13C CPMAS NMR of Bright and Burley Tobaccos

13C CPMAS NMR spectra were obtained of the leaf laminae and stems of cured bright and burley tobaccos. The solid phase NMR spectra of some of the most abundant tobacco components were also obtained, including cellulose, hemicellulose, and pectin (each isolated from tobacco), calcium and potassium salts of malic and citric acid, calcium oxalate, rutin, chlorogenic acid, and nicotine (in the form of a crystalline ditartrate salt). The tobacco spectra have been interpreted in light of these reference materials, as well as the chemical analyses of similar samples. Multiple cross-polarization contact times, interrupted decoupling, and single-pulse excitation were employed to improve the discrimination between overlapping resonances, to reveal new spectral features, and to detect tobacco components obscured by the complexity of the spectra. These alternative pulse experiments permitted the selective detection of microscopic calcium oxalate crystals, solanesol and other mobile waxes, nicotine, citrate, and fructose