Salumycin, A New Pyrazolequinone From Astreptomyces Albusj1074 Mutant Strain

Heterocyclic natural products with various bioactivities play significant roles in pharmaceuticals. Here, we isolated a heterocyclic compound salumycin (1) from aStreptomyces albusJ1074 mutant strain. The structure of (1) was elucidated via single-crystal X-ray diffraction, mass spectrometry (MS), fourier transform infrared spectrometer (FTIR), and nuclear magnetic resonance (NMR) data analysis. Salumycin (1) contained a novel pyrazolequinone ring, which had never been previously reported in a natural product. Salumycin (1) exhibited moderate 2,2 '-diphenyl-1-picrylhydrazyl (DPPH)-radical scavenging activity (EC50 = 46.3 +/- 2.2 mu M) compared withtert-butylhydroquinone (EC50 = 4.7 +/- 0.3 mu M). This study provides a new example of discovering novel natural products from bacteria.