Studies On Chemical Constituents And Antifungal Activities Of The Husk Of Carya Cathayensis Sarg

Carya cathayensis Sarg is a species of Juglandaceae Family,Carya Genus.It's an endemic woody oil plant of China and mainly distributed in the Tianmu Mountainous region between Zhejiang province and Anhui province.As far,the chemical constituents and biological activities of some plants of Juglandaceae have been researched and reported,those of the husk of C.cathayensis Sarg,however,have not still been reported. From the view of phytochemistry and pesticide science,this thesis primarily studied on the chemical constituents and antifungal activities of C.cathayensis Sarg.The main results are as follows.1.Inhibition effects of extracts from the husk of C.cathayensis Sarg against Alternaria solani,Exserohilum turcicum,Valsa mali,Fusaium graminerum,Pyricularia oryzae,Rhizoctonia solani,Sclerotinia sclerotiorum(Lib) de Bary were tested by mycelium growth rate method.The results showed that the n-butanol phase had the highest activities and it was up to 100%,then the chloroform phase and the petroleum ether phase, the ethyl acetate phase had the lowest activities.Under the tested concentration,the higher the concentration of the four phases,the greater the inhibition effects,and Valsa mali had the hightest sensitivity to the four phase.2.Eight compounds were isolated and identified.Compound 1 isβ-sitosterol, Compound 2 is pinostrobin or 5-hydroxy-7-methoxy-flavanone,Compound 3 is Flavokawain B,Compound 4 is 5-hydroxy-4',7-dimethoxyflavanone,Compound 5 is 5-hydroxy-2-methoxy-1,4-naphthoquinone,Compound 6 is Onysilin,Compound 7 is 2,6-dihydroxy-3-Phenyl-4-methoxy-benzofuran acrylophenonesone,Compound 8 is pinocembrin or 5,7-dihydroxy-flavanone.All of the eight compounds were isolated from C.cathayensis Sarg.for the first time,and the Compound 7 has not been reported in literature,and it is probobaly a new one.3.Inhibition effects of the eight compounds against spore germination of Exserohilum turcicum and Pyricularia oryzae were tested by spore germination method.The results showed that all the eight compounds had effects on the two plant pathogens.The effects on the Exserohilum turcicum were higher than that on the Pyricularia oryzae.When the concentration of the compounds is 0.1 mg/mL,the inhibition rate of compound 1.5,6.7.8 against Exserohilum turcicum is up to more than 90%.the inhibition rate of compound 5 and 6 against yricularia oryzae is up to more than 90%..the inhibition rates of the new coumpound against Exserohilum turcicum and Pyricularia oryzae were 95.8%and 86.7%.