Abstract
Quinic acid [D(-)-quinic acid, (1S, 3R,4S,5R)-1,3,4,5-tetrahydroxycyclohexanecarboxylic acid], and inositol [myoinositol, (1R,2R,3S,4S,5R,6S-cyclohexane-1,2,3,4,5,6-hexol or cis-1,2,3,5-trans-4,6-cyclohexane-hexol] are oxygenated compounds well known as tobacco constituents. Although mentioned in the literature as constituents of tobacco leaf as early as 1930, very little information is offered regarding the quantitation of quinic acid and inositol, up to the present day. This study describes a simple procedure for the analysis of quinic acid and myo-inositol in tobacco and reports the levels of these two analytes in various single grade and blended tobaccos from commercial and Kentucky reference cigarettes. The procedure is based on an original LC/MS/MS analysis of the tobacco extract. This method and its validation are described in this paper.
A wide range of levels of the analytes was observed from sample to sample. Burley samples were in general low in both quinic acid and inositol compared to flue-cured tobaccos. The levels of myo-inositol detected in the analyzed samples were consistent with previously reported results for flue-cured tobaccos, but significantly lower than those reported for Burley. Besides myo-inositol, a number of naturally occurring stereoisomers of inositol are known. These include scyllo-, muco-, D-chiro- and neo-inositol. Other isomers are possible, including L-chiro-, allo-, epiand cis-inositol, but they are less common. No previous study has been reported regarding the evaluation of these compounds in tobacco, and the present study indicated that only myo-inositol and D(-)-quinic acid are found in tobacco.