Stereoselective synthesis of norephedrine and norpseudoephedrine by using asymmetric transfer hydrogenation accompanied by dynamic kinetic resolution.

Each of the enantiomers of both norephedrine and norpseudoephedrine were stereoselectively prepared from the common, prochiral cyclic sulfamidate imine of racemic 1-hydroxy-1-phenyl-propan-2-one by employing asymmetric transfer hydrogenation (ATH) catalyzed by the well-defined chiral Rh-complexes, (S,S)- or (R,R)-Cp*RhCl(TsDPEN), and HCO(2)H/Et(3)N as the hydrogen source. The ATH processes are carried out under mild conditions (rt, 15 min) and are accompanied by dynamic kinetic resolution.

Identification of 3-acyl-2-phenylamino-1,4-dihydroquinolin-4-one derivatives as inhibitors of the phosphatase SerB653 in Porphyromonas gingivalis, implicated in periodontitis.

The serine phosphatase SerB653 plays a crucial role in the infection of Porphyromonas gingivalis, which contributes to the pathogenesis of periodontitis, an inflammatory disease of teeth-supporting tissues. Because functional loss of SerB653 eliminates the virulence of P. gingivalis, SerB653 inhibitors are considered potential periodontitis therapeutic or preventive agents. To identify SerB653 inhibitors with potent anti-periodontitis activity, we conducted a high-throughput screen of a representative 6800-compound subset of a synthetic chemical library of the Korea Chemical Bank (KCB) for compounds with activity against SerB653. The primary screening yielded 150 hits, and subsequent confirmatory studies identified eight compounds, mainly within a single cluster of 3-acyl-2-phenylamino-1,4-dihydroquinolin-4-one derivatives, that showed greater than 50% inhibition of SerB653 activity at a concentration of 50µM. A second screening with a focused library identified 10 compounds with IC(50) values less than 10µM. In antibacterial tests, three of these compounds showed a minimum inhibitory concentration against P. gingivalis growth of 5-50nM.

Synthesis of a new fluorescent small molecule probe and its use for in vivo lipid imaging.

A new small molecule probe for in vivo lipid imaging, LipidGreen (compound 5), was developed. LipidGreen stained lipid droplets in 3T3L1 cell lines and fat deposits in zebrafish without apparent toxicity up to 100 µM. The utility of LipidGreen as a drug screening platform for fat regulation was also demonstrated in live zebrafish.

A newly identified CG301269 improves lipid and glucose metabolism without body weight gain through activation of peroxisome proliferator-activated receptor alpha and gamma.

OBJECTIVE: Peroxisome proliferator-activated receptor (PPAR)-α/γ dual agonists have been developed to alleviate metabolic disorders. However, several PPARα/γ dual agonists are accompanied with unwanted side effects, including body weight gain, edema, and tissue failure. This study investigated the effects of a novel PPARα/γ dual agonist, CG301269, on metabolic disorders both in vitro and in vivo. RESEARCH DESIGN AND METHODS: Function of CG301269 as a PPARα/γ dual agonist was assessed in vitro by luciferase reporter assay, mammalian one-hybrid assay, and analyses of PPAR target genes. In vitro profiles on fatty acid oxidation and inflammatory responses were acquired by fatty acid oxidation assay and quantitative (q)RT-PCR of proinflammatory genes. In vivo effect of CG301269 was examined in db/db mice. Total body weight and various tissue weights were measured, and hepatic lipid profiles were analyzed. Systemic glucose and insulin tolerance were measured, and the in vivo effect of CG301269 on metabolic genes and proinflammatory genes was examined by qRT-PCR. RESULTS: CG301269 selectively stimulated the transcriptional activities of PPARα and PPARγ. CG301269 enhanced fatty acid oxidation in vitro and ameliorated insulin resistance and hyperlipidemia in vivo. In db/db mice, CG301269 reduced inflammatory responses and fatty liver, without body weight gain. CONCLUSIONS: We demonstrate that CG301269 exhibits beneficial effects on glucose and lipid metabolism by simultaneous activation of both PPARα and PPARγ. Our data suggest that CG301269 would be a potential lead compound against obesity and related metabolic disorders.

A nonthiazolidinedione peroxisome proliferator-activated receptor α/γ dual agonist CG301360 alleviates insulin resistance and lipid dysregulation in db/db mice.

