Synthesis and SAR study of novel 3,3-diphenyl-1,3-dihydroindol-2-one derivatives as potent eIF2·GTP·Met-tRNAiMet ternary complex inhibitors

Electrochemical low valent cobalt-catalyzed addition of aryl and vinyl chlorides to α-ketoamides via C-Cl bond activation

The development of an electrochemical cobalt catalyzed C-Cl bond activation at room temperature for the nucleophilic addition of aryl and vinyl chlorides to α-ketoamides is described. The overall method operates through an electrochemically induced low valent cobalt catalyst that oxidatively adds to aryl or vinyl chlorides affording medicinally important 3-hydroxy oxindole and 3-hydroxypyrrolidinone scaffolds. The development of an enantioselective version using a chiral pyrox ligand is also demonstrated.

Activity of the Di-Substituted Urea-Derived Compound I-17 in Leishmania In Vitro Infections

Protein synthesis has been a very rich target for developing drugs to control prokaryotic and eukaryotic pathogens. Despite the development of new drug formulations, treating human cutaneous and visceral Leishmaniasis still needs significant improvements due to the considerable side effects and low adherence associated with the current treatment regimen. In this work, we show that the di-substituted urea-derived compounds I-17 and 3m are effective in inhibiting the promastigote growth of different Leishmania species and reducing the macrophage intracellular load of amastigotes of the Leishmania (L.) amazonensis and L. major species, in addition to exhibiting low macrophage cytotoxicity. We also show a potential immunomodulatory effect of I-17 and 3m in infected macrophages, which exhibited increased expression of inducible Nitric Oxide Synthase (NOS2) and production of Nitric Oxide (NO). Our data indicate that I-17, 3m, and their analogs may be helpful in developing new drugs for treating leishmaniasis.

Role of symmetry in 3,3-diphenyl-1,3-dihydroindol-2-one derivatives as inhibitors of translation initiation

The ternary complex (eIF2·GTP·Met-tRNAiMet) and the eIF4F complex assembly are two major regulatory steps in the eukaryotic translation initiation. Inhibition of the ternary complex assembly is therefore a promising target for the development of novel anti-cancer therapeutics. Building on the finding that clotrimazole (CLT), a molecular probe that depletes intracellular Ca2+ stores and subsequently induce eIF2α phosphorylation, inhibit translation initiation, and reduce preferentially the expression of oncoproteins over "housekeeping" ones,1-3 we undertook structure activity relationship (SAR) studies that identified 3,3-diarylindoline-2-one #1181 as an interesting scaffold. Compound #1181 also induce phosphorylation of eIF2α thereby reducing the availability of the ternary complex, which leads to inhibition of translation initiation.4 Our subsequent efforts focused on understanding SAR iterative lead optimization to enhance potency and improve bioavailability. Herein, we report a complementing study focusing on heavily substituted symmetric and asymmetric 3,3-(o,m-disubstituted)diarylindoline-2-ones. These compounds were evaluated by the dual luciferase reporter ternary complex assay that recapitualates phosphorylation of eIF2α in a quantitative manner. We also evaluated all compounds by sulforhodamine B assay, which measures the overall effect of compounds on cell proliferations and/or viability.

Synthetic Studies toward 1,2,3,3a,4,8b-Hexahydropyrrolo[3,2-b]indole Core. Unusual Fragmentation with 1,2-Aryl Shift

Base-assisted transformations of 2-(3-oxoindolin-2-yl)acetonitriles were investigated. Unexpectedly, attempted reactions of substrates possessing nonprotected nitrogen atoms were accompanied by unusual extrusions of 2-arylacetonitriles, followed by a 1,2-aryl shift to afford 3-hydroxyindolin-2-ones. On the other hand, the reactions for N-alkyl derivatives of oxoindolines took the expected route by only providing 1,2,3,3a,4,8b-hexahydropyrrolo[3,2-b]indoles.

Recent advances and future perspectives in the pharmacological treatment of Candida auris infections

INTRODUCTION

Candida auris is responsible for hospital outbreaks worldwide. Some C. auris isolates may show concomitant resistance to azoles, echinocandins, and polyenes, thereby possibly leaving clinicians with few therapeutic options.

AREAS COVERED

Antifungal agents both in early and in late phases of clinical development showing anti-C. auris activity.

EXPERT OPINION

The research on antifungal agents active against C. auris has made important steps forward in recent years: (i) the development of drugs with novel mechanisms of action, such as ibrexafungerp and fosmanogepix, could provide a valid option against C. auris strains resistant to one or more older antifungals, including pan-resistant strains; (ii) rezafungin could allow once weekly administration of an active drug in the case of echinocandin-susceptible isolates, providing an effective outpatient treatment, while at the same time relieving selective pressure on novel classes; (iii) the development of oral formulations could allow step-down therapy and/or early discharge, or even to avoid hospitalization in mild or noninvasive diseases; (iv) according to available data, these novel agents show a good safety profile and a low potential for drug-drug interactions.

