organic chemists has shifted towards the application of usual “in-solution” radical chemistry to the solid-phase, ranging from the use of supported reagents for radical reactions, to the development of methodologies for the synthesis of small molecules or potential libraries. The aim of this review is to put in perspective radical chemistry, moving it away from its origin as a synthetic means for solid supports, to becoming a useful tool for the synthesis of small molecules.
p. 3315-3337
Received: 2 March 2011; in revised form: 7 April 2011 / Accepted: 12 April 2011 / Published: 18 April 2011
Show/Hide Abstract
| Download PDF Full-text (1267 KB) Abstract: Many phenomena, including life itself and its biochemical foundations are fundamentally rooted in chirality. Combinatorial methodologies for catalyst discovery and optimization remain an invaluable tool for gaining access to enantiomerically pure compounds in the development of pharmaceuticals, agrochemicals, and flavors. Some exotic metamaterials exhibiting negative refractive index at optical frequencies are based on chiral structures. Chiroptical activity is commonly quantified in terms of circular dichroism (CD) and optical rotatory dispersion (ORD). However, the linear nature of these effects limits their application in the far and near-UV region in highly absorbing and scattering biological systems. In order to surmount this barrier, in recent years we made important advancements on a novel non linear, low-scatter, long-wavelength CD approach called two-photon absorption circular dichroism (TPACD). Herein we present a descriptive analysis of the optics principles behind the experimental measurement of TPACD, i.e., the double L-scan technique, and its significance using pulsed lasers. We also make an instructive examination and discuss the reliability of our theoretical-computational approach, which uses modern analytical response theory, within a Time-Dependent Density Functional Theory (TD-DFT) approach. In order to illustrate the potential of this novel spectroscopic tool, we first present the experimental and theoretical results obtained in C2 -symmetric, axially chiral R -(+)-1,1'-bi(2-naphthol), R -BINOL, a molecule studied at the beginning of our investigation in this field. Next, we reveal some preliminary results obtained for (R )-3,3′-diphenyl-2,2′-bi-1-naphthol, R -VANOL, and (R )-2,2′-diphenyl-3,3′-(4-biphenanthrol), R -VAPOL. This family of optically active compounds has been proven to be a suitable model for the structure-property relationship study of TPACD, because its members are highly conjugated yet photo-stable, and easily derivatized at the 5- and 6-positions. With the publication of these outcomes we hope to motivate more members of the scientist community to engage in state-of-the-art TPACD spectroscopy.
p. 3338-3344
Received: 24 March 2011; in revised form: 14 April 2011 / Accepted: 15 April 2011 / Published: 18 April 2011
Show/Hide Abstract
| Download PDF Full-text (444 KB) Abstract: The objective of this study was to examine the biological activity of kaempferol and its rhamnosides. We isolated kaempferol (1 ), a-rhamnoisorobin (2 ), afzelin (3 ), and kaempferitrin (4 ) as pure compounds by far-infrared (FIR) irradiation of kenaf (Hibiscus cannabinus L.) leaves. The depigmenting and anti-inflammatory activity of the compounds was evaluated by analyzing their structure-activity relationships. The order of the inhibitory activity with regard to depigmentation and nitric oxide (NO) production was kaempferol (1 ) > a-rhamnoisorobin (2 ) > afzelin (3 ) > kaempferitrin (4 ). However, a-rhamnoisorobin (2 ) was more potent than kaempferol (1 ) in NF-kB-mediated luciferase assays. From these results, we conclude that the 3-hydroxyl group of kaempferol is an important pharmacophore and that additional rhamnose moieties affect the biological activity negatively.
p. 3345-3350
Received: 22 February 2011; in revised form: 26 March 2011 / Accepted: 30 March 2011 / Published: 19 April 2011
Show/Hide Abstract
| Download PDF Full-text (140 KB) | Abstract: Three diterpenoid alkaloids, including an unreported compound, were isolated from the roots of Aconitum kusnezoffii Reichb. On the basis of spectral analysis, these three compounds were determined to be 1,15-dimethoxy-3-hydroxy-14-benzoyl-16-ketoneoline, benzoylaconine and aconitine.
