Misoprostol | Prostaglandin E1 Analog | CAS 59122-46-2

Product Name: Misoprostol
CAS No.: 59122-46-2
Chemical Name: (±)-methyl-(1R,2R,3R)-3-hydroxy-2-[(E)-(4RS)-4-hydroxy-4-methyloct-1-enyl]-5-oxocyclopentylheptanoate
Molecular Formula: C₂₂H₃₈O₅
Appearance: Light yellow viscous liquid or white/almost white crystalline solid
Solubility: Freely soluble in ethanol, chloroform, and ether; sparingly soluble in water
Stability: Sensitive to moisture and high temperatures
Stereochemistry: Racemic mixture of four stereoisomers; two are biologically active

1. Introduction

Misoprostol is a synthetic analog of prostaglandin E1. It has gastroprotective effects, reducing gastric acid secretion and increasing protective mucus production. It also has pronounced uterotonic effects. It is used for the prevention of NSAID-induced gastropathy and in obstetrics.

Prostaglandins play an important role in the regulation of many physiological processes, including protection of the gastrointestinal mucosa and uterine contractile activity. Misoprostol was developed as a stable synthetic analog of prostaglandin E1 (PGE1) to harness its therapeutic properties.

2. Chemical Structure & Synthesis

Misoprostol is a synthetic analog of prostaglandin E1. The synthesis of misoprostol is a complex multi-step process involving the construction of a cyclopentane ring with side chains characteristic of prostaglandins and the introduction of a methyl group into one of the side chains.

3. Mechanism of Action

Gastroprotective action: Binds to prostaglandin receptors (EP3) on gastric parietal cells, inhibiting hydrochloric acid secretion. Stimulates bicarbonate and mucus secretion and improves blood flow to the gastric mucosa.

Uterotonic action: Stimulates myometrial contractile activity and promotes cervical ripening by binding to prostaglandin receptors in the uterus.

4. Pharmacokinetics

Rapidly and almost completely absorbed after oral administration. Actively metabolized in the liver to its major active metabolite – misoprostol acid. Excreted primarily via the kidneys.

5. Applications

• Prevention and treatment of gastric and duodenal ulcers caused by nonsteroidal anti-inflammatory drugs (NSAIDs)

• Obstetrics and gynecology (often under strict medical supervision):

  • Induction of labor

  • Cervical ripening before delivery

  • Medical termination of pregnancy (usually in combination with mifepristone)

  • Treatment and prevention of postpartum hemorrhage due to uterine atony

6. Conclusion

Misoprostol is an important drug with dual therapeutic potential: as a gastroprotectant and as a potent uterotonic agent. Its use in gastroenterology reduces the risk of NSAID-induced gastrointestinal lesions, while in obstetrics and gynecology it plays a key role in several reproductive health procedures. The use of misoprostol requires strict medical supervision due to its strong effects on the uterus.