Activation of peroxisome proliferator-activated receptors (PPARs) have been implicated in the treatment of metabolic disorders with different mechanisms; PPARα agonists promote fatty acid oxidation and reduce hyperlipidemia, whereas PPARγ agonists regulate lipid redistribution from visceral fat to subcutaneous fat and enhance insulin sensitivity. To achieve combined benefits from activated PPARs on lipid metabolism and insulin sensitivity, a number of PPARα/γ dual agonists have been developed. However, several adverse effects such as weight gain and organ failure of PPARα/γ dual agonists have been reported. By use of virtual ligand screening, we identified and characterized a novel PPARα/γ dual agonist, (R)-1-(4-(2-(5-methyl-2-p-tolyloxazol-4-yl)ethoxy)benzyl)piperidine-2-carboxylic acid (CG301360), exhibiting the improvement in insulin sensitivity and lipid metabolism. CG301360 selectively stimulated transcriptional activities of PPARα and PPARγ and induced expression of their target genes in a PPARα- and PPARγ-dependent manner. In cultured cells, CG301360 enhanced fatty acid oxidation and glucose uptake and it reduced pro-inflammatory gene expression. In db/db mice, CG301360 also restored insulin sensitivity and lipid homeostasis. Collectively, these data suggest that CG301360 would be a novel PPARα/γ agonist, which might be a potential lead compound to develop against insulin resistance and hyperlipidemia.

Enantioselective synthesis of cyclic sulfamidates by using chiral rhodium-catalyzed asymmetric transfer hydrogenation.

Asymmetric transfer hydrogenation (ATH) of cyclic sulfamidate imines 4 and 9, using a HCO(2)H/Et(3)N mixture as the hydrogen source and well-defined chiral Rh catalysts (S,S)- or (R,R)-2, Cp*RhCl(TsDPEN), effectively produces the corresponding cyclic sulfamidates with excellent yields and enantioselectivities at room temperature within 0.5 h. ATH of 4,5-disubstituted imines 9, having preexisting stereogenic centers, is shown to take place with dynamic kinetic resolution.

Anthelmintic activity of KSI-4088 against Caenorhabditis elegans.

Anthelmintic resistance is a serious global problem because of the worldwide spread of resistant nematodes in animals and humans. This has triggered increasing investment in research for new anthelmintics. Over the past decade, Caenorhabditis elegans has become a popular model organism for parasitic nematode research, and many examples have been published to illustrate its use. In this study, we investigated the effect of KSI-4088 on the egg hatching, larval development, and migration of the nematode worm C. elegans compared with ivermectin and levamisole (well-known anthelmintic drugs). KSI-4088 demonstrated anthelmintic activity on all assays of C. elegans. The anthelmintic activity of KSI-4088 on egg hatching and larval development showed especially strong activity, but assays showed that ivermectin and levamisole had no effects on C. elegans. In addition, KSI-4088 was capable of producing a change in the timing of the development of the worms at the L1-L3 and L4 stage. Also, we demonstrate that C. elegans L3-4 are more sensitive than adults to KSI-4088 in assay of migration. Our results indicate that KSI-4088 is an active anthelmintic compound that should be further investigated with the aim of developing a potent drug against nematodes.

The current status and future perspectives of studies of cannabinoid receptor 1 antagonists as anti-obesity agents.

Since the discovery of rimonabant (Acomplia: 1), a large effort has been directed at the discovery of new, potent and selective CB(1)R antagonists that serve as anti obesity drugs. As a result, a number of compounds reached various stages of clinical trials by late 2008. However, the announcement by Sanofi-Aventis that they were discontinuing all ongoing trials with rimonabant, as a result of the finding that risks associated with depression and anxiety outweighed its benefits, had a major impact on this area. A wave of terminations of programs targeting the development of CB(1)R blockers for treatment of obesity ensued. However, abandoning this CB(1)R therapeutic target for anti-obesity drug development seems to be premature, since there are a number of potential approaches have been uncovered to circumvent the problems of the current agents. In this review, we summarize advances that have been made and the status of studies of a diverse array of CB(1)R antagonists that have been identified mainly based on modifications of the first-in-class CB(1)R antagonist, rimonabant. Various approaches have been employed to design these analogs, such as bioisosteric replacement, introduction of conformational constraints, scaffold hopping and ligand-based molecular modeling. In addition, current approaches that have been uncovered to avoid psychiatric side effects of CB(1)R antagonists are summarized. Finally, the design of non-brain penetrating and peripherally acting CB(1)R antagonists, allosteric modulators of CB(1)R, and neutral antagonists for CB(1)R is also discussed in this review.