Helenalin Acetate in in vitro Propagated Plants of Arnica montana.

Propagated "IN VITRO" shoots and plantlets of ARNICA MONTANA L. (Asteraceae) have been shown to produce sesquiterpene lactones, i.e. helenalin and 11,13-dihydrohelenalin esters. The compounds were detected in green organs only; roots of the plantlets contained no sesquiterpene lactones. The helenalin acetate content in leaves of the plantlets (0.073% dry wt) was 4-times higher than in proliferated shoots (0.016% dry wt). The best rate of shoot multiplication was achieved on MS medium, supplemented with NAA 0.5mg/l and Kn 2.5 mg/l (formation of 22 shoots within 8 weeks).