Constituents of Bulbs of three Species of the Hyacinthaceae (Hyacinthoideae): Eucomis vandermerwei, E. zambesiaca and Resnova humifusa.

Phytochemical analyses of the bulbs of Eucomis vandermerwei and E. zambesiaca yielded homoisoflavonoids and triterpenoid derivatives. A new (17S*23S*)-epoxy-3β,15β,29-trihydroxy-27-norlanost-8-en-24-one) was isolated from E. zambesiaca. Resnova humifusa yielded homoisoflavonoids, and a tetrahydropyran derivative, 2-methyl-3-(4S*,5R *,7S*-trihydroxy-8S*-hydroxymethyltetrahydro-6H-4-pyranyl)-2-propenoic acid. All compounds were assayed for COX-2 inhibition of cyclooxygenase; 3,5,7-trihydroxy-3-(4'-methoxybenzyl)-4-chromanone was found to have significant activity.