Six new ergostane-type steroids from king trumpet mushroom (Pleurotus eryngii) and their inhibitory effects on nitric oxide production.

Six new ergostane-type steroids; (22E)-3ß,5α,6α,11-tetrahydroxy-9(11)-seco-ergosta-7,22-dien-9-one (1), (22E)-8,14-epoxyergosta-6,22-diene-3ß,5α,9α-triol (2), (22E)-4α,5α-epoxyergosta-7,22-diene-3ß,6ß-diol (3), (22E)-3ß,4ß,5α-trihydroxyergosta-7,22-dien-6-one (4), (22E)-ergosta-7,22-diene-3ß,5ß,6α-triol (5), and (22E)-6ß-methoxyergosta-7,22-diene-3ß,5α-diol 3-O-ß-d-glucopyranoside (6) were isolated from the fruiting bodies of king trumpet mushroom (Pleurotus eryngii), along with fourteen known compounds (7-20). All isolated compounds were evaluated for their inhibitory effects on macrophage activation using a nitric oxide production inhibition assay.