As an important agricultural product, cigar tobacco lacks reports on chemical compositions. The investigation on characteristic components of Yunnan local cigar tobacco revealed 15 Cembrane-type diterpenes including nine undescribed ones (1-9). Their structures were elucidated on the basis of extensive spectroscopic analysis, computational calculations, and X-ray diffraction. The skeleton of Cigarcembrane (1) with a new 6/12-ring system was previously undescribed. This is the first time to report eunicellane (2-7) and gersemiane (8-9) skeletons from plant resources. The transformation mechanism of cigarcembrane, eunicellane, and gersemiane from Cembrane during cigar fermentation was postulated. Chromatographic analysis revealed 10 as a marker for cigars. All the isolated compounds showed the promotion of hOMF cell proliferation, enlightening us to seek lead compounds in mouth care.
Keywords: cembrane; characteristic component; cigar tobacco; cigarcembrane; eunicellane; gersemiane; marker; mouth care.