ABSTRACT
This chapter describes the pathways leading to the production of the major plant product, the alkaloids. Almost all of the alkaloids are alkaline in solution. Alkaloids serve a range of functions in plants: as poisons, feeding deterrents, antimicrobial defenses, and germination inhibitors. Alkaloids are nearly always poisonous but in appropriate doses many of them have valuable medicinal properties. The hallucinogenic effects of the tropane alkaloids have made them subjects of abuse, often with fatal consequences. There are about 3000 different types of terpenoid indole alkaloids. Isoquinoline alkaloids are produced from tyrosine. Tropane alkaloids are esters of carboxylic acids and tropine. Tropane alkaloids are produced near to the root apex and accumulate in the shoots of the plant. The purine alkaloids—caffeine and theobromine are found in a limited number of species. Among the most important reactions that introduce chemical variety into the alkaloids are: oxidation, acylation, glucosylation, and methylation.
