A new series of substituted ethyl 7-cyclopropyl-2-(2-aryloxo)-3-nitro-4-oxo-4,7-dihydrothieno[2,3-b]pyridine-5-carboxylates 3a-e were prepared by utilizing ethyl 2-chloro-7-cyclopropyl-3-nitro-4-oxo-4,7-dihydrothieno[2,3-b]pyridine-5-carboxylate (1) and replacing of the 2-chlorine with anions obtained from phenol (2a), salicylaldehyde derivatives 2b-d or thiophenol (2e), leading to the respective ethyl 7-cyclopropyl-2-(2-aryloxo)-3-nitro-4-oxo-4,7-dihydrothieno[2,3-b]pyridine-5-carboxylates 3a-e. The new compounds were evaluated for their in vitro cytotoxicity towards sensitive CCRF-CEM and multidrug-resistant CEM/ADR5000 leukemia cells. The screening revealed that compounds 3a, 3b, and 3e inhibited the growth of both cell lines.
View Article and Find Full Text PDFA series of isoxazole and triazole derivatives, with interesting bioactive scaffolds, were examined for their antibacterial, antifungal, and antiprotozoal activities. These compounds exhibited antitrypanosomal activity comparable to difluoromethylornithine (DMFO), a drug used in the treatment of human African trypanosomiasis. Isoxazole analogues , and , and triazole derivatives , , , , and showed the highest antitrypanosomal activity with IC values of 17.
View Article and Find Full Text PDFThree new compounds, (2S,3S)-5-methyldihydromyricetin (1), (2S,3S)-5-methyldihydromyricetin-3'-O-sulfate (2) and β-d-glucopyranoside, 3-methyl, but-3-en-1-yl 4-O-α-l-rhamnopyranosyl (3) have been isolated from the Limonium caspium, together with dihydromyricetin (4), dihydromyricetin-3'-O-sulfate (5), myricetin-3'-O-sulfate (6), 5-methylmyricetin (7), myricetin (8), myricetin-3-O-β-glucoside (9), as well as phloridzin (10), and tyramine (11). Compounds 5 and 6 were isolated for the first time as acids. This is the first report of all these compounds from this plant.
View Article and Find Full Text PDFThe antifungal activity of twenty-two common spices was evaluated against plant pathogens using direct-bioautography coupled Colletotrichum bioassays. Turmeric, nutmeg, ginger, clove, oregano, cinnamon, anise, fennel, basil, black cumin, and black pepper showed antifungal activity against the plant pathogens Colletotrichum acutatum, Colletotrichum fragariae, and Colletotrichum gloeosporioides. Among the active extracts, turmeric and nutmeg were the most active and were chosen for further investigation.
View Article and Find Full Text PDFA glycosidic flavanone miconioside C () has been isolated from the methanolic extract of the stems of , together with 7--β-D-apiofuranosyl-(1→6)-β-D-glucopyranosylmatteucinol (), miconioside B (), matteucinol (), farrerol () and desmethoxymatteucinol (). Their structures were mainly established by extensive NMR studies (H NMR, C NMR, DEPT, H-H COSY, HSQC, HMBC) and mass spectrometry. The compounds - were evaluated for binding assays using cannabinoid receptors (CB1 and CB2).
View Article and Find Full Text PDFA new polyketide derivative koninginin H (1), has been isolated from the fungus Emericella nidulans, together with koninginin E (2), koninginin A (3), trichodermatide B (4), citrantifidiol (5), (4S,5R)-4-hydroxy-5-methylfuran-2-one (6), the glycerol derivatives gingerglycolipid B (7), (2S)-bis[9Z,12Z]-1-O, 2-O-dilinoleoyl-3-O-[alpha-D-galactopyranosyl-(1" --> 6') beta-D-galactopyranosyl]glycerol (8), (2S)-bis[9Z,12Z]-1-O, 2-O-dilinoleoyl-3-O-beta-D-galactopyranosylglycerol (9), the cerebroside flavuside B (10), and the known sterols beta-sitosterol glucoside and ergosta-5,7,22-trien-3-ol. Their structures were established by extensive NMR studies (1H NMR, 13C NMR, DEPT, 1H-1H COSY, HSQC, HMBC) and mass spectrometry. The antibacterial, antimalarial, antifungal and antileishmanial activities of compounds 1-10 were examined and the results indicated that compound 4 showed good antifungal activity against Cryptococcus neoformans with an IC50 value of 4.
View Article and Find Full Text PDFBioassay-guided fractionation of the EtOAc extracts of the epiphytic fungus Emericella nidulans resulted in the isolation of a mixture of two fatty acids. This mixture showed 98% binding affinity to human δ opioid receptor. These two fatty acids were identified as palmitic (PAM), 1, and linoleic acids (LNA), 2, by 1D NMR as well as by GC/MS analysis, after their methylation.
View Article and Find Full Text PDFBioassay-guided fractionation of Cladosporium cladosporioides (Fresen.) de Vries extracts led to the isolation of four compounds, including cladosporin, 1; isocladosporin, 2; 5'-hydroxyasperentin, 3; and cladosporin-8-methyl ether, 4. An additional compound, 5',6-diacetylcladosporin, 5, was synthesized by acetylation of compound 3.
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