Antibacterial and antifungal effects of walnut (Juglans regia L.) leaf exracts and juglone

In this study, antibacterial and antifungal effects of juglone and walnut (Juglans regiaL.) cultivars (Yalova-2, Yalova-3, Yalova-4, Sebin, 1974-7) leaf exracts were investigated.Juglone and walnut leaf exracts were found to inhibit five bacteria (Pseudomonas gingeri,Pseudomonas phaseolica, Staphylococcus aureus, Bacillus ceraus, Yersinia enterocolitica)among ten bacterial species tested in the study. Nine fungi species (Aspergillus niger, A.fumigatus, A. flavus, A. parasiticus, Fusarium solani, F. graminearum, Geotrichium candidum,Botrytis cinerea ve Candida albicans) were tested in the study and all of them were inhibited bythe treatments. MIC values of juglone and leaf exracts of J. regia L. cv. sebin were alsodetermined. The lowest MIC value was found as 3,125 µg/ml for S. aureus bacterium. As aresult of thin layer chromatography (TLC), it has been shown that juglone is exist in all leavesof the walnut varieties used in the study.Key Words: Antibacterial effect, Antifungal effect, Juglone, MIC, TLC, Walnut.