Biotransformation of caffeine in oolong tea by Paecilomyces gunnii

摘要

The entomogenous fungus Paecilomyces gunnii was cultured in Chinese oolong tea medium and changes in the chemical composition of this fermented oolong tea are here explored. The alkaloids of this fermented oolong tea were isolated and purified using column chromatography over RP-18, Sephadex LH-20 and silica gel. Their structures were identified using NMR data and single-crystal X-ray diffraction. Thin-layer chromatography and high-performance liquid chromatography indicated that the caffeine in oolong tea was biotransformed to theophylline and 1,7-dimethylxanthine. It was concluded that Paecilomyces gunnii had the ability to perform N-demethylation to degrade caffeine to theophylline and 1,7-dimethylxanthines. (C) 2016 Elsevier Ltd. All rights reserved.