长江三角洲石荠苧属植物的精油成分及其与系统发育的关系

本文运用色谱/质谱/计算机联用方法,对长江三角洲地区石荠苧属Mosla 5种植物进行分析比较,发现这5个种在精油成分的组成上基本可分为两个类型:一个类型含有大量的香荆芥酚和其他单萜类化合物,倍半萜成分很少,酚酯类化合物几乎没有;另一个类型则在精油中含有大量的倍半萜和酚酯类化合物。笔者在化学分子水平上探讨了它们的种间亲缘关系和可能的演化途径。

AN ANALYSIS OF THE CHEMICAL COMPOSITION OF ESSENTIAL OIL OF MOSLA IN THE YANGTZE DELTA AND ITS BEARING ON PHYLOGENY

This paper is a continuation of the previous one which has been dealing with a numerical taxonomic study on the variation patterns on population level of 5 species of Mosla (Labiatae) in the same region2],In the previous paper, we have come to the conclusion that the 5 species of Mosla had differentiated into two main phylads in its early stage of evolution. In the present study, the essential oil extracted from the same species was analysed by means of a gas chromatograph-mass spectral in order to reveal the phylogenetic relationships of the said species on chemical level. Results of chemical analysis have revealed: (1) the occurrence of large amounts of carvacrol (50%) (with a small amount of thymol) and other mono-lerpenes (40%) in both Mosla chinensis Maxim, and M. hangchowensis Matsuda indicates a close relationship between these two species- ( 2 )M.scabra (Thunb.) C. Y. Wu et H. W. Li has a close affinity to M. soochowensis Matsuda, since methyleugenols and cineoles are principal components (ca. 45%) in both species, and the other contituents of secondary importance are monoter penes (30-35%)and sesquiterpenes(ca. 18%); ( 3 )M.dianthera (Buch-Ham.) Maxim., which mainly contains sesquiterpenes (ca. 62%), some phenolic compounds (ca. 32%), and a very small amout of monoterpenes (less than 5%), is chemically quite different from the other four species. It is thus evident that the differentiation patterns of chemical composition of essential oil of the 5 species of Mosla are closely correlated with their phenetic variation patterns of populations. Based upon chemical composition of essential oil, the 5 species can also be classified into two groups. The first group including M, chinensis and M. hangchowensis is characterized by containing a large amount of monoterpenoids and phenolic compounds, very little amount of sesquiterpenes, and almost lacking of phenolic esters. The great similarity between M.chinensis and M. hangchowensis in the constituents of essential oil is closely correlated to their similarity in morphological features. The second group including M. soochowensis, M,scabra and M. dianthera is distinguished by the existence of large amounts of sesquiterpc noids and phenolic ester compounds. Some authors (e. g. Fujita 1965)1]hold that the presence of the constituents of essential oil is irreversible. It is, therefore, suggested that species of the first group are more primitive than species of the second group. The genus Mosla had probably differentiated into two main phylads in its early evolutionary stage. The phylad represented by M. chinensis and M. hangchowensis is probably of more ancient origin and has preserved more primitive characters. The other phylad including M. scabra, M. soochowensis and M, dianthera is phylogenetically more advanced, probably has evolved more rapidly, and has greatly differentiated from their ancestor stock at present. In this phylad, the branch represented by M.dianthera seems to be a most specialized one.