Phytochemical Constituents of the Stems from Amoora cucullata

Abstract

Chemical investigation on the stems of A. cucullata led to the isolation of one aporphine alkaloid, 6a,7-didehydrobulbocapnine methyl ether (1) and two protoberberine alkaloids, 9-demethyloxypalmatine (2), and 8,13-dioxo-14-hydroxytetrahydropalmatine (3). Their structures were characterized by mainly ¹H and ¹³C NMR spectral data and compared with previously reported. Compounds 1-3 were also evaluated for antimicrobial activities against Staphylococcus aureus (ATCC25923), Bacillus subtilis (ATCC6633), Methicillin-resistant Staphylococcus aureus (SK1), Pseudomonas aeruginosa (ATCC27853) and Escherichia coli (ATCC25922) by broth micro dilution method. Compound 2 was found to be the most active compound, while compound 3 was the least active. The lowest minimum inhibitory concentration (MIC) values of compound 2 were 25.0 µg/mL on S. aureus (ATCC25923) and B. subtilis (ATCC6633), and 50.0 µg/mL on Methicillin-resistant Staphylococcus aureus (SK1).