RESUMEN
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.
RESUMEN
The components with hypoglycemic activity in Plumeria rubra were isolated and purified by various column chromatography techniques and activity tracing methods. The physical and chemical properties of all the purified monomer compounds were characterized and analyzed, and a total of six compounds were isolated and identified, including 6â³-acetyl-6-hydroxy-benzyl-benzoate-2-O-ß-D-glucoside(1), 6î-acetyl-6-hydroxy-benzyl-benzoate-2-O-ß-D-glucoside-(1îâ6â³)-ß-D-glucoside(2), 2-hydroxy-6-methoxy-benzyl-benzoate-2-O-ß-D-glucoside(3), 6-hydroxy-benzyl-benzoate-2-O-ß-D-glucoside(4), 6-hydroxy-benzyl-benzoate-2-O-ß-D-glucoside-(1îâ6â³)-ß-D-glucoside(5), and 6-hydroxy-benzyl-benzoate-2-O-ß-D-glucoside-(1îâ6â³)-ß-D-xyloside(6). Compounds 1 and 2 were new compounds, and compounds 3-6 were isolated from Plumeria for the first time. The α-glucosidase inhibitory activity of six identified compounds was tested. The results show that compounds 1-6 show certain inhibitory activity with an IC_(50) value ranging from 8.2 to 33.5 µmol·L~(-1).