Studies On Chemical Constituents From Halimeda Xishaensis And Spongia Suriganensis

I have researched the chemical constituents of Halimeda xishaensis and Spongia suriganensis which collected from China South Sea. Three novel ceramides of same series were found .Four single hydroxyl sterols, 2,3-dihydroxypropyl tricosanoate (II), Stigmast - 4 - ene - 36 , 66 - diol (III), N - ( (E)- 1,3- dihydroxyhexadec - 4 - en - 2 - yl ) heptacosanamide (IV), butantetraol (V) have been isolated from the algae Halimeda xishaensis collected from the Xisha YongXing island. The crystal structure of compound III was first studied too.Nine single hydroxyl sterols, three ceramides: 2-hydroxy -N-(l,3,4-trihydroxy-17-methyloctadecan-2-yl)- 18-methylicosanamide ( Vila ) , 2-hydroxy-N-(l,3,4-trihydroxy- 17- methyloctadecan-2-yl)-19- methylhenicosanamide(VIIb), 2- hydroxy-N- (1,3,4- trihydroxy-17- methyloctadecan- 2-yl)-20- methyldocosanamide (We) , stigmast-5-ene-38,4B-diol (Vffi) have been isolated from the Spongia suriganensis collected from NaoZhou island in ZhanJiang. The three ceramides IIa-JIIc) are new compounds, every one included a iso branching and an ante iso branching, it is quite unusual for that.The sterol and ceramide are physiological activities, and the chemical analysis of two species fit with the need of researching about marine natural products.