General relationships among plants and their alkaloids

Abstract

A statistical analysis was made of the 3600 species of plants known to contain alkaloids and their 2000 alkaloids to determine distribution by families, diversity of occurrence of individual alkaloids, how the size of the alkaloids (number of carbons) in species may be correlated with habit, habitat, family and geographic location. The categories used for comparison were woody, herbaceous, temperate, tropical, monocot, dicot and native to Australia. Woody-temperate species have larger alkaloids than herbaceous-temperate. All woody, including both temperate and tropical, have larger alkaloids than all herbaceous. In both herbaceous and woody, the strictly tropical and temperate species have larger alkaloids than the sub-tropical and the warm-temperate. Within the herbaceous species, monocot-temperate have much larger alkaloids than dieot-temperate, but those of the dicot-tropical are larger than the monocot-tropical. In families containing 60 or more kinds of alkaloids, there is a tendency for the number of alkaloids having the same number of carbons to follow a normal distribution curve, or, so to speak, for the family to specialize in aklaloids of a given size. The peak, or the size representing the greatest number of alkaloids, is characteristic of the family and varies from 15 to 27 carbons. Caffeine occurs in the largest number of families (14), lycorine in the largest number of genera (30) and berberinc in the largest number of species (89).