Production of verbascoside and phenolic acids in biomass of Verbena officinalis L. (vervain) cultured under different in vitro conditions
Methanolic extracts from the biomass of Verbena officinalis cultured under continuous artificial light and in darkness on 12 variants of the Murashige and Skoog medium containing different concentrations (0.5–3.0 mg/L) of plant growth regulators: 6-benzyladenine, kinetin, 1-naphthaleneacetic acid and indole-3-butyric acid, were analysed for the amounts of verbascoside and phenolic acids, before and after acid hydrolysis, using the HPLC-DAD method. The amounts of verbascoside were very high (max. 2454.12 mg/100 g DW – light, and 2135.59 mg/100 g DW – darkness). The total amounts of phenolic acids reached a maximum of 46.02 mg/100 g DW (free phenolic acids) and 141.05 mg/100 g DW (bound compounds). The main metabolites were: ferulic, o-coumaric and caffeic acids. The maximum amount of verbascoside was 3.28 times higher than in extracts from the herb of the parent plant. The cultures could be proposed as a potential biotechnological source for selected biologically active compounds.