Abstract:

An ecological study was carried out on secondary metabolites(bioactive constituents)in the leaves of Eucommia ulmoides through determining the contents of the metabolites and ecological factors in the leaves collected from different regions.The results were as follows :The contents of metabolites in the leaves collected from different regions showed significant differences.The leaves collected from Zunyi contained the highest contents of geniposide, chlorogenic acid, aucubin, and flavonoids. Geniposidic acid reached the highest content in the leaves from Cili.The leaves from Luoyang showed the lowest content of geniposide.The contents of chlorogenic acid, aucubin, geniposidic acid and flavonoids were the lowest in the leaves from Yichang, but hightest gutta-percha.These showed that ecological factor was also an improtant one in regulating secondary metabolism.Stepwise regression analysis and path analysis indicated that the major factor influencing the synthesis and accumulation of metabolites was the contents of trace elements, meteorological factor however, showed little influence. The relationship between the contents of available trace elements in the soil and in the leaves was not in completely direct correlation.Different results were obtained in stepwise regression analysis and path analyses when the contents of trace elements in the soil and in the leaves were used as the main factors respectively.Through systematic cluster and fuzzy complex discrimination, it was concluded that the contents of secondary metabolites were high in the leaves from Zunyi(Guizhou Province), Cili(Hunan Province), Lueyang(Shaanxi Province), Tongjiang(Sichuan Province).

Key words: Eucommia ulmoides lea, Secondary metabolites, Ecological factor, Trace element