Ruta graveolens L.: a promising species for the production of furanocoumarins

Psoralen and its derivatives (linear furanocoumarins) are used in dermatolo gy, and are also very promising in the treatment of other diseases. These s econdary metabolites occur naturally in plants. Ruta chalepensis, R. angust ifolia, R. graveolens and R. montana (Rutaceae) have been studied to evalua te their potential for the production of furanocoumarins (psoralen, xanthot oxin, bergapten, isopimpinellin). The Ruta species contained from 4 to 17 m g g(-1) dry weight (DW) of furanocoumarins (FCs). These concentrations were higher than those found in other families known to produce the same compou nds (Moraceae, Apiacae and Fabaceae). Among the four species tested, R. gra veolens exhibited high concentrations of FCs and the best biomass productio n. Sixteen different R. graveolens origins were cultivated in order to find the best candidate for FC production. Plants contained an average concentr ation of 10 mg g(-1) DW of FCs, ranging from 2.8 to 17.5 mg g(-1) DW, but t here was no;statistical difference due to origins. FCs allocation was studi ed within R. graveolens in different parts of the plant. Fruits had a great er FCs concentration, five-tenfold higher than roots, stems or leaves. Isop impinellin, a minor FC in other organs, was highly concentrated in roots, w here it reached 25% of the total FCs. Potential yield of FCs is the result of both biomass and secondary metabolite production. These parameters were affected by the phenological stage of plants, with greatest production from fruits, which had the highest concentrations, biomass and therefore yield of FCs. R. graveolens plants cultivated in field could possibly produce 12 kg of FCs per hectare, mainly in fruits and leaves. (C) 2001 Elsevier Scien ce Ireland Ltd. All rights reserved.