(S)-Higenamine ((S)-Norcoclaurine) hydrobromide, a S-enantiomer of Higenamine, is the entry compound in benzylisoquinoline alkaloid biosynthesis. (S)-Higenamine hydrobromide is produced by the condensation of dopamine and 4-hydroxyphenylacetaldehyde (4-HPAA) by norcoclaurine synthase (NCS)[1].
The biosynthetic pathway leading to benzylisoquinoline alkaloids originates from the enzyme-catalyzed condensation of dopamine and 4-hydrophenylacetaldehyde to yield (S)-norcoclaurine. Both substrates are secondary metabolites derived from the decarboxylation/hydroxylation/deamination of tyrosine[1].
[1]. Minami H, et al. Functional analysis of norcoclaurine synthase in Coptis japonica. J Biol Chem. 2007;282(9):6274‐6282.