Chemical investigations of herbarium material for alkaloids

The chemical and biological screening of plants is reviewed briefly as an introduction to the concept of the use of herbarium material for investigations into the chemical constituents of plants. Such materials have been examined for a wide range of chemicals, and in particular, examples of the extraction of alkaloids from species of Rubiaceae and Papaveraceae are discussed. The present state of the art of such physical techniques as mass and nuclear magnetic resonance spectrometry for these investigations is commented upon and the plea is made that, wherever possible, wider use be made of herbarium material for chemical studies.