| Ardisia gigantifolia stapf, which is mainly produced in Yunnan,Guangxi, Guangdong, Jiangxi, Fujian and other places, is the dried rhizomeof Myrsinaceae Ardisia plants used as the treatment of rheumatism, achingof muscles and bones, hemostasis and promoting granulation. More andmore bioactive components, especially triterpenoid saponins which havesignificant anti-tumor activity against gastric cancer, liver cancer, coloncancer, nasopharyngeal cancer, cervical cancer, lung cancer, bladder cancer,thymus cancer, etc are found from this genus. To study their structure-function relationship of anti-tumor activity, this study focuses on theseparation and purification of saponins substance and totally got six knownTriterpenoid saponins and five transformation products through thebiotransformation method, choosing Alternaria alternata, Aspergillusavenaceus as fermentation strains and compound CyclamiretinA3-O-{-L-rhamnopyranosyl-(1â†'3)-[β-D-xylopyranosyl-(1â†'2)]--D-glucopyranosyl-(1â†'4)-[-D-glucopyranosyl-(1â†'2)]--L-arabinopyranoside}(call Ag3for short) as target substrate. These five compounds including four newcompounds were successfully separated by the means of MPLC, PHPLCand recrystallization and their structures were identified on the basis ofmodern spectra, such as MS,1D-NMR and2D-NMR.Known compounds were identified and named separatedly asCyclamiretin A3-O-{-L-rhamnopyranosyl-(1â†'3)-[β-D-xylopyranosyl-(1â†'2)]--D-glucopyranosyl-(1â†'4)-[-D-glucopyranosyl-(1â†'2)]--L-arabinopyranoside}(1);3β-O-{-L-rhamnopyranosyl-(1â†'3)-[-D-Glucopyranosyl-(1â†'3)--D-xylopyranosyl-(1â†'2)]--D-glucopyranosyl-(1â†'4)-[-D-glucopyranosyl-(1â†'2)]--L-arabinopyranoside}-16-hydroxy-13,28- epoxy-oleanane(2); lysikoianoside(3);3β-O-{-L-rhamnopyranosyl-(1â†'3)-[-D-xylopyranosyl-(1â†'2)]--D-glucopyranosyl-(1â†'4)-[-D-glucopyranosyl-(1â†'2)]--L-arabinopyranoside}-16-hydroxy-13,28-epoxy-oleanane(4); CyclamiretinA3-O-{-L-rhamnopyranosyl-(1â†'3)-[-D-glucopyranosyl-(1â†'3)--D-xylopyranosyl-(1â†'2)]--D-glucopyranosyl-(1â†'4)-[-D-glucopyranosyl-(1â†'2)]--L-arabinopyranoside}(5);3β-O-{-L-rhamnopyranosyl-(1â†'3)-[-D-glucopyranosyl-(1â†'3)--D-xylopyranosyl-(1â†'2)]--D-glucopyranosyl-(1â†'4)-[-D-glucopyranosyl-(1â†'2)]--L-arabinopyranoside}-16-hydroxy-30-acetoxy-13,28-epoxy-oleanane(6);3β-O-{-L-rhamnopyranosyl-(1â†'3)-[β-D-xylopyranosyl-(1â†'2)]--D-glucopyranosyl-(1â†'4)-[-D-glucopyranosyl-(1â†'2)]--L-arabinopyranoside}-16-hydroxy-13,28-epoxy-30-acetoxy-oleanane(7).The new compounds were identified separatedly3-O-{-L-Rhamnopyranosyl-(1â†'3)-[β-D-xylopyranosyl-(1â†'2)]--D-glucopyranosyl-(1â†'4)--L-arabinopyranoside}-3β,16,30-trihydroxy-13,28-epoxy-oleanane(8*);Cyclamiretin A3-O-{-L-rhamnopyranosyl-(1â†'3)-[β-D-Xylopyranosyl-(1â†'2)]--D-glucopyranosyl-(1â†'4)--L-arabinopyranoside}(9*);3-O-{-L-rhamnopyranosyl-(1â†'3)-[β-D-xylopyranosyl-(1â†'2)]--D-glucopyranosyl-(1â†'4)-[-D-glucopyranosyl-(1â†'2)]--L-arabinopyranoside}-3β,16α,22α-trihydroxy-13,28-epoxy-30-al-oleanane(10*);3-O-{-L-rhamnopyranosyl-(1â†'3)-[β-D-xylopyranosyl-(1â†'2)]--D-glucopyranosyl-(1â†'4)-[-D-glucopyranosyl-(1â†'2)]--L-arabinopyranoside}-3β,16α,22α-trihydroxy-13,28-epoxy-oleanane(11*).We used the CCK method to screen the anti-tumor activity of Ag3isolated from Ardisia gigantifolia stapf and converted products namedcompound8,9,10and11using hepatoma cells Bel-7402, HepG2,SMMC-7721and normal liver cell L02. And all compounds were found todisplay certain anti-tumor activity Among them, compound8showedobvious inhibition of HepG2and smaller toxicity compared with positivedrug epirubicin, which indicates that compound8can be applied to clinic. And in the further study, we investigated the effect of compound8on theapoptosis and cell cycle of HepG2. Consequently, we speculate thatcompound8may impair the DNA of tumor cell and block the cell in Sphase and inhibit the synthesis of protein and RNA, which consequentlyrestrain the cell proliferation. However, the detailed mechanism needs to bedeeply studied.In this summary, we expect to conclude the structure-functionrelationship of anti-tumor activity, we selected hepatoma cell HepG2astargeted cell and used the CCK method to screening the anti-tumor activityof11compounds. The results show that compound Ag3,4,5,6,7,8,10and11have obvious activity of inhibiting tumor cell proliferationcontrasted with positive drug epirubicin, which indicates that there is noobvious relationship between antitumor activity and the number of sugar insugar chain. And the product of acid hydrolysis were inactive, indicatingthat13,28epoxy ether bridge structure and30groups may be the locus ofantitumor activity, which provides the basis for furter research ofstructure-activity relationship. Because the compounds concerned areinsufficient, we just concluded preliminary antitumor structure-activityrelationships but the detailed mechanism still needs to be further studied. Infurther research, we can isolate these compounds by using the method ofchemical synthesis. We can also provide the theoretical and experimentalbasis for the development and research of Chinese herbal medicine. |
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