A Call for Systematic Research on Solute Carriers.

Solute carrier (SLC) membrane transport proteins control essential physiological functions, including nutrient uptake, ion transport, and waste removal. SLCs interact with several important drugs, and a quarter of the more than 400 SLC genes are associated with human diseases. Yet, compared to other gene families of similar stature, SLCs are relatively understudied. The time is right for a systematic attack on SLC structure, specificity, and function, taking into account kinship and expression, as well as the dependencies that arise from the common metabolic space.

Nanofibers Produced from Agro-Industrial Plant Waste Using Entirely Enzymatic Pretreatments.

Cellulose fibers can be freed from the cell-wall skeleton via high-shear homogenization, to produce cellulose nanofibers (CNF) that can be used, for example, as the reinforcing phase in composite materials. Nanofiber production from agro-industrial byproducts normally involves harsh chemical-pretreatments and high temperatures to remove noncellulosic polysaccharides (20-70% of dry weight). However, this is expensive for large-scale processing and environmentally damaging. An enzyme-only pretreatment to obtain CNF from agro-industrial byproducts (potato and sugar beet) was developed with targeted commercial enzyme mixtures. It is hypothesized that cellulose can be isolated from the biomass, using enzymes only, due to the low lignin content, facilitating greater liberation of CNF via high-shear homogenization. Comprehensive Microarray Polymer Profiling (CoMPP) measured remaining extractable polysaccharides, showing that the enzyme-pretreatment was more successful at removing noncellulosic polysaccharides than alkaline- or acid-hydrolysis alone. While effective alone, the effect of the enzyme-pretreatment was bolstered via combination with a mild high-pH pretreatment. Dynamic rheology was used to estimate the proportion of CNF in resultant suspensions. Enzyme-pretreated suspensions showed 4-fold and 10-fold increases in the storage modulus for potato and sugar beet, respectively, compared to untreated samples. A greener yet facile method for producing CNF from vegetable waste is presented here.

Virus-Like Particle Facilitated Deposition of Hydroxyapatite Bone Mineral on Nanocellulose after Exposure to Phosphate and Calcium Precursors.

We produced and isolated tobacco mosaic virus-like particles (TMV VLPs) from bacteria, which are devoid of infectious genomes, and found that they have a net negative charge and can bind calcium ions. Moreover, we showed that the TMV VLPs could associate strongly with nanocellulose slurry after a simple mixing step. We sequentially exposed nanocellulose alone or slurries mixed with the TMV VLPs to calcium and phosphate salts and utilized physicochemical approaches to demonstrate that bone mineral (hydroxyapatite) was deposited only in nanocellulose mixed with the TMV VLPs. The TMV VLPs confer mineralization properties to the nanocellulose for the generation of new composite materials.

Efficacy and Pharmacology of the NLRP3 Inflammasome Inhibitor CP-456,773 (CRID3) in Murine Models of Dermal and Pulmonary Inflammation.

A critical component of innate immune response to infection and tissue damage is the NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome, and this pathway and its activation products have been implicated in the pathophysiology of a variety of diseases. NLRP3 inflammasome activation leads to the cleavage of pro-IL-1ß and pro-IL-18, as well as the subsequent release of biologically active IL-1ß, IL-18, and other soluble mediators of inflammation. In this study, we further define the pharmacology of the previously reported NLRP3 inflammasome-selective, IL-1ß processing inhibitor CP-456,773 (also known as MCC950), and we demonstrate its efficacy in two in vivo models of inflammation. Specifically, we show that in human and mouse innate immune cells CP-456,773 is an inhibitor of the cellular release of IL-1ß, IL-1α, and IL-18, that CP-456,773 prevents inflammasome activation induced by disease-relevant soluble and crystalline NLRP3 stimuli, and that CP-456,773 inhibits R848- and imiquimod-induced IL-1ß release. In mice, CP-456,773 demonstrates potent inhibition of the release of proinflammatory cytokines following acute i.p. challenge with LPS plus ATP in a manner that is proportional to the free/unbound concentrations of the drug, thereby establishing an in vivo pharmacokinetic/pharmacodynamic model for CP-456,773. Furthermore, CP-456,773 reduces ear swelling in an imiquimod cream-induced mouse model of skin inflammation, and it reduces airway inflammation in mice following acute challenge with house dust mite extract. These data implicate the NLRP3 inflammasome in the pathogenesis of dermal and airway inflammation, and they highlight the utility of CP-456,773 for interrogating the contribution of the NLRP3 inflammasome and its outputs in preclinical models of inflammation and disease.

A potentiator of orthosteric ligand activity at GLP-1R acts via covalent modification.

