Secretin Acetate | CAS 17034-35-4 / 17034-34-3 | Secretin Receptor Agonist (Research Use Only) | Knowlux

Product Description

Secretin Acetate, CAS 17034-35-4 (free base registry) / 17034-34-3 (x-acetate salt), is a synthetic 27-amino-acid peptide hormone corresponding to porcine secretin, supplied by Knowlux for laboratory research use. The sequence is H-His-Ser-Asp-Gly-Thr-Phe-Thr-Ser-Glu-Leu-Ser-Arg-Leu-Arg-Asp-Ser-Ala-Arg-Leu-Gln-Arg-Leu-Leu-Gln-Gly-Leu-Val-NH2, with a free N-terminal histidine and an amidated C-terminal valinamide. The free peptide molecular formula is C130H220N44O41 and the molecular weight is 3055.41 g/mol. Secretin is the first hormone ever identified and is the prototype of the secretin/glucagon/VIP/PACAP peptide family. Each lot is released with a lot-specific COA, MSDS and analytical traceability.

CAS and Salt Form Clarification: The CAS landscape for Secretin is frequently misrepresented in commercial listings, and the misrepresentation has direct procurement consequences. CAS 17034-35-4 is the free base registry, confirmed by PubChem, ChemicalBook, MedChemExpress, Selleck, and GL Biochem, but it is widely used for both the free peptide and the acetate salt. BOC Sciences resolves the ambiguity explicitly: CAS 17034-35-4 is annotated as free base, CAS 17034-34-3 as the x-acetate salt (C130H220N44O41.xC2H4O2, MW 3055.41 on a free-base basis), and CAS 101301-47-7 as the monoacetate salt (C130H220N44O41.C2H4O2, MW 3115.49). BenchChem lists Secretin acetate under CAS 17034-34-3 with the x-acetate formula. A separate CAS, 10813-74-8, appears in some Chinese supplier listings as a legacy porcine secretin registry and is not adopted as a primary identifier here. Knowlux declares the salt form, counter-ion identity, and counter-ion content per lot on the COA. Buyers should confirm whether the quoted material is free base, monoacetate, or x-acetate before procurement.

Species and Sequence Note: Porcine and human secretin differ at only two positions: position 15 is Asp in pig and Glu in human, and position 16 is Ser in pig and Gly in human. Porcine secretin is the form most commonly supplied for research and is widely used as a surrogate for the human hormone because of the high sequence homology. The entire 27-amino-acid sequence is required for full activity, and the amidated C-terminus is essential. Secretin is linear, contains no cysteine, and has no intramolecular cross-link, which simplifies handling with respect to reducing agents. The peptide contains no methionine and no tryptophan, giving it a favorable intrinsic oxidation profile.

Product Parameters

Product Details

1. Overview

Secretin is a 27-residue neuroendocrine hormone secreted by S cells in the duodenal mucosa and is the first hormone ever identified. It is released in response to acid in the small intestine and acts on the pancreatic ductal epithelium to stimulate secretion of a bicarbonate-rich fluid, neutralizing gastric acid and regulating duodenal pH. Secretin also stimulates biliary bicarbonate secretion, inhibits gastrin release and gastric acid secretion, inhibits gastrointestinal peristalsis, and delays gastric emptying. The peptide is structurally related to glucagon, VIP, PACAP, GIP, GHRH, and PHI/PHM, which together form the secretin peptide family. Secretin is a class B GPCR agonist, and its receptor (SCTR) is Gs-coupled and elevates intracellular cAMP. The material supplied under this specification is research-grade and is not intended for human administration.

2. Receptor Pharmacology and Selectivity

Secretin binds the secretin receptor (SCTR), a class B GPCR that couples positively to adenylyl cyclase and elevates cAMP. Reported constants show substantial amplification between receptor occupancy and downstream response. BenchChem reports a Ki of 4.6 +/- 1.0 nM at the human SCTR and an EC50 of 0.01 +/- 0.01 nM for cAMP activation. A separate pharmacological characterization at the human recombinant SCTR reports a mean pEC50 of 9.9 +/- 0.2 M (0.13 nM) for human secretin-stimulated cAMP elevation. For the rat SCTR, GLPBIO reports a Ki of 3.3 nM and an EC50 of 1 nM for cAMP accumulation in COS cells, with 7.2-fold receptor phosphorylation at 0.1 microM. A 2024 profiling study reports an hSCTR EC50 of 0.0023 nM alongside an hGLP-1R EC50 of 2300 nM, giving a selectivity ratio of approximately 10^6 for SCTR over GLP-1R. This selectivity supports the use of secretin as an SCTR-specific tool where VIP, PACAP, or GLP-1 receptor cross-talk could confound interpretation. These values are assay- and system-dependent and are provided for scientific reference only.

