[A new eudesmane-type sesquiterpenoid from Sanguisorba officinalis]

The chemical constituents from Sanguisorba officinalis were isolated and purified through macroporous resin, silica gel, polyamide, ODS, Sephadex LH-20 column chromatography, and preparative HPLC. Their structures were determined by extensive analysis of data from MS, NMR, OR, and calculated NMR and ECD. Twenty-six compounds(1-26) were isolated from the 95% ethanol extract of S. officinalis and identified as(1S,4S,5R,7S,10R,11R)-1α,11,12-trihydroxy-eudesmane(1), vomifolilol(2),(3S,5R,6R,7E)-3,5,6-trihydroxy-7-megastigmen-9-one(3), threo-1,2-bis-(4-hydroxy-3-methoxyphenyl)-propane-1,3-diol(4), erythro-1,2-bis-(4-hydroxy-3-methoxyphenyl)-propane-1,3-diol(5), phenylformic acid(6), vanillic acid(7), veratric acid(8), 3,4-dimethoxy-5-hydroxybenzoic acid(9), 4-(1-hydroxy-1-methylethyl)-benzoic acid(10), p-hydrocoumaric acid(11), 4-hydroxyphenethyl alcohol(12), ω-hydroxypropioguaiacone(13), cytosporone V(14), indazole(15), 1H-indole-3-carboxylic acid(16), 7,8-dimethyl-iso-alloxazine(17),(-)-jasmonic acid(18), 12-hydroxyjasmonic acid(19),(-)-methyl 12-hydroxyjasmonate(20), 5-hydroxyhexan-4-olide(21),(8R~*,9R~*,10S~*,6Z)-trihydroxyoctadec-6-enoic acid(22),(9S,10R,11E,13R)-9,10,13-trihydroxyoctadec-11-enoic acid(23), methyl(9S,10R,11E,13R)-9,10,13-trihydroxyoctadec-11-enoate(24), pinellic acid(25), and(9E)-8,11,12-trihydroxyoctadecenoic acid methyl ester(26). Compound 1 was a new eudesmane-type sesquiterpenoid and named sanguisorbaol M. Compounds 3-5, 8, 10, 14-17, 19-23, 25, and 26 were isolated from Rosaceae for the first time. Compounds 2, 11, 12, 18, and 24 were firstly isolated from the genus Sanguisorba and compound 6 was isolated from S. officinalis for the first time. The inhibitory effects of the isolated compounds on melanin synthesis were evaluated via the 3-isobutyl-1-methylxanthine(IBMX)-induced B16F10 melanoma cell model. The results showed that compounds 1-3 at a concentration of 50 μmol·L~(-1) had a significant anti-melanogenic activity.