Bioorganic & Medicinal Chemistry最新文献

Epidermal growth factor receptor (EGFR) kinase has been implicated in the uncontrolled cell growth associated with non-small cell lung cancer (NSCLC). This has prompted the development of 3 generations of EGFR inhibitors over the last 2 decades due to the rapid development of drug resistance issues caused by clinical mutations, including T790M, L858R and the double mutant T790M & L858R. In this work we report the design, preparation and biological assessment of new irreversible 2,4-diaminopyrimidine-based inhibitors of EGFR kinase. Twenty new compounds have been prepared and evaluated which incorporate a range of electrophilic moieties. These include acrylamide, 2-chloroacetamide and (2E)-3-phenylprop-2-enamide, to allow reaction with residue Cys797. In addition, more polar groups have been incorporated to provide a better balance of physical properties than clinical candidate Rociletinib. Inhibitory activities against EGFR wildtype (WT) and EGFR T790M & L858R have been evaluated along with cytotoxicity against EGFR-overexpressing (A549, A431) and normal cell lines (HepG2). Selectivity against JAK3 kinase as well as physicochemical properties determination (logD_7.4 and phosphate buffer solubility) have been used to profile the compounds. We have identified 20, 21 and 23 as potent mutant EGFR inhibitors (≤20 nM), with comparable or better selectivity over WT EGFR, and lower activity at JAK3, than Osimertinib or Rociletinib. Compounds 21 displayed the best combination of EGFR mutant activity, JAK3 selectivity, cellular activity and physicochemical properties. Finally, kinetic studies on 21 were performed, confirming a covalent mechanism of action at EGFR.

CYP5122A1, an enzyme involved in sterol biosynthesis in Leishmania, was recently characterized as a sterol C4-methyl oxidase. Screening of a library of compounds against CYP5122A1 and CYP51 from Leishmania resulted in the identification of two structurally related classes of inhibitors of these enzymes. Analogs of screening hit N-(3,5-dimethylphenyl)-4-(pyridin-4-ylmethyl)piperazine-1-carboxamide (4a) were generally strong inhibitors of CYP51 but were less potent against CYP5122A1 and typically displayed weak inhibition of L. donovani promastigote growth. Analogs of screening hit N-(4-(benzyloxy)phenyl)-4-(2-(pyridin-4-yl)ethyl)piperazine-1-carboxamide (18a) were stronger inhibitors of both CYP5122A1 and L. donovani promastigote proliferation but also remained selective for inhibition of CYP51. Two compounds in this series, N-(4-((3,5-bis(trifluoromethyl)benzyl)oxy)phenyl)-4-(2-(pyridin-4-yl)ethyl)piperazine-1-carboxamide (18e) and N-(4-((3,5-di-tert-butylbenzyl)oxy)phenyl)-4-(2-(pyridin-4-yl)ethyl)piperazine-1-carboxamide (18i) showed modest selectivity for inhibiting L. donovani promastigote proliferation compared to J774 macrophages and were effective against intracellular L. donovani with EC₅₀ values in the low micromolar range. Replacement of the 4-pyridyl ring present in 18e with imidazole resulted in a compound (4-(2-(1H-imidazol-1-yl)ethyl)-N-(4-((3,5-bis(trifluoromethyl)benzyl)oxy)phenyl)piperazine-1-carboxamide, 18p) with approximately fourfold selectivity for CYP5122A1 over CYP51 that inhibited both enzymes with IC₅₀ values ≤ 1 µM, although selective potency against L. donovani promastigotes was lost. Compound 18p also inhibited the proliferation of L. major promastigotes and caused the accumulation of 4-methylated sterols in L. major membranes, indicating that this compound blocks sterol demethylation at the 4-position in Leishmania parasites. The molecules described here may therefore be useful for the future identification of dual inhibitors of CYP51 and CYP5122A1 as potential antileishmanial drug candidates and as probes to shed further light on sterol biosynthesis in Leishmania and related parasites.

Rhein, as a plant antibiotic, demonstrates a broad spectrum of pharmacological effects. Nevertheless, its limited water solubility, low bioavailability, and potential hepatotoxicity and nephrotoxicity making it difficult to directly become a medicine, thereby imposing significant constraints on its clinical application. In recent decades, extensive researches have been proceeded on the multifaceted structural modifications of rhein, resulting in notable improvements on pharmacological activities and druggabilities. This review offers a comprehensive overview and advanced update on the biological potential and structural–activity relationships (SARs) of various rhein derivatives, delineating the sites of structural modification and corresponding activity trends of rhein derivatives for future.

The potential of Strained-Promoted Sydnone-Alkyne Cycloaddition (SPSAC) for radioiodination was evaluated with model cyclooctyne-conjugated peptides. Starting with a series of sydnones with varying N₃ and C₄ substitution, a preliminary kinetic study with non-radioactive iodinated compounds highlighted the superiority of an arylsydnone substituted by a chlorine atom in C₄ position. Interestingly, reaction rate up to 11 times higher than using an azide was achieved with the best system. Access to ¹²⁵I-labelled sydnones was granted with high efficiency from arylboronic acid precursors by copper catalyzed nucleophilic substitution. Application of SPSAC on the model peptide in radiotracer conditions showed the same trend than in non-radioactive kinetic study and complete reactions could be achieved within less than an hour for the best systems. These results are favorable for use in the production of radiopharmaceuticals with heavy halogens and increase the diversity of available bioorthogonal reaction for nuclear imaging and therapy.

