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.
New isolates from leaves of Nicotiana tabacum and their biological activities
Abstract Three new isolates (1−3) including one new sterol and two new flavonoids together with three known sterols (4−6) were isolated from the leaves of Nicotiana tabacum. Their structures were determined mainly by spectroscopic methods, including extensive 1D and 2D NMR techniques. All compounds were evaluated for their anti-tobacco mosaic virus and cytotoxic activities. The results showed that compounds 2 and 3 exhibited high anti-TMV activity with inhibition rate of 34.2 and 33.4%, respectively, which were roughly equivalent to that of positive control. The cytotoxicities of compounds 1 and 4–6 against five human tumour cell lines were also tested, and tested compounds showed weak inhibitory activities against some tested human tumour cell lines.
Sesquiterpenoid stress compounds from Nicotiana species
Abstract Solavetivone, 3-hydroxysolavetivone, solanascone, phytuberin and phytuberol were identified as stress compounds in leaves of Nicotiana tabacum cv Samsun NN. N. sylvestris , which is the maternal progenitor of N. tabacum , produced all the above compounds except 3-hydroxysolavetivone. In the F 1 , hybrid of N. tabacum and N. glutinosa , all the stress compounds produced by N. tabacum and N. glutinosa , respectively, were accumulated.