A Validated Method for Gas Chromatographic Analysis of γ-Aminobutyric Acid in Tall Fescue Herbage

Abstract

Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter in animals that is also found in plants and has been associated with plant responses to stress. A simple and relatively rapid method of GABA separation and quantification was developed from a commercially available kit for serum amino acids (Phenomenex EZ:faast) and validated for tall fescue (Festuca arundinacea). Extraction in ethanol/water (80:20, v/v) at ambient temperature yielded detectable amounts of GABA. Clean separation from other amino acids in 28 min was achieved by gas chromatography (GC) with flame ionization detection (FID), using a 30 m, 5% phenyl/95% dimethylpolysiloxane column. The identity of the putative GABA peak was confirmed by GC with mass spectrometric (MS) detection. The relatively small effects of the sample matrix on GABA measurement were verified by demonstrating slope parallelism of GABA curves prepared in the presence and absence of fescue extracts. Limits of quantification and detection were 2.00 and 1.00 nmol/100 microL, respectively. Method recoveries at two different spike levels were 96.4 and 94.2%, with coefficients of variation of 7.3 and 7.2%, respectively.

Identification, Expression and Preliminary Characterization of a Recombinant Bifunctional Enzyme of Photobacterium damselae subsp. piscicida with Glutamate Decarboxylase/Transaminase Activity

“…In Saccharomyces cerevisiae, GAD is required for normal oxidative stress tolerance [7]. In plants, GABA accumulation has been reported in response to stress conditions such as anoxia, decreasing cellular pH, temperature changes, mechanical handling, and pathogen infections, and it has been associated with plant growth response [5,8]. Furthermore, in plants and microbes, GABA is an important intermediate of the GABA shunt, the metabolic pathway that converts glutamate to succinate, directing the carbon atoms into the Krebs cycle [9].…”

Electrochemical sensor of 4-aminobutyric acid based on molecularly imprinted electropolymer

“…1 It has been suggested that it is involved in the cortical reorganization that follows a limited sensory deprivation. [2][3][4][5] Several techniques, such as magnetic resonance spectrometry, 6 electroanalysis, 7 fluorescence, 8 spectrophotometric, 9 capillary electrophoresis, 10 gas 11,12 and liquid chromatography, 13,14 have been developed for the determination of 4-ABA. The most common method employed for the determination of 4-ABA is liquid chromatography.…”