Molecules, Volume 12, Issue 3

A fast and efficient solid state method for the chemoselective room temperature oxidative coupling of thiols to afford their corresponding disulfides using inexpensive and readily available moist sodiumperiodate as the reagent is described. The react...

Liquid chromatography/ultraviolet (LC/UV) and mass spectrometry/mass spectrometry (MS/MS) libraries containing 39 phenolic compounds were established by coupling a LC and an ion trap MS with an electrospray ionization (ESI) source, operated in negati...

This paper reports a novel synthesis of gefitinib starting from methyl3-hydroxy-4-methoxybenzoate. The process starts with alkylation of the starting material, followed by nitration, reduction, cyclization, chlorination and two successive amination r...

Aflatoxins, a group of structurally related mycotoxins, are well known for their toxic and carcinogenic effects in humans and animals. Aflatoxin derivatives and protein conjugates are needed for diverse analytical applications. This work describes a...

Oxidation of quercetin by air oxygen takes place in water and aqueous ethanol solutions under mild conditions, namely in moderately-basic media (pH ∼ 8-10) at ambient temperature and in the absence of any radical initiators, without enzymatic catalys...

A series of benzothiazol-2-yl-dithiocarbamates 3a-d along with their copper complexes 4a-c were synthesized via the reaction of suitable alkyl, aralkyl or heteroaryl halides with the sodium salt of benzothiazol-2-yl-dithiocarbamic acid, followed by c...

5-Acetoxymethyl- and 5-hydroxymethyl-2-vinylfuran were synthesized by two routes. The first route starts from 2-methylfuran and the second from furfuryl acetate. The latter route, involving successive Vilsmeier-Haack and Wittig reactions, is suitable...

To investigate the enzyme variations responsible for the synthesis of phenolics, 40 day-old adventitious roots of Panax ginseng were treated with 200 μM methyl jasmonate (MJ) or salicylic acid (SA) in a 5 L bioreactor suspension culture (working volu...

Liquid-liquid phase transfer alkylation of 4-methoxy-pyrazolo[3,4-d]-pyrimidine (1a) with a dichloromethane/dibromomethane mixture (3:1, v/v) gave the regioisomeric methylenebis(heterocycles) 3a–5a. These were converted by dilute aqueous sodium hydro...

The contents and antioxidant ability of various classes of phenolic compounds present in the seeds of twenty soybean hybrids were evaluated. Total phenolics, tannins and proanthocyanidins were determined spectrophotometrically, after extraction of se...

Chemical examination of the green alga Cladophora fascicularis resulted in the isolation and characterization of a new porphyrin derivative, porphyrinolactone (1), along with five known phaeophytins 2-6 and fourteen sterols and cycloartanes. The stru...

HPLC-DAD coupled with mass spectrometry in the positive ionization mode was applied to study the fragmentation of twelve selected flavonoids. Compounds belonging to all the major subgroups found in common plants, i.e. flavonols, flavones, dihydroflav...

The flavonoid phlorhizin is abundant in the leaves of Sweet Tea(ST, Lithocarpus Polystachyus Rehd). Phlorhizinwas preparatively separated and purified from a crude ST extract containing 40% total flavonoids by static adsorption and dynamic desorption...

A simple, rapid, and regioselective approach for the synthesis of N-(methoxy-carbonylmethyl)- and N-(n-propoxycarbonylmethyl) nucleobases was developed. By using DMF as the solvent and in the presence of K₂CO₃ as the base, all the desired products we...

Selenium-containingheterocyclic compounds have been well recognized, not only because of their remarkable reactivities and chemical properties, but also because of their diverse pharmaceutical applications. In this context, isoselenocyanates have bee...

A phytochemical study of the ethanolic extract of Stachyurus imalaicus var. himalaicus was undertaken and as a result a new polyoxygenated steroid, named stachsterol ((20S)-20, 25-dihydroxy-4-cholesten-3-one, 1) and three known ecdysteroids, 20-hydro...

Model tetrahydropyrido[3',2':4,5]thieno[2,3-b][1,4]thiazines 9a-c were synthesized via reductive lactamization, using sodium dithionite, of the respective 2-[(carboxyalkyl)thio]-3-nitro-4,7-dihydrothieno[2,3-b]pyridine-5-carboxylic acids 7a-c. The la...

This paper presents a review on kaurane diterpenes and their glycoside derivatives, covering aspects of their occurrence, biological activities and the synthesis of these natural products and their analogues. First, it shows and classifies diterpenes...

