Efficient synthesis of tert-butyl 3-cyano-3-cyclopropyl-2-oxopyrrolidine-4-carboxylates: Highly functionalized 2-pyrrolidinone enabling access to novel macrocyclic Tyk2 inhibitors

Diastereoselective Synthesis of Highly Functionalized γ-Lactams via Ugi Reaction/Michael Addition

The γ-lactam ring is a prominent feature in medicinal chemistry, and its synthesis has garnered significant interest due to its valuable properties. Among the γ-lactams, 2-oxopyrrolidine-3-carbonitrile derivatives stand out as versatile synthons that can be readily transformed into a variety of other functional groups. In this work, we successfully synthesized highly functionalized 3-cyano-2-pyrrolidinones with moderate to good overall yields using the Ugi reaction followed by intramolecular Michael addition. The process demonstrated excellent diastereoselectivity and showed good tolerance to a range of isonitriles and carbonyl compounds.

Synthesis and In Vitro Evaluation as Potential Anticancer and Antioxidant Agents of Diphenylamine-Pyrrolidin-2-one-Hydrazone Derivatives

The title compounds were synthesized by the reaction of 5-oxo-1-(4-(phenylamino)phenyl)pyrrolidine-3-carbohydrazide with various aldehydes bearing aromatic and heterocyclic moieties and acetophenones, and their cytotoxicity was tested via MTT assay against human triple-negative breast cancer MDA-MB-231, human melanoma IGR39, human pancreatic carcinoma Panc-1, and prostate cancer cell line PPC-1. Furthermore, the selectivity of compounds towards cancer cells compared to fibroblasts was also investigated. Four compounds were identified as the most promising anticancer agents out of a series of pyrrolidinone-hydrazone derivatives bearing a diphenylamine moiety. These compounds were most selective against the prostate cancer cell line PPC-1 and the melanoma cell lines IGR39, with EC50 values in the range of 2.5-20.2 µM against these cell lines. In general, the compounds were less active against triple-negative breast cancer MDA-MB-231 cell line, and none of them showed an inhibitory effect on the migration of these cells. In the 'wound healing' assay, N'-((5-nitrothiophen-2-yl)methylene)-5-oxo-1-(4-(phenylamino)phenyl)pyrrolidine-3-carbohydrazide was identified as the most promising derivative that could be further developed as an antimetastatic agent. N'-(5-chloro- and N'-(3,4-dichlorobenzylidene)-5-oxo-1-(4-(phenylamino)phenyl)pyrrolidine-3-carbohydrazides most efficiently reduced the cell viability in IGR39 cell spheroids, while there was no effect of the investigated pyrrolidinone-hydrazone derivatives on PPC-1 3D cell cultures. Antioxidant activity determined via FRAP assay of N'-(1-(4-aminophenyl)ethylidene)-5-oxo-1-(4-(phenylamino)phenyl)pyrrolidine-3-carbohydrazide was 1.2 times higher than that of protocatechuic acid.

Discovery of a potent and subtype-selective TYK2 degrader based on an allosteric TYK2 inhibitor

TYK2, a member of the JAK family of proximal membrane-bound tyrosine kinases, has emerged as an attractive target for the treatment of autoimmune diseases. Herein, we report the discovery of first-in-class potent and subtype-selective TYK2 degraders. By conjugating a TYK2 ligand from a known allosteric TYK2 inhibitor with a VHL ligand as the E3 ligase ligand via alkyl linkers of various lengths, we rapidly identified TYK2 degrader 5 with moderate TYK2 degradation activity. Degrader 5 induced TYK2 degradation without affecting the protein level of subtype kinases (JAK1, JAK2, and JAK3) in Jurkat cellular assays. Furthermore, modifying the TYK2 ligand moiety of degrader 5 yielded the more potent TYK2 degrader 37 with retained selectivity for JAKs. Our subtype-selective TYK2 degraders represent valuable chemical probes for investigating the biology of TYK2 degradation.

Green synthesis, structure optimization and biological evalution of Rhopaladins’ analog 2–styryl–5-oxopyrrolidine-2- carboxamide RPDPRH on CaSki cells

We have synthesized Rhopaladins’ analog (2E,4E)-4-chlorobenzylidene-2-(4-chlorostyryl)-N-cyclohexyl-1-(4-fluorophenyl)-5-oxopyrrolidine-2-carboxamide (RPDPRH) via a highly facile, inexpensive and green approach and verified the structural superiority of compound RPDPRH through molecular docking. Moreover, we further detected the anti-proliferation, apoptosis and HPV E6/E7 effects of RPDPRH on CaSki cells. Finally, we confirmed that compared with the previous compound (E)-N-(tert-butyl)-2-(4-chlorobenzoyl)-4-(4-fluorobenzylidene)-1-isopropyl-5-oxopyrrolidine-2-carboxamide (RPDPB), RPDPRH could better inhibit proliferation, induce apoptosis, and down-regulate HPV E6/E7 mRNA expression on Caski cells. And preliminary RT-PCR experiments have demonstrated that RPDPRH also could affect the expression of Bcl-2, Bax and Caspase-3 mRNA in Caski cells. In summary, RPDPRH has potential as an effective agent against cervical cancer and will play an important role in our subsequent research.

