Specialized metabolites degradation by microorganisms.

Secondary metabolites are specialized metabolic products synthesized by plants, insects, and bacteria, some of which exhibit significant physiological activities against other organisms. Plants containing bioactive secondary metabolites have been used in traditional medicine for centuries. In developed countries, one-fourth of medicines directly contain plant-derived compounds or indirectly contain them via semi-synthesis. These compounds have contributed considerably to the development of not only medicine but also molecular biology. Moreover, the biosynthesis of these physiologically active secondary metabolites has attracted substantial interest and has been extensively studied. However, in many cases, the degradation mechanisms of these secondary metabolites remain unclear. In this review, some unique microbial degradation pathways for lignans and C-glycosides are explored.