title: A review of the receptor-binding properties of p-synephrine as related to its pharmacological effects.
abstract: Bitter orange (Citrus aurantium) extract and its primary protoalkaloid p-synephrine are used widely in weight loss/weight management and sports performance products. Because of structural similarities, the pharmacological effects of p-synephrine are widely assumed to be similar to those of ephedrine, m-synephrine (phenylephrine), and endogenous amine neurotransmitters as norepinephrine and epinephrine. However, small structural changes result in the receptor binding characteristics of these amines that are markedly different, providing a plausible explanation for the paucity of adverse effects associated with the wide-spread consumption of p-synephrine in the form of dietary supplements as well as in various Citrus foods and juices. This paper summarizes the adrenoreceptor binding characteristics of p-synephrine relative to m-synephrine, norepinephrine, and other amines as related to the observed pharmacological effects.
authors: School of Pharmacy and Health Professions, Creighton University Medical Center, Omaha, NE 68178, USA. sstohs@yahoo.com
authors: Sidney J
authors: SJ
authors: Stohs
authors: Harry G
authors: HG
authors: Preuss
authors: Mohd
authors: M
authors: Shara
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002957:Citrus / Q000737:chemistry; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D015394:Molecular Structure; D009638:Norepinephrine / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D011943:Receptors, Adrenergic, beta / Q000378:metabolism; D013578:Synephrine / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D011943:Receptors, Adrenergic, beta; D013578:Synephrine; D009638:Norepinephrine