Anti-vibriosis bioactive molecules from marine-derived variant Streptomyces sp. ZZ741A.

The infection of vibrio is an important cause of huge economic losses in aquaculture industry. At present, antibiotics are mainly used to prevent and reduce the infection of the vibrio , which has accelerated the emergence of multi-drug-resistant strains. New generation alternative anti- vibrio drugs were in urgent to solve this problem. In this study, six compounds ( 1-6 ) were isolated from the Streptomyces sp. ZZ741A, a marine-derived Streptomyces variant, including one new compound, 2-carbamoylphenyl isobutyrate ( 1 ), five known ones, nocardamine ( 2 ), dehydroxynocardamine ( 3 ), phenylacetic acid ( 4 ), thiophenol ( 5 ) and 2,3-dihydroxybenzoic acid ( 6 ). The anti - vibriosis assay showed that compounds 2 and 3 had specific inhibition activity against Vibrio vulnificus , Vibrio alginolyticus , and Vibrio parahaemolyticus with the MIC values ranging from 8 to 128 μg/mL. The molecular docking study of their possible mechanism of anti-vibriosis activity showed that the activity might come from the inhibition of Outer membrane protein U (OmpU).