Menthol and geraniol biotransformation and glycosylation capacity of Levisticum officinale hairy roots

The biotransformation capacity of Levisticum officinale hairy roots cultures was studied by evaluating the effect of the addition of 25mg.l^-1 menthol or geraniol in the morphology, growth and volatiles production. L. officinale hairy root cultures were maintained for 7 weeks in SH medium [1], in darkness at 24°C and 80r.p.m. and the monoterpenes were added 15 days after inoculation. Growth was evaluated by measurement of the fresh and dry weight and by the dissimilation method [2]. The volatiles were isolated by distillation-extraction using a Likens-Nickerson type apparatus, and analyzed by GC and GC-MS. Glycosidic bound volatiles were evaluated by the method of Baerheim Svendsen and Merkx [3].

The hairy root morphology and growth were not influenced by substrate addition. No new volatiles were detected after menthol addition and, like the control cultures, the volatiles of these hairy roots were dominated by Z-falcarinol (1–45%), n-octanal (3–8%) and Z-ligustilide (2–9%). The addition of geraniol induced the production of 6 new volatiles, linalool (0.1–1.2%), α-terpineol (0.2–3%), nerol/citronellol/neral (traces-15%) and geranyl acetate (traces-2%). The relative amounts of the substrates and some of its biotransformation products decreased during the course of the experiment.

The analysis of the extracted volatiles, after the addition of β-glycosidase to the remaining distillation water, showed that lovage hairy roots were able to convert both substrates and their biotransformation products into the glycosidic forms.

References: 1. Schenk, U.R., Hildebrandt, A.C. (1972) Can. J. Bot. 50: 199–204

2. Schripsema, J. et al. (1990) Plant Cell Tiss. Org. Cult. 22: 55–64.

3. Baerheim Svendsen, A., Merkx, I.J.M. (1989) Planta Med. 55: 38–40.