Article · Wikipedia archive · Last revised Jul 17, 2026

B7-33

B7-33 is a synthetic 26-amino acid peptide with the sequence VIKLSGRELVRAQIAISGMSTWSKRSL or 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. It is an N-terminal truncated, C-terminal extended fragment from the B chain of human relaxin-2, and has similar anti-fibrotic effects to the full length peptide. It has been researched for conditions where excess fibrosis plays a role, such as cardiac fibrosis and pulmonary fibrosis.

Last revised
Jul 17, 2026
Read time
≈ 2 min
Length
375 w
Citations
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Source
Wikipedia ↗
B7-33
Identifiers
  • (4S)-5-[[(2S)-1-[[(2S)-1-[[(2S)-1-[[(2S)-1-[[(2S)-5-amino-1-[[(2S,3S)-1-[[(2S)-1-[[(2S,3S)-1-[[(2S)-1-[[2-[[(2S)-1-[[(2S)-1-[[(2S,3R)-1-[[(2S)-1-[[(2S)-1-[[(2S)-6-amino-1-[[(2S)-1-[[(2S)-1-[[(2S)-1-amino-4-methyl-1-oxopentan-2-yl]amino]-3-hydroxy-1-oxopropan-2-yl]amino]-5-carbamimidamido-1-oxopentan-2-yl]amino]-1-oxohexan-2-yl]amino]-3-hydroxy-1-oxopropan-2-yl]amino]-3-(1H-indol-3-yl)-1-oxopropan-2-yl]amino]-3-hydroxy-1-oxobutan-2-yl]amino]-3-hydroxy-1-oxopropan-2-yl]amino]-4-methylsulfanyl-1-oxobutan-2-yl]amino]-2-oxoethyl]amino]-3-hydroxy-1-oxopropan-2-yl]amino]-3-methyl-1-oxopentan-2-yl]amino]-1-oxopropan-2-yl]amino]-3-methyl-1-oxopentan-2-yl]amino]-1,5-dioxopentan-2-yl]amino]-1-oxopropan-2-yl]amino]-5-carbamimidamido-1-oxopentan-2-yl]amino]-3-methyl-1-oxobutan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]amino]-4-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-6-amino-2-[[(2S,3S)-2-[[(2S)-2-amino-3-methylbutanoyl]amino]-3-methylpentanoyl]amino]hexanoyl]amino]-4-methylpentanoyl]amino]-3-hydroxypropanoyl]amino]acetyl]amino]-5-carbamimidamidopentanoyl]amino]-5-oxopentanoic acid
CAS Number
PubChem CID
ChemSpider
ChEMBL
Chemical and physical data
FormulaC131H229N41O36S
Molar mass2986.58 g·mol−1
3D model (JSmol)
  • CC[C@H](C)[C@@H](C(=O)N[C@@H](CO)C(=O)NCC(=O)N[C@@H](CCSC)C(=O)N[C@@H](CO)C(=O)N[C@@H]([C@@H](C)O)C(=O)N[C@@H](CC1=CNC2=CC=CC=C21)C(=O)N[C@@H](CO)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CO)C(=O)N[C@@H](CC(C)C)C(=O)N)NC(=O)[C@H](C)NC(=O)[C@H]([C@@H](C)CC)NC(=O)[C@H](CCC(=O)N)NC(=O)[C@H](C)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](C(C)C)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCCNC(=N)N)NC(=O)CNC(=O)[C@H](CO)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCCCN)NC(=O)[C@H]([C@@H](C)CC)NC(=O)[C@H](C(C)C)N
  • InChI=1S/C131H229N41O36S/c1-21-68(14)100(125(205)150-72(18)106(186)169-101(69(15)22-2)127(207)167-90(59-174)108(188)148-57-96(181)152-84(44-50-209-20)115(195)165-93(62-177)122(202)172-103(73(19)178)128(208)162-88(54-74-55-146-76-34-25-24-33-75(74)76)118(198)166-91(60-175)120(200)155-78(35-26-28-45-132)111(191)154-81(39-32-49-145-131(141)142)113(193)164-92(61-176)121(201)159-85(104(136)184)51-63(4)5)170-116(196)82(40-42-94(134)179)153-105(185)71(17)149-109(189)80(38-31-48-144-130(139)140)157-124(204)99(67(12)13)168-119(199)87(53-65(8)9)161-114(194)83(41-43-97(182)183)156-110(190)77(37-30-47-143-129(137)138)151-95(180)56-147-107(187)89(58-173)163-117(197)86(52-64(6)7)160-112(192)79(36-27-29-46-133)158-126(206)102(70(16)23-3)171-123(203)98(135)66(10)11/h24-25,33-34,55,63-73,77-93,98-103,146,173-178H,21-23,26-32,35-54,56-62,132-133,135H2,1-20H3,(H2,134,179)(H2,136,184)(H,147,187)(H,148,188)(H,149,189)(H,150,205)(H,151,180)(H,152,181)(H,153,185)(H,154,191)(H,155,200)(H,156,190)(H,157,204)(H,158,206)(H,159,201)(H,160,192)(H,161,194)(H,162,208)(H,163,197)(H,164,193)(H,165,195)(H,166,198)(H,167,207)(H,168,199)(H,169,186)(H,170,196)(H,171,203)(H,172,202)(H,182,183)(H4,137,138,143)(H4,139,140,144)(H4,141,142,145)/t68-,69-,70-,71-,72-,73+,77-,78-,79-,80-,81-,82-,83-,84-,85-,86-,87-,88-,89-,90-,91-,92-,93-,98-,99-,100-,101-,102-,103-/m0/s1
  • Key:UAGASAJLEJWQIF-GARFIVTISA-N

