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p. 4804-4813
Received: 26 October 2009; in revised form: 9 November 2009 / Accepted: 11 November 2009 / Published: 25 November 2009
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| Download PDF Full-text (477 KB) Abstract: Three new cucurbitane triterpenoids 1–3 and one new steroidal glycoside 4, were isolated together with ten known compounds from Momordica charantia . The structures of new compounds were determined to be 19(R )-n -butanoxy-5β ,19-epoxycucurbita-6,23-diene-3β ,25-diol 3-O -β -glucopyranoside (1), 23-O -β -allopyranosylecucurbita-5,24-dien-7α ,3β ,22(R ),23(S )-tetraol 3-O -β -allopyranoside. (2), 23(R ),24(S ),25-trihydroxycucurbit-5-ene 3-O -{[β -glucopyranosyl(1→6)]-O -β -glucopyranosyl}-25-O -β -glucopyranoside (3), and 24(R )-stigmastan-3β ,5α ,6β -triol-25-ene 3-O -β -glucopyranoside (4), respectively. Their structures were elucidated by the combination of mass spectrometry (MS), one and two-dimensional NMR experiments and chemical reactions.
p. 4814-4837
Received: 10 October 2009; in revised form: 9 November 2009 / Accepted: 12 November 2009 / Published: 25 November 2009
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| Download PDF Full-text (352 KB) Abstract: Molecular iodine has established itself as a readily available and easy-to-handle electrophilic and oxidizing reagent used in various organic transformations. In this review attention is focused on the use of molecular iodine in promoting cyclization (iodocyclization and cyclodehydroiodination) of tethered heteroatom-containing alkenyl or alkynyl systems.
p. 4838-4848
Received: 22 October 2009; in revised form: 17 November 2009 / Accepted: 23 November 2009 / Published: 25 November 2009
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| Download PDF Full-text (280 KB) Abstract: Novel coumarin derivatives, 2-oxo-2H -chromenecarbaldehyde hydrazones were prepared by reaction of substituted 2-oxo-2H -chromenecarbaldehydes with N -aminoimides in ethanol in the presence of 4-toluenesulfonic acid as catalyst. The photochromic and thermochromic properties of the prepared compounds were investigated.
p. 4849-4857
Received: 8 October 2009; in revised form: 4 November 2009 / Accepted: 25 November 2009 / Published: 25 November 2009
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| Download PDF Full-text (565 KB) Abstract: Cyclocondensation of 2-[bis(methylthio)methylene]malononitrile (1) and cysteamine (2) afforded 2-(thiazolidin-2-ylidene)malononitrile (3). This compound on treatment with NaSH gave the corresponding thioamide derivative 4a in a regioselective manner on the basis of its single crystal X-ray diffraction analysis. Reaction of this compound with several α-bromocarbonyl compounds gave new 2-(E )-cyano(thiazolidin-2-ylidene)thiazoles 5a-g.
p. 4858-4865
Received: 21 October 2009; in revised form: 10 November 2009 / Accepted: 11 November 2009 / Published: 26 November 2009
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| Download PDF Full-text (153 KB) Abstract: Structurally diverse thiazoles with electron-donating and electron-withdrawing groups were conveniently synthesized through manganese dioxide (MnO2 ) oxidation of the corresponding thiazolines. The effect of substitution at the 2- and 4-positions was investigated. The desired thiazoles with aryl or vinyl substitutions at the 2- or 4-position can be obtained in good to excellent yields.
p. 4866-4879
Received: 30 September 2009; in revised form: 19 November 2009 / Accepted: 25 November 2009 / Published: 27 November 2009
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| Download PDF Full-text (405 KB) Abstract: The synthetic route for introduction of fluorophenylalkyl (compounds 5, 7, 14 and 15) and fluorophenylalkenyl (compounds 4E and 13) side chains at C-6 of the pyrimidine nucleus involved the lithiation of the pyrimidine derivatives 1, 2 and 11 and subsequent nucleophilic addition or substitution reactions of the organolithium intermediate thus obtained with 2-fluorophenylacetone, 4-fluoroacetophenone or ethyl 4-fluorobenzoate as electrophiles. The structures of novel compounds were confirmed by 1 H-, 19 F- and 13 C-NMR and MS. Compounds 8 and 10 containing unsaturated fluorophenylalkyl side chains showed better inhibitory effect than their saturated fluorophenylalkylated pyrimidine counterparts 7 and 9. A conformational study based on NOE enhancements showed the importance of the double bond and substitution in the side chain for the conformational preferences in relation to inhibitory activity. Among all tested compounds, C-5 furyl (12) and phenyl (13 and 15) substituted pyrimidine derivatives showed significant cytostatic activities against all tested tumor cell lines.
