Evolution of Benzylisoquinolines in Magnoliiflorae

Abstract

Phenylalanine, through benzyltetrahydroisoquinoline (BTIQ) intermediates, is responsible for the biosynthesis of three alkaloidal types headed by aporphines (skeleta prefixed 11–19), berberines (21) and morphines (31–34), the benzylisoquinoline (BIQ) biogenetic group of alkaloids. The code of each skeleton of the BIQ — alkaloids (Table 6.1) indicates its position on a biogenetic map (for the analogous derivation of codes see Figs. 10.1, 10.2, 14.1) on which the reaction sequences are written from top to bottom in order of the diminishing number of derivatives they generate. Higher and more complex codes thus represent more specialized skeletal types.