DEGRADATION AND PRODUCT ANALYSIS OF CAFFEINE AND RELATED DIMETHYLXANTHINES BY FILAMENTOUS FUNGI

Twenty strains of filamentous fungi were tested for their ability to g row on a liquid medium containing caffeine (1,3,7-trimethylxanthine) a s a sole nitrogen source. Seven strains which were able to grow on caf feine belong to the Aspergillus and Penicillium genuses. They all pres ented the snr?le degradation pathways but varied in the efficiency by which degradation took place. Caffeine was first demethylated in posit ion 7; this lead to the formation of theophylline (1,3-dimethylxanthin e). This compound was next demethylated in position I to give 3-methyl xanthine. All these strains were also able to grow on theophylline, th eobromine (3,7-dimethylxanthine), and paraxanthine (1,7-dimethylxanthi ne) as a sole nitrogen source. All degradation intermediates detected were methylxanthines. (C) 1998 Elsevier Science Inc.