Double drugging of prolyl-tRNA synthetase provides a new paradigm for anti-infective drug development

Toxoplasmosis is caused by Toxoplasma gondii and in immunocompromised patients it may lead to seizures, encephalitis or death. The conserved enzyme prolyl-tRNA synthetase (PRS) is a validated druggable target in Toxoplasma gondii but the traditional ‘single target–single drug’ approach has its caveats. Here, we describe two potent inhibitors namely halofuginone (HFG) and a novel ATP mimetic (L95) that bind to Toxoplasma gondii PRS simultaneously at different neighbouring sites to cover all three of the enzyme substrate subsites. HFG and L95 act as one triple-site inhibitor in tandem and form an unusual ternary complex wherein HFG occupies the 3’-end of tRNA and the L-proline (L-pro) binding sites while L95 occupies the ATP pocket. These inhibitors exhibit nanomolar IC₅₀ and EC₅₀ values independently, and when given together reveal an additive mode of action in parasite inhibition assays. This work validates a novel approach and lays a structural framework for further drug development based on simultaneous targeting of multiple pockets to inhibit druggable proteins.

Among infectious diseases, parasitic diseases are a major cause of death and morbidity. Toxoplasmosis is caused by an infection of the apicomplexan parasite Toxoplasma gondii. In immunocompromised patients Toxoplasmosis may lead to seizures, encephalitis or death. Novel therapeutics for human parasites are constantly needed. In recent years, the aminoacyl-tRNA synthetase (aaRS) enzyme family has been validated as a drug target for several parasitic infections. The Toxoplasma gondii prolyl-tRNA synthetase inhibitor halofuginone (HFG) has been validated earlier but here we show that an ATP-mimic called L95 is a potent inhibitor and can bind to the target enzyme in the presence of HFG. Thus, the two inhibitors described in this study simultaneously occupy all three natural substrate (ATP, L-amino acid and 3’-end of tRNA) binding pockets and thereby inhibit the enzyme leading to parasite death. This unprecedented double drugging of a pathogen enzyme may delay resistance mutation generation and this approach opens the path to multi-drugging of validated parasite proteins.

Selective TYK2 inhibitors as potential therapeutic agents: a patent review (2019-2021)

INTRODUCTION

Tyrosine kinase 2 (TYK2) is a member of the JAK family class of kinases that is responsible for mediating the immune response to IL-12, IL-23, and IFNα. The therapeutic value of targeting this pathway in autoimmune diseases is supported by human genetics and multiple companies are developing small molecule inhibitors as potential new treatments. In this article, the more recent literature and business activity of the TYK2 field is summarized.

AREAS COVERED

This article seeks to give a comprehensive review of the applications related to selective small molecule TYK2 inhibition since the publication of the last manuscript in this journal in 2019. Recent regulatory activity in the JAK family of approved kinase inhibitors, emerging clinical data, and new companies entering the clinic with selective TYK2 inhibitors will also be discussed.

EXPERT OPINION

Over the past three years there has been an increase in the number of companies and patent applications claiming selective TYK2 inhibitors. Deucravacitinib, an allosteric TYK2 inhibitor discovered by BMS, is the most advanced molecule in clinical development. In 2021, this compound received positive phase 3 data for the treatment of plaque psoriasis and is undergoing additional trials in psoriatic arthritis, lupus, ulcerative colitis, and Crohn's disease. This positive data has spurred a renewed interest in targeting TYK2 with selective inhibitors and several new molecules have entered phase 1 trials this year. The research interest in this area is likely to further increase as additional clinical data with deucravacitinib and other TYK2 inhibitors continue to emerge.

Sterically enriched bulky 1,3-bis(N,N′-aralkyl)benzimidazolium based Pd-PEPPSI complexes for Buchwald–Hartwig amination reactions

A simple and efficient synthesis of a series of unexisting Pd-PEPPSI complexes is summarized. These complexes are exploited for their high catalytic activity towards Buchwald–Hartwig amination.