Antimicrobial and antioxidant activities of extracts from walnut green husks
This research aimed to evaluate the antimierobial and antioxidant activities of walnut green husks,and to explore possible ways to efficiently utilize the bioresource.After walnut green husks were extracted by different reagents,the antimicrobial capacity of the extracts was measured by Oxford Cup method; the antioxidant capacity was assessed by total phenolic content,reducing power assay and scavenging effects on DPPH (2,2-diphe-nyl-1-picrylhydrazyl) radicals.All extracts showed different antimicrobial activities against Gram negative (Escherichia coii,Pseudomonas aeruginosa),Gram positive (Staphyloccocus aureus,Bacillus subtilis) bacteria,and fungi (Canidia albicans,Penicillium italicum,Peniicilbum digitatum,Phytophthora capsici).The walnut green husks extracted with ethyl acetate and chloroform showed the highest activities against bacteria tested,with minimum inhibitory concentrations (MIC) against the four bacteria about 6.25/6.25,6.25/1.56,3.13/3.13,6.25/3.13 mg/mL,respectively.On the other hand,antifungal substances existed in petroleum ether extracts,with MIC against Penicillium italicum,Peniicilbum digitatum and Canidia albicans about 3.13,6.25 and 6.25 mg/mL respectively.The total phenol contents in ethyl acetate and chloroform extracts were about 193.52 and 174.64 mg GAEs/g respectively their EC50 of scavenging DPPH radical activity about 14.05 and 26.11 μg/mL,EC50 of reducing power about 34.70 and 44.60 μg/mL.The antioxidant activities of the extracts with other solvents were much lower than those extracted with ethyl acetate and chloroform.Our research showed that walnut green husk contains antibacterial and antioxidant material in its ethyl acetate and chloroform extracts,and antifungal material in its petroleum ether extracts.
walnut green huskextractsantimicrobial activityantioxidant activity
NETL
NSTL
万方数据
维普
