Study On The Bioactive Constituents In Leaves Of Juglans Regia (Ⅲ)

Allelopathy is a common phenomenon in biosphere. In this thesis, history and current situation of research on plant allelopathy was discussed. And the methods of allelochemicals isolation, mechanism of allelopathy, the factors of affecting allelopathy etc. was reported .The research on allelopathy effects of Juglans regiaL was summarized. The purpose of this paper is to study further allelopathy effects of J. regia L. Two compounds were isolated from the petroleum ether extraction of walnut leaf by TLC, VLC, CC. They are Compoundâ… and Compound â…¡. Physical constant, chemical action, spectrum (EI MS) of Compoundâ… were measured and compared with standard compound. Its structure was determined as octa-thio-cyclic ether; Physical constant, chemical action, spectrum (EI MS, 1H NMR, 13C NMR) of Compound â…¡were measured. It was supposed to be one of lipoalcohol. The allelopathic effects of Compoundâ… on three plant acceptors, lettuce, wheat and cucumber were explored by germination and growth experiments. The result showed the germination rate, seedling root length and seedling height of three acceptors were inhibited by Compoundâ… , and the inhibitory effect degree was stronger with the Compoundâ… concentration getting more. This trend was almost accord with the one of petroleum ether extracts. This indicated Compoundâ… was one of the allelochemicals in walnut leaf. The same treatment affected the three indexes of plant acceptors differently and their inhibitory degrees were as follows: root length>seedling height>germination rate. This trend was also accorded with the one of petroleum ether extracts. Through statistics analysis the regression equation of Compoundâ… and the indexes of three acceptors were obtained; The lowest inhibitory concentration to the three measured indexes of lettuce were respectively 0.09,0.03 and 0.07mg/mL; The lowest inhibitory concentration to the three measured indexes of wheat were respectively 0.14,0.05 and 0.09mg/mL; The lowest inhibitory concentration to the three measured indexes of cucumber were respectively 0.15,0.04 and 0.09mg/mL .