Biotransformations of baccharin from green propolis using filamentous fungi and bacteria from the intestinal microbiota

Abstract

Green propolis has high commercial and medicinal value and among its constituents is baccharin, one of the major compounds found in Baccharis dracunculifolia, the main botanical source of green propolis. Baccharin is notable for inhibiting the enzyme aldo-keto reductase 1C3, which in the mammary gland converts 4-androstane-3,17-dione into testosterone which can subsequently be converted to 17²-estradiol, in addition to converting estrone to 17²-estradiol . In the prostate this enzyme converts 4-androstene-3,17-dione and 5±-androstane-3,17-dione to testosterone and 5±-dihydrotestosterone, respectively. Therefore, the inhibition of this enzyme is beneficial to prevent the proliferation of tumor cells in two types of highly prevalent neoplasias: breast and prostate cancer. Biotransformation studies with filamentous fungi may provide the same metabolite produced in the human organism and the use of bacteria from the intestinal microbiota in in vitro metabolism studies is important because these microorganisms are able to metabolize drugs and foods after ingestion. In this project, it is proposed to carry out biotransformation studies of baccharin starting with a screening involving two strains of filamentous fungi and three strains of bacteria from the gastrointestinal tract in isolated and mixed cultures. Extracts from the cultures will be obtained and analyzed by TLC and HPLC-DAD. The most promising process will be selected for large-scale development and the major compounds will be isolated and elucidated. There are no biotransformation studies of baccharin and the aim of this study is to obtain information to understand how baccharin could be transformed into human organism, as well as to contribute to obtain new derivatives. (AU)