Anaritide | CAS 95896-08-5 | Atrial Natriuretic Peptide (102-126) Fragment (Research Use Only) | Knowlux

Product Description

Anaritide, CAS 95896-08-5, is a synthetic 25-amino-acid peptide corresponding to the human atrial natriuretic peptide (ANP) fragment (102-126), supplied by Knowlux for laboratory research use. The peptide is constrained by a single intramolecular disulfide bridge and carries a free C-terminal tyrosine carboxylate. The molecular formula is C112H175N39O35S3 and the molecular weight is 2724.02 g/mol. Each lot is released with a lot-specific COA, MSDS and analytical traceability.

CAS and Salt Form Clarification: CAS 95896-08-5 is the free peptide registry and is the identifier most consistently applied across MedChemExpress, Adooq, PeptideDB, Biorbyt, and ChemicalBook. The acetate salt carries a separate registry, CAS 104595-79-1, confirmed by KEGG DRUG, MeSH, NCI Thesaurus, DrugBank, and InvivoChem. The acetate molecular formula is C112H175N39O35S3.C2H4O2 (equivalently C114H179N39O37S3), and the counter-ion adds approximately 60 g/mol to the free-peptide mass. A substantial proportion of supplier listings use CAS 95896-08-5 under the product name Anaritide while supplying the acetate salt or without declaring the salt basis at all. Knowlux specifies the salt form, counter-ion identity, and counter-ion 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 reconcile the molecular weight on the COA (2724.02 for free peptide versus approximately 2784.07 for monoacetate) against the declared salt form.

Structural and Positional Note: Anaritide corresponds to the 25-residue C-terminal fragment of ANP, spanning residues 102-126 of the ANP prohormone. It lacks the four N-terminal residues (Ser-Leu-Arg-Arg) present in the full-length ANP(1-28) and lacks the four-residue N-terminal extension (Thr-Ala-Pro-Arg) that distinguishes Ularitide (urodilatin) from ANP. The disulfide connectivity in the sourced literature is reported with two numbering conventions: MedChemExpress, Adooq, PeptideDB, and NovoPro list the bridge as Cys4-Cys20 (numbering from the Anaritide N-terminus), while one Biorbyt datasheet lists Cys7-Cys23, which is the equivalent bridge under full-length ANP numbering. Both descriptions refer to the same conserved 17-residue disulfide-linked ring, and the Cys4-Cys20 convention is adopted throughout this specification for consistency with the 25-residue sequence. The peptide contains a methionine at position 12, introducing a thioether oxidation liability; unlike the lactam-bridged Elcatonin, the disulfide bridge is reducible and is sensitive to reducing agents.

Product Parameters

Product Details

1. Overview

Anaritide is a 25-residue synthetic peptide corresponding to the C-terminal fragment of human atrial natriuretic peptide (ANP), spanning prohormone residues 102-126. ANP is released from atrial myocytes in response to mechanical stretch and acts as an endogenous regulator of blood volume and vascular tone. Anaritide retains the conserved 17-residue disulfide-linked ring required for natriuretic peptide receptor binding and the full C-terminal segment, while lacking the four N-terminal residues of ANP(1-28). Its principal research interest lies in renal hemodynamics and acute kidney injury: Anaritide increases glomerular filtration rate by dilating afferent arterioles and constricting efferent arterioles, and it has been evaluated clinically in acute tubular necrosis. The material supplied under this specification is research-grade and is not intended for human administration. Knowlux supplies Anaritide strictly for laboratory investigation of natriuretic peptide receptor pharmacology, renal hemodynamics, and acute kidney injury mechanisms.

2. Receptor Pharmacology and Clinical Pharmacology Context

Anaritide is a direct agonist of natriuretic peptide receptor-A (NPR-A), the particulate guanylyl cyclase that mediates the natriuretic, vasodilatory, and renin-angiotensin-aldosterone suppressing actions of the ANP/BNP family. NPR-A activation raises intracellular cGMP and triggers protein kinase G-dependent signaling in vascular smooth muscle, renal tubules, and adrenal glomerulosa cells. The receptor-level pharmacology of Anaritide is less extensively tabulated in public supplier databases than that of full-length ANP or BNP; researchers characterizing potency in their own assay systems should establish NPR-A EC50 values empirically rather than relying on catalogue constants.

