Purification, identification and properties of a new blue pigment produced from Streptomyces sp. A1013Y

A novel blue pigment was first isolated from Streptomyces sp. A1013Y. The purified component was identified as 4,8,13-trihydroxy-6,11-dione-trihydrogranaticins A (TDTA). Its physical properties were found to be: Molecular weight 462 Da; Color value, E^0.1%_1cm580 nm = 80; Solubility, it dissolved in organic solvents. In addition, the color of TDTA changed with pH but was found to be relatively stable between 20 and 100 °C, from pH 3 to pH 11, and under UV-light or darkness. TDTA's functional properties was as follows: TDTA showed excellent free radical scavenging properties, IC₅₀ 41.04 µg/mL and 13.75 µg/mL using 2, 20-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-n-(3, 2-ethyl-benzothiazole-6-sulfonic acid) ammonium salt (ABTS) respectively. TDTA might be a promising source of natural pigment and bioactive compound used as additive in food industry.