Study On Antifungal Activities Of Extracts From Walnut Green Peel (Juglans Regia)

The fungistasis effect of different extracts was tested with 6 fungi, such as Physalospora nasei, Valsa mali, Monilinia fiucticola, Alternaria alternata f.sp. mali, Fusarium oxysporium and Fusarium graminearum. The main results were as follows:1. Walnut peel was extracted by using five kinds of solvents. The fungistasis effect of different extracts was tested with 6 fungi, The results showed that the water extracts had the strongest fungistasis effect among 6 fungi, the inhibition rates were more than 96%. The inhibition rates of petroleum ether extract to 6 fungi was lowest.2. The methanol extracts were dissolved by water. Water extracts re-exacted by using petroleum ether, chloroform and ethyl acetate respectively, and the six fungi were tested at the different concentration of extracts. The results showed that the fungistasis effect of different extracts rose with concentration rose. At the concentration of 4 mg·mL-1, the water-chloroform re-extracts had the strongest fungistasis effect on Monilinia fiucticola, and the inhibition rates was 71.54%. The inhibition rates of the water-ethyl acetate re-extracts against Fusarium graminearum was 18.32%.3. Furthermore, the water-chloroform re-extracts were separated by using column chromatography (CC) and were analyzed by using thin-layer chromatography (TLC). The absorbant was silica gel, and the eluting solvents were resolvent mixed with petroleum ether and chloroform according to the different ratio. And the inhibition rate of every composition was tested. The results showed that the compositionⅥhad the best fungistasis effect on Monilinia fiucticola, and the inhibition rate was 24.5%. The fungistasis effect of compositionⅤwas secondary, and the inhibition rate was 16.62%.4. Observed with microscope, the shape and structure of bacterial filament was visibly destructed by compositionⅥ. The appearances included the fragmentation of bacterial filament. The cell was intumescence and appeared vesicle. And then, the bacterial filament appeared bead-like and fragmentated to several segments. The cytoplasm was outleakage.