Study On Steroidal Saponin Constituents Of The Rhizoma Of Smilax China L.and Their Anti-tumor Activity

Smilax china L.is a perennial medicinal plants from Liliaceae,which is mainly distributed in the south of the Yangtze River in China and usually used to treat rheumatoid arthritis and woman ailments.According to literatures,the rhizomes of S.china L.contain steroidal saponins,flavonoids,phenylpropanoid,stilbenes,organic acid and other chemical components.Steroidal saponins is one of the main chemical constituents of S.china L.Steroidal saponins are an important constituents with biological activities in natural products.They show various pharmacological activites,such as antitumor,antibiosis,anti-inflammatory,antioxidant,anti-hyperuricemia,diuretic,antithrombosis and so on.So they have highly medicinal value and development potential.However,there are few studies on the development of steroidal saponins at present.In order to deeply understand steroidal saponin contents from S.china L.,we carried out systematic phytochemistry research of steroidal saponin components and evaluated the preliminary antitumor activities of isolated monomer saponins.Firstly,a review was elaborated on extraction and isolation,structure elucidation,chemical constituents and pharmacological activities of steroidal saponins from the genus Smilax based on the previous research.Secondly,from the 95%methanol extract of the rhizomes of S.china L.,ten steroidal saponin compounds were isolated using chromatographic methods such as silica gel c.c.,polyamide c.c.,MCI CHP20P,Sephadex LH-20,Toyopearl HW40F,ODS etc.On the basis of physico-chemical properties and NMR(1H NMR,13C NMR,1H-1H COSY,HSQC,HMBC,NOESY),MS data,the structures of the 10 compounds were identified as follows:(25R)26-O-β-D-glucopyranosyl-3β,20α,26-trihydroxy-furostan-5,22-diene-3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→4)]-O-β-D-glucopyranoside(1),26-O-β-D-glucopyranosyl-3β,23,26-triol-25(R)-furostan-5,20(22)-diene-3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→4]-O-β-D-glucopyranoside(2),trinervulosides A(3),methyl protodioscin(4),25(S)26-O-β-D-glucopyranosyl-22-methoxy-3β,26-dihydroxy-5-en-furosta-3-O-α-L-rhamnopyrano-syl-(1→4)-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-O-β-D-gluc-opyranoside(5),25(R)26-O-β-D-glucopyranosyl-22-methoxy-3β,26-dihydroxy-5-en-furosta-3-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamno-pyranosyl-(1→2)]-O-β-D-glucopyranoside(6),dioscoreside E(7),dioscoresides C(8),26-O-β-D-glucopyranosyl-3β,26-dyhydroxy-20,22-seco-25(R)-furosta-5-en-22-one-3-O-α-L-rhamnopyranosyl-(1→2)-[a-L-rhamnopyranosyl-(1→4)]-O-β-D-glucopyranos-ide(9),26-O-β-D-glucopyranosyl-3β,26-dyhydroxy-22-hydroperoxyl-25(R)-furosta-5-en-3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→4)]-O-β-D-glucop-yranoside(10).Among them,compounds 1,4 have been isolated from plant of S.china L.,compound 3 was discovered in plants of S.China L.for the first time,compounds 2,5,6,7,8 were isolated from the genus Smilax for the first time,compounds 9,10 were new compounds.Compound 10 is characterized by a novel type of steroidal saponin containing a hydroperoxyl group(-OOH).Finally,the effect of compounds 1-9 on the proliferation of human lung adenocarcinoma cell line HCC-78 and human non-small cell lung cancer cell line H3122 were detected by MTT method,thereby,the monomer steroidal saponin with potential antitumor effect was screened out.The results indicated that compound 7 had a weak inhibitory effect on HCC-78 cells,but had a moderate inhibitory effect on H3122 cells;Compounds 4,5,6 and 8 showed a good inhibitory effect on two lung cancer cells,among which compounds 4,5 and 6 displayed the strongest inhibitory effects and the IC50 values of compounds 4,5,6 on HCC-78 and H3122 were 0.73,0.92,0.035μM and 1.4,0.74,1.51μM,respectively.Therefore,compounds 4,5,6 have very good antitumor activity,and can be used as good antitumor leading compounds.