Melatonin belongs to the indole heterocyclic class of compounds, with the chemical name N-[2-(5-methoxy-1H-indole-3-yl)ethyl]acetamide, also known as melatonin. It typically appears as a white or off-white crystalline powder, poorly soluble in water (slightly soluble), and soluble in organic solvents (such as acetone and ethanol). Melatonin has a melting point of approximately 116-118℃; above this temperature, it will change from a solid to a liquid state. Furthermore, it is relatively sensitive to light and cannot be exposed to strong light for extended periods; it needs to be stored away from light. The molecular structure of melatonin is somewhat unique; its amide and methoxy functional groups can participate in certain organic chemical reactions. The atomic structure of melatonin determines that the amide group can undergo hydrolysis reactions under certain conditions; however, under normal physiological conditions and during routine storage, these reactions usually do not occur spontaneously in large quantities.