Chapter 60 - The Biosynthesis of Plant Alkaloids and Nitrogenous Microbial Metabolites

Abstract

This chapter reviews the results of investigations into the biosynthesis of alkaloids as well as those of, the quite often related, microbial metabolites containing nitrogen. It covers the biosynthesis of pyrrolidine alkaloids, which include tropane and related alkaloids, nicotine, pyrrolizidine alkaloids, phenanthroindolizidine and related alkaloids. Piperidine alkaloids are a large group of alkaloids, whose structures contain a piperidine ring. They consist of alkaloids derived exclusively from acetate and alkaloids derived from lysine, such as simple piperidine bases, tetrahydroanabasine alkaloids, lythraceae alkaloids, lycopodium alkaloids, quinolizidine alkaloids, pipecolic acid and slaframine. Anthranilic acid is an intermediate on the biosynthetic pathway to tryptophan and it serves as a starting point for the elaboration of a number of metabolites of plant and microbial origin. Bases derived from the tryptophan pathway include gramine, dimethyltryptamine derivatives, indolmycin, pyrrolnitrin, sporidesmin, β-Carboline alkaloids, calycanthine and folicanthine, isoprenoid indole bases, such as echinulin and brevianamide, cyclopiazonic acid, ergot alkaloids and terpenoid indole alkaloids, phenoxazinones, damascenine, quinoline alkaloids, such as echinorine, pseudans, furoquinoline and related alkaloids, acridone alkaloids, graveoline, quinazoline alkaloids, rutaecarpine and evodiamine, benzodiazepine bases, benzoxazinones, phenazines, and shihunine. Many of the complex alkaloids, which have their origins in the aromatic amino acids phenylalanine and tyrosine arise by a combination of two units derived from these precursors.