Analysis Of Volatile Components And The Study On Antioxidant Mechanism Of Natural Active Components In Lysimachia L.

Lysiachia barystachys and Lysimachia stenosepala are two Chinese traditionalherbs belong to the family Lysimachia L, which distribute widely in southwest, eastof China. The whole two plants can be used as medicine to treat inflammation,hypertension, toxin, and so on. It is very significant to extract the active ingredient ofthe Lysimachia L, which benefit to find leadcompound and to synthesize newmedicines. This paper described the analysis of volatile components from Lysiachiabarystachys , Lysimachia stenosepala and the study on antioxidant mechanism ofnatural active components in Lysimachia L. The contents were as following:(1) The whole plant of Lysiachia barystachys was diped in 95% alcoholsolution, then the solution was transfer into distillation bottle to obtain soddenmixture. Petroleum ether, chloroform and ethyl acetate were used as extraction agentsuccessively to extract volatile components. The separated volatile components wereanalyzed by gas chromatography-mass spectrometry. There appeared 108 peaks inTIC, and 77 componds were identified, which included ascorbyl dipalmitate,9,12,15-octadecatrienoicacid,ethyl ester, n-hexadecanoic acid, eugenol ramification,isophorone ramification, 1,2:5,6-dianhydrogalactitol, 2-nonadecylthiophene etc.(2) The whole plant of Lysimachia stenosepala was diped in 95% alcoholsolution, then the solution was transfer into distillation bottle to obtain soddenmixture. Petroleum ether and chloroform acetate were used as extraction agentsuccessively to extract volatile components. The separated volatile components wereanalyzed by gas chromatography-mass spectrometry. There appeared 77 peaks inTIC, and 56 componds were identified, which included linolenic acid ethyl ester, 1-(+)-ascorbic acid 2,6-dihexadecanoate, 6,9,12,15-docosatetraenoic acid,methylester, hexadecanic acid,ethyl ester, isophorone ramification, bisaboleneepoxide,2-butenedioic acid (E)-, 3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acidetc.(3) The eugenol and its analogues were isolated from Lysiachia barystachys,and they have aroused much interest because of their various antioxidant activities.The O-H bond dissociation enthalpies (BDEs), the best indicator of the anti-radicalproperty of these compounds, were calculated by a kind of combined quantumchemisty method(AM1/DFT), by which the antioxidative activities of thesecompounds were evaluated and the structure-activity relationship of thesecompounds was also discussed. It was found that the anti-radical activity of4-(3-methoxypropenyl)-2-methoxyphenol and isoeugenol was just a little weakerthan the gallic acid in non-polar solvents, and they also showed powerfulantioxidative activities.(4)Flavonoids, such as quercetin and kaempferol, is one of the phennolicantioxidants widely existing in the plants of family Lysimachia L. To calculate theantioxidative activities of the four flavonids and two traditionalantioxidants(BHT,PG), the combined quantum chemisty method(AM1/DFT) wasused to calculate the O-H bond dissociation enthalpies (BDEs). The results indicatedthat the BDEs of myricetin and PG seem to be equal to each other, which showedhigh antioxidative activities. The antioxidative activities of quercetin, kaempferol,and norizalpinin were a little weaker ,but all of them were better than the BHT.