Antimicrobial quercetin 3-O-glucoside derivative isolated from Streptomyces antibioticus strain ess_amA8.

Streptomyces antibioticus strain ess_amA8 was isolated from the insect Tapinoma simrothi , and was tested for the production of compounds that inhibit the growth of microorganisms. The cultural and physiological descriptions of the strain revealed that it belonged to the Streptomyces genus. The 16S rRNA gene from the Streptomyces isolate was sequenced, and its length was 1156 bp and it was submitted to Genbank (KF996507). According to molecular and morphological studies, the isolated strain was ultimately identified as strain ess_amA8 of Streptomyces antibioticus. The key compound was extracted from the strain ess_amA8, which was active in vitro , against a wide range of microorganisms, such as Staphylococcus aureus ATCC6538, Bacillus subtilis ATCC 6633, Pseudomonas aeruginosa ATCC 9027, Escherichia coli ATCC-7839, Candida albicans , Fusarium moniliforme , Aspergillus niger , and Aspergillus flavus. The physico-chemical property of the purified antimicrobial compound analyzed and its proposed empirical formula was C 27 H 25 O 13. According to the IUPAC name, this compound was identified as 5,7-diethoxy-2-(3-methoxy-4-methylphenyl)-3-[(2R,3S,4R,5R,6S)-3,4,5,6-tetrahydroxy-2-(hydroxymethyl)tetrahydro-2H-pyran-3-yl] oxy-4H-chromen-4-one, and was a quercetin 3-O-glucoside derivative. In summary, the present study highlights the fact that the purified quercetin 3-O-glucoside antimicrobial derivative, first report to this Streptomyces sp., and it is a flavanone glycoside. [ABSTRACT FROM AUTHOR]