Oxidation of synephrine by type A and type B monoamine oxidase

  title={Oxidation of synephrine by type A and type B monoamine oxidase},
  author={Osamu Suzuki and T. Matsumoto and Masakazu Oya and Yoshinao Katsumata},
Synephrine (SP) was found to be a substrate for monoamine oxidase (MAO) in rat brain mitochondria, showing the Km and Vmax values of 250 μM and 32.6 nmoles/mg of protein/30 min respectively. The inhibition studies showed that the SP oxidation was carried out by both type A and type B MAO and a major part of the activity was due to type A MAO. 

Methoxyphenylethylamines as substrates for type A and type B monoamine oxidase

Results suggest that O-methylation in the para-position increases the preference of the substrate for type B MAO, while a methoxy-group in the meta-position contributes to the substance being a type A substrate.

Fast hepatic biotransformation of p-synephrine and p-octopamine and implications for their oral intake.

The rapid hepatic transformation of p-synephrine and p-octopamine means that their concentration in the portal vein exceeds that in the systemic circulation during absorption, and their metabolic effects will be exerted predominantly in the liver.

Synephrine: from trace concentrations to massive consumption in weight-loss.

Synephrine , Octopamine and Caffeine Health Risk Assessment ( HRA ) Report

Issue Assessment of the potential risks to health from natural health products containing synephrine and/or octopamine in combination with caffeine. various products not licensed for sale in Canada

Phytochemical compounds in sport nutrition: Synephrine and hydroxycitric acid (HCA) as examples for evaluation of possible health risks.

Animal and human studies, as well as case reports, provide evidence for cardiovascular effects due to ingestion of high synephrine doses, especially in combination with caffeine and physical exertion, and substantial uncertainties exist regarding the safety of supplements containing high amounts of HCA.

American Botanical Council Bitter Orange Peel and Synephrine

The announcement in late December by the U.S. Food and Drug Administration (FDA) that it intends to issue regulations banning the sale of dietary supplements containing the controversial herb ephedra

Critical review of electrochemical advanced oxidation processes for water treatment applications.

  • B. Chaplin
  • Materials Science
    Environmental science. Processes & impacts
  • 2014
Key challenges facing EAOP technologies are related to toxic byproduct formation and low electro-active surface areas and must be addressed in future research in order for EAOPs to realize their full potential for water treatment.

Bitter Orange (Citrus aurantium var. amara) Extracts and Constituents (±)-p-Synephrine [CAS No. 94-07-5] and (±)-p-Octopamine [CAS No. 104-14-3] Review of Toxicological Literature

  • Biology, Chemistry
  • 2004
The basis for Nomination is a meta-analysis of chemical Identification and Analysis, which examines the relationships between Chemical Disposition, Metabolism, and Toxicokinetics, and the Receptor Pharmacology of Octopamine, Synephrine, and Other Biogenic Monoamines.

Potential Herb–Drug Interactions in the Management of Age-Related Cognitive Dysfunction

Reviewing the potential interactions between selected bioactive compounds used by seniors for cognitive enhancement and representative drugs commonly prescribed to the middle-aged adults to anticipate and prevent risks arising from their co-administration finds interaction with other drugs affecting the same targets may be anticipated and prevented.


The focus of this chapter is on the development of a model for pre-SYSTEMIC SULFATION of PHENYLEPHRINE with LS180 CELL MODEL, which has shown promising results in the past.



Multiplicity of monoamine oxidase in chick brain

It was found that neither 5-hydroxytryptamine nor β-phenylethylamine is the specific substrate for type A and type B MAO in chick brain.

Beta-phenylethylamine: a specific substrate for type B monoamine oxidase of brain.

  • H. Y. YangN. Neff
  • Chemistry, Biology
    The Journal of pharmacology and experimental therapeutics
  • 1973
It is concluded that the amines of brain may be cataboblized by specific types of monoamine oxidase in vivo.

A kinetic evaluation of monoamine oxidase activity in rat liver mitochondrial outer membranes.

1. A preparation of mitochondrial outer membranes from rat liver can be shown to contain two kinetically distinct monoamine oxidase activities. These activities are distinguishable by their different

Biosynthesis of cerebral phenolic amines. I. In vivo formation of p-tyramine, octopamine, and synephrine.

Differences in the amounts of the phenolicamines formed suggest that mechanisms other than just decarboxylation are involved in the formation of phenolic amines.

The monoamine oxidases of brain: selective inhibition with drugs and the consequences for the metabolism of the biogenic amines.

  • H. Y. YangN. Neff
  • Biology, Chemistry
    The Journal of pharmacology and experimental therapeutics
  • 1974
It is postulate that it may be possible to alter selectively the metabolism of the putative transmitter amines in man by administration of monoamine oxidase inhibitor drugs that preferentially inactivate a specific type of monoamines.

Identification of p-hydroxy-alpha-(methylaminomethyl) benzyl alcohol (synephrine) in human urine.

Studies by a variety of procedures have definitely established its identity as p-hydroxy-oc-(methylaminomethyl)benzyl alcohol (synephrine, Sympatol), which suggested that the unknown base in urine was a derivative of p-Hydroxyphenylethanolamine.

A simple and sensitive fluorescence assay for monoamine oxidase and diamine oxidase.

  • S. SnyderE. Hendley
  • Biology, Chemistry
    The Journal of pharmacology and experimental therapeutics
  • 1968
Diamine oxidase from rat small intestine oxidized putrescine, cadaverine, histamine and 1,4- methyl histamine, but appeared to have a greater affinity for histamine than for the other sub strates tested, while monoamine oxidase in rat brain and liver had the same relative activities toward a number of substrates.

The phenolic amines of human urine.