Black tea was extracted for 2, 8 and 18 h with absolute acetone, N,N-dimethyl-formamide (DMF), ethanol and methanol and their 50% aqueous solutions. The extracts were screened for total polyphenol contents, antioxidant and antibacterial activities. T...

We have synthesized a novel chiral NADH model compound, N-methyl-(R)-3-(tert-butyl)-sulphinyl-1,4-dihydropyridine with high enantioselectivity and used it in the reduction of methyl benzoylformate, producing (S)-methyl mandelate in 95% ee. The absolu...

Aqueous extracts of green yerba maté (Ilex paraguariensis) and green tea (Camellia sinensis) are good sources of phenolic antioxidants, as already described in the literature. The subject of this study were organic extracts from yerba maté, both gree...

A variety of Hantzsch 1,4-dihydropyridines were oxidized to their corresponding pyridines in high yields in the presence of Cu(C₂₂H₂₂N₂O₂) in refluxing acetic acid.

We have previously reported a new synthesis of amides from esters and amines under microwave irradiation, offering much higher yields than those achieved with conventional heating [1]. We have now extended these studies to the ring closure of neat im...

The first synthesis of a series of ketones naturally occurring in E. pallida is described. The natural distribution of these ketones among different Echinacea species is also reported.

Exhaustive hydro-distillation of the leaves of Piper aduncum and fruits of Piper gibbilimbum (Piperaceae) afforded colorless and pale orange colored oils in 0.35 and 0.30 % yields, respectively. Detailed chemical analysis by GC/MS indicated the volat...

Isoxazoline analogues of artemisinin were obtained in low yield and low diastereoselectivity from the 1,3-dipolar cycloaddition of nitrile oxides. Alternatively, starting from the aldehyde 7, a number of transformations - Wittig reaction and reductio...

Four new diterpenoid alkaloids: tiantaishansine (1), tiantaishannine (2), tiantaishanmine (3), and tiantaishandine (4) have been isolated from the roots of Delphinium tiantaishan. Their structures were elucidated by chemical evidence andspectral anal...

2-Oxo-4-phenyl-1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile (10) reacted with hydrazine hydrate, phenylisothiocyanate or benzoyl chloride to give derivatives 12, 13 and 15, respectively. The latter two products were treated with hydrazine hydrate to...

While the mammalian eye is seldom considered an organ of drug metabolism, the capacity for biotransformation is present. Compared to the liver, the metabolic capabilities of the eye are minuscule; however, phase I and phase II metabolic activities ha...

The isolation of four novel acylated flavonoid glycosides from the roots of Saussurea lappa and their identification using a combination of 1D and 2D NMR and mass spectrometry is described. The in vitro antifungal and antibacterial activities of the...

1,3-Disubstituted-2,3-dihydro-1H-naphth[1,2-e][1,3]oxazines were prepared through the ring-closurereactions of the aminobenzylnaphthols with substituted aryl-andheteroarylaldehydes.

Mistletonone, a novel diarylheptanoid, was isolated from the branches and leaves of Viscum coloratum (Kom.) Nakai (Loranthaceae). It was identified as 1,7-di-(p-hydroxyphenyl)-5-hydroxyl-cis-2,3-epoxy-1-one on the basis of spectral evidence. The comp...

A selective route for the degradation of the unsaturated side chain of ent-labdanes has been devised, giving two useful synthons: 2β-acetoxy-14,15,17-trinor-ent-labdane-8,13- dione (5) and 2β-acetoxy-14,15-dinor-ent-labd-8(17)-en-13-one (7), the use...

A series of 6-aryl-3-(3-hydroxypropyl)-7H-1,2,4-triazolo[3,4-b][1,3,4]-thia-diazines were synthesized by the reaction of 4-amino-3-(3-hydroxypropyl)-5-mercapto-1,2,4-triazole (1) with substituted ω-haloacetophenones. Their structures were confirmed b...

A “green” highly selective oxidation of organic sulfides to the corresponding sulfoxides was developed using hydrogen peroxide and glacial acetic acid under transition metal-free and mild conditions. The oxidation procedure is very simple and the pro...

The results obtained show that Bosnian pine is richin glycosidically bound volatile compounds with strong free radical scavengingproperties. Since volatiles can be released from nonvolatile glycosideprecursors, these compounds can be considered as a...

In the present work, the pyrolysis of acetylene was studied under steel vacuumcarburizing conditions in a tubular flow reactor. The pyrolysis temperature ranged from650 °C to 1050 °C. The partial pressure of acetylene in the feed mixture was 10 and 2...