p. 4880-4891
Received: 23 October 2009; in revised form: 18 November 2009 / Accepted: 27 November 2009 / Published: 30 November 2009
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| Download PDF Full-text (335 KB) Abstract: The diversity of selenoproteins raises the question of why so many life forms require selenium. Selenoproteins are found in bacteria, archaea, and many eukaryotes. In photosynthetic microorganisms, the essential requirement for selenium has been reported in 33 species belonging to six phyla, although its biochemical significance is still unclear. According to genome databases, 20 species are defined as selenoprotein-producing organisms, including five photosynthetic organisms. In a marine coccolithophorid, Emiliania huxleyi (Haptophyta), we recently found unique characteristics of selenium utilization and novel selenoproteins using 75 Se-tracer experiments. In E. huxleyi , selenite, not selenate, is the main substrate used and its uptake is driven by an ATP-dependent highaffinity, active transport system. Selenite is immediately metabolized to low-molecular mass compounds and partly converted to at least six selenoproteins, named EhSEP1–6. The most (EhSEP2) and second-most abundant selenoproteins (EhSEP1) are disulfide isomerase (PDI) homologous protein and thioredoxin reductase (TR) 1, respectively. Involvement of selenium in PDI is unique in this organism, while TR1 is also found in other organisms. In this review, we summarize physiological, biochemical, and molecular aspects of selenium utilization by microalgae and discuss their strategy of selenium utilization.
p. 4892-4914
Received: 6 November 2009; in revised form: 24 November 2009 / Accepted: 27 November 2009 / Published: 30 November 2009
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| Download PDF Full-text (754 KB) Abstract: Phosphatidylserine (PS), a phospholipid predominantly found in the inner leaflet of eukaryotic cellular membranes, plays important roles in many biological processes. During apoptosis, the asymmetric distribution of phospholipids of the plasma membrane gets lost and PS is translocated to the outer leaflet of the plasma membrane. There, PS acts as one major “eat me” signal that ensures efficient recognition and uptake of apoptotic cells by phagocytes. PS recognition of activated phagocytes induces the secretion of anti-inflammatory cytokines like interleukin-10 and transforming grow factor-beta. Deficiencies in the clearance of apoptotic cells result in the occurrence of secondarily necrotic cells. The latter have lost the membrane integrity and release immune activating danger signals, which may induce inflammatory responses. Accumulation of dead cells containing nuclear autoantigens in sites of immune selection may provide survival signals for autoreactive B-cells. The production of antibodies against nuclear structures determines the initiation of chronic autoimmunity in systemic lupus erythematosus. Since PS on apoptotic cells is an important modulator of the immune response, natural occurring ligands for PS like annexinA5 have profound effects on immune responses against dead and dying cells, including tumour cells. In this review we will focus on the role of PS exposure in the clearance process of dead cells and its implications in clinical situations where apoptosis plays a relevant role, like in cancer, chronic autoimmunity, and infections. Relevance of other phospholipids during the apoptosis process is also discussed.
p. 4915-4921
Received: 26 October 2009; in revised form: 24 November 2009 / Accepted: 27 November 2009 / Published: 1 December 2009
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| Download PDF Full-text (59 KB) Abstract: Four novel bisquaternary aldoxime cholinesterase reactivators differing in their chemical structure were prepared. Afterwards, their biological activity was evaluated for their ability to reactivate acetylcholinesterase (AChE; EC 3.1.1.7) and butyrylcholinesterase (BuChE; EC 3.1.1.8) inhibited by paraoxon. Their reactivation activity was compared with standard reactivators—pralidoxime, obidoxime and HI-6—which are clinically used at present. As it resulted, none of the prepared compounds surpassed obidoxime, which is considered to be the most potent compound if used for reactivation of AChE inhibited by paraoxon. In case of BuChE reactivation, two compounds (K053 and K068) achieved similar results as obidoxime.
p. 4922-4935
Received: 27 September 2009; in revised form: 17 November 2009 / Accepted: 24 November 2009 / Published: 1 December 2009
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| Download PDF Full-text (205 KB) Abstract: Phenolic compound profiles were investigated by HPLC-MS in two consecutive years to assess genotypic variation in berry skins of nine red Vitis vinifera cultivars. The results showed that the types and levels of phenolic compounds greatly varied with cultivar. Common wine grape cultivars such as Syrah, Cabernet Sauvignon, Cabernet Gernischt and Merlot contained more types of anthocyanins, flavonols, flavan-3-ols, stilbenes and phenolic acids than Gamay, Yan73, Pinot Noir, Zinfandel and Мускат Розовый. Yan 73 and Pinot Noir had abundant anthocyanins, but only a few nonanthocyanin phenolic compounds. Gamay, Zinfandel and Мускат Розовый contained only a few anthocyanins and flavonols. For a grape cultivar, the ratio of one anthocyanin content to total anthocyanin content did not change greatly from one year to the next, unlike for non-anthocyanins. Cluster analysis showed that except for Syrah and Yan 73, the phenolic profiles in the tested grape cultivars had no significant year-to-year variations.
