Gas-Liquid Chromatography and Mass Spectrometry of Quinoxalines Derived from Various Homoglucans by Alkaline o-Phenylenediamine Method

Abstract

Quinoxalines derived from various homoglucans by the alkaline OPD method were subjected to GLC and GC-MS analyses.
The main quinoxalines derived from amylose and curdlan were identified as 2-hydroxymethyl-3-(2', 3'-dihydroxypropyl) quinoxaline (M- 1) and 2-(2', 3', 4'-trihydroxybutyl) quinoxaline (G-1), respectively, using a 2% OV-210 column after trimethylsilylation. Two quinoxalines M-1 and G-1 were formed from barley glucan and lichenan, and the approximate molar ratios of the 1, 4- to 1, 3-linkage in both glucans were estimated to be 1.6 and 2.2, respectively. From scleroglucan, G-1 and 2-(2', 3'-dihydroxy-4'-D-glucopyranosyl) quinoxaline were produced, reflecting a 1, 3- and branched 1, 6-linkage in the glucan. The ratios of the 1, 4- to 1, 3-linkage of barley glucan and lichenan, or the 1, 6- to 1, 3-linkage of scleroglucan estimated from the formed quinoxalines were in accordance with those obtained by conventional methylation analysis.