Preliminary Study On Chemical Composition And The Activity Of Dracocephalum Heterophyllum

Dracocephalum heterophyllum, as a kind of perennial herb, is one species of D., Labi atae family. It contains essential oils, flavonoids, polysaccharides, terpenoids, lignans and o thers with clearing heat and detoxication expectorant, alleviates shortness of breath. So, it is a traditionally medicine herb by Uighur and Tibetan used for treating chronic bronchitis, bronchitis, and stomach trouble. In our research, the chemical constituent of the aerial pa rts of this herb was studied. The effects of the aerial parts extract, fractions prepared with different solvents and the compounds isolated from D. heterophyllum on the Arabidopsis t haliana, Lactuca saliva and Trifolium pratense were preliminarily tested by living-bioassay methods. This would provide some morphological basis for chemical ecological mechanis m elucidating on the compounds and allelopathy of D. heterophyllum, and also for biologi cal pesticide exploitation. The results were as follows:1. Twelve compounds were obtained from the petroleum ether extract of D. Heteroph yllum. They are (1) Linolenic acid,(2) Methyl linolenate,(3) Ethyl linolenate,(4) Linoleic acid,(5) Methyl linoleate,(6) Ethyl ester,(7) Dilinolein,(8) l-linoloyl-3-palmitoylglycerol,(9) Citronello,(10) Stigmastero,(11) β-Sitosterol and (12)2-Acetyl-benzal dehyde, respect ively. Compound1,2,3,4,5and10were firstly obtained from D. Heterophyllum, and c ompound7,8and12were firstly obtained from the genus of Dracocephalum.2. The ethanol, ethylacetate, aqueous, chloroform and emulsion phase extract had a si gnificant negative effect on the growth of A. thaliana or its root length. These extracts co uld be acted as the effective phytotoxic fractions of D. heterophyllum.3. The effects of Linolenic acid, Linoleic acid, Methyl linolenate, Methyl linoleate,1-1inoloyl-3-palmitoylglycerol, Citronello,(3-Sitosterol and Stigmastero on the A. thaliana, L. s ativa and T. pratense varied among different compounds and plant species. Linolenic acid and l-linoloyl-3-palmitoylglycerol had a significant positive effect on aerial parts of A. Th aliana growth, whereas the other six compounds had a significant negative effect on A. th aliana growth. Except for Methyl linolenate, the other seven compounds had a significant negative effect on L saliva growth.(3-Sitosterol, Stigmastero. Methyl linoleate and l-linolo yl-3-palmitoylglycerol had a significant positive effect on T. pratense growth, whereas Lino lenic acid, Linoleic acid and Methyl linolenate had a significant negative effect on T. prat ense growth. Methyl linolenate was the potential allelochemicals.