In memoriam

Sad news reached the scientific community in April 2007: Robert Hegnauer, honorary member of the Gesellschaft für Arzneipflanzenforschung (GA) passed away in Leiden, The Netherlands, on April 14 at the age of 87, after a hip fracture and an infection that followed a subsequent surgery. He is survived by his beloved wife, Minie Hegnauer-Vogelenzang, three children and their families with grandchildren and great-grandchildren.[]

Prof. Dr. Drs. h. c. Robert Hegnauer
(1919 - 2007)

Robert Hegnauer was born in Aarau (canton of Aargau, Switzerland) on Aug. 1, 1919. He received his pharmaceutical education at the Universities of Bern and Zürich and graduated as PhD in 1948 under the supervision of the well known Prof. Flück with his thesis ”Beitrag zur chemischen und morphologischen Kenntnis der schweizerischen Thymus-Formen” (Contribution to the chemistry and morphology of the Thymus forms of Switzerland); a topic that already clearly characterized his later research activities and interests. In 1949 he moved to the Rijksuniversiteit of Leiden, where he met his wife and started a family and an academic career. He was appointed Professor of Pharmacognosy in 1952; ten years later, after a period of successful research, he became Professor of Experimental Plant Systematics, a position particularly suited to his research interests. He retired from this position in 1979 due to health issues resulting from a car accident.

Professor Hegnauer has published more than 120 papers in scientific journals, among them several important reviews which gave strong impulses to the inclusion of chemical, biogenetic and physiological data into plant systematics. Just to mention some of them: Problems in chemotaxonomy, illustrated by cyanogenic plant substances. Pharm Act Helv 46, 585 - 601, 1971 · Plant constituents and plant taxonomy. Naturwissenschaften 58, 585 - 98, 1971 · Biological and systematic meaning of chemodemes. Planta Med 28, 230 - 43, 1975 · The taxonomic significance of iridoids of Tubiflorae sensu Wettstein. Planta Med 33, 1 - 33, 1973 (zus. mit Kooiman) · Medicinal plants - past, present and future. Planta Med 34, 1 - 25, 1978 · Distribution of the essential oils in the plant kingdom. Erfahrungsheilkunde 29, 454 - 9, 1980 · Phytochemistry and plant taxonomy - an essay on the chemotaxonomy of higher plants. Phytochemistry 25, 1519 - 35, 1986 · Biochemistry, distribution and taxonomic relevance of higher plant alkaloids. Phytochemistry 27, 2423 - 7, 1988. In addition, many contributions to books add to the list of Robert Hegnauer’s publications.

His research on the distribution of cyanogenic glycosides, iridoids, alkaloids and essential oils in taxa such as the Umbelliferae, Compositae, Rutales, Rosales and many others inspired young scientists and drew their attention to the interesting fields of phytochemical relationships but also to the variability of secondary constituents in higher plants with emphasis on those medicinally used. Particularly all aspects of the cyanogenic glycosides as well as the iridoids in plants and arthropods were close to his heart. Most of Prof. Hegnauer’s research papers were published in the Dutch journal Pharmaceutisch Weekblad (more than 33 papers), but Planta Medica was on position two of his favorite journals (more than 20), followed by Pharmaceutica Acta Helvetiae (13).

But he had more to communicate to the scientific community than he had published in research papers. Outside the small group of specialized scientists, Prof. Hegnauer is best known for his admirable general survey of ”Chemotaxonomie der Pflanzen” that is probably the last standard series of worldwide importance written in the German language. Starting with the first volume in 1962 and finishing after 13 volumes in 2001, the last four co-authored by Minie Hegnauer, he compiled the known phytochemical data of higher plants, discussed their occurrence and taxonomic impact, their variation in different taxa, their biochemical pathways and biological function; this broad view of plant natural products, performed without online access to databases, is unprecedented; no wonder that still today ”Hegnauer’s Chemotaxonomie” is cited in many phytochemical papers. It characterizes Professor Hegnauer’s mode of work when he tried to receive every paper cited in his volumes, even when going back for many years (his collection of reprints filled more than 1 floor of his domicile in Leiden), and to evaluate and discuss its data critically, adequately and honestly.

Prof. Hegnauer was associated with Planta Medica since this journal was founded in 1953. He was a member of the board for 25 years from 1953 to 1977 thereby influencing the early development of the growing journal. He also served as a Board member of the Gesellschaft für Arzneipflanzenforschung in 1960 and 1961 and later from 1974 to 1983. GA honored him by the honorary membership (1978), and for his outstanding life work with the Egon-Stahl-Award in Gold (1999). He received highly esteemed honors from the American Society of Pharmacognosy and the Deutsche Botanische Gesellschaft (honorary membership; 1970 and 1983 resp.), the ETH Zürich and the University of Utrecht (honorary doctorate; 1971 and 1987 resp.); he received the Flückiger medal of the Flückiger Foundation (1976) and the Silver Medal of the Phytochemical Society of Europe (1987); he was member of the Deutsche Akademie der Naturforscher Leopoldina (1972) and the Koninklijke Nederlandse Akademie van de Wetenschapen (1973).

In spite of all his success and honors, Professor Hegnauer was always of reserved politeness, open minded, non-biased, fair and honest. He was open for discussions for everyone and never hesitated to help with any scientific problem. With his broad knowledge and critical sense he has stimulated many young and older scientists. Students and colleagues visiting him in Leiden will remember his and Minie’s warm hospitality in their homely condominium in Cobetstraat 49, with its backyard full of medicinal plants. Robert Hegnauer’s loss will be deeply felt in the world of plant sciences; we will miss him as a friend and faithful academic fellow; he will live on in his life’s work and our commemoration.
Adolf Nahrstedt