3. Research Applications

Published pharmacological characterizations and documented protocols describe the following research applications:

• Secretin receptor (SCTR) binding and functional assays (cAMP accumulation, receptor phosphorylation)

• Pancreatic exocrine function and bicarbonate secretion studies

• Biliary growth and cholangiocyte proliferation research (SCTR-dependent cAMP signaling)

• Gastric acid secretion and gastrin release regulation studies

• Adipocyte lipolysis and fatty acid uptake research (PKA and HSL signaling)

• Neuroendocrine and gut-brain axis studies (catecholamine secretion in PC12 neurons, ambulation in hyperactivity models)

• Gastrointestinal motility and ICC-DMP signaling studies

• Reference standard development for HPLC and LC-MS analytical methods

LKT Labs documents adipocyte-specific activities: secretin stimulates lipolysis via PKA and hormone-sensitive lipase signaling, induces fatty acid uptake, and increases MCP-1 and adiponectin secretion. MedChemExpress documents biliary growth effects: secretin stimulates biliary proliferation through SCTR interaction, and SCTR knockout reduces biliary proliferation by downregulating cAMP-dependent signaling. These descriptions are derived from published research and are provided for scientific reference only.

Quality Control

The quality specifications for Secretin Acetate span several supplier tiers. GL Biochem and SBS Genetech specify HPLC purity >=98.0%, single impurity <=1.0%, peptide content >=80.0% by nitrogen analysis, water content <=6.0% by Karl Fischer, acetate content <=15.0% by HPIC, amino acid composition within +/-10% of theoretical, and mass balance of 95.0%-105.0%. Typeptide offers a lower-cost research grade at >=98.0% HPLC purity with single impurity <=2.0%, peptide content >=75.0%, amino acid composition within +/-15%, and endotoxin <=50 EU/mg. LKT Labs and Abbexa specify >=95% by HPLC. Aladdin specifies >=97% by HPLC. The Peptide Institute supplies a premium grade at >=99.0% by HPLC. A ChemicalBook listing reports a batch purity of 98.88% for a 5 mg lot. The principal quality consideration is the salt-form ambiguity: a lot reported at MW 3055.41 is on a free-base basis, whereas a lot at 3115.49 is on a monoacetate basis. Researchers preparing molar solutions should use the peptide content value and the acetate content declared on the COA rather than the HPLC purity figure alone.

Solubility and Handling

Solubility: Secretin Acetate solubility is reported inconsistently across suppliers. ChemicalBook describes the compound as soluble in water, physiological saline, and aqueous organic solvents. LKT Labs specifies solubility in water or saline. MedChemExpress reports DMSO solubility of 66.67 mg/mL (21.82 mM) with sonication for its Secretin (swine) lot. The Peptide Institute, by contrast, lists water solubility of only 0.1 mM, approximately 0.31 mg/mL, a figure more than two orders of magnitude lower than the qualitative "soluble" designation. Typeptide lists H2O/DMSO without a numeric limit. This divergence likely reflects differences in salt form, lot history, and whether the measurement was performed on a saturated solution with or without sonication. For practical stock preparation, DMSO at 66.67 mg/mL is the most consistently supported numeric value, and water or saline are viable at lower working concentrations. Aqueous stock solutions should be prepared fresh and not stored beyond one day; general guidance recommends that stock solutions be aliquoted, tightly sealed, and used within 1 month, with avoidance of repeated freeze-thaw cycles.

