Name:Synephrine Synonyms:1-(4-Hydroxyphenyl)-2-(methylamino)ethanol; 4-Hydroxy-alpha-(methylaminomethyl)benzyl alcohol; Oxedrine Molecular Formula:C9H13NO2 Molecular Weight:167.21 CAS Registry Number:94-07-5 EINECS:202-300-9 While its effectiveness is widely debated. Synephrine is derived primarily from the fruit of Citrus aurantium, a relatively small citrus tree, of which several of its more common names include Bitter Orange, Sour Orange, and Zhi shi.