Small molecule inhibitors targeting the bromodomain and extra-terminal domain (BET) family proteins have emerged as a promising class of anti-cancer drugs. Nevertheless, the clinical advancement of these agents has been significantly hampered by challenges related to their potency, oral bioavailability, or toxicity. In this study, virtual screening approaches were employed to discover novel inhibitors of the bromodomain-containing protein 4 (BRD4) by analyzing their comparable chemical structural features to established BRD4 inhibitors. Several of these compounds exhibited inhibitory effects on BRD4 activity ranging from 60 % to 70 % at 100 µM concentrations, while one compound also exhibited an 84 % inhibition of Sirtuin 2 (SIRT2) activity. Furthermore, a subset of structurally diverse compounds from the BRD4 inhibitors was selected to investigate their anti-cancer properties in both 2D and 3D cell cultures. These compounds exhibited varying effects on cell numbers depending on the specific cell line, and some of them induced cell cycle arrest in the G0/G1 phase in breast cancer (MDA-MB-231) cells. Moreover, all the compounds studied reduced the sizes of spheroids, and the most potent compound exhibited a 90 % decrease in growth at a concentration of 10 µM in T47D cells. These compounds hold potential as epigenetic regulators for future studies.

The synthesis of C-disaccharides of α-d-galactopyranosyl-(1 → 3)-d-galactopyranose (α-Gal), potential tools for studying the biology of α-Gal glycans, is described. The synthetic strategy, centers on the reaction of two easily available precursors 1,2-O-isopropylidene-d-glyceraldehyde and an α-C-glactosyl-E-crotylboronate, which affords a mixture of two diastereomeric anti-crotylation products. The stereoselectivity of this reaction was controlled with (R)- and (S)-TRIP catalysts, and the appropriate diastereomer was transformed to C-linked disaccharides of α-Gal, in which the aglycone segment comprised O-, C- and S-glycoside entities that can enable glycoconjugate synthesis.

In the development of covalent inhibitors, acrylamides warhead is one of the most popular classes of covalent warheads. In recent years, researchers have made different structural modifications to acrylamides warheads, resulting in the creation of fluorinated acrylamide warheads and cyano acrylamide warheads. These new warheads exhibit superior selectivity, intracellular accumulation, and pharmacokinetic properties. Additionally, although ketoamide warheads have been applied in the design of covalent inhibitors for viral proteins, it has not received sufficient attention. Combined with the studies in kinase inhibitors and antiviral drugs, this review presents the structural features and the progression of acrylamides warheads, offering a perspective on future research and development in this field.

Inflammation is a hallmark of many diseases, including cancer, neurodegenerative diseases like Alzheimer’s, type II diabetes, rheumatoid arthritis, and asthma. Nonsteroidal anti-inflammatory drugs (NSAIDs) have been a cornerstone in the management of various inflammatory, pain, and fever-related conditions. As a result, NSAIDs have found their applications in new therapeutic areas. NSAIDs are known to act by inhibiting the cyclooxygenase (COX) pathway. In recent years, new strategies have been proposed to counter inflammation and develop safer COX inhibitors. This review discusses the design of new COX inhibitors, the derivatization of conventional NSAIDs, and their biological applications. The review also presents an integrated classification of NSAIDs incorporating both traditional chemical-based and function-based approaches, including a brief overview of the NSAIDs of natural origins. Additionally, the review addresses adverse effects associated with different NSAIDs, including effects associated with cardiovascular, renal, and hepatic complications emphasizing the need for the development of new and safer COX inhibitors.

Multidrug-resistant (MDR) bacterial infections are becoming a life-threatening issue in public health; therefore, it is urgent to develop novel antibacterial agents for treating infections caused by MDR bacteria. The 20(S)-protopanaxadiol (PPD) derivative 9 was identified as a novel antibacterial hit compound in screening of our small synthetic natural product-like (NPL) library. A series of novel PPD derivatives with heterocyclic rings fused at the C-2 and C-3 positions of the A-ring were synthesized and their antibacterial activities against Staphylococcus aureus (S. aureus) Newman strain and MDR S. aureus strains (USA300, NRS-1, NRS-70, NRS-100, NRS-108, NRS-271, XJ017, and XJ036) were evaluated. Among these compounds, quinoxaline derivative 56 (SH617) exhibited the highest activity with MICs of 0.5–4 μg/mL against the S. aureus Newman strain and the eight MDR S. aureus strains. Its antibacterial activity was comparable to that of the positive control, vancomycin. In the zebrafish, 56 revealed no obvious toxicity even at a high administered dose. In vivo, following a lethal infection induced by USA300 strains in zebrafish, 56 exhibited significantly increased survival rates in a dose-dependent manner.

The incorporation of non-canonical amino acids (ncAAs) into the metal coordination environments of proteins has endowed metalloproteins with enhanced properties and novel activities, particularly in hemoproteins. In this work, we disclose a scalable synthetic strategy that enables the production of myoglobin (Mb) variants with non-canonical heme ligands, i.e., HoCys and f4Tyr. The ncAA-containing Mb* variants (with H64V/V68A mutations) were obtained through two consecutive native chemical ligations and a subsequent desulfurization step, with overall isolated yield up to 28.6 % in over 10-milligram scales. After refolding and heme b cofactor reconstitution, the synthetic Mb* variants showed typical electronic absorption bands. When subjected to the catalysis of the cyclopropanation of styrene, both synthetic variants, however, were not as competent as the His-ligated Mb*. We envisioned that the synthetic method reported herein would be useful for incorporating a variety of ncAAs with diverse structures and properties into Mb for varied purposes.