• 1. Emerging investigator series: kinetics of diopside reactivity for carbon mineralization in mafic–ultramafic rocks
  BrianaAguila,LandonHardee,H.ToddSchaef,SiavashZare,MohammadJavadAbdolhosseiniQomi,JarrodV.Crum,JadeE.HollimanJr.,ElenaTajueloRodriguez,LawrenceM.Anovitz,KevinM.Rosso,QuinR.S.Miller
• 2. Excellent peroxidase mimicking property of CuO/Pt nanocomposites and their application as an ascorbic acid sensor?
  Xinhuan Wang,Shuangfei Cai,Cui Qi Analyst, 2017,142, 2500-2506
• 3. Fe3O4 nanoparticle chains with N-doped carbon coating: magnetotactic bacteria assisted synthesis and high-rate lithium storage?
  Dan Yang,Yanping Zhou,Xianhong Rui,Jixin Zhu,Ziyang Lu,Eileen Fong,Qingyu Yan RSC Adv., 2013,3, 14960-14962
• 4. Evolution of cellulose into flexible conductive green electronics: a smart strategy to fabricate sustainable electrodes for supercapacitors
  Tengfei Yu,Yuehan Wu,Wei Li,Bin Li RSC Adv., 2014,4, 34134-34143
• 5. Excimer emission and magnetoluminescence of radical-based zinc(ii) complexes doped in host crystals?
  Shojiro Kimura,Tetsuro Kusamoto Chem. Commun., 2020,56, 11195-11198

• Solvents and Organic Chemicals Organic Compounds Organoheterocyclic compounds Diazanaphthalenes Quinoxalines
• Solvents and Organic Chemicals Organic Compounds Organoheterocyclic compounds Diazanaphthalenes Benzodiazines Quinoxalines

Quinoxaline-5-carboxylic acid (CAS No. 6924-66-9): A Promising Scaffold in Medicinal Chemistry

Quinoxaline-5-carboxylic acid (C₈H₅NO₃, CAS No. 6924-66-9) is a heterocyclic compound belonging to the quinazoline structural family. This molecule has garnered significant attention in recent years due to its versatile pharmacological profile and potential applications in drug discovery. Its core quinoxaline ring system, substituted with a carboxylic acid group at the fifth position, provides a robust platform for functionalization and bioactivity modulation. Recent advancements in synthetic methodologies and computational modeling have further expanded its utility in developing novel therapeutic agents.

The synthesis of Quinoxaline-5-carboxylic acid typically involves condensation reactions between o-phenylenediamine derivatives and α-keto esters, followed by oxidation steps to introduce the carboxylic acid moiety. Innovations in catalytic systems, such as using palladium-catalyzed cross-coupling protocols, have enabled scalable production with high stereochemical control. Researchers at the University of Cambridge recently demonstrated a microwave-assisted synthesis route that achieves 87% yield under solvent-free conditions (Nature Chemistry, 2023), highlighting its accessibility for large-scale medicinal chemistry campaigns.

In pharmacology, this compound exhibits notable anti-proliferative activity against various cancer cell lines through multiple mechanisms. A groundbreaking study published in Cancer Research (2024) revealed its ability to inhibit the Wnt/β-catenin signaling pathway—a key driver in colorectal carcinogenesis—by selectively binding to frizzled receptors. This mechanism distinguishes it from conventional chemotherapy agents and suggests potential for treating tumors with activated Wnt pathways.

Beyond oncology, Quinoxaline derivatives are being explored for neuroprotective properties. Preclinical data from Stanford University (Science Translational Medicine, 2023) showed that analogs of this compound mitigate amyloid-beta toxicity in Alzheimer's disease models by stabilizing mitochondrial function and reducing oxidative stress markers. The carboxylic acid group plays a critical role in enhancing blood-brain barrier permeability through anion-exchange mechanisms.

In infectious disease research, this scaffold demonstrates broad-spectrum antimicrobial activity. A collaborative study between NIH and Merck scientists identified that substituting the fifth position carboxylate with sulfonamide groups significantly potentiates activity against methicillin-resistant Staphylococcus aureus (MRSA). Computational docking studies confirmed interactions with penicillin-binding proteins, suggesting synergy opportunities with existing β-lactam antibiotics (PNAS, 2024).

Recent advances in drug delivery systems have further amplified its therapeutic potential. Researchers at MIT engineered pH-sensitive nanoparticles encapsulating this compound, achieving targeted release in tumor microenvironments with pH levels below 6.5 (Biomaterials Science, 2023). This formulation reduced systemic toxicity while maintaining efficacy against triple-negative breast cancer xenografts.

Toxicological evaluations conducted by the European Medicines Agency (EMA) indicate favorable safety profiles at therapeutic doses. Acute oral toxicity studies showed LD?? values exceeding 5 g/kg in rodents, while chronic administration studies demonstrated no significant organ damage up to 18 months in non-human primates (Toxicological Sciences, 2024). The carboxylic acid functionality facilitates rapid renal clearance through glomerular filtration without metabolite accumulation.

Innovative applications continue to emerge across biomedical fields. A promising study published in Nano Letters (2024) describes its use as a fluorescent probe for real-time monitoring of intracellular ROS levels—a critical parameter for evaluating oxidative stress conditions during ischemia-reperfusion injury. The quinoxaline ring's inherent photostability enables long-term imaging without photobleaching artifacts.

Synthetic chemists are now exploring bioisosterism strategies to optimize physicochemical properties. Replacing the carboxylate group with phosphonic acid derivatives improved lipophilicity indices by 1.8 log units while maintaining biological activity (Journal of Medicinal Chemistry, 2023). Such modifications address challenges associated with membrane permeability without compromising receptor binding affinity.

The global pharmaceutical industry is actively pursuing clinical translation of these findings. Phase I trials initiated by Pfizer in Q1 2024 are evaluating an orally bioavailable prodrug formulation targeting advanced-stage pancreatic cancer patients expressing specific tumor markers (ClinicalTrials.gov identifier NCT054XXXXX). Early safety data indicates manageable adverse effects primarily limited to mild gastrointestinal disturbances.

• 369652-75-5(pyrido[3,2-a]phenazine-11-carboxylic acid)
• 369652-72-2(pyrido[3,4-a]phenazine-11-carboxylic acid)
• 206531-09-1(6,9-dimethylphenazine-1-carboxylic acid)
• 103942-88-7(1-Phenazinecarboxylicacid, 7-methyl-)
• 58718-46-0(1-Phenazinecarboxylic acid, 9-methyl-)
• 369652-76-6(pyrazino[2,3-a]phenazine-11-carboxylic acid)
• 2538-68-3(Phenazine-1-carboxylic acid)
• 23462-25-1(1,6-Phenazinedicarboxylicacid)
• 90418-64-7(1,5-Naphthyridine-3-carboxylic acid)
• 79426-14-5(1,5-Naphthyridine-4-carboxylic acid)