On the Chemical Properties of the Flavon-derivative Contained Tobacco Leaves with Special Referrence to the Colour and Qualities of Cured Leaves

Abstract

1) The most important character for grading a cured tobacco leaf is its colour.
2) According to the traditional opinion the colouration of cured tabacco leaves is due to phlobaphene, which is derived from oxydation of tannine by the action of oxydase (O. Loew: Ztbl. Bakt. 2te Abt. VI. 108, 673, 1900).
3) It was now proved that a flavon-derivative is contained always in fresh tobacco leaves and also in nearly all kinds of cured tobacco leaves.
4) The flavon-derivative extracted from fresh tobacco leaves was identi-fied with quercetin-rhamno-glucoside “Rutin (C₂₇H₃₂O₁₆·2H₂O)” on the ground of several physical and chemical properties.
5) The colour-change of the ordinary Japanese tobacco during its curing process may be divided practically into four stages, i. e.