Elcatonin | CAS 60731-46-6 | Calcitonin Receptor Agonist (Research Use Only) | Knowlux

Product Description

Elcatonin (Carbocalcitonin), CAS 60731-46-6, is a synthetic 31-amino-acid calcitonin analogue derived from eel calcitonin, supplied by Knowlux for laboratory research use. The sequence is Ser-Asn-Leu-Ser-Thr-Asu-Val-Leu-Gly-Lys-Leu-Ser-Gln-Glu-Leu-His-Lys-Leu-Gln-Thr-Tyr-Pro-Arg-Thr-Asp-Val-Gly-Ala-Gly-Thr-Pro-NH2, where Asu denotes alpha-aminosuberic acid and the peptide is cyclized via a lactam bridge between Ser1 and Asu6. The molecular formula is C148H244N42O47 and the molecular weight is 3363.77 g/mol. Each lot is released with a lot-specific COA, MSDS and analytical traceability.

CAS, Salt Form, and Potency Clarification: Elcatonin presents a salt-form documentation pattern distinct from the acetate/free-base splits seen with Degarelix, Pasireotide, or Carperitide. CAS 60731-46-6 is the registry most consistently applied to Elcatonin across ChemicalBook, MedChemExpress, PeptideDB, the Japanese Pharmacopoeia name database, and the majority of Chinese and international suppliers, and it is used for both the free peptide and the acetate salt in commercial listings. The Japanese Pharmacopoeia assigns C148H244N42O47 and MW 3363.77 to this CAS and specifies a potency of 5,000 to 7,000 Elcatonin units per mg of peptide calculated on a water-free and acetic-acid-free basis, which confirms that the JP material is the acetate salt while the CAS itself is not salt-specific. A separate acetate registry, CAS 160649-04-7, appears on InvivoChem's catalogue and is used by that supplier to distinguish Elcatonin acetate from the CAS 60731-46-6 material; this registry is not adopted by the majority of suppliers and should be confirmed against the lot COA before use in a procurement or regulatory document. A formula variant, C146H241N43O47S2 (MW 3414.9), appears in a BenchChem listing; this formula contains two sulfur atoms and one additional nitrogen relative to the consensus C148H244N42O47, and it corresponds to a disulfide-containing calcitonin rather than the lactam-bridged Elcatonin structure. It is treated as a data entry error rather than a second polymorph or salt form. Knowlux specifies the salt basis, acetate content, and water content per lot on the COA. Buyers should confirm whether the quoted material is reported on a free-peptide or acetate-salt basis before procurement, and should note that potency is expressed in International Units (IU) or Elcatonin units rather than by mass alone.

Structural Note: Elcatonin's defining modification is the replacement of the natural Cys1-Cys7 disulfide bridge of eel calcitonin with a stable Ser1-Asu6 lactam (amide) bridge. This structural change is the basis for the analogue's improved chemical stability relative to the parent calcitonin while retaining hypocalcemic activity. The peptide contains no free cysteine and no reducible disulfide bond, distinguishing its handling profile from salmon calcitonin, Carbetocin, and the other disulfide-constrained peptides in this catalogue. The C-terminus is prolinamide (Pro-NH2), amidated against carboxypeptidase degradation, and the N-terminus is free serine. The sequence contains no methionine and no tryptophan, which gives it a comparatively favorable intrinsic oxidation profile; the Asu residue and the lactam bridge are the principal non-natural structural elements.

