Incretin and insulin responses to nutrient loads are suppressed in persons with diabetes, resulting in decreased glycemic control. Agents including sulfonylureas and dipeptidyl peptidase-4 inhibitors (DPP4i) partially reverse these effects and provide therapeutic benefit; however, their modes of action limit efficacy. Because somatostatin (SST) has been shown to suppress insulin and glucagonlike peptide-1 (GLP-1) secretion through the Gi-coupled SST receptor 5 (SSTR5) isoform in vitro, antagonism of SSTR5 may improve glycemic control via intervention in both pathways. Here, we show that a potent and selective SSTR5 antagonist reverses the blunting effects of SST on insulin secretion from isolated human islets, and demonstrate that SSTR5 antagonism affords increased levels of systemic GLP-1 in vivo. Knocking out Sstr5 in mice provided a similar increase in systemic GLP-1 levels, which were not increased further by treatment with the antagonist. Treatment of mice with the SSTR5 antagonist in combination with a DPP4i resulted in increases in systemic GLP-1 levels that were more than additive and resulted in greater glycemic control compared with either agent alone. In isolated human islets, the SSTR5 antagonist completely reversed the inhibitory effect of exogenous SST-14 on insulin secretion. Taken together, these data suggest that SSTR5 antagonism should increase circulating GLP-1 levels and stimulate insulin secretion (directly and via GLP-1) in humans, improving glycemic control in patients with diabetes.

In an effort to develop a novel therapeutic agent aimed at addressing the unmet need of patients with osteoarthritis pain, we set out to develop an inhibitor for autotaxin with excellent potency and physical properties to allow for the clinical investigation of autotaxin-induced nociceptive and neuropathic pain. An initial hit identification campaign led to an aminopyrimidine series with an autotaxin IC50 of 500 nM. X-ray crystallography enabled the optimization to a lead compound that demonstrated favorable potency (IC50 = 2 nM), PK properties, and a robust PK/PD relationship.

A convenient, general, and high yielding Pd-catalyzed cross-coupling of methanesulfonamide with aryl bromides and chlorides is reported. The use of this method eliminates concern over genotoxic impurities that can arise when an aniline is reacted with methanesulfonyl chloride. The application of this method to the synthesis of dofetilide is also reported.

Azlactone-functional dispersion and reverse phase suspension polymer supports were examined as immobilizing media for Penicillin G Acylase (PGA). Results indicated that the most effective supports were those that also contained primary and/or secondary amide functional groups. A combination of hydrophobic interactions and hydrogen bonding between amide groups on the support and enzyme was proposed to provide important and intimate association between PGA and support prior to covalent coupling. Relative to an oxirane-functional commercial standard, the azlactone biocatalyst supports featured shorter coupling times and higher catalytic activities.

Covalent attachment of pig liver esterase (E.C.3.1.1.1) to cross-linked dispersion polymer supports was effectively accomplished using azlactone [5(4H)-oxazolone] reactive groups. The binding process required about one hour at room temperature, and it was imperative that a relatively high concentration of a salt co-solute be present along with the enzyme. Under these conditions the enzyme rapidly bound onto the polymeric supports via hydrophobic interaction and then covalent attachment proceeded at effective rates. Up to 10wt.% of the enzyme could be quantitatively bound to supports with retention of high levels of catalytic function, e.g., 68% specific activity at 4wt.%. The non-reactive content of the polymeric support and especially the hydrophilic–hydrophobic balance were shown to be very important, with the hydrophilic supports providing the more favorable environment for hydrolytic esterase activity.

Background: During the past decade, Taxol has assumed an important role in cancer chemotherapy. The search for novel compounds with a mechanism of action similar to that of Taxol, but with greater efficacy particularly in Taxol-resistant cells, has led to the isolation of new natural products. One such compound, (+)-discodermolide, although structurally distinct from Taxol, has a similar ability to stabilize microtubules. In addition, (+)-discodermolide is active in Taxol-resistant cell lines that overexpress P-glycoprotein, the multidrug-resistant transporter. Interestingly, (+)-discodermolide demonstrates a profound enhancement of the initiation process of microtubule polymerization compared to Taxol.Results: The synthesis of (+)-discodermolide analogs exploiting our highly efficient, triply convergent approach has permitted structure–activity relationship (SAR) studies. Small changes to the (+)-discodermolide structure resulted in a dramatic decrease in the ability of all four discodermolide analogs to initiate tubulin polymerization. Two of the analogs also demonstrated a decrease in total tubulin polymerization, while a change in the olefin geometry at the C8 position produced a significant decrease in cytotoxic activity.Conclusions: The availability of (+)-discodermolide and the analogs, and the resultant SAR analysis, have permitted an exploration of the similarities and differences between (+)-discodermolide and Taxol. Docking of the X-ray/solution structure of (+)-discodermolide into the Taxol binding site of β-tubulin revealed two possible binding modes (models I and II). The preferred pharmacophore model (I), in which the C19 side chain of (+)-discodermolide matches with the C2 benzoyl group of Taxol and the δ-lactone ring of (+)-discodermolide overlays with the C13 side chain of Taxol, concurred with the results of the SAR analysis.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

An efficient, highly convergent, stereocontrolled total synthesis of the potent antimitotic agent (+)-discodermolide (1) has been achieved on gram scale. Key elements of the successful strategy include (1) elaboration of three advanced fragments from a common precursor (CP) which embodies the repeating stereochemical triad of the discodermolide backbone, (2) σ-bond installation of the Z trisubstituted olefin, exploiting a modified Negishi cross-coupling reaction, (3) synthesis of a late-stage phosphonium salt utilizing high pressure, and (4) Wittig installation of the Z disubstituted olefin and the terminal (Z)-diene.

La presente invention se rapporte a des procedes de synthese de composes contenant de la lactone, comme les discodermolides, et a des composes qui imitent l'activite chimique et/ou biologique de ces derniers, ainsi qu'a des procedes et des intermediaires utilises pour leur preparation.