Abstract:

From the preliminary screen it was found that the ethanol extracts from airy parts of Sophora alopecaroidescould inhibit G.cingulata effectively.Four parts were separated from the ethanol extracts of S. alopecuroides under conditions of certain pH and using certain solvents.Bioassay showed that the alkaloid part was the strongest portion to inhibit the fungus.Seven monomers were isolated from the alkaloid part by chromatog raphy on an alumina column and they were identified as sophocarpine, matrine, sophoramine, lehmanine, sophoradine, aloperine and cytisine in comparison with the measured data of m.p., IR optical rotation and MS and those from literature.Bioassay using the paper ring method indicated that all the seven alkaloids were of relatively strong activity to inhibit germination of the conidia of G.cingnalata, their EC₅₀ were 72.0μg/mL for aloperine, 227.0μg/mL for cytisine, 190.0μg/mL for sophoramine, 86.0 μg/mL for matrine, 24.0μg/mL for sophocarpine, 26.0 μg/mL for sophoradine, 126.0μg/m L for lehanine; the EC₅₀ for the common fungicides, 75 %Daconial and 70 % Topsin-M, were 82.0 and 118.0μg/mL respectively under the same conditions of the bioassay.

Key words: Sophora alopecuroides L., Alkaloid, Glomerella cingulata(Stonem) Schr et Spauld, Conidium, EC₅₀