A New 6-deoxy-talopyranoside derivative with antibacterial and radical-scavenging activities from Streptomyces sp. HDSJ4

Chemical investigation of the secondary metabolites from a Streptomyces sp. strain yielded two compounds (1 and 2), including an undescribed 6-deoxy-talopyranoside derivative, designated strepyranin A (1). The structure of strepyranin A was unambiguously established based on comprehensive spectroscopic analyses, including 1D and 2D NMR spectra, together with HRESIMS data. Compound 1 was assayed for its antibacterial and radical-scavenging activities. Bioassays revealed that strepyranin A (1) exhibited weak antibacterial activity against Pseudomonas aeruginosa and Streptococcus pneumoniae, with minimum inhibitory concentration (MIC) values of 64 μg/mL and 128 μg/mL, respectively, and moderate DPPH radical-scavenging activity with an RSA of 36.4%.