Phytochemical Investigation Of Some Traditional Chinese Medicines And Endophyte Cultures

Abstract

For many social and environmental reasons, over the last few decades, there has been an increase in chronic and life-threatening diseases including mycoses, hyperuricemia-related disorders and some mental illnesses such as depression, anxiety and Parkinson’s disease. In order to fight these diseases, compounds acting on various biological targets, including enzymes such as xanthine oxidase or monoamine oxidase, have to be screened. The enzyme xanthine oxidase catalyses the oxidation of hypoxanthine to xanthine and then to uric acid, which plays a crucial role in hyperuricemiarelated disorders such as gout and renal stones. One of the therapeutic approaches to treat these diseases is the use of xanthine oxidase inhibitors that block the production of uric acid. Monoamine oxidases (E.C.1.4.3.4) A and B catalyse the oxidative deamination of monoamines in the central nervous system and peripheral tissues. Inhibitors of MAO A are clinically useful to treat anxiety and depression since they are expected to increase both noradrenalin and serotonin levels in the brain. On the other hand, inhibition of MAO B appears to be an effective approach for the prevention and adjunct treatment of Parkinson’s disease. In traditional Chinese medical practice, many medicinal herbs have been used to treat chronic diseases such as fungal infections, hyperuricemia-based disorders and mental illnesses. This usage is indicative for the presumable presence of antifungal phytochemicals and inhibitors of xanthine and monoamine oxidases. Plants do not represent the only source for interesting natural products; some endophytes (‘special’ microorganisms living inside the healthy host plant) are also known to produce secondary metabolites of promising pharmaceutical and/or agricultural potential. The above observations prompted us to search for natural antifungal compounds and inhibitors of xanthine and monoamine oxidases in different Chinese plants and endophyte cultures. The active constituents isolated were mainly mono-, sesqui-, di-, and triterpenes, sterols, coumarins, flavonoids, phenylethanoids, stilbenoids, alkaloids and alcohols.