Synephrine

Description

Synephrine is a sympathomimetic alkaloid naturally present in citrus plants from the Rutaceae family, which can function as a mild stimulant and is utilized in various clinical treatments as well as in the pharmaceutical and food industries.

Chemical properties

Synephrine, also known as Analeptin or p-synephrine, is naturally occurring alkaloid. It is an off-white to beige powder that is derived from the fruit of small citrus trees (Citrus aurantium). It is soluble in water, insoluble in ether, almost insoluble in chloroform, ether. Synephrine is related structurally to endogenous neurotransmitters (adrenaline and noradrenaline), and acts on several adrenergic and serotonergic receptors.

The Uses of Synephrine

(±)-Synephrine has been used as an alkaloid to investigate its in vitro antiviral, antibacterial, antifungal and cytotoxicity activities.

Definition

ChEBI: Synephrine is a phenethylamine alkaloid that is 4-(2-aminoethyl)phenol substituted by a hydroxy group at position 1 and a methyl group at the amino nitrogen. It has a role as a plant metabolite and an alpha-adrenergic agonist. It is a phenethylamine alkaloid, a member of phenols and a member of ethanolamines. It is a conjugate base of a synephrinium.

Synthesis Reference(s)

Journal of the American Chemical Society, 71, p. 1045, 1949 DOI: 10.1021/ja01171a079

General Description

Synephrine is a sympathomimetic amine from the plant?Citrus aurantium and is identified as a major active component of dietary supplements.

Biochem/physiol Actions

Synephrine is naturally found in citrus plants belonging to the Rutaceae family. It is a sympathomimetic alkaloid. Synephrine has 3 isomeric forms, such as m-synephrine, p-synephrine and o-synephrine. It exhibits β-adrenergic properties.

Synephrine Application

Synephrine is a α-adrenergic receptor agonist, vasoconstrictor that has been reported to have thermogenic properties. Therefore, it is widely used as a dietary supplement to enhance energy and promote weight loss. It is reported that the (-)-form of synephrine has more potent than that of the (+)-form. (The product is for research purpose only.)

Synthesis

A synthesis route beginning with the O-benzoylation of p-hydroxy-phenacyl chloride, followed by reaction of the resulting O-protected chloride with N-methyl-benzylamine to give an amino-ketone. This intermediate was then hydrolyzed with HCl/alcohol to the p-hydroxy-aminoketone, and the product then reduced catalytically to give (racemic) synephrine.