Composition of trace alkaloids in tobacco leaf lamina.

Abstract

Changes were investigated in trace alkaloid composition of and leaf lamina during curing. Seventeen alkaloids were identified. The total level of trace alkaloids decreased by approximately 60% in both MC-1 (flue-cured) and Burley-21 (air-cured).Although the level of most alkaloids also decreased, 2,3 /-bipyridyl and four nornicotine derivatives, i.e. N'-hexanoyl-, TV'-octanoyl-, r-(6-hydroxyoctanoyl)-and r-(7-hydroxyoctanoyl)-nornicotine, increased during curing in both varieties. Differences in the trace alkaloid composition of cured leaf lamina among MC-1 (bright), Burley-21 (burley) and Basma (Orient) were also studied. In all varieties, TV'-formylnornicotine, nicotyrine, anabasine and cotinine were present at high concentrations relative to the other trace alkaloids. The alkaloids which were present in a relatively high concentration in particular varieties, were as follows: MC-1; TV'-formylanabasine, Burley-21; TV'-hexanoyl-and TV'-octanoyl-nornicotine, and Basma; cotinine and TV'-formylanatabine.

Enantioselective Demethylation of Nicotine as a Mechanism for Variable Nornicotine Composition in Tobacco Leaf

“…4), was chosen to test the substrate specificities of the three nicotine demethylases. Very low concentrations of methylanabasine can be found naturally in tobacco leaves (27), and this compound can also be formed in tobacco and Nicotiana glauca by aberrant biosynthesis through the feeding of NЈ-methyl-⌬ 1 -piperideinium choride (28). Anabasine was formed from methylanabasine by microsome preparations of yeast expressing CYP82E4, CYP82E5v2, and CYP82E10; product identity was confirmed by GC-MS (supplemental Fig.…”