Studies On Chemical Constituents And Bioactivities Of Oxytropis Latibracteata

Oxytropis latibracteata Jurtz is widely distributed in Gansu province, Qinghai province and northwest Sichuan region. Recent years, the toxic pathology research and nutrition constituets of O. latibracteata have been reported, the bioactivity and chemical constituents, however, have not still been studied. From the view of pesticide science , this thesis primarily studied on the bioactivities and chemical constituents . The main results are as follows.1. The chemical constituents of the aerial part of O. latibracteata had been primarily studied with tube test. The results indicated that O. latibracteata contains phenols, tannins, carbohydrates, saponins ,alkaloids, flavonoids and its glycosides,amino acids and cyonogenetic. In addition, the bioactivities, including insecticidal, fungicidal and herbicidal activities, of the aerial part of O. latibracteata had also been screened. The results showed that petrolem ether extract, ether acetate extract, methanol extract of O. latibracteata had no evident contact poison and stomach poison activity against 3rd instar larvae of Mythimna separata Walker at the concentration of 5% and low inhibiting rate against Fusarium graminearum, Botrytis cirerea , Alternaria solani, Alternaria alternata and Glomerella cingulata at the concentration of 1000 mg·L-1. Ether acetate extract of O. latibracteata , however, showed intensive inhibiting effect on Amaranthus retroflexus L. and Brassiica campestris . The values of EC50 of ether acetate extract against germination and plant height of Amaranthus retroflexus L. were 129.192 mg·L-1, 55.676 mg·L-1 and the values of EC50 of ether acetate extract against germination and plant height of Brassiica campestris were 423.874 mg·L-1, 173.595mg·L-1 respectively.2.. After repeatedly open column chromatography, compound 1#, compound 2#, compound 3# and compound 6# were obtained from ethyl acetate extract of the aerial part of O. latibracteata with bioactivity-guided fractionated. Comparing with the standard spectra of chromatography chart such as MS, 1H NMR and 13C NMR, compound 1# and compound 2# were primarily identitied as fatty alcohol and salicylic acid easter, compound 3# and compound 6# were identified as β-sitosterol and stearic acid. The four compounds were all isolated from O. latibracteata. for the first time. Fourthmore, the herbicidal activity of the four constituents against Amaranthus retroflexus L. were tested. The results indicated that compound 1# and compound 6# had higher herbicidal activity than compound 2# and compound 3#. Inhibiting rates of compound 1# and compound 6# against the plant height of Amaranthus retroflexus L were 73.54% and 65.07% at the concentration of 250mg·L-1.