Effect of light on contents of coumarin compounds in shoots of Ruta graveolens L. cultivated in vitro

Shoots of Ruta graveolens L. (Rutaceae) were cultivated in stationary liquid culture under different light conditions: constant artificial light (900 lx), darkness, constant artificial light (900 ix) following irradiation with UV-C light. The contents of five furanocoumarins: psoralen, bergapten, xanthotoxin, isopimpinellin and imperatorin, as well as biogenetic precursor of these metabolites, umbelliferone, were determined by HPLC method in shoots cultivated in vitro and in overground parts of plants growing in open air. It was shown that light conditions, tested in these experiments, significantly influenced contents of the metabolites in shoots cultivated in in vitro culture. Total content of the coumarin compounds in shoots cultivated under constant artificial light (900 lx) was equal or higher than in plants growing under natural conditions. Therefore, it is suggested that stationary liquid shoot culture of R. graveolens. can be an alternative source for obtaining biologically active furanocoumarins