Biotransformation of menthol and geraniol by hairy root cultures of Anethum graveolens: effect on growth and volatile components

Abstract

Two oxygen-containing monoterpene substrates, menthol or geraniol (25 mg l(-1)), were added to Anethum graveolens hairy root cultures to evaluate the influence of the biotransformation capacity on growth and production of volatile compounds. Growth was assessed by the dissimilation method and by fresh and dry weight measurement. The volatiles were analyzed by GC and GC-MS. The total constitutive volatile component was composed, in more than 50%, by falcarinol (17-52%), apiole (11-24%), palmitic acid (7-16%), linoleic acid (4-9%), myristicin (4-8%) and n-octanal (2-5%). Substrate addition had no negative influence on growth. The relative amount of menthol quickly decreased 48 h after addition, and the biotransformation product menthyl acetate was concomitantly formed. Likewise, the added geraniol quickly decreased over 48 h alongside with the production of the biotransformation products. The added geraniol was biotransformed in 10 new products, the alcohols linalool, alpha-terpineol and citronellol, the aldehydes neral and geranial, the esters citronellyl, neryl and geranyl acetates and linalool and nerol oxides.

Nematotoxic and phytotoxic activity of Satureja montana and Ruta graveolens essential oils on Pinus pinaster shoot cultures and P. pinaster with Bursaphelenchus xylophilus in vitro co-cultures

“…Part of this decrease can be due to volatilization, as this was also detected in controls of EO evaporation and decomposition (carvacrol 95-97% and ␥-terpinene 0.4-0.5%). Nevertheless, since in vitro cultures are known to have biotransformation capacity (Giri et al, 2001;Faria et al, 2009;Nunes et al, 2009), the conversion of ␥-terpinene into a nonvolatile glycosylated form, can also partly explain the difference between ␥-terpinene percentage in S. montana EO and in S. montana EO added cultures (PpiSm). Despite the transference of the shoots to EO-free medium, at the end of phase 3 (recovery time), carvacrol was still detected in high relative amount (19%).…”

Metabolomic Analysis of Methyl Jasmonate-Induced Triterpenoid Production in the Medicinal Herb Centella asiatica (L.) Urban

“…The effects of a number of different elicitors, including yeast extract (YE), cadmium chloride, copper chloride and MeJa have been used to enhance asiaticoside production in cultured whole plants [ 5 , 13 ], with only MeJa and YE being able to significantly stimulate asiaticoside production. Different approaches to modify the biosynthetic pathway have also been carried out, given that the last steps of the biosynthetic pathway for triterpenoid saponins are still unknown [ 14 , 15 ], and are likely to involve enzymes that catalyse reactions such as oxidation and glycosylation [ 16 ]. The most common strategy is feeding plant cell cultures with commercially available or easily extractable metabolic precursors and substrates [ 6 , 17 ].…”

Engineering secondary metabolite production in hairy roots

“…. Anethum graveolens hairy root cultures were studied by Faria et al (2009) for the production of volatile compounds. Menthol was biotransformed into menthyl acetate on addition of two oxygen-containing monoterpene substrates, menthol and geranoil (25 mgl -1 ), 15 days after subculture.…”

“…Menthol was biotransformed into menthyl acetate on addition of two oxygen-containing monoterpene substrates, menthol and geranoil (25 mgl -1 ), 15 days after subculture. Geraniol was biotransformed into 10 new geranyl acetates and, in traces, linalool and nerol oxides (Faria et al, 2009). The biotransformation of exogenous p-hydroxybenzyl alcohol to p-hydroxymethyl-phenolb-D-glucoside (gastrodin) using hairy root cultures of Datura tatula L.was studied by Peng et al (2008).…”