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.