Insight into the Characteristic Components of Cigar Tobacco.

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 (-). Their structures were elucidated on the basis of extensive spectroscopic analysis, computational calculations, and X-ray diffraction.

Ionones from cigar tobacco leaves.

Phytochemical studies on cigar tobacco leaves led to the isolation of 18 ionone-type compounds, including previously undescribed cigatobanes E () and F (). Additionally, compounds vomifoliol acetate (, dehydrovomifoliol (, 8,9-dihydromegastigmane-4,6-diene-3-one (, 7,8-epoxyblumenol B (, 3-oxoactinidol (), and loliolide acetate (), 4-hydroxy-dihydroactinidiolide (), were found in tobacco leaves for the first time. The structural elucidation of all compounds was accomplished through rigorous spectral analysis.

Sesquiterpenoids from cigar tobacco leaves.

Phytochemical investigation on cigar tobacco leaves led to four unknown sesquiterpenoids as well as nine reported ones. Among of them, 3-acetoxy--damascone was first found in tobacco leaves. All the structures were elucidated by intensive spectroscopic analyses and X-ray diffraction.

Extraction and characterization of anti-virus anthraquinones from Nicotiana tabacum-derived Aspergillus oryzae YNCA1220.

In this study, seven novel anthraquinones (1-7) and four described anthraquinones (8-11) were purified from Nicotiana tabacum-derived Aspergillus oryzae YNCA1220. It is worth noting that only analogs of 4 and 5 have been reported as natural products to date, while the nuclei of compounds 1-3, 6 and 7 were isolated for the first time in nature. Among them, compounds 1-3 bear an unusual anthra[2,3-b]furan-9,10-dione nucleus, 4 and 5 possess a rare 3-methyl-1H-pyrrol-2-yl substituent, and 6 and 7 are new framework anthraquinones bearing a 6-methyl-1,7-dihydro-2H-azepin-2-one ring.

Three novel xanthones from Garcinia paucinervis and their anti-TMV activity.

Phytochemical investigations of the leaves of Garcinia paucinervis resulted in the isolation of three new xanthones 1-3 and five known analogues 4-8. Structural elucidations of 1-3 were performed by spectral methods such as 1D and 2D (HMQC, HMBC, and ROESY) NMR spectroscopy, in addition to high resolution mass spectrometry. Compounds 1-3 showed anti-TMV activities, with inhibition rates above 20%, especially for 1, which had a lower IC₅₀ value of 21.