A new hexenoic acid glycoside (1) together with known compounds, flavonol glycosides (2-4), iridoid glycoside (5), megastigmane glycoside (6), and amino acid (7) were isolated from the leaves of P. luzoniensis by resin column chromatography and preparative HPLC. Their structures were determined based on spectroscopic analysis, including HRFABMS and NMR (1H and 13C, 1H-1H COSY, HMQC, and HMBC) data. All compounds tested for cytotoxicity were active (IC50 < 50 μM) with IC50 values ranging from 1.97 to 32.85 μM against human colon adenocarcinoma cell line, compared to etoposide (IC50 1.19 μM).
Keywords: Psychotria luzoniensis; cytotoxicity; hexenoic acid glycoside.