Chemical Constituents Of Sapium Baccatum And Their Biological Activities

Sapium baccatum,a tall arboreal plant,is a member of the genus Sapium in the family Euphorbiaceae.S.baccatum has important economic value.It is used widely as wood due to rapid growth,light and soft characteristics.The edible sweet fruits of S.baccatum are used to extract industrial oil for its high oil content.Meanwhile,S.baccatum has been commonly used to treat abscesses in Malaysia and extensively as ingredients in Chinese prescriptions for the treatment of scapulohumeral periarthritis,cerebral infarction,gouty arthritis,and other conditions.Recent studies have shown that S.baccatum possesses multiple pharmacological effects such as anti-inflammation,antibacteria and hypotensive effect.It was also reported for some toxic substances.To further develop the medicinal values of S.baccatum and benefit from the rich resources in China,this work attempted to discover novel bioactive compounds from S.baccatum using multiple separation techniques and bioactivity screening tests,including anti-inflammatory,antifungal and antitumor activities.The petroleum ether part and ethyl acetate part from 95%ethanol extract of S.baccatum were separated using various chromatography methods,including silica gel column,reverse phase medium-pressure liquid chromatography,gel column chromatography,high performance liquid chromatography and high-speed countercurrent chromatography.Thirty-one compounds were isolated and identified,including eight coumarins,twelve tannins,four terpenoids,two steroids,one anthraquinonoid,two aliphatics and two simple benzoids.Their structures were determined by extensive spectroscopic methods,including electrospray ionization mass spectrometry,high resolution electrospray ionization mass spectrometry,nuclear magnetic resonance,ultraviolet spectrophotometry and infrared spectrophotometry.Eight new phenolic compounds,namely,seven coumarins(1-7)and one monoterpene galloylglycoside(8)were obtained,together with fifteen compounds isolated from S.baccatum for the first time,i.e.Ellagic acid(9),Ethyl gallate(11),Brevifolin(12),Ethyl brevifolin carboxylate(13),1,2,3,4,6-penta-O-gally-β-D-glucopyranose(15),Isocorilagin(16),3,3’-Di-O-methyl-ellagicacid-4’-O-α-L-rhamnopyranoside(18),3,3’-Di-O-methylellagic acid-4’-O-β-D-xylopyranoside(19),28-Hydroxy-14-taraxeren-3-one(22),β-sitostenone(25),Chrysophanol(26),Scopoletin(27),Hexadecanoic acid(29),Squalene(30)and Dibutyl phthalate(31).Compounds 1,2 and 7 were confirmed as racemic mixtures respectively on the basis of HPLC chiral analysis,electronic circular dichroism data and optical rotations.Two coumarins 1 and 2 were proven as methylation products of compounds 3 and 4 respectively through HPLC analysis.The antifungal activity of crude extracts and some isolated compounds were determined.The results showed that these extracts had a distinct inhibitory effect on sclerotinia sclerotiorum,especially the ethyl acetate extracts with 77.10%and 82.36%inhibition in 1000 and 2000 μg/mL respectively.Compounds 14 and 15 showed weak antifungal activity against Candida albicans SC5314 with MIC values both at 64μg/mL.The anti-inflammatory of some compounds were evaluated.The inhibitory effects on TNF-a secretion were examined biologically in LPS-induced BV2 microglia cells and all of the tested compounds exhibited significant inhibitory activity,especially new compound 1 possessed stronger inhibitory effects than the positive control quercetin.In addition,the cytotoxicity of these compounds were tested using lung cancer cells A549,prostate cancer cells PC-3,hepatocellular carcinoma cells HepG2 and breast cancer cell MCF-7.Compound 15 has a good cytotoxic activity(IC50=14.26μM)against PC-3 and the new compounds 2-6,8 showed moderate cytotoxic activities against MCF-7(IC50 = 27.71,23.25,26.35,22.73,26.69 and 20.86 μM,respectively).The work further added the chemical compositions of S.baccatum and elucidated its pharmacological effects and the effective substances through assigning new compounds of coumarins,studying their antifungal,anti-inflammatory and anti-tumor activities,which can provide a good foundation for future phytochemical and pharmacological investigation on S.baccatum,even genus Sapium.