p. 4936-4972
Received: 6 November 2009; in revised form: 17 November 2009 / Accepted: 26 November 2009 / Published: 1 December 2009
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| Download PDF Full-text (532 KB) Abstract: In the manner that very important research is often performed by multidisciplinary research teams, the applications of multicomponent reactions involving the combination of multiple starting materials with different functional groups leading to the higher efficiency and environmentally friendly construction of multifunctional/complex target molecules is growing in importance. This review will explore the advances and advantages in microwave multicomponent synthesis (MMS) that have been achieved over the last five years.
p. 4973-4986
Received: 5 November 2009; in revised form: 24 November 2009 / Accepted: 30 November 2009 / Published: 1 December 2009
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| Download PDF Full-text (244 KB) Abstract: Commercial dehydroacetic acid was converted into 4-hydroxy-6-methylpyridin-2(1H )-one (3), which was then condensed with several aliphatic aldehydes to produce seven new title compounds in variable yields (35–92%). Reaction of 3 with α,β-unsaturated aldehydes resulted in the formation of condensed pyran derivatives 4g' and 4h'. A mechanism is proposed to explain the formation of such compounds. The effects of all methylpyridin-2(1H )-one derivatives on the development of the dicotyledonous species Ipomoea grandifolia and Cucumis sativus and the monocotyledonous species Sorghum bicolor were evaluated. At the dose of 6.7 × 10-8 mol a.i./g substrate the compounds showed some phytotoxic selectivity, being more active against the dicotyledonous species. These compounds can be used as lead structures for the development of more active phytotoxic products.
p. 4987-5000
Received: 9 October 2009; in revised form: 23 November 2009 / Accepted: 27 November 2009 / Published: 1 December 2009
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| Download PDF Full-text (769 KB) Abstract: Aqueous extracts from seeds of Areca catechu L. (Arecaceae) (AC) and nutgalls of Quercus infectoria Oliv. (Fagaceae) (QI) were investigated for their hepatoprotective potential by studying their antioxidant capacity using four different methods, by determining their in vitro anti−inflammatory activity against 5-lipoxygenase, and by evaluating their hepatoprotective potential against liver injury induced by carbon tetrachloride (CCl4 ) in rats. AC and QI extracts exhibited potent antioxidant and anti-inflammatory activities. Treatment of rats with AC and QI extracts reversed oxidative damage in hepatic tissues induced by CCl4 . It is suggested that extracts rich in either condensed or hydrolysable tannins and known for their potent antioxidant and anti-inflammatory activities, may potentially confer protection against oxidative stress−induced liver injury. These data should contribute to evidence-based traditional medicines for anti-inflammatory and hepatoprotective effects of both extracts.
p. 5001-5016
Received: 1 September 2009; in revised form: 24 November 2009 / Accepted: 27 November 2009 / Published: 2 December 2009
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| Download PDF Full-text (278 KB) Abstract: The pH-profiles of the extraction of Cs+ into four conventional (1-butyl-3-methylimidazolium hexafluorophosphate and bis[trifluoromethyl)sulphonyl]imides of 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, and 1-(2-ethylhexyl)-3- methylimidazolium) and two novel (trioctylmethylammonium salicylate and tetrahexylammonium dihexylsulfosuccinate) room temperature ionic liquids have been determined both in the absence and in the presence of crown ether (18-crown-6 or dibenzo-18-crown-6). The pH-profiles of distribution ratio of crown ethers have been established in the same conditions. The relationship of cesium extraction efficiency both with the stability of its complexes with crown ethers and crown ethers’ distribution ratio has been clarified.
p. 5017-5026
Received: 30 September 2009; in revised form: 22 November 2009 / Accepted: 30 November 2009 / Published: 2 December 2009
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| Download PDF Full-text (452 KB) Abstract: Proteins and peptides in mammals are based exclusively on L-amino acids. Recent investigations show that D-amino acids exhibit physiological effects in vivo , despite of their very small quantities. We have investigated the hepatoprotective effects of the Land D-enantiomers of α-melanocortin peptide (α-MSH). The results showed that peptideenantiomerism is related to the protective effects of melanocortin peptides in vivo . L-α-MSH exhibited potent hepatoprotective effect in the experimental model of acetaminophen induced hepatotoxicity in male CBA mice, while its D-mirror image was inefficient. Furthermore, the antibody to the L-peptide did not recognize the D-structure. The results indicate that the opposite peptide configuration may be used to modulate its function and metabolism in vivo and in vitro .
