V. DIE SYSTEMATISCHE BEDEUTUNG DES ALKALOIDMERKMALES¹

Summary

The distribution of alkaloids among Cormophytes is discussed from a taxo–nomical point of view.

The author considers the distribution of biogenetically linked alkaloidal types of primary importance for chemotaxonomical considerations.

The structurally known alkaloids are considered to belong to 8 different „al–kaloidal families”: Phenylalanine–derivatives, tryptophane–derivatives, ornithine–derivatives, lysine–derivatives, anthranilic acid–derivatives, nicotinic acid–derivatives and the group of alkaloids not related to amino acids called the „Alcaloida imperfecta”.

The distribution of these alkaloidal families and of some individual alkaloids in the plant kingdom is analized and the following conclusions are reached: The Polycarpicae (sensu Wettstein) together with the Papaveraceae form a very natural group characterized by the synthesis of alkaloids of the phenylalanine–Type. More sporadically however the tryptophane–family (Calycanthaceae) and the lysine–family (Berberidaceae) of alkaloids are also represented in this group. With this group of families the Rutaceae on the one hand and the Rosales and Centrospermae on the other hand seem to be linked directly by the alkaloids which are found in them. The ornithin–type of alkaloids is especially concentrated in the families of Erythroxylaceae, Convolvidaceae and Solanaceae. This perhaps indicates a relation between Tubiflorae (isensu Wettstein) and Linaceae – Erythroxylaceae. The more elaborated alkaloids of the tryptophan–type are only found within Loganiaceae, Apocynaceae and Rubiaceae which indicates that taxonomists like Hallier and Hutchinson who derive Rubiaceae from loganiaceous–like ancestors are right. The author thinks that our knowledge of plant constituents has now been developped far enough to make possible a trial of phylogenetic interpretation of some chemical characteristics of plants.