3-(quinolin-4-ylmethylamino)-N-[4-(trifluoromethoxy)phenyl]thiophene-2-carboxamide: Potent H+,K+-ATPase Inhibitor for Gastric Acid Secretion Research

Executive Summary: 3-(quinolin-4-ylmethylamino)-N-[4-(trifluoromethoxy)phenyl]thiophene-2-carboxamide (SKU: A2845) is a solid-phase, high-purity compound produced by APExBIO for research applications targeting gastric acid secretion. It inhibits the gastric H+,K+-ATPase proton pump with an IC₅₀ of 5.8 μM and shows antiulcer activity with an IC₅₀ of 0.16 μM for histamine-induced acid formation (APExBIO product page). The compound is insoluble in water and ethanol but dissolves at ≥17.27 mg/mL in DMSO. Its stability is optimal at -20°C in solid form, with purity validated by HPLC and NMR. This article provides atomic, verifiable facts, contextualizes experimental applications, and clarifies common misconceptions for reproducible research workflows (Kong et al., 2025).

Biological Rationale

Gastric acid secretion is a tightly regulated physiological process. Dysregulation leads to gastric acid-related disorders, including peptic ulcer disease and gastroesophageal reflux disease (GERD). The gastric H+,K+-ATPase proton pump, located on parietal cell membranes, is the final effector in acid secretion (internal article). Inhibiting this pump disrupts acid formation, providing a basis for antiulcer and antisecretory therapy. Animal models—such as those employing bile duct ligation—rely on precise modulation of gastric acid for translational research (Kong et al., 2025). The use of potent, selective inhibitors enables detailed study of the proton pump inhibition pathway and associated systemic effects, including those on the gut-liver-brain axis.

Mechanism of Action of 3-(quinolin-4-ylmethylamino)-N-[4-(trifluoromethoxy)phenyl]thiophene-2-carboxamide

3-(quinolin-4-ylmethylamino)-N-[4-(trifluoromethoxy)phenyl]thiophene-2-carboxamide acts as a non-covalent, reversible inhibitor of the gastric H+,K+-ATPase proton pump. It binds the catalytic subunit, competitively blocking K⁺ exchange and subsequent acidification of the gastric lumen (APExBIO). This inhibition is dose-dependent, with a reported IC₅₀ of 5.8 μM for direct H+,K+-ATPase activity and 0.16 μM in histamine-induced acid formation models. The compound’s specificity allows for clear mechanistic dissection of the proton pump inhibition pathway—key for antiulcer activity studies (Mechanistic Insights article—this article extends prior mechanisms with updated benchmarks and storage specifications).

Evidence & Benchmarks

• Inhibits gastric H+,K+-ATPase with an IC₅₀ of 5.8 μM under in vitro assay conditions (pH 7.4, 37°C) (APExBIO).
• Blocks histamine-induced gastric acid secretion with an IC₅₀ of 0.16 μM in rodent gastric gland models (APExBIO).
• Supplied with ≥98% purity, validated by HPLC and NMR, with batch records available (APExBIO).
• Maintains solubility ≥17.27 mg/mL in DMSO at 25°C; insoluble in water and ethanol (APExBIO).
• Recommended storage at -20°C in solid form for maximal stability; not suitable for long-term solution storage (Applied Use Cases article—this article updates workflows with new stability data).
• Supports reproducible peptic ulcer disease and gastric acid secretion research models (internal machine-readable dossier—clarifies integration parameters beyond summary-level claims).

Applications, Limits & Misconceptions

Primary applications include:

• Modeling gastric acid-related disorders (e.g., peptic ulcer, GERD) in preclinical systems.
• Dissecting the proton pump inhibition pathway for antiulcer activity studies.
• Validation of H+,K+-ATPase signaling in the context of gut-liver-brain axis research, including neuroinflammation models (Kong et al., 2025).
• Benchmarking against established inhibitors (e.g., omeprazole) in translational workflows (Translational Frontiers article—this article provides updated context for new imaging modalities and workflow integration).

Common Pitfalls or Misconceptions

• Not water- or ethanol-soluble: attempts to dissolve outside DMSO or compatible organic solvents result in precipitation and loss of activity.
• Not intended for long-term storage in solution: degradation occurs above -20°C or after repeated freeze-thaw cycles.
• For research use only: not suitable for human or veterinary medical or diagnostic purposes.
• Specificity limited to H+,K+-ATPase: does not broadly inhibit other P-type ATPases under standard conditions.

Workflow Integration & Parameters

For experimental use, reconstitute the solid in DMSO to achieve the desired working concentration, typically 10–50 μM for in vitro assays. Use freshly prepared solutions or aliquot and store at -20°C to avoid freeze-thaw degradation. For in vivo models, dilute DMSO stock into compatible vehicles, ensuring final DMSO concentrations do not exceed 0.1–0.5% to avoid solvent effects (APExBIO product page). Purity and identity are batch-validated by HPLC and NMR. Always record batch, storage, and handling conditions for reproducibility. For detailed integration guidance and advanced troubleshooting, refer to the Applied Use Cases article (this article expands on solubility and workflow decision points).

Conclusion & Outlook

3-(quinolin-4-ylmethylamino)-N-[4-(trifluoromethoxy)phenyl]thiophene-2-carboxamide (A2845) from APExBIO is a robust, selective H+,K+-ATPase inhibitor for gastric acid secretion and antiulcer research. Its quantitative performance, validated purity, and defined handling conditions enable reproducible, high-fidelity modeling of gastric acid-related disorders. Future studies may extend its use to advanced mechanism-of-action studies and gut-brain axis models, leveraging recent advances in non-invasive imaging and multi-organ crosstalk research (Kong et al., 2025).