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Xanthine oxidase (XO) is a key enzyme in the generation and development of hyperuricemia. Thiazolidine-2-thione, a typical heterocyclic compound, have been widely used in the field of drug synthesis. In this study, a series of novel thiazolidine-2-thione derivatives were synthesized as XO inhibitors, and the XO inhibitory potencies of obtained compounds were evaluated by in vitro enzyme catalysis. The result shown that compound 6k behaved the strongest XO inhibitory activity with an IC50 value of 3.56 μmol/L, which was approximately 2.5-fold more potent than allopurinol. The structure-activity relationship revealed that the phenyl-sulfonamide group was indispensable for thiazolidine-2-thione derivatives to produce XO inhibitory activity. The enzyme inhibition kinetics analyses confirmed that compound 6k exerted a mixed-type XO inhibition. Additionally, the molecular docking results suggested that the 4-fluorophenyl-sulfonyl moiety could interact with Gly260 and Ile264 in the innermost part of the active pocket through 2 hydrogen bonds, while the thiazolidinethione moiety could form two hydrogen bonds with Glu263 and Ser347 in hydrophobic pockets. In summary, the results described above suggested that compound 6k could be a valuable lead compound for the treatment of hyperuricemia as a novel XO inhibitor. [ABSTRACT FROM AUTHOR]

Chronic inflammation is a fundamental symptom of many diseases. Catechin possesses anti-oxidant and anti-inflammatory properties. However, the mechanism of catechin to prevent inflammation in 3T3-L1 adipocytes caused by TNF-α remains unknown. Therefore, the effects of catechin on the gene expression of cytokines and the activation of cell signals in TNF-α induced 3T3-L1 adipocytes were investigated. The effects of catechin on adipogenesis and cell viability were detected by Oil Red O staining and CCK-8 assay, respectively. The genes expression of cytokines was determined by real-time RT-PCR. The expression of NF-κB, AMPK, FOXO3a and SIRT1 on translation level was determined by western blotting analysis. The results demonstrated that catechin significantly enhanced adipogenesis and cell viability. catechin inhibited the gene expression of pro-inflammatory cytokines including IL-1α, IL-1β, IL-6, IL-12p35, and inflammatory enzymes including iNOS and COX-2, but enhanced the gene expression of anti-inflammatory cytokines including IL-4 and IL-10. Catechin also inhibited the activation of NF-κB, AMPK, FOXO3a and SIRT1, but increased the phosphorylation level of the above factors. All these results indicated that as a potential therapeutic strategy catechin has the ability of attenuating inflammatory response triggered by TNF-α through signaling cascades involved in inflammation and cytokines. [ABSTRACT FROM AUTHOR]

Three new lupane-triterpenoids (1–3) along with six known compounds (4–9) were isolated from the ethanolic extract of whole plant of Potentilla discolor Bunge. The structures of Compounds 1–3 were established by extensive 1D and 2D NMR together with other spectrum analysis, indicating that their C-27 positions were highly oxygenated, which were rarely found in nature. Their in vitro anti-proliferative activities against HepG-2, MCF-7 and T-84 cell lines were evaluated by Cell Counting Kit-8 (CCK-8) assay, and the results showed different activities for three cell lines with IC50 values ranging from 17.84 to 40.64 μM. In addition, the results from Hoechst 33258 and AO/EB staining as well as annexinV-FITC assays exhibited Compound 1 caused a markedly increased HepG-2 cellular apoptosis in a dose-dependent manner. The further mechanisms of Compound 1-induced cellular apoptosis were confirmed that 1 induced the production of ROS and the alteration of pro- and anti-apoptotic proteins, which led to the dysfunction of mitochondria and activation of caspase-9 and caspase-3 and finally caused cellular apoptosis. These results would be useful in search for new potential antitumor agents and for developing semisynthetic lupane-triterpenoid derivatives with high antitumor activity. [ABSTRACT FROM AUTHOR]