Melatonin | Sleep Hormone | CAS 73-31-4 | Circadian Rhythm

Product Name: Melatonin
CAS No.: 73-31-4
Molecular Formula: C₁₃H₁₆N₂O₂
Structure: Indole core with methoxy substitution at position 5 and an acetyl group on the amino group
Appearance: White crystalline powder
Melting Point: 116–118 °C
Solubility: Poorly soluble in water (0.1 g/L); freely soluble in ethanol and DMSO
Stability: Degrades in light and heat; store in a dark place

1. Introduction

Melatonin (N-acetyl-5-methoxytryptamine) is an endogenous pineal gland hormone that regulates circadian rhythms and sleep. It possesses hypnotic, anxiolytic, and antioxidant effects.

Blood melatonin levels rise in the evening, promoting sleep onset. Exogenous melatonin is prescribed for jet lag, shift work, and insomnia to normalize sleep and improve rest quality.

2. Synthesis

Industrial synthesis:

• 5-Methoxyindole → reduction to 5-methoxytryptamine

• Acetylation of 5-methoxytryptamine with acetic anhydride or acetyl chloride

3. Properties

• Appearance: White crystalline powder

• Melting Point: 116–118 °C

• Solubility: Poorly soluble in water (0.1 g/L); freely soluble in ethanol and DMSO

• Stability: Degrades in light and heat; store in a dark place

4. Applications

• Treatment of sleep disorders and circadian rhythm disturbances – doses 0.5–5 mg, 30–60 minutes before sleep

• Antioxidant support – neurodegenerative diseases

• Jet lag and shift work assistance

5. Conclusion

Melatonin is a safe and effective sleep regulator. With short-term use, side effects are minimal; long-term courses require medical supervision.