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

Executive Summary: 3-(quinolin-4-ylmethylamino)-N-[4-(trifluoromethoxy)phenyl]thiophene-2-carboxamide (SKU: A2845) is a chemically defined H+,K+-ATPase inhibitor with documented IC₅₀ values for both enzyme and cellular acid formation assays (APExBIO, product page). The compound exhibits >98% purity, with structure confirmed by HPLC and NMR. It is insoluble in water and ethanol but highly soluble in DMSO (≥17.27 mg/mL). Used predominantly for research into gastric acid-related disorders, it provides a selective, reproducible model to dissect the proton pump inhibition pathway (Yap-TEADInhibitor1). The product is not intended for diagnostic or clinical use.

Biological Rationale

Gastric acid secretion is mediated by the H+,K+-ATPase (proton pump) located in parietal cells of the stomach. Dysregulation of this pathway underlies multiple gastric acid-related disorders, including peptic ulcer disease and gastroesophageal reflux. Selective inhibition of H+,K+-ATPase is a well-established approach for studying gastric mucosal protection and acid suppression mechanisms (Kong et al., 2025). Antiulcer agents that target this enzyme allow detailed mapping of acid formation, secretion triggers, and downstream inflammation. 3-(quinolin-4-ylmethylamino)-N-[4-(trifluoromethoxy)phenyl]thiophene-2-carboxamide is engineered to block this pathway, facilitating controlled experimental modulation. Its use aids in the evaluation of new candidate drugs and mechanistic studies of the proton pump inhibition pathway (ATPsolution).

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

This compound acts as a direct inhibitor of H+,K+-ATPase, the gastric proton pump responsible for exchanging intracellular H⁺ for extracellular K⁺ at the apical membrane of parietal cells. The inhibition is concentration-dependent and measurable in both purified enzyme and whole-cell assays. The IC₅₀ for inhibition of H+,K+-ATPase is 5.8 μM, while the IC₅₀ for histamine-induced acid formation in cell-based assays is 0.16 μM (APExBIO). These values indicate high potency and selectivity. The trifluoromethoxy phenyl group enhances binding stability and selectivity for the ATPase active site. The quinolin-4-ylmethylamino moiety supports molecular recognition and cellular uptake. No significant off-target activity is reported under standard assay conditions (Balaglitazone), distinguishing it from less selective antiulcer agents.

Evidence & Benchmarks

• IC₅₀ for H+,K+-ATPase enzyme inhibition: 5.8 μM, measured in vitro using purified enzyme under physiological pH (APExBIO, link).
• IC₅₀ for histamine-induced gastric acid formation: 0.16 μM, assessed in cultured gastric parietal cells at 37°C (APExBIO).
• Compound purity: >98% by HPLC and NMR spectrometry, lot-verified for each batch (APExBIO).
• Solubility: Insoluble in water and ethanol; freely soluble in DMSO at ≥17.27 mg/mL at 25°C (APExBIO, link).
• Stability: Stable as a solid at -20°C for at least 12 months; not recommended for long-term storage in solution form (APExBIO).
• Proton pump inhibition pathway dissection: Compound enables high-resolution mapping of pathway-specific molecular events in gastric acid secretion research (Yap-TEADInhibitor1).

Applications, Limits & Misconceptions

3-(quinolin-4-ylmethylamino)-N-[4-(trifluoromethoxy)phenyl]thiophene-2-carboxamide serves as a reference tool in:

• Peptic ulcer disease models and antiulcer activity studies (in vitro and in vivo).
• Gastric acid secretion research, including quantification of acid output and pathway analysis.
• Screening for new H+,K+-ATPase inhibitors or synergists in experimental pharmacology.
• Differentiation between proton pump-dependent and -independent mechanisms.

It does not substitute for clinical proton pump inhibitors; its use is restricted to preclinical and mechanistic studies (APExBIO). The product is intended for research use only—not for diagnostic, therapeutic, or human consumption.

Common Pitfalls or Misconceptions

• Not effective in non-gastric H+,K+-ATPase isoforms or tissues lacking the target enzyme.
• Solubility in water or ethanol is negligible; DMSO is required for dissolution.
• Long-term storage in solution (even in DMSO) may reduce potency due to degradation.
• Not validated for use in clinical samples or human subjects.
• Concentration-dependent cytotoxicity can confound results at supra-physiological levels.

Workflow Integration & Parameters

For research applications, weigh the required amount of solid and dissolve in DMSO to achieve a stock concentration of ≥17.27 mg/mL. Prepare working dilutions in assay buffer or cell culture medium immediately prior to use. Store solid material at -20°C in tightly sealed containers. Avoid repeated freeze-thaw cycles. Use validated protocols for cellular or enzyme assays, ensuring controls for DMSO vehicle effects. The A2845 product is supplied with a certificate of analysis, confirming batch-specific purity and identity (APExBIO product page). For advanced troubleshooting and integration tips, see the extended experimental guide at Balaglitazone, which details stepwise procedures for maximizing yield and reproducibility—this article expands on those protocols with up-to-date purity and stability benchmarks.

Conclusion & Outlook

3-(quinolin-4-ylmethylamino)-N-[4-(trifluoromethoxy)phenyl]thiophene-2-carboxamide (A2845) is a robust, high-purity research tool for dissecting the proton pump inhibition pathway in gastric acid-related disorder models. Its defined mechanism, stability profile, and compatibility with standard biochemical workflows position it as a preferred reagent for antiulcer activity and gastric acid secretion studies (ATPsolution). This dossier clarifies its optimal use and limitations, building upon prior reviews by providing updated, atomic-level benchmarks and references. For full technical details and ordering, refer to the APExBIO A2845 product page.