B7-33

Single-chain relaxin-2 mimetic · biased RXFP1 agonist

≥ 99.0% · target, verify batch COACAS 1818415-56-3RUO

Research statusPreclinical only; no published or registered human study identified

Supplied formHeptacosapeptide (linear, disulfide-free)

Lead time14–21 days

B7-33 — Lot-specific lyophilized research peptide; confirm released-lot appearance on the COA

B7-33 — Lot-specific lyophilized research peptide; confirm released-lot appearance on the COA · Representative packaging image · verify the ordered lot

Representative packaging image · verify the ordered lot

Decision summary

Key benefits

Single-chain, disulfide-free design simplifies analytical comparison with two-chain relaxin-2.
Published RXFP1 signaling and preclinical model data provide a defined experimental context.
Identity should be confirmed by intact mass and, where required, sequence-level evidence for the released lot.

Published research context is presented for literature orientation only. It is not a dosing, treatment or human-use instruction.

Qualification data

Specifications to confirm against the released lot

CAS: 1818415-56-3
Formula: C₁₃₁H₂₂₉N₄₁O₃₆S
Molecular weight: 2986.5 g/mol
Appearance: Lot-specific lyophilized research peptide; confirm released-lot appearance on the COA
Purity: ≥ 99.0% · target, verify batch COA
Storage: Follow the released-lot storage statement and SDS. Protect lyophilized material from moisture and light; do not infer solution stability from the reported in-vitro serum degradation result.
MOQ: On request
Lead time: 14–21 days

PubChem CID 162662592

Qualification matrix

Identity, purity and content are separate release questions.

Identity

Confirm the stated molecule and supplied form. Start with the matching batch COA; request sequence-level evidence only when the buyer's written procedure requires it and availability or a separate scope has been agreed.

Purity

Review RP-HPLC method conditions, wavelength, integration and related-peak handling. A percentage without the method is not enough.

Content

Net peptide content is not the same as gross lyophilized powder weight. Ask which assay supports the stated amount and whether water/counter-ion is addressed.

Stability

Define long-term storage and transit exposure separately. Cold-chain can be quoted when the buyer’s risk assessment requires it and adds cost.

Research context

What researchers study about B7-33

B7-33 is a synthetic, single-chain 27-residue analog derived from the B chain of human relaxin-2. Published work describes receptor and signaling experiments plus rodent fibrosis and remodeling models. It has not been established as a clinically validated material, and the reported approximately 6-minute value is an in-vitro human-serum stability result rather than an in-vivo pharmacokinetic half-life.

RXFP1 biased-signaling assays
ERK1/2 and MMP-2 pathway research
Preclinical fibrosis and tissue-remodeling models

Mechanism context

The question the literature is testing

In the foundational study, B7-33 bound RXFP1 and favored ERK1/2 and MMP-2-associated signaling over cAMP in cells expressing RXFP1. The proposed anti-fibrotic pathway involves RXFP1 and angiotensin II type-2 receptor functional crosstalk. These findings are preclinical and model-dependent.

Evidence map

Research routes and exposure context

Evidence tierMixed evidence context

Research areaRepair and regenerative research

Routes reported in sources

No administration route applies

Dose / exposure contextProtocol-specific; verify the cited primary source

Routes and exposure contexts summarize cited studies or approved finished-product labels. They are not instructions for administering this RUO material; no customer dose is provided.

Evidence boundaries

Compatibility, limitations and decision context

No human safety data were identified; all reported evidence is from in-vitro and animal research.
The in-vitro serum stability result must not be represented as a measured in-vivo half-life.

Interactions reported in the literature

Published mechanistic work evaluates RXFP1 and angiotensin II type-2 receptor crosstalk; this is not a general compatibility statement for laboratory mixtures.

Literature context is not a supplier release result or human-use instruction. Follow your institution's approved laboratory risk assessment.

Factory batch documentation

B7-33 factory batch COAs

No factory batch COA is published for this product yet. Ask sales for the latest available document.

Representative records, refreshed periodically

Published COAs show representative factory batches and may not be the latest available. For a current quote or shipment, our sales team can confirm the applicable lot and provide its COA.

Independent testing, arranged on request

Third-party reports are not routinely published. If independent verification is required, we can agree the laboratory, method, acceptance criteria and remedy before testing. If the agreed specification is not met, an appropriate resolution—including a refund where applicable—can be discussed under the agreed terms. Unless otherwise agreed in writing, the buyer pays the cost of this optional testing.

Help reviewing your COA

Need help reading a factory COA or third-party report? Our sales team can clarify test items, specifications and how the results relate to the lot under discussion.

Ask for the current packet, not a generic certificate

Confirm the 27-residue identity, termini, supplied form and theoretical mass on the released-lot COA.
Review the matching batch COA first
Include LC-MS/MS sequence coverage only when the buyer's written procedure requires it and method, reporting, timing and cost have been agreed.

