Determination of Perillic Acid in Bioconversion Supernatants by Gas Chromatography ()
ABSTRACT
Perillic
acid can be obtained from microbial oxidation of the exocyclic methyl group of
limonene. Due to the pharmacological potential of such a metabolite, the
biotransformation processes leading to its synthesis have been approached in recent studies. A robust
analytical method is needed to assess the performance of such studies. An
analytical method was developed and validated to determine perillic acid in the
supernatants of a yeast-induced bioconversion of limonene, involving gas
chromatography (GC) and an acid-induced precipitation during the sample
preparation. GC analysis was performed using a column with polyethylene glycol
as stationary phase (HP-Innowax) which resulted in higher loads and better peak
shape. The sample preparation involved the supernatant initial filtration and
precipitation with 0.6 M HCl followed by centrifugation and dissolution in
ethyl acetate. GC analysis conditions were oven from 50°C to 250°C at 20°C·min-1, and then
held 5 min (total runtime 15 min). Injector was set at 280°C, and detector at 300°C.
Helium was the carrier gas at 1 ml·min-1.
Injections of 1.0 μl were at the
split ratio 25:1. The method was validated: Linearity with R2 of
0.9992, Accuracy of 98.3% in the range 190 - 950 μg·ml-1; Limit
of detection of 10.4 μg·ml-1; Repeatability
of 2.1% RSD. Thus, a complete methodology to determine perillic acid in a
bioconversion supernatant was developed and validated. This overall approach
may be useful for bioconversions of monoterpenes by other microorganisms that
metabolize limonene.
Share and Cite:
Carvalho, E. , Siani, A. , Cardoso, I. , Correia, V. , Ferrara, M. , Bon, E. and Tappin, M. (2017) Determination of Perillic Acid in Bioconversion Supernatants by Gas Chromatography.
American Journal of Analytical Chemistry,
8, 636-644. doi:
10.4236/ajac.2017.810046.