We report that 4-(3-(benzyloxy)phenyl)-2-ethylsulfinyl-6-(trifluoromethyl)pyrimidine (BETP), which behaves as a positive allosteric modulator at the glucagon-like peptide-1 receptor (GLP-1R), covalently modifies cysteines 347 and 438 in GLP-1R. C347, located in intracellular loop 3 of GLP-1R, is critical to the activity of BETP and a structurally distinct GLP-1R ago-allosteric modulator, N-(tert-butyl)-6,7-dichloro-3-(methylsulfonyl)quinoxalin-2-amine. We further show that substitution of cysteine for phenylalanine 345 in the glucagon receptor is sufficient to confer sensitivity to BETP.

Everyone can draw: An inclusive and transformative activity for conceptualization of topographic anatomy.

Anatomical drawing traditionally involves illustration of labeled diagrams on two-dimensional surfaces to represent topographical features. Despite the visual nature of anatomy, many learners perceive that they lack drawing skills and do not engage in art-based learning. Recent advances in the capabilities of technology-enhanced learning have enabled the rapid and inexpensive production of three-dimensional anatomical models. This work describes a "drawing on model" activity in which learners observe and draw specific structures onto three-dimensional models. Sport and exercise sciences (SES, n = 79) and medical (MED, n = 156) students at a United Kingdom medical school completed this activity using heart and femur models, respectively. Learner demographics, their perceptions of anatomy learning approaches, the value of the activity, and their confidence in understanding anatomical features, were obtained via validated questionnaire. Responses to 7-point Likert-type and free-text items were analyzed by descriptive statistics and semi-quantitative content analysis. Learners valued art-based study (SES mean = 5.94 SD ±0.98; MED = 5.92 ± 1.05) and the "drawing on model" activity (SES = 6.33 ± 0.93; MED = 6.21 ± 0.94) and reported enhanced confidence in understanding of cardiac anatomy (5.61 ± 1.11), coronary arteries (6.03 ± 0.83), femur osteology (6.07 ± 1.07), and hip joint muscle actions (5.80 ± 1.20). Perceptions of learners were independent of both their sex and their art-based study preferences (p < 0.05). Themes constructed from free-text responses identified "interactivity," "topography," "transformative," and "visualization," as key elements of the approach, in addition to revealing some limitations. This work will have implications for anatomy educators seeking to engage learners in an inclusive, interactive, and effective learning activity for supporting three-dimensional anatomical understanding.

Error reporting in a large animal veterinary teaching hospital identifies medication errors occur most often in the prescribing phase of therapy.

OBJECTIVE: To identify the rate at which medication errors occurred over a 2-year period in a large animal veterinary teaching hospital and describe the types of errors that occurred. SAMPLE: 226 medication errors over 6,155 large animal visits occurred during the study period. Multiple errors may have affected the same patient. METHODS: Medication error reports from March 1, 2021, to March 31, 2023, were reviewed retrospectively and classified by species, type of drug, and month and day of the week the error occurred. Errors were categorized according to multiple previously developed systems to allow for comparison to other studies. RESULTS: 226 medication errors occurred over 6,155 patient visits in a 2-year period: 57.5% (130/226) were identified by a dedicated large animal pharmacist, and 64.2% (145/226) of errors were identified and corrected before reaching the patient. Prescription/medication order errors (58.4% [132/226]) occurred significantly more often than errors in medication preparation (21.7% [49/226]; P < .001) and administration (19.6%; P < .001). Antibiotics (48.7% [110/226]) and NSAIDs (17.7% [40/226]) were the drug classes most involved in errors. CLINICAL RELEVANCE: Most medication errors in this study occurred in the ordering/prescribing phase. This is similar to reports in human medicine, where standardized medication error reporting strategies exist. Developing and applying similar strategies in veterinary medicine may improve patient safety and outcome.

Large-scale chemoproteomics expedites ligand discovery and predicts ligand behavior in cells.

Chemical modulation of proteins enables a mechanistic understanding of biology and represents the foundation of most therapeutics. However, despite decades of research, 80% of the human proteome lacks functional ligands. Chemical proteomics has advanced fragment-based ligand discovery toward cellular systems, but throughput limitations have stymied the scalable identification of fragment-protein interactions. We report proteome-wide maps of protein-binding propensity for 407 structurally diverse small-molecule fragments. We verified that identified interactions can be advanced to active chemical probes of E3 ubiquitin ligases, transporters, and kinases. Integrating machine learning binary classifiers further enabled interpretable predictions of fragment behavior in cells. The resulting resource of fragment-protein interactions and predictive models will help to elucidate principles of molecular recognition and expedite ligand discovery efforts for hitherto undrugged proteins.

Insights into the novel hydrolytic mechanism of a diethyl 2-phenyl-2-(2-arylacetoxy)methyl malonate ester-based microsomal triglyceride transfer protein (MTP) inhibitor.

