Chunbo Liu

Anti-TMV activity flavones from the leaves of Yunnan local air cured tobacco.

Four new flavones, tobaflavones E-H (1-4), together with two known flavones (5 and 6), were isolated from the leaves of Dali Tiandeng tobacco (a variety of Yunnan local air cured tobacco). Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D NMR techniques. Compound 2 is the first naturally occurring flavone bearing a (4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)methyl moiety. These compounds were also evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results revealed that compounds 1 and 2 exhibited high anti-TMV activity with inhibition rate of 35.3% and 39.6%, respectively. The rates are higher than those of positive control. The other compounds also showed potential anti-TMV activity with inhibition rates in the range of 18.7-28.4%, respectively.

Two new benzolactones from the leaves of Nicotiana tabacum and their anti-tobacco mosaic virus activities.

Abstract Two new benzolactones, 5-methyl-6-prenyl-isobenzofuran-1(3H)-one (1), 5-hydroxymethyl-6-prenyl-isobenzofuran-1(3H)-one (2), together with four known phenolic compounds (3–6), were isolated from the leaves of Nicotiana tabacum. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1–6 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compounds 1–6 exhibited high anti-TMV activities with inhibition rates in the range of 16.9–26.2%, respectively.

Two new sesquiterpenes from the leaves of Nicotiana tabacum and their anti-tobacco mosaic virus activities

Abstract Two new sesquiterpenes, nicotianasesterpenes A and B (1 and 2), together with five known sesquiterpenes (3–7) were isolated from the leaves of Nicotiana tabacum. Their structures were determined mainly by spectroscopic methods, including extensive 1D- and 2D-NMR techniques. The anti-tobacco mosaic virus (anti-TMV) activities of compounds 1–7 were evaluated. The results revealed that compound 1 exhibited high anti-TMV activities with inhibition rates of 33.6%. This rate is high than that of positive control. The other compounds also showed potential activities with inhibition rates in the range of 18.8–28.4%, respectively. Graphical abstract The structures of compounds 1–2.

Three new phenylpropanoids from Lavandula angustifolia and their bioactivities.

Abstract Three new phenylpropanoids, 3-(3,4-dimethoxy-5-methylphenyl)-3-oxopropyl acetate (1), 3-hydroxy-1-(3,4-dimethoxy-5-methylphenyl)propan-1-one (2), and 3-hydroxy-1-(4-methylbenzo[d][1,3]dioxol-6-yl) propan-1-one (3), together with three known phenylpropanoids (4–6) were isolated from the whole plant of Lavandula angustifolia. Their structures were determined by means of HRESIMS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1–6 were tested for their anti-tobacoo mosaic virus (TMV) activities and cytotoxicity activities. The results revealed that compounds 1–3 showed high anti-TMV activity with inhibition rate of 35.2, 38.4 and 33.9%. These rates are higher than that of positive control. The other compounds also showed potential anti-TMV activities with inhibition rates in the range of 26.8–28.9%, respectively. Compounds 1–6 also showed weak inhibitory activities against some tested human tumour cell lines with IC50 values in the range of 3.8–8.8 μM.

Three new isobenzofurans from the roots of Nicotiana Tabacum and their bioactivities

Abstract Three new isobenzofurans (1–3), together with four known phenylpropanoids (4–7) were isolated from the roots of Nicotiana tabacum. Their structures were determined by means of HRESIMS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1–6 were tested for their anti-tobacco mosaic virus (anti-TMV) activities and cytotoxicity activities. The results showed that compounds 5 and 6 exhibited high anti-TMV activities with inhibition rates of 35.1 and 33.4%, respectively. The cytotoxicities of compounds 1–7 against five human tumor cell lines (NB4, A549, SHSY5Y, PC3 were also tested. Compounds 1–7 showed weak inhibitory activities against some tested human tumor cell lines with IC50 values in the range of 3.8–9.6 μM.

Three new benzolactones from Lavandula angustifolia and their bioactivities

Abstract Three new benzolactones (1–3), together with four known ones (4–7), were isolated from the whole herb of Lavandula angustifolia. Their structures were established on the basis of detailed spectroscopic analysis (1D- and 2D-NMR, HRESIMS, UV, and IR) and comparison with data reported in the literature. New compounds were evaluated for their anti-tobacco mosaic virus (TMV) activities and cytotoxic activities. The results revealed that compounds 1–3 showed obvious anti-TMV activities with inhibition rates of 26.9, 30.2, and 28.4%, which were at the same grade as positive control. Compounds 1–3 also showed weak inhibitory activities against some tested human tumor cell lines with IC50 values in the range of 32.1–7.6 μM.

Dihydroxanthenones from the Fermentation Product of the Endophytic Fungus Gliomastix murorum

Two new dihydroxanthones, muroxanthenones D and E (1 and 2), were isolated from the fermentation products of the endophytic fungus Gliomastix murorum. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were tested for their anti-tobacco mosaic virus (anti-TMV) activity, and they exhibited activity with inhibition rates of 16.4 and 15.3%, respectively.

Coumarins from the Leaves of Nicotiana tabacum and Their Anti-Tobacco Mosaic Virus Activities

Two new coumarins, 6-hydroxy-7-methyl-3-(4′-methoxyphenyl)-coumarin (1) and 6-hydroxy-5-methoxy-7-methyl-3-(4′-methoxyphenyl)-coumarin (2), together with five known coumarins (3–7), were isolated from the leaves of Nicotiana tabacum. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1–7 were tested for their anti-tobacco mosaic virus (anti-TMV) activities. Compound 2 showed high anti-TMV activity with inhibition rate of 28.6%. This rate is close to that of the positive control. The other compounds also showed potential anti-TMV activity with inhibition rates in the ranges of 13.7–23.2%, respectively.

Furan-2-Carboxylic Acids from the Roots of Nicotiana tabacum and their Bioactivities

Two new furan-2-carboxylic acids, 5-(3-hydroxy-5-(hydroxymethyl)-4-methoxyphenyl)-3-methylfuran-2-carboxylic acid (1) and 5-(4-hydroxy-5-methoxy-2-methylphenyl)-3-methylfuran-2-carboxylic acid (2), together with two known furan-2-carboxylic acids (3 and 4) were isolated from the roots of Nicotiana tabacum. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1 and 2 were tested for their anti-tobacco mosaic virus (TMV) and cytotoxicity activities. The results revealed that compounds 1 and 2 showed high anti-TMV activity with inhibition rate of 35.8 and 32.6%. These rates are close to that of positive control. Compounds 1 and 2 also showed moderate to weak inhibitory activities against some tested human tumor cell lines with IC50 values in the range of 1.5–6.0 μM.

Two New Benzolactones from the Leaves of Yunnan Local Sun Cured Tobacco and Their Bioactivities

Two new benzolactones, 4-methoxy-6-(2-oxopropyl)isobenzofuran-1(3H)-one (1) and 4-methyl-6-(2-oxopropyl)isobenzofuran-1(3H)-one (2), were isolated from the leaves of Yunnan local sun cured tobacco. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1 and 2 were tested for their anti-tobacoo mosaic virus (TMV) activities and cytotoxicity activities. The results revealed that compounds 1 and 2 showed high anti-TMV activity with inhibition rates of 32.6 and 30.2%. These rates are close to that of positive control. Compounds 1 and 2 also showed weak inhibitory activities against some tested human tumor cell lines.