(This article belongs to the Special Issue
Prodrugs )
p. 5027-5041
Received: 4 November 2009; in revised form: 23 November 2009 / Accepted: 30 November 2009 / Published: 4 December 2009
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| Download PDF Full-text (550 KB) Abstract: In this study, we aimed to dissolve microcrystalline cellulose (MCC) with phosphoric acid to obtain high-quality fermentable saccharides. MCC was directly dissolved in phosphoric acid (the concentration was 83%) for 10 hours at temperatures of 30, 50, and 70 °C. The structural changes of MCC were determined in detail with X-ray powder diffraction, solid-state cross-polarization magic angle spinning 13 C-NMR, and X-ray photoelectron spectroscopy. The kinetics of MCC decrystallization during treatment with phosphoric acid was also compared at 30, 50, and 70 °C. With the assumption of first order kinetics, the Arrhenius parameters of K , A 0 and E a were calculated. The rate constants of decrystallization reaction (K ) were 0.06, 0.17, and 0.12 h-1 respectively. The pre-exponential factor (A 0 ) was 1.2 × 106 h-1 , and the activation energy (E a ) was 42.4 kJ/mol.
p. 5042-5053
Received: 26 October 2009; in revised form: 25 November 2009 / Accepted: 2 December 2009 / Published: 7 December 2009
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| Download PDF Full-text (179 KB) Abstract: A series of phenanthrene-based tylophorine derivatives (PBTs) were synthesized and their cytotoxic activities against the H460 human large-cell lung carcinoma cell line were evaluated. Among these compounds, N -(3-hydroxy-2,6,7-tri-methoxyphenanthr-9-ylmethyl)-L-prolinol (5a ), and N -(3-hydroxy-2,6,7-trimethoxy-phenanthr-9-ylmethyl)-L-valinol (9 ) exhibited good activities, with IC50 values of 11.6 and 6.1 mM, respectively.
p. 5054-5102
Received: 12 November 2009; in revised form: 30 November 2009 / Accepted: 4 December 2009 / Published: 7 December 2009
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| Download PDF Full-text (283 KB) Abstract: Neurodegeneration is frequently associated with damage by free radicals. However, increases in reactive oxygen and nitrogen species, which may ultimately lead to neuronal cell death, do not necessarily reflect its primary cause, but can be a consequence of otherwise induced cellular dysfunction. Detrimental processes which promote free radical formation are initiated, e.g., by disturbances in calcium homeostasis, mitochondrial malfunction, and an age-related decline in the circadian oscillator system. Free radicals generated at high rates under pathophysiological conditions are insufficiently detoxified by scavengers. Interventions at the primary causes of dysfunction, which avoid secondary rises in radical formation, may be more efficient. The aim of such approaches should be to prevent calcium overload, to reduce mitochondrial electron dissipation, to support electron transport capacity, and to avoid circadian perturbations. l-Theanine and several amphiphilic nitrones are capable of counteracting excitotoxicity and/or mitochondrial radical formation. Resveratrol seems to promote mitochondrial biogenesis. Mitochondrial effects of leptin include attenuation of electron leakage. Melatonin combines all the requirements mentioned, additionally regulates anti- and pro-oxidant enzymes and is, with few exceptions, very well tolerated. In this review, the perspectives, problems and limits of drugs are compared which may be suitable for reducing the formation of free radicals.
p. 5103-5114
Received: 18 November 2009; in revised form: 8 December 2009 / Accepted: 8 December 2009 / Published: 8 December 2009
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| Download PDF Full-text (145 KB) Abstract: Ultra-short peptides 1-9 were designed and synthesized with phenylalanine, ornithine and proline amino acid residues and their effect on antimalarial activity was analyzed. On the basis of the IC50 data for these compounds, the effects of nature, polarity, and amino acid sequence on Plasmodium berghei schizont cultures were analyzed too. Tetrapeptides Phe-Orn-Phe-Orn (4 ) and Lys-Phe-Phe-Orn (5 ) showed a very important activity with IC50 values of 3.31 and 2.57 μM, respectively. These two tetrapeptides are candidates for subsequent in vivo assays and SARS investigations.
