Bioactive compounds from Peperomia pellucida

Five new compounds (1-5), including two secolignans, two tetrahydrofuran lignans, and one highly methoxylated dihydronaphthalenone, were isolated from the whole plant of Peperomia pellucida. These compounds were accompanied by the known peperomins A, B, C, and E, 7,8-trans-8,8'-trans-7',8'-cis-7,7'-bis (5-methoxy-3,4-methylenedioxyphenyl)-8-acetoxymethyl-8'-hydroxymethltetrahydrofuran, 7,8-trans-8,81-trans-7',8'-cis-7-(5-methoxy-3,4-methylenedioxyphenyl)7'-(4-hydroxy-3,5-dimethoxyphenyl)-8,8'-diacetoxymethyltetrahydrofuran, sesamin, and isoswertisin. New structures were elucidated mainly by NMR and MS techniques, and anticancer activities evaluated in HL-60, MCF-7, and HeLa cell lines. Compound 1 and peperomin E show growth inhibitory effects on the three cancer cell lines with IC50 values ranging between 1.4 and 9.1 and between 1.8 and 11.1 mu M, respectively. Compound 2 has a weak suppressive activity on HL-60 cells (IC50 = 10.8 mu M), while 7,8-trans-8,8'-trans-7',8'-cis-7,7'-bis (5-methoxy-3,4-methylenedioxyphenyl)8-acetoxymethyl-8'-hydroxymethyltetrahydrofuran exhibits estrogen-like properties (EC50 = 3.1 mu M) in CV-1 cells transfected with human estrogen receptor (ER alpha).