Studies On Chemical Constituents And Biological Activity Of Abrus Mollis

As traditional Chinese medicine, Abrus cantoniensis Hance has two species, Abrus cantoniensis and Abrus mollis Hance. Abrus cantoniensis was only distributed in China, especially in Guangxi province and employed by Pharmacopoeia of the People’s Republic of China; Abrus mollis was used as folk herbal medicine in Guangxi province and the chief material of the Abrus herb capsule, a therapeutic medicine for hepatitis. Abrus mollis was usually used as a substitute for Abrus cantoniensis and was only recorded by Standard of traditional Chinese medicine of Guangxi province. In order to make full use of the genetic diversity of Abrus cantoniensis, to understand the quality characteristics of Abrus mollis, the chemical constituents were analysed, the effects of different solvent extracts on bioactivities of chemical compounds were investigated in this thesis. The main conclusions were as follow:1. The antioxidant activity was detected in different solvent extracts of Abrus mollis, the strongest activity was EtOAc extract, followed by petroleum-ether extract. The FRAP method was used to analyze the free radical scavenging ability and the results indicated that95%-ethanol extract was most active, followed by EtOAc and then petroleum-ether extract, all were more active than FeSO4and vitamin C. The weakest active antioxidant occurred in n-butyl alcohol extract.The antibacterial activity was measured by K-B paper and double dilution tests in vitro. The result showed that, the95%-ethanol extract and different solvent extract had a significantly resemble inhibitory effect against Bacillus subtilis, Escherichia coli., Staphylococcus and Agrobacterium, but they had no antibacterial activity to Trichoderma spp. and Aspergillus niger. The antibacterial action of95%-ethanol extract and EtOAc extract was higher than that of petroleum-ether extract and n-butyl alcohol extract.2. Twenty compounds were isolated and purified from the whole Plant of Abrus mollis by various column chromatography. Among them, fifteen compounds were identified by means of physical-chemical methods and spectral analysis including1H-NMR,13C-NMR and EIMS etc. Their structures were elucidated as ethyl gallate(Abr-1),3,4-dihydroxybenzoic acid(Abr-2),5,7-dihydroxy-3-methoxyflavone(Abr-3),3,4,3’-trihydroxy-7,4’-dimethoxy-flavan(Abr-4),3,4-dihydroxybenzoic acid ether(Abr-5), methyl gallate(Abr-6),7,3’,4’-trihydroxyflavanone(Abr-9), galic acid(Abr-10), indole-3-carboxylic acid(Abr-13),4-hydroxy-hexenal(Abr-14), Stigmasterol(Abr-15), β-Sitosterol(Abr-16), Abrine(Abr-17), monopalmitin(Abr-18), Ursolic acid(Abr-19). Compounds Abr-4, Abr-9, Abr-14and Abr-18were firstly isolated from the plants of Abrus Adans; except compounds Abr-15, Abr-16, Abr-17, and Abr-19, the other compounds were firstly isolated from this plant.3. In order to compare the eliminating capability with that of FeSO4and VC, the antioxidant effect of chemical constituents from Abrus mollis on total antioxidation (T-AOC) and radicals scavenging of OH·was tested. SPSS with remarkable difference analysis showed that, all compounds exhibited antioxidant activity, especially compound Abr-1; The T-AOC and the ability of scavenging OH·of compound Abr-5and Abr-6were significantly higher than that of FeSO4and vitamin C, among which compound Abr-5was significantly higher than that of compound Abr-6; The antioxidant activity of compounds Abr-3and Abr-9were lower than that of compound Abr-1and vitamin C, but they were higher than that of FeSO4; The antioxidant activity of the other compounds were all lower than that of FeSO4and vitamin C. Meanwhile, the antibacterial activity of twelve compounds was studied by double dilution method. It was showed that twelve compounds had a positive inhibitory activity against Bacillus subtilis and Staphylococcus, but weak antibacterial effect on Escherichia coli. and Agrobacterium, meanwhile, they had no inhibitory action to Trichoderma spp. and Aspergillus niger. The compounds of Abr-15、 Abr-16, Abr-1, Abr-9and Abr-9had a strongest inhibitory effect on Bacillus subtilis, Escherichia coli., Staphylococcus and Agrobacterium (their MIC were166.67,166.67,31.25,41.67and83.33μg/mL respectively); The compound Abr-13had a lowest antibacterial action to Bacillus subtilis, Escherichia coli., Staphylococcus and Agrobacterium (their MIC were1666.67,833.33,416.67and833.33μg/mL respectively).