ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Antifungal activity and mode of action of saponins from Madhuca butyracea Macb.

Lalitha, T.; Venkataraman, L. V.;

Indian Journal of Experimental Biology Year: 1991 Vol: 29 Issue: 6 Pages: 558-562 Ref: 14 ref.

1991

บทคัดย่อ

The antifungal activity of saponins isolated from the defatted flour of M. butyracea [Diploknema butyracea] seeds on pathogenic fungi associated with postharvest spoilage was evaluated. Saponins caused max. growth inhibition of Penicillium expansum, Cephalosporium acremonium [Acremonium strictum], Helminthosporium oryzae [Cochliobolus miyabeanus] and Trichoderma viride (LD50 <500 p.p.m.). Other fungi tested showed varying degrees of sensitivity to the saponins: growth stimulation was observed for Botryodiplodia theobromae and Pythium sp., Penicillium and Fusarium spp. were variously sensitive. In shake cultures of T. viride containing 500, 1000 or 2000 p.p.m. of saponins, T. viride showed a sharp growth increase after reaching a min. at 6 h. The saponin concn decreased steadily over the experimental period, but remained constant in uninoculated controls, and it is suggested the saponins were being degraded by the fungus. A dose-dependant increase in proteins and nucleic acids in the cell free medium was observed in saponin treated mycelia of T. viride, indicating that saponins cause leakage of cellular components into the medium. This was supported by the reduction in the trichloroacetic acid extractables in the saponin treated mycelia. It is concluded that the saponins cause the leakage of small molecular weight compounds.