B7-33 is a synthetic 26-amino acid peptide with the sequence VIKLSGRELVRAQIAISGMSTWSKRSL or 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. It is an N-terminal truncated, C-terminal extended fragment from the B chain of human relaxin-2, and has similar anti-fibrotic effects to the full length peptide. It has been researched for conditions where excess fibrosis plays a role, such as cardiac fibrosis and pulmonary fibrosis.1234567

See also

See also

References

References

  1. Hossain MA, Kocan M, Yao ST, Royce SG, Nair VB, Siwek C, et al. (June 2016). "A single-chain derivative of the relaxin hormone is a functionally selective agonist of the G protein-coupled receptor, RXFP1". Chemical Science. 7 (6): 3805–3819. doi:10.1039/c5sc04754d. PMC 6013806. PMID 30155023.
  2. Praveen P, Kocan M, Valkovic A, Bathgate R, Hossain MA (May 2019). "Single chain peptide agonists of relaxin receptors". Molecular and Cellular Endocrinology. 487: 34–39. doi:10.1016/j.mce.2019.01.008. PMID 30641102.
  3. Devarakonda T, Mauro AG, Guzman G, Hovsepian S, Cain C, Das A, et al. (April 2020). "B7-33, a Functionally Selective Relaxin Receptor 1 Agonist, Attenuates Myocardial Infarction-Related Adverse Cardiac Remodeling in Mice". Journal of the American Heart Association. 9 (8) e015748. doi:10.1161/JAHA.119.015748. PMC 7428518. PMID 32295457.
  4. Abboud C, Brochoire L, Drouet A, Hossain MA, Hleihel W, Gundlach AL, et al. (2021). "Analgesic effect of central relaxin receptor activation on persistent inflammatory pain in mice: behavioral and neurochemical data". Pain Reports. 6 (2): e937. doi:10.1097/PR9.0000000000000937. PMC 8213244. PMID 34159282.
  5. Alam F, Gaspari TA, Kemp-Harper BK, Low E, Aw A, Ferens D, et al. (April 2023). "The single-chain relaxin mimetic, B7-33, maintains the cardioprotective effects of relaxin and more rapidly reduces left ventricular fibrosis compared to perindopril in an experimental model of cardiomyopathy". Biomedicine & Pharmacotherapy. 160 114370. doi:10.1016/j.biopha.2023.114370. PMID 36753958.
  6. Praveen P, Wang C, Handley TN, Wu H, Samuel CS, Bathgate RA, et al. (April 2023). "A Lipidated Single-B-Chain Derivative of Relaxin Exhibits Improved In Vitro Serum Stability without Altering Activity". International Journal of Molecular Sciences. 24 (7): 6616. doi:10.3390/ijms24076616. PMC 10094921. PMID 37047588.
  7. Handley TN, Praveen P, Tailhades J, Wu H, Bathgate RA, Hossain MA (August 2023). "Further Developments towards a Minimal Potent Derivative of Human Relaxin-2". International Journal of Molecular Sciences. 24 (16) 12670. doi:10.3390/ijms241612670. PMC 10454739. PMID 37628851.