Inhibition of intestinal and hepatic microsomal triglyceride transfer protein (MTP) is a potential strategy for the treatment of dyslipidemia and related metabolic disorders. Inhibition of hepatic MTP, however, results in elevated liver transaminases and increased hepatic fat deposition consistent with hepatic steatosis. Diethyl 2-((2-(3-(dimethylcarbamoyl)-4-(4'-(trifluoromethyl)-[1,1'-biphenyl]-2-ylcarboxamido)phenyl)acetoxy)methyl)-2-phenylmalonate (JTT-130) is an intestine-specific inhibitor of MTP and does not cause increases in transaminases in short-term clinical trials in patients with dyslipidemia. Selective inhibition of intestinal MTP is achieved via rapid hydrolysis of its ester linkage by liver-specific carboxylesterase(s), resulting in the formation of an inactive carboxylic acid metabolite 1. In the course of discovery efforts around tissue-specific inhibitors of MTP, the mechanism of JTT-130 hydrolysis was examined in detail. Lack of ¹8O incorporation in 1 following the incubation of JTT-130 in human liver microsomes in the presence of H2¹8O suggested that hydrolysis did not occur via a simple cleavage of the ester linkage. The characterization of atropic acid (2-phenylacrylic acid) as a metabolite was consistent with a hydrolytic pathway involving initial hydrolysis of one of the pendant malonate ethyl ester groups followed by decarboxylative fragmentation to 1 and the concomitant liberation of the potentially electrophilic acrylate species. Glutathione conjugates of atropic acid and its ethyl ester were also observed in microsomal incubations of JTT-130 that were supplemented with the thiol nucleophile. Additional support for the hydrolysis mechanism was obtained from analogous studies on diethyl 2-(2-(2-(3-(dimethylcarbamoyl)-4-(4'-trifluoromethyl)-[1,1'-biphenyl]-2-ylcarboxamido)phenyl)acetoxy)ethyl)-2-phenylmalonate (3), which cannot participate in hydrolysis via the fragmentation pathway because of the additional methylene group. Unlike the case with JTT-130, ¹8O was readily incorporated into 1 during the enzymatic hydrolysis of 3, suggestive of a mechanism involving direct hydrolytic cleavage of the ester group in 3. Finally, 3-(ethylamino)-2-(ethylcarbamoyl)-3-oxo-2-phenylpropyl 2-(3-(dimethylcarbamoyl)-4-(4'-(trifluoromethyl)-[1,1'-biphenyl]-2-ylcarboxamido)phenyl)acetate (4), which possessed an N,N-diethyl-2-phenylmalonamide substituent (in lieu of the diethyl-2-phenylmalonate motif in JTT-130) proved to be resistant to the hydrolytic cleavage/decarboxylative fragmentation pathway that yielded 1, a phenomenon that further confirmed our hypothesis. From a toxicological standpoint, it is noteworthy to point out that the liberation of the electrophilic acrylic acid species as a byproduct of JTT-130 hydrolysis is similar to the bioactivation mechanism established for felbamate, an anticonvulsant agent associated with idiosyncratic aplastic anemia and hepatotoxicity.

Shaping a screening file for maximal lead discovery efficiency and effectiveness: elimination of molecular redundancy.

High Throughput Screening (HTS) is a successful strategy for finding hits and leads that have the opportunity to be converted into drugs. In this paper we highlight novel computational methods used to select compounds to build a new screening file at Pfizer and the analytical methods we used to assess their quality. We also introduce the novel concept of molecular redundancy to help decide on the density of compounds required in any region of chemical space in order to be confident of running successful HTS campaigns.

Designing small molecules for therapeutic success: A contemporary perspective.

Successful small-molecule drug design requires a molecular target with inherent therapeutic potential and a molecule with the right properties to unlock its potential. Present-day drug design strategies have evolved to leave little room for improvement in drug-like properties. As a result, inadequate safety or efficacy associated with molecular targets now constitutes the primary cause of attrition in preclinical development through Phase II. This finding has led to a deeper focus on target selection. In this current reality, design tactics that enable rapid identification of risk-balanced clinical candidates, translation of clinical experience into meaningful differentiation strategies, and expansion of the druggable proteome represent significant levers by which drug designers can accelerate the discovery of the next generation of medicines.

Discovery of a Series of Pyrimidine Carboxamides as Inhibitors of Vanin-1.

A diaryl ketone series was identified as vanin-1 inhibitors from a high-throughput screening campaign. While this novel scaffold provided valuable probe 2 that was used to build target confidence, concerns over the ketone moiety led to the replacement of this group. The successful replacement of this moiety was achieved with pyrimidine carboxamides derived from cyclic secondary amines that were extensively characterized using biophysical and crystallographic methods as competitive inhibitors of vanin-1. Through optimization of potency and physicochemical and ADME properties, and guided by co-crystal structures with vanin-1, 3 was identified with a suitable profile for advancement into preclinical development.

