Search

In previous studies, several isoindolin-1-one analogs that exhibited significant anti-tobacco mosaic virus (anti-TMV) activities were isolated from Nicotiana tabacum. Since gene-editing mutants provide a new sample for the discovery of active metabolites, we focused on the stems of YN-18-23 (a mutant N. tabacum for gene editing with the alkaloid metabolic pathway cultivated by Yunnan Tobacco Company), which led to the isolation of four new (1-4) and four known (5-8) isoindolin-1-ones. To the best of our knowledge, nicindole C (3) is the first subclass of isoindolin-1-one bearing a pentacyclic ketone, while nicindole D (4) is the first example of isoindolin-1-one bearing a methyl-pyridin-2-(1H)-one moiety. Compounds 1-4 were tested for their anti-TMV activities, and the results revealed that compounds 1, 3, and 4 exhibited high anti-TMV activities at concentrations of 20 μM with inhibition rates of 48.6, 42.8, and 71.5%, respectively. These rates are higher than the inhibition rate of the positive control (33.2%). The mechanistic study of compound 4, which had the highest anti-TMV activity revealed that increased potentiation of defense-related enzyme activities and downregulation of expression of the NtHsp70 protein may induce resistance in tobacco against the viral pathogen TMV. Molecular docking studies also revealed that the isoindolin-1-one substructure is fundamental for anti-TMV activity. The methyl-pyridin-2-(1H)-one moiety in compound 4 and the 2-oxopropyl groups in compounds 1 and 3 at the N-2 position may increase inhibitory activities. This study of the structure-activity relationship is helpful for finding new anti-TMV activity inhibitors. To study whether the isoindolin-1-ones have broader antiviral activities, compounds 1-4 were also tested for their anti-rotavirus activities. Compound 4 exhibited high anti-rotavirus activity with a therapeutic index (TI) value of 20.7. This TI value is close to that of the positive control (20.2).

The structural derivatization of the fungal meroditerpenoid chevalone E was achieved by biocatalytic and chemical approaches. Some of the new chevalone analogues, in combination with doxorubicin, synergistically inhibit the growth of breast cancer cells.

Eight phenolic compounds (1–8), including two new compounds (1 and 2), were isolated from the twigs of Gardenia jasminoides. Their structures were determined by means of extensive 1D and 2D NMR spectroscopic studies. Compounds 1–4 were tested for their antimethicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results revealed that compounds 1–4 showed good inhibition with IZD of 12.2 ± 2.2, 13.8 ± 2.4, 15.2 ± 2.8, and 12.9 ± 2.5 mm, respectively.

Two new isobenzofuranone derivatives (1 and 2) together with six known compounds (3–8) were isolated from the roots of Phlomis betonicoides, a highly sweet plant in China. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1–8 were tested for their anti-rotavirus activity. The results showed that compounds 1–8 exhibited potent anti-rotavirus activity with therapeutic index value 7.5–16.4.

Three new anthraquinones (1–3), together with four known analogues (4–7) were isolated from the twigs of Cassia auriculata Linn.. Their structures were elucidated by extensive spectroscopic analysis and comparison of spectroscopic data with those reported in literatures. All compounds were tested for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. Compounds 1, 2 and 7 showed modest antibacterial activity against MRSA with MIC values of 4.2, 5.0, 4.7 μg/mL, and compounds 3, 4, 5 and 6 showed weak antibacterial activity against MRSA with MIC valves of 9.2, 7.6, 7.1, 9.6 μg/mL, respectively.

