Two new epoxysteroids from Helianthus tuberosus

Abstract

Two new epoxy steroids, 5α,8α-epidioxy-22β,23β- epoxyergosta-6-en-3β-ol (1) and 5α,8α-epidioxy-22α, 23α-epoxyergosta-6-en-3β-ol (2), and ten known steroids including (24R)-5α,8α-epidioxyergosta-6-en-3β-ol (3), (22E,24R)-5α,8α-epidioxyergosta-6,22-dien-3β-ol (4), (22E,24R)-5α,8α-epidioxyergosta-6,9(11),22-trien-3β-ol (5), β-sitosterol (6), sitost-5-en-3β-ol acetate (7), 7α- hydroxysitosterol (8), schleicheol 2 (9), (24R)-24-ethyl-5α-cholestane- 3β,5α,6β-triol (10), 7α-hydroxystigmasterol (11), and stigmasterol (12) were isolated from Helianthus tuberosus grown in Laizhou salinized land of coastal zone of Bohai Sea, China. The structures of these compounds were unambiguously established by 1D, 2D NMR and mass spectroscopic techniques. The new compounds 1 and 2 exhibited weak antibacterial activity and no antifungal activity.