p. 5115-5123
Received: 20 October 2009; in revised form: 26 November 2009 / Accepted: 4 December 2009 / Published: 9 December 2009
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| Download PDF Full-text (432 KB) Abstract: Calcium-induced, calpain-mediated proteolysis (CMSP) has recently been implicated to the pathogenesis of diffuse (traumatic) axonal injury (TAI). Some studies suggested that subaxolemmal CMSP may contribute to axolemmal permeability (AP) alterations observed in TAI. Seeking direct evidence for this premise we investigated whether subaxolemmal CMSP may contribute to axolemmal permeability alterations (APA) and pre-injury calpain-inhibition could reduce AP in a rat model of TAI. Horseradish peroxidase (HRP, a tracer that accumulates in axons with APA) was administered one hour prior to injury into the lateral ventricle; 30 min preinjury a single tail vein bolus injection of 30 mg/kg MDL-28170 (a calpain inhibitor) or its vehicle was applied in Wistar rats exposed to impact acceleration brain injury. Histological detection of traumatically injured axonal segments accumulating HRP and statistical analysis revealed that pre-injury administration of the calpain inhibitor MDL-28170 significantly reduced the average length of HRP-labeled axonal segments. The axono-protective effect of pre-injury calpain inhibition recently demonstrated with classical immunohistochemical markers of TAI was further corroborated in this experiment; significant reduction of the length of labeled axons in the drug-treated rats implicate CMSP in the progression of altered AP in TAI.
p. 5124-5143
Received: 13 November 2009; in revised form: 26 November 2009 / Accepted: 7 December 2009 / Published: 9 December 2009
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| Download PDF Full-text (240 KB) Abstract: A versatile method for the synthesis of chiral 1,4-disubstituted-1,2,3-triazole derivatives starting from easily accessible naturally occurring D-or L-amino acids as chiral synthons is described. The amino acids were converted into azido alcohols, followed by copper catalyzed [3+2] cycloaddition reactions between the azido alcohols and methyl propiolate and subsequent ester aminolysis with primary and secondary amines furnished the target compounds, which were obtained in excellent yields with no racemization. Docking of selected target compounds shows that the chiral 1,4-disubstituted-1,2,3-triazoles derivatives has the potential of mimicking the binding mode of known purine analogues.
p. 5144-5164
Received: 3 November 2009; in revised form: 3 December 2009 / Accepted: 8 December 2009 / Published: 9 December 2009
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| Download PDF Full-text (319 KB) Abstract: Coconut water (coconut liquid endosperm), with its many applications, is one of the world’s most versatile natural product. This refreshing beverage is consumed worldwide as it is nutritious and beneficial for health. There is increasing scientific evidence that supports the role of coconut water in health and medicinal applications. Coconut water is traditionally used as a growth supplement in plant tissue culture/micropropagation. The wide applications of coconut water can be justified by its unique chemical composition of sugars, vitamins, minerals, amino acids and phytohormones. This review attempts to summarise and evaluate the chemical composition and biological properties of coconut water.
p. 5165-5168
Received: 17 November 2009; in revised form: 8 December 2009 / Accepted: 8 December 2009 / Published: 9 December 2009
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| Download PDF Full-text (137 KB) Abstract: A new 2-(2-phenylethyl)chromone, 5,6,7,8-tetrahydroxy-2-(3-hydroxy-4-methoxyphenethyl)-5,6,7,8-tetrahydro-4H -chromen-4-one (1 ) was isolated from the Chinese eaglewood [Aquilaria sinensis (Lour.) Gilg]. Its structure was established by detailed MS and NMR spectroscopic analysis, as well as comparison with literature data.
p. 5169-5178
Received: 10 November 2009; in revised form: 4 December 2009 / Accepted: 9 December 2009 / Published: 10 December 2009
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| Download PDF Full-text (416 KB) Abstract: CuO/AB was found to be a simple and efficient catalyst for the N -arylation of a variety of nitrogen-containing heterocycles, giving the products in excellent yields.
p. 5179-5188
Received: 2 November 2009; in revised form: 4 December 2009 / Accepted: 10 December 2009 / Published: 11 December 2009
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| Download PDF Full-text (377 KB) Abstract: The pore forming properties of synthetic cecropin-melittin hybrid peptide (Acetyl-KWKLFKKIGAVLKVL-CONH2 ; CM15 ) were investigated by using photoreceptor rod outer segments (OS) isolated from frog retinae obtained by using the whole-cell configuration of the patch-clamp technique. CM15 was applied (and removed) to (from) the OS in ~50 ms with a computer-controlled microperfusion system. Once the main OS endogenous conductance was blocked with light, the OS membrane resistance was ≥1 GΩ, allowing high resolution, low-noise recordings. Different to alamethicines, CM15 produced voltage-independent membrane permeabilisation, repetitive peptide application caused a progressive permeabilisation increase, and no single-channel events were detected at low peptide concentrations. Collectively, these results indicate a toroidal mechanism of pore formation by CM15 .
