34 research outputs found
On DABAL-Me₃ promoted formation of amides
The range and utility of DABAL-Me3 couplings of methyl esters and free carboxylic acids with primary and secondary amines under a variety of conditions (reflux, sealed tube, microwave) has been compared for a significant range of coupling partners of relevance to the preparation of amides of interest in pharmaceutical chemistry. Commercial microwave reactors promote the fastest couplings and allow the use of significantly sterically hindered amines (primary and secondary) and carboxylic acids derivatives. The influence of microwave energy on the reaction system was shown to be typically related to thermal effects (over-pressuring and superheating)
PS-IIDQ: an efficient polymer-supported amide coupling reagent
Polystyrene-IIDQis a polymer-supported coupling reagent that couples carboxylic acids to amines in good yields and high purity without the requirement of a pre-activation step. Importantly the order of addition of the amine, acid or coupling agent makes no difference to the efficiency of the coupling reaction and the reagent can be readily regenerated
Emerging modes-of-action in drug discovery
An increasing focus on complex biology to cure diseases rather than merely treat symptoms has transformed how drug discovery can be approached. Instead of activating or blocking protein function, a growing repertoire of drug modalities can be leveraged or engineered to hijack cellular processes, such as translational regulation or degradation mechanisms. Drug hunters can therefore access a wider arsenal of modes-of-action to modulate biological processes and this review summarises these emerging strategies by highlighting the most representative examples of these approaches
Emerging modes-of-action in drug discovery
\u3cp\u3eAn increasing focus on complex biology to cure diseases rather than merely treat symptoms has transformed how drug discovery can be approached. Instead of activating or blocking protein function, a growing repertoire of drug modalities can be leveraged or engineered to hijack cellular processes, such as translational regulation or degradation mechanisms. Drug hunters can therefore access a wider arsenal of modes-of-action to modulate biological processes and this review summarises these emerging strategies by highlighting the most representative examples of these approaches.\u3c/p\u3
Late-Stage Functionalization of Histidine in Unprotected Peptides
The late‐stage functionalization (LSF) of peptides represents a valuable strategy for the design of potent peptide pharmaceuticals by enabling rapid exploration of chemical diversity and offering novel opportunities for peptide conjugation. While the C(sp2)−H activation of tryptophan (Trp) is well documented, the resurgence of radical chemistry is opening new avenues for the C−H functionalization of other aromatic side‐chains. Herein, we report the first example of LSF at C2 of histidine (His) utilizing a broad scope of aliphatic sulfinate salts as radical precursors. In this work, the exquisite selectivity for histidine functionalization was demonstrated through the alkylation of complex unprotected peptides in aqueous media. Finally, this methodology was extended for the installation of a ketone handle, providing an unprecedented anchor for selective oxime/hydrazone conjugation at histidine
Inhibition of low-density lipoprotein receptor degradation with a cyclic peptide that disrupts the homodimerization of IDOL E3 ubiquitin ligase
Cellular uptake of circulating cholesterol occurs via the low density lipoprotein receptor (LDLR). The E3 ubiquitin ligase IDOL is a mediator of LDLR degradation, with IDOL homodimerization thought to be required for its activity. To probe the possibility of modulating LDLR levels with an inhibitor of IDOL homodimerization, we screened a SICLOPPS library of 3.2 million cyclic peptides for compounds that disrupt this protein-protein interaction. We identified cyclo-CFFLYT as the lead inhibitor, and improved its activity through the incorporation of non-natural amino acids. The activity of the optimized cyclic peptide was assessed in hepatic cells, with a dose-dependent increase in LDLR levels observed in the presence of our IDOL homodimerization inhibitor
Prediction of all-cause mortality and heart failure admissions from global left ventricular longitudinal strain in patients with acute myocardial infarction and preserved left ventricular ejection fraction
ObjectivesThis study sought to test the hypothesis that semiautomated calculation of left ventricular global longitudinal strain (GLS) can identify high-risk subjects among patients with myocardial infarctions (MIs) with left ventricular ejection fractions (LVEFs) >40%.BackgroundLVEF is a key determinant in decision making after acute MI, yet it is relatively indiscriminant within the normal range. Novel echocardiographic deformation parameters may be of particular clinical relevance in patients with relatively preserved LVEFs.MethodsPatients with MIs and LVEFs >40% within 48 h of admission for coronary angiography were prospectively included. All patients underwent echocardiography with semiautomated measurement of GLS. The primary composite endpoint (all-cause mortality and hospitalization for heart failure) was analyzed using Cox regression analyses. The secondary endpoints were cardiac death and heart failure hospitalization.ResultsA total of 849 patients (mean age 61.9 ± 12.0 years, 73% men) were included, and 57 (6.7%) reached the primary endpoint (median follow-up 30 months). Significant prognostic value was found for GLS (hazard ratio [HR]: 1.20; 95% confidence interval [CI]: 1.10 to 1.32; p < 0.001). GLS > −14% was associated with a 3-fold increase in risk for the combined endpoint (HR: 3.21; 95% CI: 1.82 to 5.67; p < 0.001). After adjustment for other variables, GLS remained independently related to the combined endpoint (HR: 1.14; 95% CI: 1.04 to 1.26; p = 0.007). For the secondary endpoints, GLS > −14% was significantly associated with cardiovascular death (HR: 12.7; 95% CI: 3.0 to 54.6; p < 0.001) and heart failure hospitalization (HR: 5.31; 95% CI: 1.50 to 18.82; p < 0.001).ConclusionsAssessment of GLS using a semiautomated algorithm provides important prognostic information in patients with LVEFs >40% above and beyond traditional indexes of high-risk MI