Design of a multi-purpose fragment screening library using molecular complexity and orthogonal diversity metrics.

Fragment Based Drug Discovery (FBDD) continues to advance as an efficient and alternative screening paradigm for the identification and optimization of novel chemical matter. To enable FBDD across a wide range of pharmaceutical targets, a fragment screening library is required to be chemically diverse and synthetically expandable to enable critical decision making for chemical follow-up and assessing new target druggability. In this manuscript, the Pfizer fragment library design strategy which utilized multiple and orthogonal metrics to incorporate structure, pharmacophore and pharmacological space diversity is described. Appropriate measures of molecular complexity were also employed to maximize the probability of detection of fragment hits using a variety of biophysical and biochemical screening methods. In addition, structural integrity, purity, solubility, fragment and analog availability as well as cost were important considerations in the selection process. Preliminary analysis of primary screening results for 13 targets using NMR Saturation Transfer Difference (STD) indicates the identification of uM-mM hits and the uniqueness of hits at weak binding affinities for these targets.

On the origins of diastereoselectivity in the alkylation of enolates derived from N-1-(1'-naphthyl)ethyl-O-tert-butylhydroxamates: chiral Weinreb amide equivalents.

The stereochemical outcome observed upon alkylation of enolates derived from N-1-(1'-naphthyl)ethyl-O-tert-butylhydroxamates (chiral Weinreb amide equivalents) may be rationalized by a chiral relay mechanism. Deprotonation with KHMDS leads to a nonchelated (Z)-enolate in which the oxygen atoms adopt an anti-periplanar conformation. The configuration of the N-1-(1'-naphthyl)ethyl group dictates the conformation of the O-tert-butyl group and the configuration adopted by the adjacent pyramidal nitrogen atom. Highly diastereoselective enolate alkylation then proceeds anti to both the bulky tert-butyl group (sterically driven) and the N-lone pair (stereoelectronically driven).

Pharmacokinetics and elucidation of the rates and routes of N-glucuronidation of PF-592379, an oral dopamine 3 agonist in rat, dog, and human.

PF-592379 is a potent, selective agonist of the dopamine 3 receptor, for the treatment of male erectile dysfunction and female sexual dysfunction. In vivo, PF-592379 has low-moderate clearance relative to liver blood flow of 6.3 and 8.5 ml/min/kg in dog and 44.8 and 58.2 ml/min/kg in rat. It has high permeability in Caco-2 cells and was completely absorbed in rat and dog pharmacokinetic studies with an oral bioavailability of 28% in both rats and 61 and 87% in the dogs. These data are consistent with the physicochemical properties of PF-592379, which indicate complete absorption by the transcellular route. Elimination of PF-592379 was predominantly metabolic in nature. In vitro routes of metabolism studies indicate that metabolism in the rat is a combination of P450 mechanisms and N-glucuronidation, whereas in dog and human, N-glucuronidation is the major route. NMR analysis indicates that N-glucuronidation is non-quaternary in nature and occurs on both the pyridyl amine and ring nitrogen. Rates of clearance via N-glucuronidation were predicted to be low in humans compared with acyl or phenolic glucuronidation. PF-592379 was predicted to have complete absorption from the gastrointestinal tract and an oral bioavailability of >60% in the clinic. Clinical data verified that PF-592379 is a low clearance compound in human, with a mean oral clearance of 6.5 ml/min/kg following a 200 mg oral dose. PF-592379 has ideal pharmacokinetic properties for an oral D3 agonist, intended for on demand dosing.

Efficient base catalyzed alkylation reactions with aziridine electrophiles.

N-Mesitylene sulfonyl and N-tosyl aziridines have been identified as effective electrophiles in alkylation reactions of carbon acids catalyzed by the organic phosphorine base BEMP; yields of up to 99% for a range of pro-nucleophiles under mild reaction conditions are reported.

Design and synthesis of fluorescent SGLT2 inhibitors.

The design and synthesis of the first fluorophore-conjugated SGLT2 inhibitors is described. The mode of linking the fluorophore to the SGLT2 pharmacophore was found to be crucial in achieving optimum potency. Superior potency to phlorizin was provided by examples containing TAMRA, BODIPY, Cy3B and NBD fluorophores.

Designing rapid onset selective serotonin re-uptake inhibitors. Part 3: Site-directed metabolism as a strategy to avoid active circulating metabolites: structure-activity relationships of (thioalkyl)phenoxy benzylamines.

A series of thio-alkyl containing diphenylethers were designed and evaluated, as a strategy to competitively direct metabolism away from unwanted amine N-demethylation and deliver a pharmacologically inactive S-oxide metabolite. Overall, sulfonamide 20 was found to possess the best balance of target pharmacology, pharmacokinetics and metabolism profile.