Two New Compounds from Schisandra propinqua var.propinqua

Schisanpropinoic acid(1),a new bergamotane sesquiterpenoid,and schisanpropinin(2),a new tetrahydrofuran lignan with a rare epoxyethane unit,were identified from the stems and leaves of Schisandra propinqua var.propinqua.Their structures were determined based on comprehensive spectroscopic and mass spectrometric analysis.The absolute configuration of 1 was determined by X-ray analysis.Compounds 1 and 2 were tested for their cytotoxic activity against five human tumor cell lines.

Two Natural ent-kauranoids as Novel Wnt Signaling Inhibitors

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 dualluciferase 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 from Isodon eriocalyx var.laxiflora

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 C_(24) 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).

Isorosthornins A-C,new ent-kaurane diterpenoids from Isodon rosthornii

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.

Two new guaianolide-type sesquiterpenoids from Kadsura interior

Received 22 November 2012 Received in revised form 25 December 2012 Accepted 2B December 2012 Available online 4 February 2013

6,7-seco-ent-Kaurane diterpenoids from Isodon sculponeatus and their bioactivity

One new 6,7-seco-ent-kaurane diterpenoid, sculponin T （1）, was isolated from the aerial parts of lsodon sculponeatus, along with four known analogs, sculponeatin J （2）, sculponeatin K （3）, sculponeatin C （4）, and sculponeatin Q （5）. Their structures were elucidated by extensive spectroscopic analysis and by comparison with data reported in the literature. Significant cytotoxic activity was observed for compound 2 against five human tumor cell lines with IC50 values ranging from 1.8 μmol/L to 3.3 μmol/L, and it also inhibited NO production in LPS-stimulated RAW264.7 cells, with IC50 value of 3.3 μmol/L.