Background Since Nicotiana tabacum (tobacco) has important significance to humans for their medicinal uses, to find antivirus activities inhibitors from tobacco, increase its medicinal value, and comprehensive utilization of its by-products, our group had investigated the chemical constituents of the stems of Y-202, a cultivar of tobacco which high resistance to tobacco mosaic virus (TMV). Results Four new isoindolinone-type alkaloids, nicoisoindoles A–D (1–4), along with four known isoindole derivatives (5–8) were isolated. Compounds 1–4 represent a new subclass of isoindolinone alkaloids with rare cyclopenta[f]isoindole-1-one frameworks. Among them, nicoisoindole C (3) possesses an unusual N-2-(5-methoxy-6-methylpyridin-2-yl) ethyl moiety, while nicoisoindole D (4) has a novel a N-(3-methyl-6-oxo-1,6-dihydropyridin-2-yl)methyl substituent. Interestingly, compounds 1, 3, and 4 showed high anti-TMV activities with inhibition rates of 43.8%, 58.8%, and 67.8% at the concentration of 20 μM, and IC50 values of 23.6, 19.5 and 15.4 μM, respectively, even more potent than that of positive control. Conclusions The successful isolation and structure identification of new oxocyclopenta[f]isoindole-1-ones provide materials for the screening of antivirus activities inhibitors, and contribute to the development and utilization of the waste from tobacco cultivation. Graphical Abstract

Three new isochromenes, (5-methoxy-7-prenyl-1

Two new (1 and 2) compounds, together with five known (3–7) chromone derivatives, were isolated from the whole plants of Cassia pumila. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1–7 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results revealed that compounds 1, 2, 5, and 6 showed good inhibition with IZD of 13.4 ± 2.5, 12.2 ± 2.0, 14.6 ± 2.2, and 14.2 ± 2.6 mm, and compounds 3, 4, and 7 showed weak inhibition with IZD of 10.7 ± 2.2, 11.3 ± 2.0, and 10.8 ± 2.1 mm, respectively.

Two new compounds (1 and 2), together with five known (3–7) stilbene derivatives, were isolated from the leaves and stems of Bletilla striata. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were evaluated for their cytotoxicity against five human tumor cell lines. Compound 1 showed cytotoxicity against SHSY5Y and MCF7 cells with IC50 values of 2.8 and 2.2 μM. Compound 2 showed cytotoxicity against SHSY5Y and MCF7 cells with IC50 values of 2.2 and 2.4 μM, respectively. Moreover, compound 1 was found to trigger both apoptosis and autophagy in Hela cells, as indicated by increased cleaved PARP and LC3B, respectively. The enhanced autophagy induced by compound 1 was further confirmed by imaging detection of more autophagosomes (mRFP–GFP–LC3+ puncta) and autolysosomes (mRFP–LC3+ puncta), as well as a low GFP/RFP fluorescence ratio of GFP-LC3-RFP. Signal pathway analysis indicated compound 1 might inhibit mTOR signaling to stimulate autophagy.

Two new chromone derivatives (1 and 2), together with four known (3–6) ones, were isolated from the stems of a local sun cured tobacco (Fenghuang tobacco, widely cultivated in Shifang prefecture, Sichuan Province). 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. The results showed that compounds 1 and 2 exhibited high anti-TMV activities with inhibition rates of 35.8 and 28.6% at the concentration of 20 μM. These rates are close to that of the positive control.

Two new naphthalene derivatives, 1-(3-hydroxy-1-(hydroxymethyl)-2-methoxy-6-methylnaphthalen-7-yl) propan-2-one (1) and 1-(3-hydroxy-1-(hydroxymethyl)-6-methylnaphthalen-7-yl)propan-2-one (2), together three known naphthalene derivatives (3–5) were isolated from the fermentation products of the endophytic fungus Phomopsis fukushii. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results showed that compounds 1 and 2 showed weak inhibition with IZD of 10.2 ± 1.8 and 11.3 ± 2.0 mm, respectively.

Two new benzazepine alkaloids (1 and 2) were isolated from the whole plants of Thalictrum wangii. 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-rotavirus activity. The results revealed that compounds 1 and 2 exhibited potent anti-rotavirus activity with TI values of 17.9 and 17.6, respectively.

Two new sesquiterpene aryl esters, armimelleolides A and B (1 and 2), and four known ones, were isolated from the EtOAc extract of Armillaria gallica 012 m by column chromatography on silica gel, r...

