Elicitation effects of synthetic 1,2,4,5-tetraoxane and 2,5-diphenyltiophene in shoot cultures of two Nepeta species

The present study was aimed to investigate the elicitation possibility of the main secondary metabolites production in Nepeta cataria L. and N. pannonica L. plants, by exposing them to synthetic compounds from the group of tetraoxanes and tiophenes. The effect of DO63 (1,2,4,5-tetraoxane) and DOVF15 (2,5-diphenyl-tiophene) on the production of cis,trans-nepetalactone (NL) and rosmarinic acid (RA) in two Nepeta species, was investigated in shoots grown on culture medium with addition of synthetic compounds in concentrations ranging from 0.1 to 2 mg L-1. The content of targeted metabolites in tested in vitro shoots depended on the type and the concentration of applied synthetic compounds. Application of DO63, primarily in concentration of 0.1 mg L-1 to 1 mg L-1, affected only NL production in both Nepeta species resulting in increased NL content in treated shoots, while production of RA was not influenced. Addition of DOVF15 caused decrease of RA content in N. pannonica shoots and increase in N. cataria shoots, whereas NL production was not affected. The presented results highlight the possibility of DO63 and DOVF15 application for the elicitation of the main secondary metabolites production in species from the genus Nepeta.