Tobacco Cembranoids

Abstract

The discovery of the first diterpenoids of the cembrane type in tobacco dates back to the early 1960's. Since then some forty tobacco cembranoids have been encountered. Most of these have a hydroxyl substituent at C-4 and are commonly divided into two series: those having a 4R- and those having a 4S-configuration. Additional oxygenation is found at C-6, C-7, C-8, C-11 or C-12. These compounds, which are present in the gummy exudate of the tobacco leaf and flower, are susceptible to biodegradation thus accounting for the presence of the large number of odoriferous norcembranoids in tobacco. They are also reported to include representatives having growth inhibiting and insect resistance properties. A considerable insight into the biological transformations of the tobacco cembranoids has been obtained by isolation and determination of the stereostructures of new compounds and by biomimetic experiments. The latter have involved singlet oxygen reactions, epoxidations and acid- and base-induced rearrangements. The results obtained support the importance of the (1S,2 E,4R,6R,7E,11 E)- and (1 S,2 E,4 S,6R,7 E,11 E)-2,7,11-cembratriene-4,6-diols, the major tobacco cembranoids, as key metabolites in the biogenesis of the other cembranic compounds. An account of these biogenetic reactions will be given and the isolation of a few new cembranoids will be reported.

(1S,2E,4S,7E,11E)-2,7,11-Cembratriene-4,6-diol semisynthetic analogs as novel c-Met inhibitors for the control of c-Met-dependent breast malignancies

“…The chemical identity of 1 was confirmed by NMR spectroscopic analysis and comparing with literature. 3–5 …”

“…Isoprenoids are biosynthesized in the glandular heads of trichomes covering tobacco leaves and flowers and extensively present in the gummy exudates. 3,4 The tobacco isoprenoid family comprises three major classes, carotenoids, labdanoids and cembranoids. The 14-membered macrocyclic diterpene cembranoids have been granted much attention due to their biological activities.…”

Draft Genome Sequence of Novosphingobium sp. Strain HII-3, a Bacterium Capable of Degrading the Cembranoid α(β)-2,7,11-Cembratriene-4,6-Diol to Farnesal

“…Cembranoids have many important bioactivities, including antimicrobial, antitumor, and neuroprotective activities ( 5 – 7 ). In some circumstances, cembranoids can be converted to solanone, which can be further transformed into useful flavor compounds, such as norsolandione, solanofuran, solanic acid, and others ( 8 ). α(β)-2,7,11-Cembratriene-4,6-diol is the largest and most important type of cembranoid.…”

Quantitative analysis of cembranoids in tobacco leaf by using heart‐cutting two‐dimensional liquid chromatography

“…Discovery of cembranoids in tobacco trace back to 1960s . Substantial amounts of cembranoids could be found in the cuticlular wax of the most tobacco leaf varieties.…”