Nicotiana tabacum (tobacco) has attracted interest as one of the most economically important industrial crops widely cultivated in China, whose dried leaves are popularly consumed medicinally and recreationally by human societies. In this study, five undescribed alkaloids derivatives, isoaspergillines A-E, together with eight known alkaloids, notoamide D, (1R,4S)-4-benzyl-1-isopropyl-2,4-dihydro-1H-pyrazino-[2,1-b]quinazoline-3,6-dione, protuboxepin K, notoamide C, notoamide M, deoxybrevianamide E, cyclo (D-Pro-L-Trp), and versicolamide B, were obtained from the culture of the Nicotiana tabacum-derived fungus Aspergillus versicolor. Their structures were mainly elucidated through comprehensive analyses of spectroscopic data. Bioactivity evaluation of all isolated compounds revealed that isoaspergilline A and notoamide M exhibited anti-TMV activities with IC

Two new coumarins, 6-hydroxymethyl-3-prenyl-7-methoxycoumarin (1) and 6-hydroxyethyl-3-prenyl-7- methoxycoumarin (2), together with three known coumarins (3–5), were isolated from the roots and stems of Yunyan-300, a variety of Nicotiana tabacum L. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were tested for their anti-methicillinresistant Staphylococcus aureus (anti-MRSA) activity and their antioxidant activity. The results revealed that compounds 1 and 2 showed good anti-MRSA inhibitions with IZD of 12.2 ± 1.8 and 11.8 ± 1.5 mm, respectively, and antioxidant activity with an IC50 value of 4.65 and 4.85 μg/mL, respectively.

Two new tricyclic alkaloids (1 and 2), together with three known (3–5) alkaloids, were isolated from the whole plants of Thalictrum cultratum. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1–5 were tested for their anti-rotavirus activity. The results revealed that compounds 1–5 exhibited potent anti-rotavirus activity with therapeutic index (TI) values in the range 10.7–17.7.

Two new (1 and 2), together with two known (3 and 4), isoquinoline alkaloids were isolated from the whole plants of Thalictrum cirrhosum. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1–4 were tested for their antirotavirus activity. The results revealed that compounds 2 exhibited high antirotavirus activity with a therapeutic index (TI) value of 19.3. This value is close to that of positive control (TI value 20.4). Compounds 1, 3, and 4 also exhibited potent antirotavirus activity with TI value above 10.

Two new anti-tobacco mosaic virus (anti-TMV) xanthones, 4,7-dimethoxy-5-hydroxymethyl-1-methylxanthone (1) and 7-hydroxy-5-hydroxymethyl-4-methoxy-1-methylxanthone (2), were isolated from the whole plants of Comastoma pedunculatum. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 showed high anti-TMV activity with inhibition rates of 48.5 and 63.6%, respectively. These rates are higher than that of positive control.

Two new compounds (1 and 2), together with three known chromone derivatives (3–5), were isolated from Cassia leschenaultiana. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compounds 1 and 2 showed potential anti-TMV activities with inhibition rates of 35.6% and 38.7% at the concentration of 20 μM, respectively. These rates are higher than that of the positive control.

Two new xanthones (1 and 2), together with three known xanthones (3–5), were isolated from the whole plants of Comastoma pulmonarium. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were also evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compounds 1 and 2 showed high anti-TMV activity with inhibition rates of 42.8% and 52.4%, respectively. These rates are higher than that of positive control.

Two new diphenyl ethers (1 and 2) were isolated from the fermentation products of an endophytic fungus Phomopsis asparagi. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results revealed that compounds 1 and 2 showed good inhibition with IZD 10.8 ± 2.0 and 11.4 ± 1.8 mm, respectively.

Seven compounds including a new one named as 13-angeloyloxy-diplosporin (1) were isolated from the endophytic Phomopsis sp. 0391 cultivated in the presence of a histone deacetylase inhibitor. All of these isolates were evaluated for lipase suppressive activities and we firstly found that compounds cytosporone B (5) and dothiorelone A (6) displayed significant lipase inhibited activities compared to the positive control (Orlistat, IC50 = 43 μg/mL) with the IC50 values at 115 and 275 μg/mL, respectively.

Two new isoflavones derivatives, 8,4′-dimethoxy-7-(3-hydroxypropyl)-isoflavone (1) and 8,4′-dimethoxy-7-(3-hydroxypropanoyl)-isoflavone (2), were isolated from the roots of Phlomis betonicoides. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were also tested for the antioxidant activity, and they show good antioxidant activity with an IC50 value of 3.8 and 3.6 μg/mL, respectively.

