Noreudesmane sesquiterpenoids from the leaves of Nicotiana tabacum.
Six new 14-noreudesmane sesquiterpenoids, nicotabacosides A-F (1-6), along with five known sesquiterpenoids (7-11), were isolated from the leaves of Nicotiana tabacum. The structures of compounds 1-6 were elucidated as isorishitin 3-O-β-D-glucopyranoside (1), rishitin 3-O-β-D-glucopyranoside (2), rishitin 2-O-β-D-glucopyranoside (3), 1, 6-dehydro-rishitin 3-O-β-D-glucopyranoside (4), 2-hydroxyl-ligudentatol 3-O-β-D-glucopyranoside (5) and oxyglutinosone 3-O-β-D-glucopyranoside (6) based on extensive spectroscopic analyses (HRESIMS, UV, IR, 1D and 2D NMR). Their absolute configurations were determined by X-ray single-crystal diffraction and comparison of their electronic circular dichroism (ECD) spectra.
GC/MS analysis of fungitoxic terpenoids from tobacco
Abstract Capsidiol, solavetivone, 3-hydroxysolavetivone, 3-hydroxylubimin, rishitin, epirishitin, glutinosone and oxyglutinosone were isolated from TMV-inoculat
Identification of Dihydroxy Aromatic Compounds in a Low-Temperature Pyrolysis Coal Tar by Gas Chromatography−Mass Spectrometry (GC−MS) and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS)
Dihydroxy aromatics in coal tar undergo rapid coupling reactions with each other and with some coal-derived species during coal pyrolysis and liquefaction. However, only limited information on the structure of dihydroxy aromatics is known. In this study, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and gas chromatography−mass spectrometry (GC−MS) were used to characterize the dihydroxy aromatics in a low-temperature pyrolyzed coal tar and its distillate and residue fractions. Negative-ion electrospray ionization (ESI) FT-ICR MS spectra of coal-tar-derived samples had low molecular masses and narrow mass ranges. Negative-ion ESI is extremely selective for the dihydroxy aromatics present in coal tar. The O2 class species had the highest ion intensity among the species in the negative-ion FT-ICR mass spectrum for each sample. Dihydroxy compounds with an aromatic core structure of benzene, indan, biphenyl (and/or acenaphthene), and naphthalene were identified in the distillate fract...