The most distinctive pharmacological data for Anaritide come from its clinical development in acute tubular necrosis (ATN), and those data inform how the peptide is used as a research tool. In a randomized, placebo-controlled trial of 504 patients with ATN (the Auriculin Anaritide Acute Renal Failure Study), Anaritide did not improve dialysis-free survival overall, but a prespecified subgroup analysis showed a differential effect by baseline oliguria status: among oliguric patients, 27% of Anaritide-treated patients survived without dialysis versus 8% of placebo-treated patients, whereas among non-oliguric patients the point estimate favored placebo. The trial also reported that blood pressure during Anaritide infusion decreased more in patients without oliguria than in those with oliguria, and the investigators concluded that the intrarenal pharmacologic actions of Anaritide may improve renal function in oliguric patients but may have no benefit, or may even be deleterious, in non-oliguric patients. This oliguria-dependent divergence is a pharmacological context that distinguishes Anaritide from full-length ANP and from Ularitide, and it is relevant to any research design using Anaritide as an NPR-A agonist in renal injury models.

3. Research Applications

Published pharmacological characterizations and clinical trial data describe the following research applications:

• NPR-A/GC-A binding and functional assays (cGMP accumulation in renal and vascular cell models)

• Renal hemodynamics and glomerular filtration rate regulation studies

• Acute tubular necrosis and acute kidney injury research models, with attention to oliguria status as a determinant of response

• Renal replacement therapy and dialysis-free survival research contexts

• Comparative pharmacology of ANP fragments versus full-length ANP(1-28) and Ularitide

• Peptide stability and methionine oxidation studies (Met12 as an oxidation hotspot)

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

These descriptions are derived from published research and are provided for scientific reference only. They do not constitute clinical guidance or dosing recommendations.

Quality Control

Solubility and Handling

Solubility: Anaritide solubility is well documented in DMSO and only qualitatively documented in water. MedChemExpress and Biorbyt both report DMSO solubility of 100 mg/mL (36.71 mM) at 25C, with sonication required. BenchChem describes the compound as soluble in water to a specified concentration but does not publish a numeric limit. GlpBio lists solubility in DMSO without a numeric value. For practical stock preparation, DMSO at 100 mg/mL is the most consistently supported condition across the principal sources. Aqueous working solutions should be prepared fresh and not relied upon for long-term storage; BenchChem states explicitly that long-term storage of Anaritide in solution is not recommended. 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. The Met12 residue is susceptible to oxidation; protect from prolonged exposure to air and light. The Cys4-Cys20 disulfide bridge is sensitive to reducing agents; avoid contact with dithiothreitol (DTT) or mercaptoethanol.

Storage and Stability

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. Anaritide has been investigated in clinical trials for acute tubular necrosis but is not approved as a medicinal product in the United States or the European Union; 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 C112H175N39O35S3 and molecular weight 2724.02 are confirmed across MedChemExpress, Adooq, PeptideDB, Biorbyt, Solarbio, and BenchChem. The sequence Arg-Ser-Ser-Cys-Phe-Gly-Gly-Arg-Met-Asp-Arg-Ile-Gly-Ala-Gln-Ser-Gly-Leu-Gly-Cys-Asn-Ser-Phe-Arg-Tyr with the Cys4-Cys20 disulfide bridge is confirmed by MedChemExpress, PeptideDB, Adooq, and NovoPro. The acetate CAS 104595-79-1 is confirmed by KEGG DRUG, MeSH, NCI Thesaurus, and DrugBank; NCI lists the acetate formula as C112H175N39O35S3.C2H4O2. The Biorbyt datasheet formula C412H4175N39O35S3 is noted as a typographical corruption and not adopted. The Biorbyt disulfide numbering Cys7-Cys23 is noted as equivalent under full-length ANP numbering but is not adopted for the 25-residue sequence. The clinical trial data (504 patients; oliguric subgroup dialysis-free survival 27% versus 8%; blood pressure decrease more pronounced in non-oliguric patients) are from the NEJM publication and the accompanying editorial commentary. Solubility values (DMSO 100 mg/mL, 36.71 mM) are from MedChemExpress and Biorbyt batch data. Storage shelf-life divergence is reported as-is; the -20C powder 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. 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.