In vitro elicitation of anthraquinones—a review.

Anthraquinones (AQs) are potent secondary metabolites distributed among plants with a multitude of bioactivities and therapeutic applications. They are most commonly present in the Rubiaceae, Leguminosae, and Polygonaceae families. At present, globally many anthraquinone-formulated products are synthesized on a commercial scale as dietary supplements and their global demand in the market is significantly increasing day by day. The synthesis of AQs in plants depends on various physiological conditions. Hence, in vitro cultures are considered as an alternative source to produce the compounds with limited availability of explants, independent of environmental conditions. Moreover, the synthesis of anthraquinones from in vitro callus, cell suspension, and organ cultures using biotechnological strategies such as the feeding of precursor or elicitors could eventually enhance the anthraquinone yield. This review, highlights the different plant sources, biosynthesis, in vitro plant cells, organ cultures, elicitation strategies, metabolic engineering, and bioreactors for enhancing anthraquinone production. [ABSTRACT FROM AUTHOR]