(This article belongs to the Special Issue
Alkaloids )
p. 3351-3359
Received: 17 March 2011; in revised form: 1 April 2011 / Accepted: 2 April 2011 / Published: 19 April 2011
Show/Hide Abstract
| Download PDF Full-text (277 KB) Abstract: Four new metabolites, including three new oblongolides named C1, P1, and X1 (1 -3 ) and 6-hydroxyphomodiol (10 ), along with eight known compounds – oblongolides B (4 ), C (5 ), D (6 ), O (7 ), P (8 ) and U (9 ), (3R ,4aR ,5S ,6R )-6-hydroxy-5-methylramulosin (11 ), and (3R )-5-methylmellein (12 ) – were isolated from the endophytic fungal strain Phomopsis sp. XZ-01 of Camptotheca acuminate . Their structures were elucidated by spectroscopic analyses, including 1 H- and 13 C-NMR, 2D NMR (HSQC, HMBC, 1 H-1 H COSY and NOESY) and HR-FT-MS. Cytotoxic activities of these compounds were evaluated. Some of them showed weak selective activities.
p. 3360-3370
Received: 7 February 2011; in revised form: 28 March 2011 / Accepted: 31 March 2011 / Published: 19 April 2011
Show/Hide Abstract
| Download PDF Full-text (195 KB) Abstract: Pseudostellaria heterophylla (Miq.) Pax is one of the most widespread herbal and healthcare products in China. Extensive clinical use has shown that it has functions which “strengthens qi and generates saliva, moistens the lung and relieves cough”. The ethyl acetate fraction extracted from the roots of the plant Pseudostellaria heterophylla exhibited a dose-dependent antitussive effect between 100 to 500 mg/kg. At a dose of 400 mg/kg, the ethyl acetate fraction treatment markedly prolonged the cough latent period and reduced the number of coughs in a guinea pig model induced by citric acid. Fall lung airway resistance, rise in dynamic lung compliance, decreased serum levels of IL-8, GM-CSF, TNF-α, and ET-1 in rat model of stable phase chronic obstructive pulmonary disease induced by cigarette smoke exposure were also observed. These results suggest that ethyl acetate fraction has antitussive activity related to its improvement in lung function via attenuation of airway inflammation by adjustment of multi-cytokine levels.
p. 3371-3379
Received: 25 March 2011; in revised form: 8 April 2011 / Accepted: 8 April 2011 / Published: 19 April 2011
Show/Hide Abstract
| Download PDF Full-text (290 KB) Abstract: Salidroside, a major component of Rhodiola rosea L . , has shown various pharmacological functions, including antioxidant effects, but the signal transduction pathway of its antioxidant effects is not very clear. In this study, we found that salidroside could attenuate hydrogen peroxide (H2 O2 )-induced HL-7702 cell damage, inhibit H2 O2 -induced cytosolic free Ca2+ ([Ca2+ ]i) elevation, scavenge reactive oxygen species (ROS) and increase 3’-5’-cyclic adenosine monophosphate (cAMP) level in a dose-dependent manner, but it couldn’t influence 3’-5’-cyclic guanosine monophosphate (cGMP) levels. Therefore, these results indicated that the antioxidant effects of salidroside were associated with down-regulation of [Ca2+ ]i, ROS occur via a cAMP-dependent pathway.
p. 3380-3390
Received: 15 March 2011; in revised form: 7 April 2011 / Accepted: 11 April 2011 / Published: 19 April 2011
Show/Hide Abstract
| Download PDF Full-text (390 KB) Abstract: A simple synthetic approach to racemic N -tert -butyloxycarbonyl-2-methyl-3-(1H -1,2,4-triazol-1-yl)alanine (5 ) in four steps and 68% overall yield starting from oxazoline derivative 1 is reported. This synthesis involves the alkylation of 1H -1,2,4-triazole with an O -tosyloxazoline derivative, followed by an oxazoline ring-opening reaction and oxidation of the N -protected β‑aminoalcohol by potassium permanganate.
p. 3391-3401
Received: 25 March 2011; in revised form: 18 April 2011 / Accepted: 18 April 2011 / Published: 20 April 2011
Show/Hide Abstract
| Download PDF Full-text (281 KB) Abstract: Macleaya microcarpa (Maxim.) Fedde belongs to the genus Macleaya , family Papaveraceae . Together with the better known and more frequently studied species M. cordata (Willd.) R. Br. it is a main source of quaternary benzo[c]phenanthridine alkaloids. Using HPLC we determined the content of eight isoquinoline alkaloids in the aerial and underground parts of 1-, 2-, 12- and 13-year old plants and followed their changes during the vegetative period. The dominant alkaloid of all samples collected in the end of this period was allocryptopine (3.8–13.6 mg/g for aerial parts, 24.2–48.9 mg/g for underground parts). Chelerythrine, sanguinarine and protopine were also present in both parts of the plant. Additionally, measurable concentrations of chelilutine (CL), chelirubine (CR), macarpine (MA) and sanguirubine (SR) were detected in underground parts. The most important finding was that contents of CR, CL, SR and MA in the 12- and 13-year old plant roots were significantly higher (approximately 3-fold for CR, 6-fold for CL, 5-fold for SR, and at least 14-fold for MA) than in 1- or 2-year old plants. The proportion of individual alkaloids in aerial and underground parts thus changed significantly during the vegetative period.