p. 5189-5202
Received: 5 November 2009; in revised form: 26 November 2009 / Accepted: 1 December 2009 / Published: 11 December 2009
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| Download PDF Full-text (427 KB) Abstract: A series of twenty arylpiperazine derivatives of 1,7,8,9-tetrachloro-10,10-dimethoxy-4-azatricyclo[5.2.1.02,6 ]dec-8-ene-3,5-dione have been prepared. These derivatives were tested in vitro with the aim of identifying novel lead compounds active against emergent and re-emergent human and cattle infectious diseases (AIDS, hepatitis B and C, tuberculosis, bovine viral diarrhea). In particular, these compounds were evaluated in vitro against representatives of different virus classes, such as a HIV-1 (Retrovirus), a HBV (Hepadnavirus) and the single-stranded RNA+ viruses Yellow fever virus (YFV) and Bovine viral diarrhea virus (BVDV), both belonging to the Flaviridae. Compounds 2c , 2g and 3d showed a modest activity against CVB-2. The molecular structures of the starting imide 1 and one of propyl-piperazine derivatives, 3b , have been determined by an X-ray crystallography study.
p. 5203-5215
Received: 16 November 2009; in revised form: 4 December 2009 / Accepted: 10 December 2009 / Published: 14 December 2009
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| Download PDF Full-text (264 KB) Abstract: Some substituted benzylidenehydrazinylpyridinium derivatives bearing benzyl, ethylphenyl and propylphenyl groups on the pyridinium nitrogen were synthesized and screened for possible antibacterial and antifungal activities against Staphylococcus aureus , Escherichia coli , Pseudomonas aeruginosa and Candida albicans using the microdilution method. Antimicrobial test results indicated that compounds containing a 3-phenylpropyl chain displayed the highest antimicrobial activity against Staphylococcus aureus and the compound 3d was the most active in the series against all tested bacteria and fungi strains.
p. 5216-5222
Received: 26 October 2009; in revised form: 17 November 2009 / Accepted: 30 November 2009 / Published: 15 December 2009
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| Download PDF Full-text (236 KB) Abstract: The four-step, asymmetric synthesis of a chiral propargyl alcohol 1 from (R )-pantolactone is described. A key feature of the synthesis is a diastereoselective acetylide addition to a chiral α-alkoxy-aldehyde 7 , in which unusual Felkin selectivity is observed, despite the potential for chelation control. Crystalline propargyl alcohol 1 is valuable for complex molecule synthesis, and is easy to prepare in multi-gram quantities and high diastereomeric purity.
p. 5223-5234
Received: 4 November 2009; in revised form: 3 December 2009 / Accepted: 14 December 2009 / Published: 15 December 2009
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| Download PDF Full-text (176 KB) Abstract: Representative benzimidazopyrimidinones were previously reported to be intercalating antitumor agents. In this work, we used 2-substituted 4,10-dihydrobenzo [4,5]imidazo[1,2-α ]pyriminin-4-ones for their diversification by regioselective alkylation. Under the conditions established, the alkylation gave 10-alkyl derivatives which permitted the parallel generation of a 500-member library of the title compounds.
p. 5235-5246
Received: 20 October 2009; in revised form: 5 December 2009 / Accepted: 10 December 2009 / Published: 15 December 2009
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| Download PDF Full-text (331 KB) Abstract: Annonaceous acetogenins are proposed as environmental neurotoxicants consumed through medicinal and alimentary habits and responsible for atypical parkinsonian syndromes observed in tropical areas. Potential sources of exposure still have to be determined, as, to date, only a few batches of products for human consumption were searched for these compounds. To assess the presence of acetogenins, we propose a fast, sensitive and accurate method of screening, using MALDI-TOF MS, with minimal sample preparation. Development of the technique is discussed. Its application to leaves of herbal tea, pulp and bottled nectar of Annona muricata is presented.
p. 5247-5280
Received: 9 October 2009; in revised form: 8 December 2009 / Accepted: 14 December 2009 / Published: 15 December 2009
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| Download PDF Full-text (394 KB) Abstract: New arylsulfonyl proton pump inhibitor (PPI) prodrug forms were synthesized. These prodrugs provided longer residence time of an effective PPI plasma concentration, resulting in better gastric acid inhibition.
