Essence of Eriocephalus punctulactus is obtained by steam distillation of the blue flowers of a bush which grows at 3000 meters on the slopes of the Lesotho mountains in South Africa. Two other species of Eriocephalus--umbellatus and africanus—are known for their essences from flowers and leaves.
E. punctulactus essence is characterized by a strong blue color and a powerful fruity, fresh odor, which reminds one of Roman chamomile. Its CPG spectrum, obtained on a Carbowax capillar column, shows more than 200 peaks, the most important not exceeding 15 percent. A primary study demonstrated that 55 percent of the essence could readily be separated by distillation of a colorless fraction. This fraction contains the classical terpenes and esters, the most important of them being 2-methyl-isobutyl isobutyrate. Further study sought to identify in the remaining blue fraction the azulenic components which are generally responsible for the blue coloration of other essences (chamomile, millefolide). TLC revealed a blue component, the Rt value of which corresponds to that of an authentic sample of chamazulene.
