B7-33
Also known as: Relaxin-2 mimetic, Mimético de Relaxina-2
Molecular Identifiers
Molecular Formula
C131H229N41O36S
CAS Number
1818415-56-3
PubChem CID
318164840Molecular Weight
2986.54 Da
Overview
Single-chain mimetic peptide of human relaxin-2, designed to selectively activate the RXFP1 receptor. Unlike native relaxin-2 which has a two-chain structure, B7-33 consists of a single chain derived from the B-chain of relaxin, simplifying production while maintaining anti-fibrotic and vasodilatory biological activity.
B7-33 draws clinical interest for its anti-fibrotic and vasodilatory activity mediated by the RXFP1 receptor. In preclinical models it has shown the ability to reduce collagen deposition and remodel extracellular matrix in cardiac, pulmonary, and hepatic fibrosis, as well as modulate pro-fibrotic signaling via TGF-β. Nitric oxide-mediated vasodilation complements the profile, positioning it as a candidate for heart failure and progressive fibrosis.
The main technical advantage of B7-33 over native relaxin-2 is structural: being a single chain, it is easier and cheaper to synthesize chemically, which makes large-scale studies feasible. Even so, it remains an experimental compound with no regulatory approval and no robust human clinical trials. Access is restricted to research-use suppliers.
VIKLSGRELVRAQIAISGMSTWSKRSL Val-Ile-Lys-Leu-Ser-Gly-Arg-Glu-Leu-Val-Arg-Ala-Gln-Ile-Ala-Ile-Ser-Gly-Met-Ser-Thr-Trp-Ser-Lys-Arg-Ser-Leu Single-chain peptide — relaxin-2 mimetic with simplified structure
Half-life
~1-2 hours
Administration Route
Subcutaneous
Category
Specialized Research
Mechanism of Action
- Selective agonism of the RXFP1 receptor (relaxin family peptide receptor 1)
- Anti-fibrotic effect via inhibition of collagen deposition and extracellular matrix remodeling
- Vasodilation mediated by nitric oxide (NO) and endothelin
- Reduction of tissue inflammation and fibrosis in target organs
- Modulation of TGF-β signaling and pro-fibrotic pathways
Reported Side Effects
Adverse effects described in the literature. Severity and frequency vary between individuals.
- Mild hypotension
- Headache
- Facial flushing
Product Properties
| Purity | >98% |
| Appearance | White lyophilized powder |
| Solubility | Soluble in water and bacteriostatic water |
| Source | Solid-phase peptide synthesis (SPPS) |
| Storage | Lyophilized: -20°C for up to 2 years, 2-8°C for up to 6 months. Reconstituted: 2-8°C for up to 2 weeks. Protect from light and moisture. Avoid repeated freeze-thaw cycles. |
Presentations & Preparation
Vials of B7-33 found in the research market:
Reconstitution
- Diluent: Bacteriostatic water
- Volume: 1-2 ml per vial
- Inject the diluent slowly against the vial wall
- Gently swirl until fully dissolved — never shake
- Wait for complete dissolution before use
Storage
- Lyophilized: Refrigerated 2-8°C
- Reconstituted: Refrigerated 2-8°C (up to 14 days)
- Protect from direct light
- Do not freeze after reconstitution
- Limited stability after reconstitution
Scientific Studies
Published studies on B7-33.
B7-33, a Functionally Selective Relaxin Receptor 1 Agonist, Attenuates Myocardial Infarction-Related Adverse Cardiac Remodeling in Mice
Devarakonda T, Mauro AG, Guzman G, Hovsepian S, Cain C, Das A, Praveen P, Hossain MA, Salloum FN
B7-33 replicates the vasoprotective functions of human relaxin-2 (serelaxin)
Marshall SA, O'Sullivan K, Ng HH, Bathgate RAD, Parry LJ, Hossain MA, Leo CH
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