(This article belongs to the Special Issue
Prodrugs )
p. 5281-5288
Received: 1 November 2009; in revised form: 7 December 2009 / Accepted: 14 December 2009 / Published: 15 December 2009
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| Download PDF Full-text (209 KB) Abstract: A new phenolic, bis(6-hydroxy-2,3,4-trimethoxylphen-1-yl)methane (1 ) and a new butanedioate, butylmethyl succinate (2 ), along with twenty-nine known compounds including one naphthoquinone derivative, two chromanones, eight benzenoids, one lignan, one tocopherol, and sixteen triterpenoids were isolated from the stems of Diospyros maritima . epi -Isoshinanolone (3 ) was isolated in pure form for the first time. In addition, 5,7-dihydroxy-2-methylchomanone (4 ) was isolated from a natural source for the first time. Their structures were established on the basis of spectroscopic data as well as direct comparison with authentic samples.
p. 5289-5297
Received: 12 November 2009; in revised form: 15 December 2009 / Accepted: 15 December 2009 / Published: 15 December 2009
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| Download PDF Full-text (123 KB) Abstract: The volatile components of the leaves of five Bursera species, B. copallifera , B. exselsa , B. mirandae , B. ruticola and B. fagaroides var. purpusii were determined by gas chromatography–mass spectrometry (GC–MS). Germacrene D was one of the predominant components (15.1–56.2%) of all of these species. Germacrene D has also been found in other Bursera species and some species of Commiphora , the sister group of Bursera , suggesting that the production of germacrene D might be an ancient trait in the genus Bursera .
p. 5298-5307
Received: 13 November 2009; in revised form: 15 December 2009 / Accepted: 15 December 2009 / Published: 16 December 2009
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| Download PDF Full-text (197 KB) Abstract: The protecting-group-free asymmetric synthesis of 1,2,4-trideoxy-1,4-imino-L-xylitol is readily achieved in five steps from 2-deoxy-D-ribose and with an overall yield of 48%. Key in this synthesis is the application of our recently developed Vasella-reductive amination and carbamate annulation methodologies to the synthesis of 2-deoxy-aza-sugars. The carbamate annulation occurred with excellent yield and diastereoselectively (>20:1 d.r. ), in favour of the 3,4-cis isomer.
p. 5308-5322
Received: 26 November 2009; in revised form: 9 December 2009 / Accepted: 15 December 2009 / Published: 16 December 2009
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| Download PDF Full-text (358 KB) Abstract: Prompted by the scant attention paid by published literature reviews to the applications of molecular iodine in oxidative aromatization reactions, we decided to review methods developed to-date involving iodine as an oxidant to promote aromatization of α,β-unsaturated cyclic compounds.
p. 5323-5327
Received: 9 November 2009; in revised form: 15 December 2009 / Accepted: 16 December 2009 / Published: 16 December 2009
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| Download PDF Full-text (150 KB) Abstract: Sorbus commixta Hedl. (Rosaceae) has been traditionally used in oriental countries for the treatment of asthma and other bronchial disorders. In this study, a chalcone glycoside was isolated from the ethyl acetate extract of the fruits of this plant. The compound was identified as neosakuranin based on the spectroscopic analysis and comparion with literature data. This is the first report of isolation of neosakuranin from Sorbus commixta .
p. 5328-5338
Received: 27 October 2009; in revised form: 20 November 2009 / Accepted: 2 December 2009 / Published: 17 December 2009
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| Download PDF Full-text (424 KB) Abstract: The cytotoxic activity of curcumin towards CCRF-CEM human T-cell leukemia cells was measured by the MTT assay. Tumor cells were more sensitive to the cytotoxic activity of curcumin or curcumin-Cu (II)compared to normal cells, and the IC50 ofcurcumin towards CCRF-CEM cells was 8.68 µM, and that ofcurcumin-Cu (II) was 8.14 µM. The cell cycle distribution of curcumin-treated CCRF-CEM cells was analyzed by flow cytometry. DNA damage induced by oxidants such as curcumin-Cu (II) ions is considered as one of the main causes of cell inactivation. Therefore, we analyzed the effect of curcumin on DNA damage by agarose gel electrophoresis and atomic force microscopy (AFM). Gel electrophoresis analyses showed that curcumin or Cu (II) alone failed to cause DNA damage in pBR322 plasmid DNA as compared with the normal plasmid. However, DNA plasmids were mostly damaged after treatment with curcumin of different concentrations in the presence of Cu (II). Two forms were observed by means of AFM: closed circular plasmids and linear plasmids. DNA damage induced by a combination of curcumin and Cu (II) was also found by agarose gel electrophoresis, which was applied as control method to verify the results obtained by AFM.
p. 5339-5348
Received: 28 November 2009; in revised form: 16 December 2009 / Accepted: 17 December 2009 / Published: 18 December 2009
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| Download PDF Full-text (498 KB) Abstract: To seek novel antitumor agents, we designed and synthesized new 1-tryptophan analogs based on tryptophan catabolism. 1-Alkyltryptophan analogues including 1-ethyltryptophan (1-ET), 1-propyltryptophan (1-PT), 1-isopropyltryptophan (1-isoPT) and 1-butyltryptophan (1-BT) were synthesized from tryptophan. We examined whether those compounds had the antiproliferative effects on SGC7901 and HeLa cells line by using MTT assay in vitro , respectively. Compared to tryptophan, all targeted compounds efficiently inhibited proliferation of two cancer cell lines at 2 mmol/L for 48 hours. Among these tryptophan analogs, 1-BT showed the most powerful cytotoxicity against SGC7901 and HeLa cells at 1 mmol/L and 2 mmol/L concentration. These data suggest that some specific tryptophan analogs could be developed as potential anti-neoplastic agents.
