Studies Of Constituents Of Three Cynanchum Plants

Cynanchum paniculatum(Bge.)Kitag,Cynanchum komarovii Al.Iljinski and Cynanchum hancockianum Maxim.are the genus Cynanchum plans in the family of Asclepiadaceae.C.paniculatum has effects of expelling wind and removing damness and relieving itching and pain,so it has been used mainly as a traditional herbal medicine for the treatment of snake bites,hives,and chronic tracheitis,and it is widely distributed in northeast China,north China,east China and so on.C.komarovii,which grows on rivers,deserts and hills,is an upright or partially upright shrub class for many years and mainly distributed in Gansu,Ningxia,Shanxi,Inner Mongolia,Sichuan,Qinghai and so on.C.hancockianum has the effects of diminish inflammation and stop bleeding and relieving pain,and it also has been used as a Chinese folk medicine for the treatment of snake bites,hives.It is mainly distributed in Shanxi,Inner Mongolia,Shanxi,Ningxia,etc.In this paper,the chemical component of three plants from the genus Cynanchum were studied.27 compounds were isolated from the 95%ethanol extract of C.paniculatum,25 of which were identified as cynapanoside A(X1),glaucogenin F(X2).glaucogenin F 3-O-β-Doleandropyranoside(X3),cynapanoside G(X4),cynatratoside A(X5),glaucoside A(X6),cynapanoside F(X7),neocynapanogenin F 3-O-,β-D-Oleandropyranoside(X8),glaucogenin A 3-O-β-D-digitoxopyranosyl-(1→4)-β-D-oleandropyranoside(X9),cynatratoside B(X10),cynatratoside D(X11),neocynapanogenin F 3-O-α-L-cymaropyranosyl-(1→4)-β-Ddigitoxopyranosyl-(1→4)-β-D-oleandropyranoside(X12),cynatratoside E(X13),cynatratoside E(X14),cynapanoside C(X15),cynapanoside E(X16),cynapanoside D(X17),3β,14-dihydroxy-14β-pren-5-en-20-one(X18),neocynapanogenin F(X19),atfinoside(X20),daucosterol(X21),isopaeonol(X22),paeonol(X23),acetovanillone(X24).syringaldehyde(X25).Among them,X2,X3,X4,X7,X16,X17 were six new C21 steroidal compounds.46 compounds were isolated from the 95%ethanol extract of C.komarovii,42 of which were identified as glaucoside A(L1),glaucogenin A 3-O-β-D-digitoxopyranosyl-(1→4)-β-Doleandropyranoside(L2),amplexicoside B(L3),tylophoside A(L4),stauntogenin 3-O-α-Loleandropyranosyl-(1→4)-O-β-D-digitoxopyranosyl-(1→4)-O-β-D-oleandropyranoside(L5),cynanside A(L6),hirundigoside B(L7),komaroside M(L8),komaroside E(L9),komaroside N(L10),komaroside A(L11),komaroside O(L12),glaucoside J(L13),cynatratoside D(L14),cynatratoside E(L15),komaroside P(L16),komaroside Q(L17),cynaforroside C(L18),glaucogenin C 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→4)-α-Loleandropyranosyl-(1→4)-β-D-digitoxopyranosyl-(1→4)-β-D-oleandropyranosie(L19),(-)R-13aα-antofine(L20),quercetin 3-O-α-L-arabinopyranoside(L21),komaroside K(L22),komaroside J(L23),inamoside C(L24),komaroside L(L25),komaroside R(L26),komaroside S(L27),cynatratoside A(L28),komaroside T(L29),komaroside U(L30),sibiricose A1(L31),komaroside C(L32),6,6’-di-O-sinapoylsurcose(L33),6-O-[E]-sinapoylD-glucopyranose(L34),antofine-9-one(L35),neohancoside C(L36),atfinoside(L37),10β(-)-antofine N-oxide(L38),10α-(-)-antofine N-oxide(L39),glycerol monolinoleate(L40),glycerol mono-(E)-8-hydroxy-linoleate(L41),sucrose(L42).Among them,L8,L10,L12,L16,L17,L26,L27,L29,L30 were nine new C21 steroidal glycoside compounds,and L41 was a new monoglyceride compound.Moreover,the aglycones of compounds L16 and L17 were two new C21 steroids.14 compounds were isolated from the 95%ethanol extract of C.hancockianum,12 of which were identified as stauntogenin 3-O-α-L-oleandropyranosyl-(1→4)-O-β-Ddigitoxopyranosyl-(1→4)-O-β-D-oleandropyranoside(H1),amplexicoside D(H2),cynanside A(H3),cynatratoside B(H4),cynatratoside A(H5),cynapanoside D(H6),amplexicoside B(H7),tylophoside A(H8),glaucoside A(H9),hancoside H(H10),hancoside I(H11),hancoside J(H12).Among them,H6,H10,H11,H12 were four new C21 steroidal glycoside compounds.Through the research of chemical constituents of three Cynanchum plants,a total of 78 compounds were isolated by a variety of separation methods,including 20 new compounds(the new compounds comprise 19 C21 steroids and 1 monoglyceride compound).There are 65 non-repititive compounds and 19 new non-repititive compounds.The in vitro growth control activities of alkaloids and some C21 steroidal glycosides against cancer cell HL-60,MCF-7,HT-29,PC-3,CACO-2,THP1 were measured.Test results show that compounds X10.X12,X13,X17;L20,L26 exhibited strong inhibitory activities against HL-60 cell line(IC50<13.4 μM);compound X10 displayed strong inhibitory activities against MCF-7,HT-29 and PC-3 cell lines(with IC50 as 34.4、19.4、7.5μM,respectively);compound L20 exhibited strong inhibitory activities against CACO-2 and THP1 cell lines(IC50<0.01 μM);compounds X5,X6,X7,X16:L4,L5,L14,L28;H6,H10.H11,H12 exhibited moderate cytotoxicity against HL-60 cell line(IC50<33.3 μM).Compounds X4,X7,X10,X16,X17 showed weak inhibition against Candida albicans with MIC>500μg/ml.The antioxidant activities of X7,X10,X16 and X17 were assessed on the basis of the radical scavenging effect of the stable DPPH free radical.All the tested compounds exhibited no potent antioxidant activities with IC50>100 μM with Vc(IC50=25.11μM)as the positive control.