Studies on Tobacco Lignin

A study was made of such characteristics as infrared and ultraviolet absorption spectra, alkaline nitrobenzene oxidation, elementary composition and constituent groups of tobacco milled wood lignin (Japanese flue-cured and Matsukawa M. W. L.).

Methoxyl contents of mid-rib and stalk M. W. L. were 12.3~13.8% and 16.6~17.0% respectively. Infrared absorption spectra showed that the relation of the absorption intensities between at 1270 cm^?1 and at 1220 cm^?1 of stalk M. W. L. was 1270 cm^?1 < 1220 cm^?1 but, on the contrary, in the case of mid-rib M. W. L., the relation of the intensities was 1270 cm^?1 = 1220 cm^?1. Alkaline nitrobenzene oxidation indicated that the nuclear structures of tobacco M. W. L. were mainly composed of p-hydroxyphenyI and guaiacyl for mid-rib, and the former two and syringyl for stalk.