As part of our continual efforts to exploit ‘Tujia Ethnomedicine’ for their pharmacophoric functionalities, we herein investigated Kadsura heteroclita collected from a deep Wulin mountain area in northern Hunan province. The current study resulted in the isolation of three new sesquiterpenes: 6α,9α,15-trihydroxycadinan-4-en-3-one (1), (+)-3,11,12-trihydroxycalamenene (2), (–)-3,10,11,12-tetrahydroxy-calamenene (3), along with four known sesquiterpenes (4–7), and a cytochalasin H (8). Their chemical structures were elucidated by 1D-, and 2D-NMR spectroscopy, and HRESI-MS, CD spectrometry. The antioxidant, and cytotoxic activities of the compounds were evaluated. Compound 8 exhibited a strong antioxidant effect with an IC₅₀ value of 3.67 µM on isolated human polymorphonuclear cells or neutrophils.

An oxidising and substituting one-pot reaction strategy has been developed to synthesise dihydromyricetin derivatives with the aim of enhancing the inhibitory activity of dihydromyricetin against SARS-CoV-2. Different ω-methoxy-ω-oxeylkyl was introduced in C₇-OH site and yielded eight analogs, all of them showed good inhibitory activity against SARS-CoV-2 3CL^pro with IC₅₀ values ranging from 0.72 to 2.36 μM. In the Vero E6-cell, compound 3 has a good activity of anti-SARS-CoV-2 virus (Omicron virus BA.5) in the prevention model, with an EC₅₀ of 15.84 μM, and so do compound 10 in the therapeutic model, with an EC₅₀ of 11.52 μM. The results suggest that the introduction of long chain ω-oxeylkyl at C₇-OH facilitate the inhibition of viral replication in the therapeutic model, which is consistent with the binding energies predicted from molecular docking conclusions. It implies that dihydromyricetin derivatives have the potential to become effective inhibitors of SARS-CoV-2 Omicron and other viruses.

Five artemisinin bivalent ligands molecules 4a–4e were designed, synthesized, and confirmed by ¹H NMR, ¹³C NMR, and low-resolution mass spectrometry, and the bioactivities of the target compounds were investigated against four human tumor cell lines in vitro, including BGC-823, HepG-2, MCF-7, and HCT-116. The results showed 4a, 4d, and 4e exhibited significantly tumor cell inhibitory activity compared with the artemisinin and dihydroartemisinin; compound 4e has good biological activity inhibiting BGC-823 with an IC₅₀ value of 8.30 μmol/L. Then, the good correlations with biological results were validated by molecular docking through the established bivalent ligands multi-target model, which showed that 4e could bind well with the antitumor protein MMP-9.