Product Parameters

Product Details

1. Overview

Elcatonin is a synthetic analogue of eel calcitonin in which the natural N-terminal disulfide bridge is replaced by a lactam ring between Ser1 and Asu6 (alpha-aminosuberic acid). This modification was designed to stabilize the peptide against reduction and disulfide exchange while preserving the hypocalcemic activity of the parent hormone. Elcatonin binds the calcitonin receptor (CALCR), a class B G protein-coupled receptor expressed on osteoclasts, renal tubular cells, and certain brain regions, and activates adenylate cyclase to raise intracellular cAMP. The downstream consequence in bone is inhibition of osteoclast-mediated resorption, and in the kidney it is increased calcium and phosphate excretion. KEGG annotates Elcatonin under target CALCR [HSA:799] within the calcitonin/secretion receptor family and classifies it as a bone resorption inhibitor and calcium regulator. The material supplied under this specification is research-grade and is not intended for human administration. Knowlux supplies this compound strictly for laboratory investigation of calcitonin receptor pharmacology, bone metabolism, and analgesic mechanisms.

2. Receptor Pharmacology and Relative Potency

Elcatonin's pharmacology is best characterized in terms of its potency relative to salmon calcitonin (sCT), the reference calcitonin used in most comparative assays. In the disaggregated rat osteoclast assay (DROcA), Elcatonin has an IC50 of 0.015 pg/mL, which is approximately 5-fold less potent than sCT in the same system. In the rat hypocalcemia bioassay, the ED15 for Elcatonin is 25.2 mg/kg, compared with 33.9 mg/kg for sCT, indicating that Elcatonin is approximately 1.34-fold more potent than sCT in this in vivo endpoint. The difference between the in vitro (less potent than sCT) and in vivo (more potent than sCT) potency rankings is consistent with the analogue's improved metabolic stability, which allows greater exposure in vivo despite a modestly lower intrinsic receptor affinity in the isolated osteoclast assay. A recombinant calcitonin receptor-transduced C2C12 cell system reports an EC50 of 25.05 microg/mL for Elcatonin-stimulated cAMP accumulation, which provides an orthogonal functional potency estimate in a defined cell background. Potency is conventionally expressed in Elcatonin units: the Japanese Pharmacopoeia specifies 5,000 to 7,000 units per mg of peptide on an anhydrous, acetic-acid-free basis, and supplier-issued COAs report specific activities of 6,065 IU/mg (Aviva Systems Biology) and 6,695.2 IU/mg (Abeomics, AssayGenie, MyBioSource) on a net-peptide basis. These unit values are the appropriate metric for in vivo dosing where the readout is hypocalcemia, and they should be used in preference to mass-based dosing when comparing Elcatonin to other calcitonins.

3. Research Applications

Published pharmacological characterizations describe the following research applications:

• Calcitonin receptor (CALCR) binding and functional assays (cAMP accumulation, adenylate cyclase activation)

• Bone resorption and osteoclast activity studies (DROcA and related assays)

• Bone mineral density and skeletal unloading research models

• Central analgesic and anti-allodynic mechanism studies (oxaliplatin-induced cold and mechanical allodynia models)

• Comparative calcitonin pharmacology (relative potency versus salmon calcitonin and eel calcitonin)

• Gastric acid secretion and plasma calcium/phosphate regulation studies

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

MedChemExpress documents in vivo activity in a rat oxaliplatin-induced allodynia model: Elcatonin at 20 U/kg subcutaneously, administered 2 days after oxaliplatin, attenuated cold and mechanical allodynia. These descriptions are derived from published research and are provided for scientific reference only.

Quality Control

The quality specifications for Elcatonin are consistent across the principal research-grade suppliers, but the potency specification is the item that requires the most attention. ChemicalBook supplier listings from Hangzhou Gotop and the GL Biochem specification report HPLC purity >=98.0%, single impurity <=2.0%, peptide content >=75.0%, acetate content 5.0%-12.0%, water content <=8.0%, amino acid composition within +/-15% of theoretical, and endotoxin <=50 EU/mg. InvivoChem, Adooq, and Parchem list >=98% purity as the standard grade, with purities up to 99% available. Potency values reported on supplier COAs range from 6,065 IU/mg to 6,695.2 IU/mg on a net-peptide basis, which sits within the JP window of 5,000-7,000 units/mg. The principal quality consideration is that mass-based dosing and unit-based dosing are not interchangeable across calcitonins, and even within Elcatonin lots the unit value varies by approximately 10% across suppliers. Researchers should use the lot-specific unit value rather than a nominal mass conversion when designing in vivo experiments. Full COA, MSDS, and lot-specific chromatograms are issued with each shipment.

