Chemical constituents from brown alga Sargassum fusiforme

Objective To study the chemical constituents of brown alga Sargassum fusiforme.Methods The compounds were isolated by silica gel chromatography,ODS chromatography,and preparative HPLC,and their structures were elucidated on the basis of chemical and spectroscopic methods,including HR EI-MS,1D and 2D NMR spectral techniques.Results Six sterols and two glycolipids were isolated from the n-hexane soluble part of ethanol extract of S.fusiforme and their structures were identified as fucosterol(Ⅰ),24R,28R-and 24S,28S-epoxy-24-ethylcholesterol(Ⅱ),24-hydroperoxy-24-vinylcholesterol(Ⅲ),29-hydroperoxystigmasta-5,24(28)-dien-3β-ol(Ⅳ),(24S)-5,28-stigmastadien-3β,24-diol(Ⅴ),(24R)-5,28-stigmastadien-3β,24-diol(Ⅵ),1-O-myristoyl-3-O-(6′-sulfo-αD-quinovopyranosyl) glycerol(Ⅶ),and 1-O-palmitoyl3-O-(6′-sulfo-α-D-quinovopyranosyl) glycerol(Ⅷ).Conclusion This is the first report for the isolation of Ⅳ,Ⅶ,and Ⅷ from alga of Sargassum(Turn.) Ag.,and compounds Ⅱ and Ⅲ from this alga.The isomers of saringosterols 24S(Ⅴ) and 24R(Ⅵ) from this alga are obtained by preparative normal-phase HPLC for the first time.