Macrocyclic Diterpenes. α- and β-4,8,13-Duvatriene-1,3-diols from Tobacco¹

Direct Demonstration of Duvatrienediol Biosynthesis in Glandular Heads of Tobacco Trichomes

“…The major diterpenes of tobacco exudate, the a and , 4,8,13 duvatriene-1,3-diols, (aDVT and (iDVT, respectively) account for a large portion ofsurface leafconstituents (5,17,21). These compounds were first isolated and characterized by Roberts and Rowland (20). While their physiological functions are not established, they are shown to have plant growth inhibitor properties (13).…”

Studies on Leaf Surface Lipid of Tobacco I. Changes in Leaf Surface Lipid and Duvatrienediol during Growth, Senescence and Curing of Tobacco Leaves

“…An interesting fact is that relative ratio of ato p-duvatrienediol did not show appreciable change throughout the curing process, though the purified a-duvatrienediol was much more labile than fi2-duvatrienediol to heat and light. 6 ) …”

Tobacco Cembranoids

“…Die Cembranoide befinden sich in dem gummiartigen Exsudat des Blattes und der Bliite der Tabakpflanze. Sie sind biologischen Abbauprozessen unterworfen und daher fUr die groBe Zahl geruchstragender Norcembranoide im Tabak These two diols [1,2], which have been found in most tobacco varieties (5) and which possess growth inhibiting (2) and insect resistance properties (6), are the major tobacco cembranoids. They are present in the cuticular wax of the leaf and flower and are prone to undergo biodegradation during the post-harvest treatment of the leaf (7) thus offering an explanation for the occurrence of the large number of norcembranoids in tobacco (8).…”

“…A plausible biogenetic route to these triols would involve attack of oxygen on the 11,12 double bond in the 4,6-diols [ 1,2] either by a singlet oxygen reaction, i. e. an ene reaction, or an enzyme-assisted reaction. The ene reaction proceeds, as shown in Scheme 1, by attachment of singlet oxygen to an s# carbon atom, rearrangement of an allylic hydrogen atom and double bond migration.…”

“…A similar mode of reaction has previously been found for acyclic compounds and compounds having other cyclic systems, cyclohexenes being exceptions (13 [21], a compound recently discovered in tobacco (Scheme 5) (2). Its generation evidently occurs by an allylic rearrangement and is analogous to the conversion of the 4R,6R-diol [1] to the 4R,8$-diol ([22], cf. Scheme 13).…”