In znodern pharznacognosy chemical and physical-cheznical methods are being used znore and more for the investigation of medicinal plants. This important fact and the increasing involvement of chemistry, biocheznistry and botany in pllarmaceuti- cal, znedicinal and general biological questions usher in a new epoch in the disco- very of medicinal substances and the development of drugs derived from the plant kingdom. One of the guiding ideas of the first "Syznposiuzn on Pharznacognosy and Phytocheznistry" was to promote these developments, to provide an additional sti- znulus and to establish a basis for better coordination and cooperation. The organizers intended that most of the modern branches of research into natural products should be represented, including analysis, structural chemistry, chemi- cal synthesis and biosynthesis, as well as pharmacology. Since the plenary lectures also reflect the present level of knowledge in some iznportant areas of natural products research, this volume will constitute an important source of information for an scientists interested in natural substances. Its usefulness is much enhanced by the fact, that the voluzne will appear only four znonths after the Symposiuzn, thanks to the kind assistance of Dr. K. F. Springer of Springer-Verlag. The organizers extend cordial thanks to an the participants for their interesting contributions and herewith invite them to attend the second Syznposium in 1973. We want to express our special thanks to Miss Seitz and Miss Hagendorn for their rapid and conscientious preparation of the manuscripts for offset-printing.