Abstract:

Methanol extract of husk of Carya cathayensis was further partitioned with petroleum ether，chloroform，ethyl acetate and n-butanol successively and obtained four crude extracts. Antifungal activity of the four crude extracts was tested against Alternaria solani， Valsa mali，Gibberella zeae，Rhizoctonia solani and Sclerotinia Sclerotiorum. It showed that the n-butanol extract had the highest activity，ed by the chloroform extract and the petroleum ether extract，and the ethyl acetate extract had the lowest activity. Seven compounds were isolated from the chloroform extract. Their structures were identified as pinostrobin，plavokawain B，5-hydroxy-4′，7-dimethoxyflavanone，5-hydroxy-2-methoxy-1，4-naphthoquinone，onysilin，pinocembrin and β-sitosterol，respectively. The Compounds were for the first time isolated from Carya cathayensis and showed to different degree inhibitory activities against the spore germination of Exserohilum turcicum and Pyricularia grisea.

Key words: Carya cathayensis, extract and isolation, bioactive ingredients, antifungal activity