A new carotane sesquiterpene from Walsura robusta

AIM:To study the chemical constituents from the leaves of Walsura robusta.METHODS:The leaves of W.robusta were extracted with MeOH and compounds isolated by silica gel,Rp-C18,Sephadex LH-20 and semipreparative HPLC.These compounds were elucidated by extensive spectroscopic analysis(MS,NMR,IR,and UV).RESULTS:Two sesquiterpenoids were obtained and their structures were identified as 10-nitro-isodauc-3-en-15-al(1) and 10-oxo-isodauc-3-en-15-al(2).CONCLUSIONS:Compound 1 was new with a nitro group.1 and 2 were isolated from genus Walsura for the first time.