Zhi-Hua Liu

Aspergillines A–E, Highly Oxygenated Hexacyclic Indole–Tetrahydrofuran–Tetramic Acid Derivatives from Aspergillus versicolor

Aspergillines A-E (1-5) are highly oxygenated cyclopiazonic acid (CPA)-derived alkaloids bearing a rigid and sterically congested hexacyclic indole-tetrahydrofuran-tetramate scaffold, isolated from the endophytic fungus Aspergillus vesicolor. Apergillines A-C represent a new subclass of CPA-derived alkaloids, and aspergillines B and E possess a butanoic acid methyl ester moiety. The structures, including absolute configuration, were elucidated by interpretation of the NMR, X-ray crystallographic, and circular dichroism data. All compounds displayed anti-TMV and cytotoxic activities.

Antiviral sesquiterpenes from leaves of Nicotiana tabacum

Three unreported sesquiterpenes possessing two new skeletons, tabasesquiterpenes A-C (1-3), together with three known sesquiterpenes (3-6) were isolated from the leaves of Nicotiana tabacum. Their structures were determined mainly 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 compound 2 exhibited high anti-TMV activity with inhibition rate of 35.2%, which were higher than that of positive control (ningnanmycin). The other compounds also showed potential anti-TMV activity with inhibition rates in the range of 20.5-28.6%.

(+)-Meyeniins A–C, Novel Hexahydroimidazo[1,5-c]thiazole Derivatives from the Tubers of Lepidium meyenii: Complete Structural Elucidation by Biomimetic Synthesis and Racemic Crystallization

(+)-Meyeniins A-C (1-3), a novel class of sulfur-containing hexahydroimidazo[1,5-c]thiazole derivatives, were isolated from the tubers of Lepidium meyenii (maca) cultivated in Lijiang, Yunnan province, China. Guided by their biosynthetic hypothesis, a stereocontrolled biomimetic synthesis of meyeniins A-C and their individual enantiomers was efficiently accomplished by a combination of a condensation reaction and Edman degradation. The formation of high-quality crystals for X-ray crystallography occurred much more readily from a racemic mixture of (±)-meyeniin A than with the single enantiomer alone in this case. These extensive strategies, combined with circular dichroism (CD) spectra, allowed the complete structural assignments of (+)-meyeniins A-C. Among them, (+)-meyeniin A showed moderate selective cytotoxicities against the HL-60, A549 and MCF-7 human cell lines with IC50 values of 14.41, 32.22, and 33.14 μM, respectively. To some extent, these findings support traditional applications of maca as healthy nutritional supplements or functional foods for cancer prevention.

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.

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.

Isopentylated diphenyl ether derivatives from the fermentation products of an endophytic fungus Phomopsis fukushii

Three new isopentylated diphenyl ethers, (1–3), together with two known isopentylated diphenyl ethers derivatives (4 and 5) were isolated from the fermentation products of an endophytic fungus Phomopsis fukushii. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D NMR techniques. Compounds 1–3 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results showed that compounds 1–3 showed strong activity with diameter of inhibition zone (IZD) of 21.8 ± 2.4 mm, 16.8 ± 2.2 mm, and 15.6 ± 2.0 mm, respectively.