p. 5349-5361
Received: 30 October 2009; in revised form: 4 December 2009 / Accepted: 14 December 2009 / Published: 21 December 2009
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| Download PDF Full-text (488 KB) Abstract: Radix Angelicae Sinensisis (RAS) is one of the most popular traditional Chinese herbal medicines. In the present study, six RAS extracts (i.e. , phenolic extract PE, petroleum ether extract PEE, ethyl acetate extract EAE, absolute ethanol extract AEE, 95% ethanol extract 95 EE, and water extract WE) were prepared and their antioxidant activities measured by DPPH (1,1-diphenyl-2-picrylhydrazyl radical), ABTS [2,2′-azino-bis(3- ethylbenzothiazoline-6-sulfonic acid diammonium salt)], Reducing power, •O2– and lipid peroxidation assays. In general, PE, PEE and EAE had relatively high antioxidant activity, followed by AEE with moderate activity, as compared with 95 EE and WE that had low activity. Their phenolic contents (including total phenolic, ferulic acid, caffeic acid, same as below) were then determined by HPLC or spectrophotometry. The sequence of phenolic contents was roughly identical with that of antioxidant activity. When the values of 1/IC50 of various antioxidant assays were used to evaluate the level of antioxidant of the RAS extracts, (plot between 1/IC50 values and phenolic contents), the correlation coefficient (R) ranged from 0.642 to 0.941, with an average value of 0.839. Significant positive correlations demonstrated that the antioxidant effects of RAS might generally be considered a result of the presence of the phenolic compounds, especially ferulic acid and caffeic acid.
p. 5362-5366
Received: 9 December 2009 / Accepted: 18 December 2009 / Published: 21 December 2009
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| Download PDF Full-text (110 KB) Abstract: Artemisinin (Qinghaosu), a new antimalarial drug, was discovered in China in the early 1970s. The discovery of artemisinin is attributed to You-You Tu, at that time a middle-aged phytochemist working in the Institute of Chinese Materia Medica, China Academy of Traditional Chinese Medicine. The following paragraph provides a brief summary of her discovery. [...]
p. 5367-5381
Received: 30 September 2009; in revised form: 16 November 2009 / Accepted: 21 December 2009 / Published: 22 December 2009
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| Download PDF Full-text (322 KB) Abstract: In the 1970s, morphological evidence collected by electron microscopy linked mineral deposition (“calcification” or “mineralization”) in newly-forming bone to membrane-encapsulated particles of a diameter of approximately 100 nm (50–200 nm) that were called “matrix vesiscles”. As the characterisation of these vesicles progressed towards their biochemical composition, the role of lipids in the biomineralization process appeared to be crucial. In particular, a group of cell-membrane phospholipids were identified as major players in the crystal formation process. Indeed, in the 1980s it became clear that phosphatidylserine, together with proteins of the annexin family, was among the most important molecules in binding calcium ions and that this phospholipid was involved in the regulation of the early stages of mineralization in vivo . During the same period of time, the number of surgical implantations of orthopaedic, dental and maxilo-facial devices requiring full integration with the treated bone prompted the study of new functionalisation molecules able to establish a stable bonding with the mineral phase of the host tissue. In the late 1990s studies started that aimed at exploiting the potential of calcium-binding phospholipids and, in particular, of the phosphatidylserine as functionalisation molecules to improve the osteointegration of artificial implants. Later, papers have been published that show the potential of the phophatidylserine and phosphatidylserine-mimicking coating technology to promote calcification both in vitro and in vivo . The promising results support the future clinical application of these novel osteointegrative biomaterials.
p. 5382-5388
Received: 28 October 2009; in revised form: 12 December 2009 / Accepted: 18 December 2009 / Published: 23 December 2009
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| Download PDF Full-text (192 KB) Abstract: Eleven new 2-styrylbenzothiazole-N -oxides have been prepared by aldol – type condensation reactions between 2-methylbenzothiazole–N -oxide and para -substituted benzaldehydes. Compounds with cyclic amino substituents showed typical push-pull molecule properties. Four compounds were tested against various bacterial strains as well as the protozoan Euglena gracilis as model microorganisms. Unlike previously prepared analogous benzothiazolium salts, only weak activity was recorded.
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