Solubility and Handling

Solubility: Elcatonin solubility is declared by suppliers as H2O/DMSO without a numeric concentration limit in most catalogue entries. InvivoChem lists the acetate salt as may dissolve in DMSO (in most cases), if not, try other solvents such as H2O, ethanol, or DMF, and provides injection formulations for in vivo work that use DMSO/Tween-80/saline and DMSO/PEG300/Tween-80/saline vehicles. The absence of a specific numeric solubility value across the sourced data means that working concentration should be established empirically on the specific lot and buffer system rather than extrapolated from a catalogue figure. For aqueous stock preparation, water is a viable solvent per the supplier declarations; for concentrated stocks or aqueous-insoluble lots, DMSO is the alternative. Prepare solutions fresh and aliquot to avoid 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. Unlike the disulfide-containing calcitonins, Elcatonin is not sensitive to reducing agents such as DTT or mercaptoethanol, because the lactam bridge is not a reducible disulfide. The principal handling consideration is the hygroscopic nature of the lyophilized powder; equilibrate vials to room temperature before opening.

Storage and Stability

Documentation Support

Per lot: COA, MSDS, HPLC chromatogram, and mass spectrometry data. Potency data (units/mg), acetate content, water content, and amino acid composition 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. Elcatonin is an approved medicinal product in certain jurisdictions (including Japan) for specific clinical indications; 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 C148H244N42O47 and molecular weight 3363.77 are confirmed by the Japanese Pharmacopoeia name database, MedChemExpress, PeptideDB, ChemicalBook, VWR, Hoelzel, and GL Biochem. The sequence Ser-Asn-Leu-Ser-Thr-Asu-Val-Leu-Gly-Lys-Leu-Ser-Gln-Glu-Leu-His-Lys-Leu-Gln-Thr-Tyr-Pro-Arg-Thr-Asp-Val-Gly-Ala-Gly-Thr-Pro-NH2 with the Ser1-Asu6 lactam bridge is confirmed by MedChemExpress, PeptideDB, ChemicalBook, VWR, and Omizzur. The structural rationale (lactam bridge replacing the Cys1-Cys7 disulfide for improved stability) is from PeptideDB and DrugFuture. CAS 60731-46-6 is used for both free peptide and acetate in the majority of listings; the JP database assigns it to the acetate material with a 5,000-7,000 units/mg potency specification. CAS 160649-04-7 appears on InvivoChem as a separate acetate registry and is flagged for supplier confirmation rather than adopted as an equivalent identifier. The BenchChem formula C146H241N43O47S2 / MW 3414.9 is noted as inconsistent with the lactam-bridged structure (contains two sulfur atoms and one additional nitrogen) and is treated as a data entry error. The potency data (IC50 0.015 pg/mL in DROcA; ED15 25.2 mg/kg versus 33.9 mg/kg for sCT; EC50 25.05 microg/mL in CalcR-transduced C2C12 cells) are from BenchChem and the PMC study. The in vivo allodynia data (20 U/kg s.c., oxaliplatin model) are from MedChemExpress. Solubility is reported as supplier-declared H2O/DMSO without a reconciled numeric value. Storage guidance is reported as-is, with -20C to -18C presented as the long-term archival condition and the room-temperature stability noted as a documented property of the lactam-stabilized analogue.

Formatting Note: All formulas, sequences, and comparison operators use plain ASCII notation to prevent character corruption on the platform. Asu is rendered as a standard abbreviation; the Greek alpha in alpha-aminosuberic acid is rendered as ASCII text. 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.