5-甲氧基色酚是存在于松果体中的甲氧基吲哚化合物。5-甲氧基色酚存在于人血浆中，并且在白天和黑暗时段都出现活性峰值。鸭松果体有节奏地产生两种5-甲氧基吲哚化合物，即5-甲氧基色氨酸和褪黑激素。5-甲氧基隐醇的水平在夜间低，白天高，而褪黑激素的浓度在夜间高，白天低。这些发现表明，在鸭的松果体中5-甲氧基色氨酸和褪黑激素的含量可能呈负相关。 5-Methoxytryptophol is a methoxyindole compound present in the pineal gland. 5-Methoxytryptophol is present in human plasma and peaks of activity occur both in the day and during the hours of darkness. The duck pineal gland rhythmically produces two 5-methoxyindole compounds, i.e. 5-methoxytryptophol and melatonin. 5-Methoxytryptophol levels are low at night and high during the day, while melatonin concentrations are high at night and low during the day. These findings indicate that in the duck the pineal production of 5-methoxytryptophol and melatonin may be inversely correlated.