5 alpha-reductase and aromatase inhibitory constituents from Brassica rapa L. pollen

In the screening of biologically active constituents from Brassica rapa pollen, the supercritical CO(2) fluid extract (SFE-CO(2)) showed potent 5 alpha-reductase and aromatase inhibiting activity. The SFE-CO(2) extract was separated by various chromatographic methods to give two new phytosterol derivatives, 24-methylenecholesterol linolenate (1) and cycloeucalenol linolenate (2), as well as eight known compounds, 24-methylenecholesterol palmitate (3), cycloeucalenol (4), pollinastanol (5), 24-methylenecholesterol (6), linolenic acid (7), palmitic acid (8), monolinolein (9) and monopalmitin (10), compounds 7 and 9 showed potent 5 alpha-reductase inhibitory activity; compounds 1-6 and 10 showed potent aromatase inhibitory activity.