Atosiban Acetate

Chemical Properties

A white or off-white powder, hygroscopic and soluble in water.

Uses

Atosiban acetate is a nonapeptide competitive vasopressin/oxytocin receptor antagonist, and is a desamino-oxytocin analogue. Atosiban is the main tocolytic agent and has the potential for spontaneous preterm labor research. As an oxytocin receptor blocker, it has demonstrated significant therapeutic effectiveness in the treatment of experimental endometriosis.

Preparation

Atosiban acetate(914453-95-5) is synthesized through a process called solid-phase peptide synthesis. The Solid phase peptide synthesis of atosiban involves coupling of the amino acid components in sequential manner.The first amino acid is selectively bound to a polymer resin. The amino group is then selectively de-blocked and condensed with the next amino acid. This completed one cycle is then repeated sequentially for coupling of remaining 8 protected amino acids. The protected atosiban is cleaved and de-protected to obtain crude active substance. This crude product is finally purified and the pure product obtained from HPLC purification is desalted and freeze dried to yield pure atosiban acetate.

General Description

Atosibana is a mixed antagonist of oxytocin and vasopressin receptors [1].
Atosibana is a peptide and is a dual antagonist of oxytocin receptor (OTR) and vasopressin receptors (V1aR, V1bR, V2R). When acted as an OTR antagonist, atosibana showed pKi values of 7.9 and 7.2 for human OTR and rat OTR, respectively. Treatment of atosibana significantly inhibited cell growth in MDCK and HEK293 cells stably transfected with the human OTR with IC50 values of 15.4 nM and 20.8 nM, respectively. When acted as a vasopressin receptor antagonist, atosibana exerted pKi values of 9.8, 7.4 and 6.5 for hV1aR, hV1bR and hV2R, respectively. Atosibana has been shown to have efficacy in inhibiting uterine contractions and delaying preterm delivery. However, atosibana can not be used for long-term maintenance treatment since it is not orally bioavailable [1].

storage

Dry, dark and at 0-4℃ for short term (days to weeks) or -20℃ for long term (months to years).

References

[1] borthwick a d. oral oxytocin antagonists. journal of medicinal chemistry, 2010, 53(18): 6525-6538.
[2] reversi a, rimoldi v, marrocco t, et al. the oxytocin receptor antagonist atosiban inhibits cell growth via a “biased agonist” mechanism. journal of biological chemistry, 2005, 280(16): 16311-16318.