Lancemaside A from Codonopsis lanceolata: Studies on Antiviral Activity and Mechanism of Action against SARS-CoV-2 and Its Variants of Concern.

Several plant-derived natural products with anti-SARS-CoV-2 activity have been evaluated for the potential to serve as chemotherapeutic agents for the treatment of COVID-19. Codonopsis lanceolata (CL) has long been used as a medicinal herb in East Asian countries to treat inflammatory diseases of the respiratory system but its antiviral activity has not been investigated so far. Here, we showed that CL extract and its active compound lancemaside A (LA) displayed potent inhibitory activity against SARS-CoV-2 infection using a pseudotyped SARS-CoV-2 entry assay system. We demonstrated that this inhibitory effect of LA was due to the alteration of membrane cholesterol and blockade of the membrane fusion between SARS-CoV-2 and host cells by filipin staining and cell-based membrane fusion assays. Our findings also showed that LA, as a membrane fusion blocker, could impede the endosomal entry pathway of SARS-CoV-2 and its variants of concern (VOCs), including Alpha (B.1.1.7), Beta (B.1.351), Delta (B.1.617.2), and Omicron (B.1.1.529), in Vero cells with similar of IC50 values ranging from 2.23 to 3.37 µM as well as the TMPRSS2-mediated viral entry pathway in A549 cells overexpressing ACE2 and TMPRSS2 with IC50 value of 3.92 µM. We further demonstrated that LA could prevent the formation of multinucleated syncytia arising from SARS-CoV-2 spike protein-mediated membrane fusion. Altogether, the findings reported here suggested that LA could be a broad-spectrum anti-SARS-CoV-2 therapeutic agent by targeting the fusion of viral envelope with the host cell membrane.

New Depsides and Neuroactive Phenolic Glucosides from the Flower Buds of Rugosa Rose ( Rosa rugosa).

The flower buds of Rosa rugosa Thunb. have been commonly used as a source of rose oil and as an ingredient in tea in eastern Asia, including China, Japan, and Korea. Repeated chromatography of a hot water extract from the flower buds of R. rugosa led to the isolation and characterization of three new depside glucosides, rosarugosides A-C (1-3), along with three phenolic compounds, one ionone glucoside, four flavonoids, and two tannins having known chemical structures. Linarionoside A and 2-phenylethyl-(6- O-galloyl)-ß-d-glucopyranoside were isolated from R. rugosa for the first time in this study. The structures of the new compounds 1-3 were elucidated by interpreting one- and two-dimensional nuclear magnetic resonance spectroscopic and mass spectrometric data. Among the isolates, a new depside glucoside (1) and two major phenolic glucosides (4 and 5) improved MK-801-induced sensorimotor gating deficits, which were measured via an acoustic startle response test in mice.