| The volatile constituents emitted from natural plants is a kind of organic compounds which the molecular weight between 100-300.It is the information compounds that plays an important role in plants or phytophagous inserts or natural enemies and relates plants and plants or inserts and plants.Because the volatile constituents have many varieties and low concentration,it needed a modern analysis technology which has efficient extraction,isolation and identification to analyze the volatiles. The volatile constituents of Mosla chinensis Maxim,Osmanthus fragrans Lour.and Chimonanthus Praecox were investigated by means of new pretreatment in this paper.A brief description was given as follows:ⅰ.The volatile constituents emitted from Mosla chinensis Maxim were investigated by means of solid-phase microextraction(SPME), liquid-phase microextraction(LPME),microwave-assisted extraction with solid-phase microextraction(MAE-SPME) and microwave-assisted extraction with liquid-phase microextraction(MAE-LPME) coupled to gas chromatography-mass spectrometry(GC-MS).The results indicated that 84 volatile constituents were identified in Mosla chinensis Maxim. Thymol,thymol acetate,p-cymene,ocimene and myrcene were the most abundant volatile constituents.There were some distinguishes in volatile constituents by different extracted methods.The sensitivity of solid-phase microextraction was higher than liquid-phase microextraction.The volatile constituents extracted by SPME and LPME can complement each other.Some storage compounds can be released from plants by microwave so that more compounds were received.ⅱ.The volatile constituents emitted from fresh Osmanthus fragrans, Osmanthus fragrans var.thunbergi and Osmanthus gragrans f Aurantiacu flowers in different florescence and different years were investigated by means of solid-phase microextraction.The results indicated that the fragrans of Osmanthus fragrans Lour.flowers not only had some resemblance,but also had some difference.4-Hexen-1-ol,acetate,acetic acid,hexyl ester,limonene,(Z)-ocimene,(E)-ocimene,(Z)-linalool oxide, linalool oxide A,β-linalool,4,8-dimethyl-1,3,7-nonatriene,(E)-linalool oxide,epoxylinalol,(Z)-butanoic acid,3-hexenyl ester,butanoic acid,hexyl ester,(E)-butanoic acid,2-hexenyl ester,cis-3-hexenyl isovalerate,geraniol,γ-decalactone,β-ionone and cedrol were the same volatile constituents released from fresh flowers of three different Osmanthus fragrans Lour.. The different varieties of fresh Osmanthus fragrans Lour.flowers were distinguished by GC-MS fingerprints.The results also showed that the volatile constituents in different florescence had some difference,the fragrans was dense and the content of volatiles was more at the early stage of flower blooming and during the flower blooming.The volatile constituents emitted from Osmanthus fragrans Lour.flowers in different years had some difference because of various factors.ⅲ.The volatile constituents emitted from fresh Chimonanthus Praecox flowers in different florescence and different years were investigated by means of solid-phase microextraction.The results indicated that benzyl alcohol,(E)-ocimene,β-linalool,benzyl acetate and methyl salicylate were the most abundant volatiles released from fresh flowers of Chimonanthus Praecox.The volatile constituents in different florescence had some difference,the fragrans was dense and the content of volatiles was more at the early stage of flower blooming and during the flower blooming.Because the influence of many factors,the volatile constituents emitted from Chimonanthus Praecox flowers in different years had some difference.ⅳ.The identified volatile constituents were studied by quantitative structure-retention relationship(QSRR).Genetic function approximation (GFA) and multiple linear regression(MLR) methods were used for building the regression models.The QSRR models were validated by predictive-ability test.The results demonstrated that the regression coefficient r~2 in models were over 0.950,the cross-validation coefficient r~2cv in models were over 0.910.The prediction results were in good agreement with the experimental values.The QSRR models had good predictive capability.The phytohormone acted as a key factor in the plant growth and development,plant defense and adaptation to environmental stress.Since the phytohormone compounds have the strong structure-activity relationships,small structural changes may lead to the biological activity changes,it is a need for study.The quantitative structure-property relationship(QSPR) of a series of phytohormone compounds were studied in this paper.A brief description was given as follows:ⅰ.The quantitative structure-property relationship of a series of jasmonates were investigated by genetic function approximation(GFA) and genetic/partial least-squares(G/PLS) models and then validated by F-test and predictive-ability test.The results demonstrated that the regression coefficient r~2 in models were higher than 0.9,the models had perfect predictive ability.3D-QSPR models investigated the substitutional requirements for the favorable receptor-drug interaction,further accounting for the credibility of 2D-QSPR models.ⅱ.The quantitative structure-property relationship of amino acid conjugates of jasmonic acid were investigated by genetic function approximation and genetic/partial least-squares models.The results demonstrated that the regression coefficient r~2 is 0.967 and the predictive capability q~2 is 0.847 in 2D-QSPR,the regression coefficient r~2 is 0.939 and the predictive capability q~2 is 0.913 in 3D-QSPR.The QSPR models had perfect predictive ability.ⅲ.The quantitative structure-property relationship of amino acid conjugates of salicylic acid were investigated by genetic function approximation and genetic/partial least-squares models.The results demonstrated that the regression coefficient r~2 is 0.974 and the predictive capability q~2 is 0.877 in 2D-QSPR,the regression coefficient r~2 is 0.922 and the predictive capability q~2 is 0.905 in 3D-QSPR.The values of cross-validation coefficient r~2cv in models were close to the values of regression coefficient r~2.The QSPR models had perfect predictive ability.The volatile constituents emitted from natural plants were investigated in this paper.It can provide some scientific evidence for understanding the plants’ volatiles changes.This study also provide academic guidance for establish the fingerprints of plants.The 2D/3D-QSPR of a series of jasmonates,amino acid conjugates of jasmonic acid and amino acid conjugates of salicylic acid were investigated by GFA and G/PLS.It can provide academic guidance of structural design and synthesis for noval compounds with high activities.This study is worthwhile in future study for design high activity plant elicitors and develop ecological pesticides of high effect. |
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