Studies On The Chemical Constituents And Bioactivities Of Erycibe Obtusfolia Benth

Erycibe obtusifolia Benth.(Convolvulaceae) was distributed in the southern China.The genus Erycibe included 11 species in China.Its roots,stems and twigs were used in Chinese folk medicine to relieve the symptoms of rheumatoid arthritis. Pharmacological study indicated that Erycibe obtusifolia showed a strong anti -inflammatory activity and the effect of muscarinic agonist.The constituents and bioactivities of Erycibe obtusifolia were studied.The dried roots of this plant were exhaustively extracted with 95%EtOH and concentrated under reduced pressure.Then the residue was suspended in H₂O and extracted successively with petroleum ether,EtOAc and n-BuOH.Sixteen compounds were isolated from the EtOAc and H₂O portions.Their structures were elucidated by spectroscopic methods including UV,IR,MS,HR-MS,1D and 2DNMR as 7,7'-dihydroxy-6,6'-dimethoxy-3,3'-biscoumarin(1),7,7'-dihydroxy-6,6'-dimethoxy -8,8'-biscoumarin(2),7-O-[4'-O-(3",4"-dihydroxycinnamyl)-β-D-glucopyranosyl]-6 -methoxycoumarin(3),methyl-3-O-(4"-hydroxy-3",5"-dimethoxybenzoyl)-chloro genate(4),methyl-4-O-(4"-hydroxy-3",5"-dimethoxybenzoyl)-chlorogenate(5), macranthion G(6),macranthoin F(7),cleomiscosin A(8),cleomiscosin B(9), scopoletin(10),scopolin(11),chlorogenic acid(12),β-sitosterol(13),daucosterol (14),alkyl alcohol(15),alkyl linked daucosterol(16).Among them,compounds 1-5 were new compounds,compounds 6-9 were isolated from genus Erycibe for the first time.Compounds 1 and 2 were the rare symmetrical coumarins coupled with carbon-carbon bonds.All extractions were investigated and assayed anti-inflammatory activities, anti-HIV activities and cytotoxic activities.95%EtOH and EtOAc portions showed obvious anti-inflammatory activities in mice and their inhibition ratio were 79.3%and 40.0%respectively.EtOAc portion showed anti-HIV activities and the inhibition ratio was 57.7%.Petroleum ether portion showed cytotoxic activities with IC₍₅₀₎ 12.65μg/ml. In vitro the compounds 1,3-11 were assayed inhibitive activities of secretion of TNFα of macrophage and the inhibition ratio were 6.2%,5.9%,6.3%,5.8%,15.8%,11.7%, 9.7%,3.6%,9.3%and 8.7%respectively.The compounds 1,3-11 were assayed anti-HIV activities with inhibition ratio 26.6%,37.0%,0.0%,20.3%,20.7%,38.8%,0.0%,0.0%,18.1%and 13.9%respectively.The compound 3 and 7 showed higher inhibitory activities.