Handling Precautions: Use powder-handling containment (glove box or fume hood with particulate control). Avoid inhalation of fine powder. Wear nitrile gloves, lab coat, and eye protection. Because the peptide contains no cysteine or methionine, reducing agents and oxidation-protection measures are not required. The lyophilized powder is hygroscopic; equilibrate vials to room temperature before opening.

Storage and Stability

Storage guidance for Secretin Acetate shows a wider spread than for most peptides in this catalogue. MedChemExpress specifies 2 years at -80C and 1 year at -20C for powder, with solutions stable for 6 months at -80C or 1 month at -20C. AbMole specifies 3 years at -20C and 2 years at 4C for powder, with the same solution windows. ChemicalBook and Sigma-Aldrich specify 2C to 8C as the storage temperature, an outlier relative to the -20C and -80C conditions from the principal peptide suppliers. One supplier lists 2C to 8C with a 3-year validity, suggesting that the 2C to 8C recommendation may be valid for specific lyophilized formats. LKT Labs recommends -20C and ships at ambient temperature. For long-term archival storage, -20C under desiccation is the most widely supported condition; -80C is the conservative choice for extended storage of either powder or solutions. The lyophilized powder is hygroscopic; equilibrate vials to room temperature before opening to prevent condensation. Protect from light and moisture throughout storage.

Documentation Support

Per lot: COA, MSDS, HPLC chromatogram, and mass spectrometry data. Acetate content, water content, peptide content, and salt-form stoichiometry available on request. Custom specifications and third-party inspection can be arranged on a project basis.

About Knowlux

Knowlux Biotechnology is a GMP-oriented manufacturer and supplier of peptides, APIs and fine-chemical research compounds, operating from Hubei, China. We serve research groups, CDMOs and distributors in more than 40 countries, and support contract synthesis, custom packaging and technical documentation requests.

Compliance Statement

FOR RESEARCH USE ONLY. NOT FOR HUMAN USE. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE.

This product is supplied for laboratory research use only. It is not for human or animal administration, not for diagnostic or therapeutic use, not for retail sale, and not for personal use. Secretin is an approved diagnostic agent in certain jurisdictions (including the SecreFlo brand for pancreatic function testing); however, the material offered under this specification is research-grade and is not intended for clinical use. The purchaser is responsible for verifying product specifications against their specific research requirements and for compliance with all applicable institutional, local, and national regulations governing research chemical acquisition, storage, and use. Research context statements are for scientific reference only and do not constitute medical advice, promotional claims, or dosing guidance.

Data Verification Notes: The molecular formula C130H220N44O41 and molecular weight 3055.41 are confirmed across PubChem, GL Biochem, SBS Genetech, Abbexa, ChemicalBook, MedChemExpress, and AbMole. The sequence His-Ser-Asp-Gly-Thr-Phe-Thr-Ser-Glu-Leu-Ser-Arg-Leu-Arg-Asp-Ser-Ala-Arg-Leu-Gln-Arg-Leu-Leu-Gln-Gly-Leu-Val-NH2 is confirmed across PubChem, GL Biochem, SBS Genetech, Abbexa, ChemicalBook, MedChemExpress, and the Peptide Institute. The CAS mapping (17034-35-4 = free base; 17034-34-3 = x-acetate salt; 101301-47-7 = monoacetate salt) is from BOC Sciences, which explicitly resolves the three registries. The monoacetate formula and MW 3115.49 are from BOC Sciences. The porcine-versus-human sequence difference is from the Gastroenterology paper and ScienceDirect. The SCTR pharmacology constants are from BenchChem, the pA2 online pharmacological characterization, GLPBIO, and the 2024 PMC profiling study. Solubility values are reported with their source and conditions rather than reconciled into a single figure because the Peptide Institute 0.1 mM water value and the ChemicalBook "soluble in water" description reflect different measurement contexts. Storage shelf-life divergence is reported as-is; the -20C condition is the most widely supported archival temperature and -80C is presented as the conservative option.

Formatting Note: All formulas, sequences, and comparison operators use plain ASCII notation to prevent character corruption on the platform. The micro symbol is rendered as "micro" or omitted, and scientific notation as "10^6" to avoid non-ASCII character risk. Section headings, table alignment, and spacing follow the approved product detail pattern. No trailing spaces or non-breaking characters are used; tables use consistent pipe alignment.