Ylangene-Type and Nardosinane-Type Sesquiterpenoids from the Soft Corals Lemnalia flava and Paralemnalia thyrsoides

Chemical investigations of the Formosan soft coral Lemnalia flava have obtained a new ylangene-type sesquiterpenoid, (1S,2S,4R,6S,7R,8S)-4α-formyloxy-β-ylangene (1), along with two known sesquiterpenoids, lemnalol (2) and isolemnalol (3). Three new nardosinane-type sesquiterpenoids, designated as paralemnolins J—L (4—6), and five known sesquiterpenoids (7—11), were isolated from the other soft coral Paralemnalia thyrsoides. The structures of metabolites 1 and 4—6 were elucidated through extensive spectroscopic analysis and chemical methods. Moreover, the anti-inflammatory activity of metabolites 1—7 and 11 was evaluated in vitro.