Synthesis and Cytotoxicity of Thieno[2,3-b]Pyridine Derivatives Toward Sensitive and Multidrug-Resistant Leukemia Cells.

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.

Identification of Human Kinin-Forming Enzyme Inhibitors from Medicinal Herbs.

The goal of this study was to assess the pharmacological effects of black tea ( var. assamica) water extract on human kinin-forming enzymes in vitro. Tea is a highly consumed beverage in the world.

Evaluation of Triazole and Isoxazole Derivatives as Potential Anti-infective Agents.

A 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.

Flavonoids from Perovskia atriplicifolia and Their in Vitro Displacement of the Respective Radioligands for Human Opioid and Cannabinoid Receptors.

Bioassay-guided fractionation of the leaves of Perovskia atriplicifolia (Russian sage) resulted in the isolation of four previously known flavonoid derivatives, 5-hydroxy-6,7,3',4'-tetramethoxyflavone (1), 5,7-dihydroxy-6,3',4'-trimethoxyflavone (2), 5-hydroxy-6,7,4'-trimethoxyflavone (3), and 5,7-dihydroxy-6,4'-dimethoxyflavone (4). Compounds 1, 3, and 4 showed displacement of the radioligand for the cloned human δ opioid receptor with Ki values ranging from 3.1 to 26.

Sulfated phenolic compounds from Limonium caspium: Isolation, structural elucidation, and biological evaluation.

Three 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.

Antifungal compounds from turmeric and nutmeg with activity against plant pathogens.

The 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.

Flavanones from .

A 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).

Secondary metabolites from the fungus Emericella nidulans.

A 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.

Fatty acids with in vitro binding affinity for human opioid receptors from the fungus Emericella nidulans.

Bioassay-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.

Antifungal activity against plant pathogens of metabolites from the endophytic fungus Cladosporium cladosporioides.

Bioassay-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.