An oxindole efflux inhibitor potentiates azoles and impairs virulence in the fungal pathogen Candida auris

Candida auris is an emerging fungal pathogen that exhibits resistance to multiple drugs, including the most commonly prescribed antifungal, fluconazole. Here, we use a combinatorial screening approach to identify a bis-benzodioxolylindolinone (azoffluxin) that synergizes with fluconazole against C. auris. Azoffluxin enhances fluconazole activity through the inhibition of efflux pump Cdr1, thus increasing intracellular fluconazole levels. This activity is conserved across most C. auris clades, with the exception of clade III. Azoffluxin also inhibits efflux in highly azole-resistant strains of Candida albicans, another human fungal pathogen, increasing their susceptibility to fluconazole. Furthermore, azoffluxin enhances fluconazole activity in mice infected with C. auris, reducing fungal burden. Our findings suggest that pharmacologically targeting Cdr1 in combination with azoles may be an effective strategy to control infection caused by azole-resistant isolates of C. auris.

Revealing quinquennial anticancer journey of morpholine: A SAR based review

Morpholine, a six-membered heterocycle containing one nitrogen and one oxygen atom, is a moiety of great significance. It forms an important intermediate in many industrial and organic syntheses. Morpholine containing drugs are of high therapeutic value. Its wide array of pharmacological activity includes anti-diabetic, anti-emetic, growth stimulant, anti-depressant, bronchodilator and anticancer. Multi-drug resistance in cancer cases have emerged in the last few years and have led to the failure of many chemotherapeutic drugs. Newer treatment methods and drugs are being developed to overcome this problem. Target based drug discovery is an effective method to develop novel anticancer drugs. To develop newer drugs, previously reported work needs to be studied. Keeping this in mind, last five year's literature on morpholine used as anticancer agents has been reviewed and summarized in the paper herein.

Palladium(II)/N-Heterocyclic Carbene Catalyzed One-Pot Sequential α-Arylation/Alkylation: Access to 3,3-Disubstituted Oxindoles

Rationally designed fluorene-based mono- and bimetallic Pd-PEPPSI complexes were synthesized and demonstrated to be effective for the one-pot sequential α-arylation/alkylation of oxindoles. This streamlined approach offers efficient access to functionalized 3,3-disubstituted oxindoles in excellent yields (up to 89%) under mild reaction conditions.

Transition-metal-free Chemoselective Oxidative C-C Coupling of the sp3 C-H Bond of Oxindoles with Arenes and Addition to Alkene: Synthesis of 3-Aryl Oxindoles, and Benzofuro- and Indoloindoles

A transition-metal (TM)-free and halogen-free NaOtBu-mediated oxidative cross-coupling between the sp³ C-H bond of oxindoles and sp² C-H bond of nitroarenes has been developed to access 3-aryl substituted and 3,3-aryldisubstituted oxindoles in DMSO at room temperature in a short time. Interestingly, the sp³ C-H bond of oxindoles could also react with styrene under TM-free conditions for the practical synthesis of quaternary 3,3-disubstituted oxindoles. The synthesized 3-oxindoles have also been further transformed into advanced heterocycles, that is, benzofuroindoles, indoloindoles, and substituted indoles. Mechanistic experiments of the reaction suggests the formation of an anion intermediate from the sp³ C-H bond of oxindole by tert-butoxide base in DMSO. The addition of nitrobenzene to the in-situ generated carbanion leads to the 3-(nitrophenyl)oxindolyl carbanion in DMSO which is subsequently oxidized to 3-(nitro-aryl) oxindole by DMSO.

Explorations of substituted urea functionality for the discovery of new activators of the heme-regulated inhibitor kinase

Heme-regulated inhibitor kinase (HRI), a eukaryotic translation initiation factor 2 alpha (eIF2α) kinase, plays critical roles in cell proliferation, differentiation, and adaptation to cytoplasmic stress. HRI is also a critical modifier of hemoglobin disorders such as β-thalassemia. We previously identified N,N'-diarylureas as potent activators of HRI suitable for studying the biology of this important kinase. To expand the repertoire of chemotypes that activate HRI, we screened a ∼1900 member N,N'-disubstituted urea library in the surrogate eIF2α phosphorylation assay, identifying N-aryl,N'-cyclohexylphenoxyurea as a promising scaffold. We validated hit compounds as a bona fide HRI activators in secondary assays and explored the contributions of substitutions on the N-aryl and N'-cyclohexylphenoxy groups to their activity by studying focused libraries of complementing analogues. We tested these N-aryl,N'-cyclohexylphenoxyureas in the surrogate eIF2α phosphorylation and cell proliferation assays, demonstrating significantly improved bioactivities and specificities. We consider these compounds to represent lead candidates for the development of potent and specific HRI activators.