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.

3, 4-Dihydroxy L-phenylalanine(L-DOPA) is considered a potent drug for the treatment of Parkinson disease. Physical and nutritional parameters where optimized by using Yarrowia lipolytica-NCIM 3450 to accomplished the highest production of L-DOPA. Screenings of critical components were completed by using a Plackett-Burman design, while further optimization was carried out using the Box-Behnken design. The optimized factor levels predicted by the model were pH 6.1, 1.659 g L^-1 yeast extract, 1.491 g L^-1 L-tyrosine and 0.0290 g L^-1 CuSO₄. The predicted yield of L-DOPA with these levels was 1.319 g L^-1, while actual yield obtained was 1.273 g L^-1. The statistical analysis revealed that model is significant with F value 19.55 and R² value 0.9514. This process resulted in a 3.594-fold increase in the yield of LDOPA. L-DOPA was confirmed by HPTLC and HPLC analysis. Thus, Yarrowia lipolytica-NCIM 3450 has potential to be a new source for the production of L-DOPA.

Five new guanacastane-type diterpenes, named guanacastepenes P-T(1-5), were isolated from cultures of the fungus Psathyrella candolleana. Their structures were elucidated on the basis of extensive spectroscopic methods. All of the compounds were tested for their 11β-hydroxysteroid dehydrogenase(11β-HSD1) inhibitory activity. Compound 3 exhibited inhibitory activity against both human and mouse isozymes of 11β-HSD1 with IC₅₀ values of 6.2 and 13.9 μM, respectively.

Two new triterpenoids(1 and 2) and a new sterol(3), together with six known constituents(4-9), were isolated from the leaves and twigs of Melia azedarach. Their chemical structures were elucidated on the basis of spectroscopic analysis.

28 Derivatives of panaxadiol(PD) and panaxatriol were synthesized and evaluated for their anti-HBV activity on HepG 2.2.15 cells, of which 17 derivatives inhibited HBV DNA replication. Compounds 4, 9, 10, 14, and 15 showed moderate activity against HBV DNA replication with IC₅₀ values ranged from 7.27 to 28.21 μM compared with PD. In particular, 3-O-20-thenoyl panaxadiol(4) inhibited not only HBV DNA replication(IC₅₀=16.5 μM, SI>115.7) but also HBsAg(IC₅₀=30.8 μM, SI>62.0) and HBeAg(IC₅₀=18.2 μM, SI>105.14) secretions. Their structure-activity relationships were discussed for guiding future research toward the discovery of new anti-HBV agents.

A new stigmasterol type natural product, viburodorol A(1), along with eleven known sterols and terpenoids(2-12), were isolated from the aerial parts of Viburnum odoratissimum. The structure of 1 was elucidated on the basis of comprehensive spectroscopic analysis. It's noteworthy that compound 2, the major constituent of this plant, can significantly stimulate glucose absorption in insulin resistant HepG2 cells without affecting cell viability. Furthermore, this compound can also restore the glucose absorption in DXMS-induced insulin resistant 3T3-L1 cells.

A small focused library which comprised of L-AA lactone derivatives was built with a facile method. This reported method was optimized by modifying the acidity of the solvent. As a result, 12 L-AA lactones were synthesized. Among these lactones, lactones 8-12 were new compounds. The cytotoxicity of these synthetic compounds were investigated.

The present study aims at defining the differential cytotoxicity effect of artemisinin toward P815(murin mastocytoma) and BSR(kidney adenocarcinoma of hamster) cell lines. Cytotoxicity was measured by the growth inhibition using MTT assay. These in vitro cytotoxicity studies were complemented by the determination of apoptotic DNA fragmentation and Annexin V-streptavidin-FITC assay. Furthermore, we examined the in vitro synergism between artemisinin and the chemotherapeutic drug, vincristin. The in vivo study was investigated using the DBA2/P815(H2d) mouse model. While artemisinin acted on both tumor cell lines, P815 was much more sensitive to this drug than BSR cells, as revealed by the respective IC₅₀ values(12 μM for P815 and 52 μM for BSR cells). On another hand, and interestingly, apoptosis was induced in P815 but not induced in BSR. These data, reveal an interesting differential cytotoxic effect, suggesting the existence of different molecular interactions between artemisinin and the studied cell lines. In vivo, our results clearly showed that the oral administration of artemisinin inhibited solid tumor development. Our study demonstrates that artemisinin caused differential cytotoxic effects depending not only on the concentration and time of exposure but also on the target cells.