3-Methoxy-4-hydroxyphenylglycol

3-Methoxy-4-hydroxyphenylglycol (MHPG) is a biogenic amine metabolite of the neurotransmitter norepinephrine (NE). It is produced in the body by the enzyme catechol-O-methyl transferase (COMT) and monoamine oxidase (MAO). MHPG is often used as a biomarker to measure the activity of norepinephrine in the body, particularly in the central nervous system (CNS).

Structure and Properties

MHPG is a phenolic compound with a molecular formula of C9H12O4. It has a molecular weight of 184.19 g/mol. The compound is a white to off-white crystalline powder that is soluble in water and alcohol.

Biosynthesis

MHPG is synthesized in the body from norepinephrine through a two-step process. First, norepinephrine is metabolized by the enzyme MAO to produce dihydroxyphenylglycol (DOPEG). This is then further metabolized by COMT to produce MHPG.

Role in the Body

As a metabolite of norepinephrine, MHPG plays a role in the regulation of mood, attention, and stress response. It is also involved in the regulation of blood pressure and heart rate. Elevated levels of MHPG have been associated with a number of psychiatric disorders, including depression, anxiety disorders, and schizophrenia.

Clinical Significance

Measurement of MHPG levels in the body can provide valuable information about the activity of norepinephrine. This can be useful in the diagnosis and treatment of a variety of psychiatric and neurological disorders. For example, elevated levels of MHPG have been found in the urine of patients with major depressive disorder (MDD), suggesting increased norepinephrine activity in these individuals.

See Also

• Norepinephrine
• Catechol-O-methyl transferase
• Monoamine oxidase
• Biogenic amine