Two new naphthalene derivatives, 5-methoxy-2-methyl-7-(3-methyl-2-oxobut-3-enyl)-1-naphthaldehyde (1) and 2-(hydroxymethyl)-5-methoxy-7-(3-methyl-2-oxobut-3-enyl)-1-naphthaldehyde (2), together with two known naphthalene derivatives (3 and 4), were isolated from the fermentation products of an endophytic fungus Phomopsis sp. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results showed that compounds 1 and 2 showed good inhibition with IZD of 14.5 ± 1.2 and 15.2 ± 1.3 mm, respectively.

Two new diphenyl ethers, 1-[2-methoxy-4-(3-methoxy-5-methylphenoxy)-6-methylphenyl]-ethanone (1) and 1-[4-(3-(hydroxymethyl)-5-methoxyphenoxy)-2-methoxy-6-methylphenyl]-ethanone (2), together five known diphenyl ether derivatives (3–7), 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 and 2 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. Compounds 1 and 2 showed good inhibition with IZD of 13.8 ± 1.5 mm and 14.6 ± 1.6 mm, respectively.

Two new isoflavones, 6-hydroxy-7-(3-hydroxypropyl)-4′-methoxyisoflavone (1) and 6,4′-dihydroxy-7-(3-hydroxypropyl)-isoflavone (2), were isolated from the flowers of Rosa damascena. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results revealed that compounds 1 and 2 showed weak inhibition with IZD of 11.6 ± 1.2 and 11.2 ± 1.0 mm, respectively. Compounds 1 and 2 were also tested for their antioxidant activity and showed good activity with an IC50 value of 4.2 and 4.0 μg/mL, respectively.

A biosynthetic gene cluster for chevalone E (1) and its oxidized derivatives have been identified within the genome of the endophytic fungus Aspergillus versicolor 0312, by a mining strategy targeting a polyketide-diterpenoid hybrid molecule. The biosynthetic pathway has been successfully reconstituted in the heterologous fungus Aspergillus oryzae. Interestingly, two P450 monooxygenases, Cle2 and Cle4, were found to transform 1 into seven new analogues including 7 and 8 that possess a unique five-membered lactone ring. Furthermore, the replacement of the terpene cyclase gene with that from another fungus led to the production of sartorypyrone D (11), which has a monocyclic terpenoid moiety. Finally, some of the compounds obtained in this study synergistically enhanced the cytotoxicity of doxorubicin (DOX) in breast cancer cells.

Indole alkaloids have attracted widespread attention of chemists and biologists. Therefore, the aim of this study is to screen more bioactivities indole alkaloids from the microorganisms. In this study, five undescribed CPA-type indole alkaloids, aspergillines F-J, and three known CPA-type indole alkaloids, aspergilline A, aspergilline C, and cyclopiamide E, were obtained from the Nicotiana tabacum-derived fungus Aspergillus versicolor. Notably, aspergillines F and G represent the first examples of indole alkaloids with a benzo[cd]indol-2(1H)-one skeleton, and aspergilline J is also the firstly obtained indole alkaloids bearing a N-1-(2-(1H-imidazole-5-yl)ethyl) moiety. Aspergillines F-J and cyclopiamide E were tested for their anti-TMV activities, and the results revealed that aspergillines G and J exhibited obvious anti-TMV activities with inhibition rates of 41.2 and 56.8% at the concentration of 20 μM, respectively. These rates are high than that of positive control (with inhibition rate of 32.5%). In addition, the molecular docking studies for the isolated CPA-type indole alkaloids may also reveal that the benzo[cd]indol-2(1H)-one substructure is the fundamental for anti-TMV activity and the oxygen-containing substituent groups at C-19 also increases the inhibitory activity. This study of structure-activity relationship is helpful to find new anti-TMV activity inhibitors.

Two new flavones, 8-hydroxy-7-(3-hydroxypropyl)-2′-methoxyflavone (1) and 8-hydroxy-7-(2-hydroxyethyl)-2′-methoxyflavone (2), together with four known flavones (3–6), were isolated from the whole plants of Cassia pumila. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compounds 1 and 2 have potential anti-TMV activities with inhibition rates of 30.2% and 28.2%, respectively.