Novel neuroprotective 5,6-dihydropyrido[2',1':2,3]imidazo[4,5-c]quinoline derivatives acting through cholinesterase inhibition and CB2 signaling modulation

Quinoline Quest: Kynurenic Acid Strategies for Next-Generation Therapeutics via Rational Drug Design

BACKGROUND

Quinoline-derived metabolites exhibit notable chemical complexity. What causes minor structural alterations to induce significant changes in disease outcomes? Historically, eclipsed by more straightforward scaffolds, these chemicals serve as a dynamic hub in tryptophan metabolism, linking immunomodulation, excitotoxicity, and cancer. However, many of these compounds struggle to cross the blood-brain barrier, and we still do not fully understand how certain structural changes affect their bioavailability or off-target effects. Thus, contemporary research highlights halogenation, esterification, and computational modeling to enhance structure-activity relationships.

SUMMARY

This narrative review emphasizes the integration of rational drug design, multi-target ligands, and prodrug methods in enhancing quinoline scaffolds. We explore each molecule's therapeutic promise, refine each scaffold's design, and develop each derivative to maximize clinical utility. Translating these laboratory findings into clinical practice, however, remains a formidable challenge.

CONCLUSIONS

Through the synthesis of findings regarding NMDA receptor antagonism, improved oral bioavailability, and reduced metabolic instability, we demonstrate how single-site changes might modulate excitotoxicity and immunological signaling. Advancing quinoline-based medicines will yield significant advancements in neurology, psychiatry, and oncology. This enlarged framework fosters collaborative discovery, engages various audiences, and advances the field towards next-generation disease-modifying therapies. Robust preclinical validation, patient classification, and comprehensive toxicity evaluations are crucial stages for achieving these extensive endeavors and fostering future therapeutic discoveries globally.

Rutaecarpine derivatives synthesized via skeletal reorganization alleviate inflammation-associated oxidative damage by inhibiting the MAPK/NF-κB signaling pathway

In recent years, skeleton reorganization based on bioactive natural products has emerged as a novel alternative strategy to the classical approach, mainly focusing on the peripheral modification of the inherent natural skeleton. Such reorganizations not only afford structurally unique molecules but also provide unanticipated bioactivities compared with the unaltered natural precursors. Herein, by rebuilding the inherent rigid skeleton of cardioprotective rutaecarpine (RUT), thirty-three structural derivatives were designed and synthesized, with 5Ci being the most representative example, which exhibited superior protective effects against inflammation-induced ROS accumulation and cellular damage compared with the clinically used anti-inflammation drug indomethacin.

Unlocking the power of imidazoquinolines: recent advances in anticancer and immunotherapeutic strategies

The challenges in drug discovery aiming to mitigate cancer progression are the thrust area of scientific research for several decades. Since the advent of heterocyclic chemistry, drug discovery programs have made significant achievements that lead to the development of numerous drugs with broad spectrum of potencies, contributing to both diagnostic and therapeutic advancements. Till date, efforts to discover more potent and efficient drug candidates are underway to minimize adverse side effects of existing chemotherapeutics. In view of the above, small-molecule agonists that can interact with different immune modulators like toll like receptor-7 (TLR-7) and TLR-8 are being investigated and explored. These candidates are expected to display profound effect on anti-tumoral activity by enhancing the production of proinflammatory cytokines. Recently, numerous imidazoquinoline derivatives with proven TLR agonist activities have emerged as promising anticancer therapeutics. With advancements in technology and the evolution of new scopes in drug discovery, different strategies are being adopted, particularly with the help of nanotechnology, immune-technology, combination drug chemistry, etc., to curb the progression of various types of cancers. Herein, the novel strategies for cancer therapeutics with imidazoquinolines reported in the last 5 years, their structure-activity relationship along with important synthetic schemes for important TLR agonists, are discussed.

Ionic-liquid-supported copper-promoted synthesis of 3,5-disubstituted-1,2,4-triazoles

The synthesis of triazoles plays an important role in drug discovery research. 1,2,4-triazoles are considered significant scaffolds among several bioactive heterocycles due to their extensive use in the pharmaceutical and agrochemical sectors. Consequently, the importance of the synthesis of 1,2,4-triazoles via a sustainable method has increased. Herein, we have utilized an ionic-liquid-supported copper(II) catalyst for the synthesis of 1,2,4-triazoles from benzonitrile derivatives and primary amines under neat conditions both in thermal and microwave heating approaches. Our approach furnished excellent yields of the target moieties (7a-r) in a comparatively short reaction time. This synthetic protocol provides the advantage of synthesizing a couple of C-N bonds and an N-N bond simultaneously from easily accessible amines and nitriles in a simple pathway via a sustainable approach.

A microwave assisted tandem synthesis of quinazolinones using ionic liquid supported copper(II) catalyst with mechanistic insights

Quinazolinone is a preferred structural motif with notable pharmacological activity that is present in a wide range of naturally occurring compounds. A microwave assisted tandem cyclooxidative method has been developed to afford quinazolinones via a recyclable ionic liquid supported copper catalyst. This sustainable method exhibits operational simplicity through a rapid, clean, and energy-efficient route and a variety of 2-substituted quinazolinones are obtained in excellent yields. In addition, this innovative approach enables us to develop a library of nitriles in an environment-friendly synthetic protocol. Moreover, the catalyst can be recycled and reused up to three consecutive cycles without any significant loss of catalytic activity. Further organic transformation of the synthesized quinazolinones was carried out to afford reported as well as novel bioactive heterocyclic compounds.