p. 3402-3409
Received: 2 March 2011; in revised form: 12 April 2011 / Accepted: 18 April 2011 / Published: 20 April 2011
Show/Hide Abstract
| Download PDF Full-text (433 KB) Abstract: A phytochemical study of the bark of Alseodaphne perakensis has yielded three aporphine alkaloids: the new compound N -cyanomethylnorboldine (1 ), and the two known alkaloids N -methyllaurotetanine (2 ) and norboldine (3 ). The isolation was achieved by chromatographic techniques and the structural elucidation was performed via spectral methods, notably 1D- and 2D-NMR, UV, IR, and HRFABMS. The vasorelaxation activity of compound 1 has been studied.
p. 3410-3419
Received: 7 March 2011; in revised form: 29 March 2011 / Accepted: 8 April 2011 / Published: 20 April 2011
Show/Hide Abstract
| Download PDF Full-text (177 KB) Abstract: The title compounds were prepared by reaction of 6-acetyltetralin (1 ) with different aromatic aldehydes 2a-c , namely 2,6-dichlorobenzaldehyde, 2,6-diflouro-benzaldehyde, and 3-ethoxy-4-hydroxybenzaldehyde, to yield the corresponding a,b-unsaturated ketones 3a-c. Compound 3b was reacted with hydrazine hydrate to yield the corresponding 2-pyrazoline 4 , while compounds 3a,b reacted with thiourea to afford the 2-thioxopyrimidine derivatives 5a ,b , respectively. The reaction of 1 , and the aromatic aldehydes 2a-c with ethyl cyanoacetate, 2-cyano-thioacetamide or malononitrile in the presence of ammonium acetate yielded the corresponding 2-oxopyridines 6a ,b , 2-thioxopyridines 7a-c or 2-iminopyridines 8a ,b , respectively. The newly prepared compounds were evaluated for anticancer activity against two human tumor cell lines. Compound 3a showed the highest potency with IC50 = 3.5 and 4.5 μg/mL against a cervix carcinoma cell line (Hela) and breast carcinoma cell line (MCF7), respectively.
p. 3420-3432
Received: 6 April 2011; in revised form: 19 April 2011 / Accepted: 20 April 2011 / Published: 21 April 2011
Show/Hide Abstract
| Download PDF Full-text (214 KB) Abstract: Propylene carbonate is shown to be an environmentally friendly and sustainable replacement for dichloromethane and acetonitrile in proline-catalysed a-hydrazinations of aldehydes and ketones. Enantioselectivities comparable to those obtained in conventional solvents or ionic liquids can be obtained, even when using a lower catalyst loading.
p. 3433-3443
Received: 28 February 2011; in revised form: 2 April 2011 / Accepted: 8 April 2011 / Published: 21 April 2011
Show/Hide Abstract
| Download PDF Full-text (100 KB) | Abstract: Aqueous and ethanol extracts of different traditional Malaysian plants (Polygonum minus , Andrographis paniculata, Curcuma xanthorrhiza , Momordica charantia and Strobilanthes crispus) were evaluated for their antioxidant properties, total phenolic content and cytotoxic activity. Antioxidant activity was evaluated by using 1,1-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The results showed that ethanol extracts contain high antioxidant activities compared to aqueous extracts. The findings exhibited a strong correlation between antioxidant activity and the total phenol contents. In addition, all the plant extracts showed non-toxic effects against a normal human lung fibroblast cell line (Hs888Lu). Although traditionally aqueous extracts are used, we determined that ethanol extracts usually achieved better activity in the assays.
p. 3444-3455
Received: 23 March 2011; in revised form: 12 April 2011 / Accepted: 12 April 2011 / Published: 21 April 2011
Show/Hide Abstract
| Download PDF Full-text (204 KB) Abstract: The antioxidant activities of the chloroform, ethyl acetate and n -butanol extract fractions from propolis collected in Anhui, China were evaluated in this study. The ethyl acetate fraction contained the highest amount of total phenolics and total flavonoids, and showed the greatest 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging capacities and Ferric Reducing/Antioxidant Power (FRAP). The antioxidant activity of twenty-two compounds isolated from the ethyl acetate fraction was also evaluated using the above-mentioned three assays. The results indicated that phenolics contributed to the antioxidant activity of propolis collected in Anhui, China. Therefore, propolis collected in Anhui, China and its phenolics might be used as a natural antioxidant.
Select/unselect all
Displaying article 1-53
Export citation of selected articles as:
Plain Text
BibTeX
BibTeX (without abstracts)
Endnote
Endnote (without abstracts)
Tab-delimited
PubMed XML
DOAJ XML
AGRIS XML