Determination of Porothramycin by Ultra-High-Performance Liquid Chromatography

Porothramycin is the antibiotic of anthramycin group and is produced by Streptomyces albus. Porothramycin is characterized by antibacterial and especially antitumor activity. But it has also been proved to be cardiotoxic; and therefore, it has not been applied in clinical practice yet. However, some genes involved in the synthesis of porothramycin can be used for the preparation of new nontoxic derivatives of antibiotics by means of combinatorial biosynthesis. For this purpose, it was necessary to develop a new routine chromatographic UHPLC-UV- MS method for analysis of porothramycin. A suitable cultivation broth for production of porothramycin was found using disk diffusion test with the sensitive strain Kocuria rhizophila. Then, 1.7 mg of porothramycin standard, which was not available on the market, was isolated from the cultivation broth and used for the development and validation of the method. Also, it was found out that apart from porothramycin, two porothramycin-related compounds were produced into the cultivation broth. In the final method for determination of porothramycin, the solid phase extraction using styren-divinylbenzene sorbent with vinylpyrrolidone functionalities was applied. The extracts were then loaded onto the UHPLC Acquity BEH C18 column and analyzed under gradient mode..