Prenylflavonoids

Prenylflavonoids are secondary metabolites found in numerous plants. Due to their antioxidant effect, they are of great interest for pharmaceutical research. Typical for the flavonoid group is their basic molecular framework consisting of a three-ring structure in which a benzene ring is bound to a pyrone or pyrone ring which is substituted with a phenyl ring. Due to its hydrophobicity, the prenyl group (3-methylbut-2-en-1-yl) contributes to the improved bioavailability of prenyl flavonoids, which are excreted much more slowly than unsubstituted flavonoids. The increased lipophilicity of the molecule favors binding to biological membranes, which makes prenylflavonoids promising drug candidates.

Prenylflavonoids are mainly found in plants from the Leguminosae (legume) and Moraceae (mulberry) families. The genus Morus (mulberry) is one of the richest sources of prenylflavonoids. Mulberry plants have been used for many centuries in traditional systems of medicine, e.g. Ayurveda, Unani and Traditional Chinese Medicine. Extracts of root and branch bark as well as the leaves are said to have anti-inflammatory, diaphoretic and soothing effects. They are traditionally used to treat inflammation, fever, liver damage and diabetes. The antioxidant, anti-inflammatory and hypoglycemic effects of mulberry recipes have also been widely documented in modern scientific studies. Mulberry recipes are also used as a so-called 'nutraceutical' (from 'nutrition' and 'pharmaceutical'), i.e. as a medically effective dietary supplement.

Among the best-studied prenlyflavonoids in mulberry plants are mulberrin and its cyclized form morusin. At the Chair of Analytical Food Chemistry we develop stable isotope dilution analyses for these analytes and quantify them in different mulberry samples. Open-chain prenylflavonoids, such as xanthohumol fround in hops are also studied in our research.