Studies On The Extraction Methods And Isolation Of Insecticidal Components From Phryma Leptostachya L.

Phryma leptostachya L.is a perennial herb of Phrymataceae,which has been used as a traditional insecticidal plant in East Asia.To further study and develop this insecticidal plant,the distribution of insecticidal components in different parts of plants and extraction process was studied.Meanwhile,a rapid,simple and efficient method of separating high active component Haedoxan A was established.The last,the insecticidal activity of the compounds isolated were evaluated.The main results are as follows:1.Through extraction of different parts?roots or stems and leaves?of Phryma leptostachya L.,different extraction methods?cold soaking and ultrasonic extraction?and different solvent?petroleum ether,ethyl acetate and methanol?extraction studies,results showed that the insecticidal active components of Phryma leptostachya L.were mainly distributed in roots and middle polarity section,and the most was ethyl acetate fraction.2.Under bioassay-guided method,the high active fraction was separated and purified by means of ordinary chromatographic separation?extraction,silica gel column chromatography,semi-preparative high performance liquid chromatography?and recrystallization.The structure of isolated compounds were identified according to the physical and chemical properties and spectral data(Mass spectrum,1H-NMR,¹³C-NMR,DEPT,HSQC,HMBC,COSY,etc.).Six monomeric compounds were identified and respectively were phrymarolin I,phrymarolin II,haedoxan A,haedoxan E,stigmasterol,?-sitosterol.3.The method of rapid acquisition of the highest insecticidal activity haedoxan A was established.The roots of Phryma leptostachya L.were extracted by methanol and ethyl acetate successively.The extractive was carried out with petroleum ether: ethyl acetate = 100: 0-0: 100 by Silica-gel Column Chromatography.The similar eluates were combined by TLC.The highest segment was found by bioassay-guided and isolated with petroleum ether: acetone = 3:1 on Silica-gel Column Chromatography,then recrystallization with methanol can obtaine haedoxan A directly.4.Insecticidal activity was evaluated for these isolated compounds.The isolated active compounds mainly acted on Lepidoptera insects and mode of action showed the stomach poisoning.While,to Aphis ciricola van der Goot,Trialeurodes vaporariorum and Tetranychina harti Ewingare,there was no activity.Phrymarolin I showed only narcosis activity to third instar M.separata and NC50 value was 3450 ?g/mL after 4 h,but had the poisoning toxicity to the third instar Plutella xylostella and LC50 value was 1432 ?g/mL after 48 h.Haedoxan A had stomach toxicity and contact toxicity against third instar M.separata,and LC50 value was 17.06 ?g/mL and 1123 ?g/mL after 24 h respectively,the stomach toxicity against third instar Plutella xylostella and LC50 value was 857 ?g/mL.Haedoxan E had stomach toxicity and contact toxicity against third instar M.separata,and LC50 value respectively was 60.51 ?g/mL and 3758 ?g/mL after 24 h,the stomach toxicity against the third instar P.xylostella the LC50 value was 1855 ?g/mL.T6 had narcosis activity against third instar M.separata,and LC50 value was 2807 ?g/mL after 24 h,but had no toxicity against the third instar P.xylostella.