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Three new isochromenes, (5-methoxy-7-prenyl-1H-isochromen-3-yl)methanol (1), 3-(3-(hydroxymethyl)-5-methoxy-1H-isochromen-7-yl)propan-1-ol (2), and (5-methoxy-7-methyl-1H-isochromen-3-yl)methanol (3), along with three known analogues (4–6) were isolated from the fermentation products of a Nicotiana tabacum-derived endophytic fungus Aspergillus versicolor. Their structures were elucidated by spectroscopic methods, including extensive 1 D and 2 D NMR techniques. Compounds 1–3 and 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 46.4%, and this rate is higher than that of positive control. Compounds 1, 3, and 6 also showed potential anti-TMV activity with inhibition rates of 28.6, 30.5, and 26.2%, respectively. The IC50 of compounds 1–3 and 6 were also tested, and showed IC50 values of 49.3, 22.4, 42.2, and 54.1 µM, respectively.

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.

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.

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

Aims Activation mapping of premature atrial complexes (PACs) proves challenging due to interference by mechanical bumping and non-targeted ectopies. This study aims to compare the mapping efficacy, instant success, and long-term recurrence of catheter ablation for PACs with non-pulmonary vein (PV) and non-superior vena cava (SVC) origins between the novel dual-reference approach (DRA) and the routine single-reference approach (SRA) of mapping. Methods and results Patients with symptomatic, drug-refractory PACs, or frequent residual PACs after atrial tachyarrhythmia ablation were enrolled. During activation mapping, the coronary sinus (CS) catheter was used as the only timing reference in the SRA group. In the DRA group, another catheter, which was spatially separated from the CS catheter, was used as the second reference. The timing difference between the two references was used to discriminate the targeted PACs from the uninterested rhythms. Procedural parameters and long-term recurrence were compared. A total of 188 patients (109 in SRA and 79 in DRA) were enrolled. The baseline characteristics were similar. Compared with the SRA group, the DRA group had less repeated mapping (1.2 ± 0.4 vs. 1.4 ± 0.5, P = 0.004), shorter mapping (15 ± 6 vs. 23 ± 7 min, P < 0.001) and procedural time (119 ± 28 vs. 132 ± 22 min, P = 0.001), similar procedural complication rates (3.6 vs. 3.8%, P > 0.999), higher instant success (96.2 vs. 87.2%, P = 0.039), and lower recurrence rate (15.2 vs. 29.3%, hazard ratio 1.943, P = 0.033) during a 24-month follow-up. Conclusion As a novel strategy, the DRA shortens the procedural time and improves both instant and long-term success of PAC ablation, serving as a promising approach in mapping PACs with non-PV and non-SVC origins.