Released-batch COARP-HPLC result and method contextIdentity result appropriate to the moleculeWater / counter-ion context where relevantSDS and handling statementAdditional testing scoped on request

Handling

Storage in the lab and temperature during transit are different decisions

Follow the released-lot storage statement and SDS. Protect lyophilized material from moisture and light; do not infer solution stability from the reported in-vitro serum degradation result.

State destination, season, acceptable transit exposure and whether your protocol requires insulated or cold-chain service. Additional temperature-control cost is quoted explicitly.

Buyer FAQ

Terms to settle before the purchase order

Can a buyer arrange third-party testing?+

Yes. Testing must be performed by a mutually accepted, established specialist laboratory. Fee allocation, specification, sampling, method and acceptance rule must be agreed before testing; if an agreed independent result shows nonconformance, the remedy follows the signed order terms. Unless otherwise agreed in writing, the buyer pays the cost of this optional testing.

Does HPLC purity prove peptide content?+

No. Chromatographic purity describes the relative peak profile under a stated method. Identity, water, counter-ion, residual solvents and assay/content may require separate methods.

Is cold-chain shipping always required?+

Not always. Heat can accelerate degradation, especially during summer and long transit. Cold-chain reduces exposure but raises cost. State the destination and stability risk so the right service can be quoted.

How are payment terms handled?+

Available methods and milestones depend on order value, destination and project type. The pro forma invoice should state currency, bank details, fees, payment milestones and the release condition.

Why must the testing laboratory understand peptide chemistry?+

Free-base and salt forms, hydrophilic and hydrophobic sequences, aggregation and adsorption can change sample preparation and method suitability. Use a laboratory experienced with the molecule class.

External qualification references

WHO good storage and distribution practices IATA Temperature Control Regulations ISO/IEC 17025 laboratory competence 21 CFR 211.84 component testing and supplier COA controls

These are buyer-qualification references, not claims that this RUO material is regulated, certified or released under those frameworks. Applicability depends on the buyer's workflow and jurisdiction.

Selected sources

Literature behind the research context

Hossain MA et al. Chem Sci. 2016;7:3805-3819. PMID 30155023.
Raleigh JV et al. J Am Heart Assoc. 2020. PMID 32295457.
Praveen P et al. Int J Mol Sci. 2023;24:6616. DOI 10.3390/ijms24076616.

01
A single-chain derivative of the relaxin hormone is a functionally selective agonist of the G protein-coupled receptor, RXFP1
Chemical Science · 2016 · peer-reviewed original research
Open source
02
B7-33, a Functionally Selective Relaxin Receptor 1 Agonist, Attenuates Myocardial Infarction-Related Adverse Cardiac Remodeling in Mice
Journal of the American Heart Association · 2020 · peer-reviewed preclinical original research
Open source
03
B7-33 — PubChem Compound Summary
PubChem, US National Library of Medicine · 2026 · authoritative chemical database
Open source

Product FAQ

Questions buyers ask about B7-33

What does 'biased agonist' mean in the context of B7-33 and RXFP1 signaling?+

A functionally selective or ‘biased’ agonist favors some receptor-linked readouts over others under defined assay conditions. In the foundational B7-33 study, the peptide showed much weaker RXFP1-mediated cAMP activity than H2 relaxin but retained strong pERK1/2 and MMP-2 responses in fibroblasts that endogenously expressed RXFP1. The study also reported rodent fibrosis and tumor-model differences, but those preclinical observations do not prove a generally safer signaling profile or predict human benefit. Bias must be quantified relative to a comparator in the same receptor-expression and assay system.

How is B7-33 easier to synthesize than native two-chain relaxin?+

Native human relaxin-2 is a 53-residue, two-chain peptide with two interchain and one intrachain disulfide bonds, so synthesis requires separate chains and controlled disulfide formation. B7-33 is a linear, single-chain 27-residue analogue without disulfide bonds and can be assembled directly by SPPS. This simplifies synthesis and analytical characterization, but it does not establish identity, receptor activity or equivalence for a commercial lot; those require released-lot sequence, mass, purity and content evidence.

B7-33

Key benefits

Specifications to confirm against the released lot

Identity, purity and content are separate release questions.

What researchers study about B7-33

The question the literature is testing

Research routes and exposure context

Compatibility, limitations and decision context

Interactions reported in the literature

B7-33 factory batch COAs

Ask for the current packet, not a generic certificate

Storage in the lab and temperature during transit are different decisions

Terms to settle before the purchase order

Literature behind the research context

A single-chain derivative of the relaxin hormone is a functionally selective agonist of the G protein-coupled receptor, RXFP1

B7-33, a Functionally Selective Relaxin Receptor 1 Agonist, Attenuates Myocardial Infarction-Related Adverse Cardiac Remodeling in Mice

B7-33 — PubChem Compound Summary

Questions buyers ask about B7-33

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