Study On Allelopathy Of Passion Fruit To Panax Notoginseng And Its Allelochemical Isolation And Identification

The disease of Panax notoginseng was a major constraint on increasing the yield and quality of Panax notoginseng. In the survey found that, with the passion fruit as shading materials to build a shading shed, The cultivation of Panax notoginseng had less diseases, there was obviously allelopathy phenomenon. For this reason, this paper based on the study of the antimicrobial activities of passion fruit on Panax notoginseng, to study the antimicrobial activities of passion fruit extracts on Alternaria panax Whetz and Colletotrichum panacicola Vyedaet Takimoto and Fusarium oxysporum E. F. Sm.& Swingle. Passion fruit extracts were separated and purified by using ethanol extraction, MCI-gel column chromatography, gel clumn chromatography, silica gel column chromatography, reverse silica gel column chromatography, high efficiency liquid chromatography and recrystallization, after that, by using IR, UV, MS, NMR to identify the structure of the allelochemicals for Panax notoginseng, the results will provide references for Panax notoginseng pathogen biological control, improving the cultivation mode of panax notoginseng, reducing the use of pesticide and guaranteeding authentic herbs.The main comclusions were as follow.(1) The experimental results of the antimicrobial effect of the water, ethanol and ethyl acetate extracts of passion fruit showed that, the leaves, stems, fruit of passion fruit extract could inhibit the propagation of Panax notoginsen pathogen. The higher concentration gave the stronger antimicrobial activities. Under the same extraction solvent and the same concentration, the leaf and stem extracts had stronger antimicrobial activities than the fruit extract. Under the same extract and the same concentration, the sensitivity index of Colletotrichum panacicola was higher than Alternaria panax and Fusarium oxysporum. The ethanol extraction of the passion fruit leaf had the better inhibitory effect to Alternaria panax by the concentration of 1g/mL, the inhibition rate was 40%. The water extraction of the passion fruit leaf had the better inhibitory effect to Colletotrichum panacicola by the concentration of 0.5g/mL, the inhibition rate was 61%. The ethyl acetate extraction of the passion fruit leaf had the better inhibitory effect to Fusarium oxysporum by the concentration of 1g/mL, the inhibition rate was 49%.(2) 12 compounds were isolated from the water and ethyl acetate extracts from the stem of passion fruit,8 of them were elucidated by nuclear magnetic resonance. They were 1,8-dimethoxynaphthalene(1), fernandoside(2), maslinic acid(3), friedelin(4), sambunigrin(5), R-mandelonitrile-β-D-glucopyranoside (6), amygdalin (7) and Cycloolivil (8).The structures of elucidated compounds as follow.Among them, 1,8-dimethoxynaphthalene(1), fernandoside(2), maslinic acid (3), friedelin (4), (R-mandelonitrile -β-D-glucopyranoside (6), Cycloolivil (8), were first found from passion fruit in China.