Optimization, purification, and structure elucidation of anthraquinone pigment derivative from Talaromyces purpureogenus as a novel promising antioxidant, anticancer, and kidney radio-imaging agent

Abstract

This study aims to investigate the bioproduction and prospective biological applications of a natural red pigment from Talaromyces purpureogenus AUMC2603. Maximum pigment yield was achieved by a numerical optimization at pH 6, temperature 25 °C, and an 18-day incubation period on Yeast Malt Broth (YMB) media. The crude pigment was separated and purified into two pigment fractions via solid-phase extraction and then characterized as anthraquinone (dominant) and herquinone by LC/MS and ¹HNMR analysis. The crude pigment extract and the two separated fractions displayed a potential antioxidant activity. Additionally, they showed a powerful anticancer activity towards cancer cell lines, MCF-7, HepG-2, and HCT116 with less cytotoxicity on normal cell lines, MCF12F and BJ-1T. The radioiodination efficiency of the radiosynthesized ^99mTc-anthraquinone pigment complex was also investigated and optimized, obtaining a radiochemical yield of 92.70 % ± 0.89 %. An in vivo biodistribution study of the ^99mTc-anthraquinone pigment complex demonstrated a high kidney uptake of 34 % injected dose per gram of organ tissue 60 min after intravenous injection, and the complex retention remained high up to 120 min. The current study is the first bioassay report on the efficacy of a purified anthraquinone from T. purpureogenus as a potent agent for kidney radio-imaging that could be applied in kidney cancer diagnosis.

Keywords: Anthraquinone pigment; Anticancer; Antioxidant; Optimization; Radio-imaging; Talaromyces purpureogenus.