银杏外种皮中银杏酸对真菌的抑制作用

Inhibition of Gingkoic acid on fungi in Ginkgo biloba testa

银杏酸是银杏外种皮中的重要功能性成分。本实验从银杏外种皮中提取银杏酸,用大孔树脂和硅胶对银杏酸进行纯化,并研究了银杏酸对真菌的抑菌活性和抑菌机理。HPLC分析结果表明银杏酸中白果酸C15:1含量最高。考察银杏酸对致病真菌球黑孢霉、链格孢霉、扩展青霉的抑制作用,结果表明其对球黑孢霉和链格孢霉的抑制作用最强,在5 mg/mL下对球黑孢霉的抑制率为65.82%。银杏酸对球黑孢霉抑菌机理可能是银杏酸可以裂解球黑孢霉细胞膜,使球黑孢霉细胞膜通透性变高,菌液电导率上升;同时造成细胞膜损伤,菌丝体蛋白质外泄,降低了球黑孢霉菌丝体中SOD、CAT酶活性,使抗性酶对球黑孢霉的保护作用变弱,呈现出银杏酸对球黑孢霉的抑制作用。

Ginkgolic acid is an important functional component in Ginkgo biloba testa.Ginkgolic acid was extracted from the Ginkgo biloba testa and purified by macroporous resin and silica gel.HPLC result showed that the content of ginkgolic acid C15:1 was the highest.The inhibitory effect of ginkgolic acid on the pathogenic fungi such as Melanomyces globosa,Alternaria alternata and Penicillium expansum were investigated.The results showed that ginkgolic acid had the strongest inhibitory effect on the pathogenic fungi,which was 65.82%at 5 mg/mL.The antibacterial mechanism of ginkgolic acid against Nigrospora sphaerica maybe that ginkgolic acid can cleave the cell membrane and then increase the permeability of the cell membrane,so that increase the electrical conductivity of the mycelia;it causes the damage of cell membrane and the leakage of protein in the mycelium,which could reduce the activity of SOD and CAT in the mycelium,and weaken the protective effect of the resistant enzyme on the fungus and show the inhibition of mould.