•Six pregnane alkaloids were isolated from Sarcococca ruscifolia.•In which, three are new compounds and one is first isolated from this plant.•All compounds showed good effects on inhibiting the growth of cancer cells.Six pregnane alkaloids were isolated from the root of Sarcococca ruscifolia. The structures of three new alkaloids, namely, sarcorucinine E–G (1–3), were elucidated using spectroscopic methods, while three known alkaloids, namely, epipachysamine D, pachysamine M, and sarcovagine D, were identified by comparing their spectral data with those of the compounds reported earlier. All compounds were evaluated for their inhibitory activities against multiple types of cancer cells.

Nine water-soluble chromone derivatives, including chromone-2-carboxylic acids, 2-methylchromones and their structural hybrids, were isolated from aerial tissues of Halenia elliptica (Gentianaceae), six of which were previously unknown. Their structures were elucidated by comprehensive mass, 1D and 2D NMR spectroscopic analyses and chemical derivatization. Two unstable structural hybrids of chromone-2-carboxylic acids and 2-methylchromones, viz. 3-acetyl-8-hydroxy-4H-1-benzopyran-4-one-2-carboxylic acid (halenic acid C) and 2-(8-hydroxy-2-methyl-4H-1-benzopyran-4-one-3-yl)-2-oxoacetic acid (halenichromone A), were isomers and were interconvertible. The proposed mechanism of their acid-catalyzed isomerization in aqueous solvent is described. In addition, 2-methylchromones, 8-hydroxy-2-methyl-4H-1-benzopyran-4-one, and 8-methoxy-2-methyl-4H-1-benzopyran-4-one, were found to exhibit a strong inhibitory effect towards hepatitis B virus (HBV) in vitro without showing significant cytotoxicity.Graphical abstractFrom the aerial tissues of Halenia elliptica (Gentianaceae), nine polar chromone derivatives were isolated and their anti-HBV activities were measured.Highlights► Nine polar chromone derivatives were isolated from Halenia elliptica. ► This is the first systematic study of H. elliptica on its water-soluble constituents. ► The mechanism of isomerization of two unstable chromones in aqueous solution is discussed. ► Some chromones show potential anti-HBV activities.

Ginkgolic acids (GAs) from the leaves and sarcotesta of Ginkgo biloba L. represent a new kind of molluscicide agent. To date, the mechanism(s) for the observed molluscicidal activity remains largely unknown. Since GA-C13:0 has effectively inhibited snail mobility, we examined the effects of the compound on mitochondrial function and gene expression as compared to niclosamide. Snail mitochondrial damage induced by GAs was tested using transmission electron microscopy (TEM) and gene-expression profiling of five mitochondrial enzymes using real-time PCR. GA-C13:0 was found to have a pronounced effect on snail mitochondria with gross ultrastructural changes. In addition, GA-C13:0 was also found to inhibit the gene expression of four mitochondrial enzymes including cytochrome c oxidase, adenosine triphosphate (ATP) synthase, cytochrome b and dihydronicotinamide adenine dinucleotide (NADH) dehydrogenase. In contrast, niclosamide did not show such effects on mitochondrial function and gene expression, suggesting that the molluscicidal activity of GA-C13:0 and niclosamide differed. Our results imply that snail mitochondria are a potential target for the molluscicidal activity of ginkgolic acids.Graphical abstractDownload full-size imageHighlights► GA-C13:0 had a pronounced effect on snail mitochondria with ultrastructural changes. ► GA-C13:0 could inhibit the gene expression of four mitochondrial enzymes. ► The molluscicidal activity of GA-C13:0 and niclosamide was different.