ABSTRACT
Three new indole alkaloids, named talatensindoids A-C (1-3), together with two known biogenetically related indole alkaloids tryptamine (4) and L-tryptophan (5) were isolated from the Talaromyces assiutensis JTY2 based on the guidance of OSMAC approach. The structures of these indole alkaloids were determined by comprehensive spectroscopic analyses. The absolute configuration of 3 was confirmed by X-ray crystallographic analysis. Compound 1 represent the rare example of a chlorine-substituted indole alkaloid from natural products. The inhibitory activity of compounds 1-5 against two phytopathogenic fungi and three phytopathogenic bacteria was evaluated. Compound 1 exhibited broad spectrum antibacterial activities.
ABSTRACT
Two rare 5/5/5/6 four-ring system iridoids, allamancinsâ A and B (1 and 2) together with one known biogenetically related iridoid derivative, 3-O-methyallamancin (3) were isolated from the flowers of Plumeria alba L. The structures of these iridoid derivatives were determined by comprehensive spectroscopic analyses. The absolute configuration of 1 was confirmed by X-ray crystallographic analysis. The inhibitory activities of compoundsâ 1-3 against nitric oxide (NO) production induced and three cancer cell lines were evaluated inâ vitro. Compoundsâ 1 and 3 showed inhibitory activities on NO production with IC50 values of 18.3±0.12 and 22.1±0.14â µM, respectively. Compoundsâ 1-3 showed moderate inhibitory activities against cancer cell lines of A549, Hela and MCF-7.
