Analysis And Bioassay Of Insecticidal And Bacteriostatic Active Ingredient From Parthenium Hysterophorus L.

Parthenium hysterophorus L., a Parthenium species of Compositae, is a kind of invasive plant. The original is North America and Mexico. Nowadays it widely distributes in the south and southwest areas of China. At present, the research focus is the allelopathy mechanism and the integrated control with Parthenium hysterophorus L.. How to rationally utilize waste and turning waste into wealth is a new idea with control invasive plants. The current research search for bioactive substances on the basis of the allelopathy research of Parthenium hysterophorus L. and it provides a new sourcethe development of botanical pesticides. It opens up the new roads to control spread of the Parthenium hysterophorus L..1. The study on chemical componentsThe volatile constituents from flowers and leaves of Parthenium hysterophorus L. from five populations were analysised by headspace absorption and GC-MS. Among them, the fatty acid derivatives were the most species and the monoterpenoids were the highest at content. The main components were mycenae, camphene, ?-pinene and ?-pinene. The volatile constituents were not significant differences from flowers and leaves of P. hysterophorus from five populations.The extractum is extracted from the plants of Parthenium hysterophorus L. with 90% ethanol,and it is separated into three parts using the system solvent separation method. The three fractions were respectively subjected to normal and reversed-phase silica gel, recrystallization repeatedly and column chromatography over macroporous resin to obtain pure compounds. The chemical structures were established on the basis of extensive spectroscopic(NMR, UV, IR, MS) data analysis and by the comparison with spectroscopic data reported in the literature. Bioassay-guided isolation studies on the stem extract of Parthenium hysterophorus L. led to the isolation of fourteen compounds: ?-sitosterol(1), parthenin(2), stigmasterol(3), daucosterol(4), stigmasterol-3-O-glucopyranoside(5), 3-O-methylquercetin(6), echinocystic acid(7),(4S,6S)-4-hydroxy-6-undecyltetrahydro-2H-pyran-2-one(8),oleanolic acid(9), 3-oxo-16-hydroxy-olean-12-en-28-oic acid(10), 4-methoxybenzoic acid(11), oleanolic acid 28-O-?-D-glucopyranoside(12), stigmasteryl-3 –arachidate(13), dichrocepholide D(14).2. The study on insecticidal and antimicrobial activityUsing spray method research activities of ethanol extract, petroleum ether part, ethyl acetate parts and water part of Parthenium hysterophorus L..The experimental subjects are Liriomyza, Aphidoidea, Tetranychus cinnbarinus. The experimental results: the corrected mortality rate of Liriomyza is respectively 96.15%?98.71%?92.32%?97.43%; the corrected mortality rate of Aphidoidea is respectively 100.00%?97.81%?98.54%?98.54%; the corrected mortality rate of Tetranychus cinnbarinus is respectively 93.53%?93.53%?94.12%?90.59%. The corrected mortality rates of three kinds of insect pests are greater than 90.00%, and the extractives have a strong insecticidal activity of Parthenium hysterophorus L..The antimicrobial activities of part of the compound were studied were studied,the results follows: Compound 12 to M. tetragenu and B. cereus has greatcertain inhibitory activity, and its MIC values of 5.0 ?g/m L; Compound 12 to B. subtilis, S. aureus and E. coli has certainweak inhibitory activity, and its MIC values of 10.0 ?g/m L. Compound 2, Compound 3, Compound 6, Compound 7, Compound 9 and Compound 11 have weak inhibitory activity to five germs, and their MIC values of 10~100 ?g/m L.