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Three new diterpene alkaloids, tangutidines A–C (1–3), and four known alkaloids (4–7) were isolated from the whole plant of Aconitum tanguticum, from which amphoteric diterpene alkaloids (1–3) were obtained for the first time. The structures of 1–3 were elucidated by detailed interpretation of spectroscopic data, including MS and NMR data. All of them were evaluated for their cytotoxic activities. Graphic Abstract

Arthrinins E–G (1–3), three new sesquiterpenoids possessing non-isoprenoid botryane skeleton, were isolated from the fermentation of an endophytic fungus named Arthrinium sp. HS66 which colonized in the stems of Isodon xerophilus. Their structures were determined by extensive spectroscopic methods. Furthermore, the structure of 1 was unambiguously confirmed by X-ray diffraction, while those of 2 and 3 were verified through quantum chemical calculation of NMR data and ECD spectra.

Four new rearranged 6/6/5/6-fused lanostane-type triterpenoids, kadcoccitanes A–D (1–4), were isolated from the roots of Kadsura coccinea, and their structures were mainly elucidated by comprehensive analysis of their spectroscopic data. Additionally, the structure of 1 was ambiguously verified by single-crystal X-ray diffraction, while the structure of 2, which features a novel 8,16-epoxy motif, was validated by quantum chemical calculation of NMR parameters and ECD spectrum. Moreover, 1 and 4 were found to exhibited anticoagulant activity, while 3 and 4 were found to possess anti-platelet aggregation activity. Electronic supplementary material The online version of this article (10.1007/s13659-019-0203-4) contains supplementary material, which is available to authorized users.

Constitutively active Wnt signaling frequently occurs in most colon cancers. Therefore, inhibitors of Wnt signaling pathway could provide rational therapeutic effects for colorectal malignancy. Within this paper, we identified two inhibitors of Wnt signaling pathway, rabdoternin B and maoecrystal I from a natural ent-kauranoid library by a dual-luciferase reporter gene assay. The two compounds inhibited Wnt signaling pathway in a concentration-dependent manner and exhibited selective cytotoxicity toward a number of colon carcinoma cell lines SW480, HCT116, and HT29, with only weak cytotoxicity towards the normal colonic epithelial cell line CCD-841-CoN. Rabdoternin B and maoecrystal I treatment induced G2/M phase arrest efficiently in SW480 cells as revealed by flow cytometry analysis. A further study found that maoecrystal I decreased the expression of Wnt signaling target genes, including c-myc, cyclin D1, survivin and Axin2 in colon cancer cells. Collectively our data suggests that rabdoternin B and maoecrystal I are novel inhibitors of canonical Wnt signaling pathway and may possess potentials for colon cancer therapy.

Four new diterpenoids, laxiflorins S-V (1–4), bearing four different types, and one known compound, laxiflorin O (5), were isolated from Isodon eriocalyx var. laxiflora. Compound 1 was the first example of ent-kauranoids bearing a unique C24 carbon framework and compound 4 was the first example of 3,4-seco-ent-abietane diterpenoids from the Isodon genus. Their structures were determined by spectroscopic methods (UV, IR, MS, NMR). Electronic Supplementary Material Supplementary material is available for this article at 10.1007/s13659-013-0057-0 and is accessible for authorized users.

Four new tetrahydrofuran lignans, schpropinrins A-D (1–4), together with five known ones, were isolated from the leaves and stems of Schisandra propinqua var. sinensis. Their structures, including absolute configurations, were characterized by means of spectroscopic analysis and ECD calculation. Compounds 1–4 featured a ketal or hemiketal substructure at C-7 and all of the isolates were tested for their anti-HIV integrase activity. Electronic Supplementary Material Supplementary material is available for this article at 10.1007/s13659-013-0017-8 and is accessible for authorized users.

Four new indole alkaloids, plasiaticines A-D (1–4), together with two known ones, were isolated from the seeds of Plantago asiatica. The structures of the new compounds were elucidated on the basis of comprehensive analysis of spectroscopic data. All compounds were tested for their cytotoxic activity, and all compounds except 4 were tested for their acetylcholinesterase (AChE) inhibitory activities.

Two new neolignans, manneoinsigins A (1) and B (2), together with four known lignans, were isolated from the leaves and stems of Manglietia insignis. The new compounds were established on the basis of extensive spectroscopic analyses. All compounds except 2 were tested for their cytotoxic activity. Compound 3 showed weak cytotoxic activity against the HL-60 human tumor cell line with the IC50 value of 23.5 µM.

Three new ent-kauranoids, isorosthornins A-C (1–3), and a new natural product, dihydroponicidin (4), together with five known ones were isolated from the aerial parts of Isodon rosthornii. The structures were determined by means of extensive spectroscopic analysis. All diterpenoids isolated were evaluated for their cytotoxicity against HL-60, SMMC-7721, A-549, MCF-7, and SW480 cell lines, and compounds 5 and 7 showed significant inhibitory effects on all cell lines. Electronic Supplementary Material Supplementary material is available for this article at 10.1007/s13659-011-0031-7 and is accessible for authorized users.

Three new highly oxygenated nortriterpenoids, wilsonianadilactones D–F (1–3), were isolated from the leaves and stems of Schisandra wilsoniana. Their structures were established by means of spectroscopic analysis. Compounds 1–3 showed weak anti-HIV-1 activity with the therapeutic index (TI) values (CC50/EC50) greater than 8.16, 14.7, and 17.5, respectively.