Obituary for Prof. Dr. Dr. hc. Otto Sticher (8. October 1936 – 11. March 2022) to commemorate his research on natural products and medicinal plants and his contributions to the GA

Otto Sticher, Emeritus and former Professor of Pharmacognosy and Pharmaceutical Biology at ETH Zurich, died peacefully on March 11 at his home in Ebmatingen, Switzerland at the age of 85.

Otto Sticher, Emeritus and former Professor of Pharmacognosy and Pharmaceutical Biology at ETH Zurich, died peacefully on March 11 at his home in Ebmatingen, Switzerland at the age of 85.

With him we lose a distinguished colleague, great mentor and most importantly, a long-standing friend. His enthusiasm for science has influenced all those who worked with him. We thankfully look back at all his contributions to pharmacognosy, and we recall how he has influenced in so many ways our lives and our ways of thinking.

A remarkable contributor to the study of natural products, Otto Sticher’s breadth of research covered the entirety of the field. His scientific approach led not only to a deep knowledge and understanding of natural products’ isolation and identification, but also opened the view of their relevance in ethnomedicinal systems and as potential drug leads. Since 1972, he had been a full Professor and Director of Pharmacognosy (later Pharmacy) at the Institute of Pharmaceutical Sciences within the Department of Applied Biosciences at ETH Zurich, from where he retired on April 1st, 2002.

Otto Sticher was born on October 8, 1936, in Hochdorf, Canton (District) Lucerne into a family of farmers and millers. He studied pharmacy and accomplished his doctorate under Professor Hans Flück at the Pharmaceutical Institute of the ETH Zurich with a thesis on the essential oils of Mentha spp. After two years as a manager of a pharmacy, he became a postdoc under Professor Hans Schmid at the Institute of Organic Chemistry at the University of Zurich and obtained a teaching assignment in pharmacognosy and phytochemistry at the ETH Zurich. On April 1st, 1972, he was appointed as an Associate Professor, and in 1979 as a Full Professor of Pharmacognosy at ETH Zurich. He has taught pharmacognosy and phytochemistry (pharmaceutical biology) for both pharmacy students of the ETH and biology students of the University of Zurich. As part of the legendary ETH pharmacognosy curriculum, Otto Sticher organized and conducted “pharmacobotanical” excursions to various areas in Switzerland. These excursions were highly appreciated both by his scientific staff and his students, as they combined knowledge from lectures with observations of plants in their natural habitat.

During his distinguished and productive scientific career which lasted over 30 years, Otto Sticher authored and coauthored close to 400 scientific publications. His important contributions to the field have been recognized through numerous honors and awards. Among those, he was awarded an honorary doctorate in 2002 from the School of Pharmacy, University of London, and the Egon-Stahl-Award in Gold from the Society for Medicinal Plant and Natural Product Research (GA) in 2011. He was also an Honorary Member of several societies, including the GA, and an Honorary Member and Fellow of the American Society of Pharmacognosy (ASP). From 1978 to 1984, he was the president of the GA, and he served as Co-editor and Editorial Advisory Board Member of the journal Planta Medica. In addition, he was a member of the ASP Foundation Board and an Editorial Advisory Board Member of the Journal of Natural Products. Otto Sticher held appointments on pharmacopeial committees in Switzerland, Europe, and the United States. He has been a member of the Federal and European Pharmacopoeia Commission, and president of the Swiss Society of Pharmaceutical Sciences.

Otto’s research has had a major impact on the international research community in the field of natural product research. Already in the early 1980s, he invited researchers from all over the world to join his research at ETH Zurich. Strong ties were formed with Turkey through the fruitful collaboration with Prof. İhsan Çaliş, with Egypt, Greece, Morocco, and Papua New Guinea where he led bioprospecting expeditions to study medicinal plants together with Prof. Topul Rali from the University of Papua New Guinea. Ethnobotanical and ethnopharmacological studies were continued through three projects in Mexico co-directed by Prof. Michael Heinrich. The PhD project among the Yanomami in Venezuela was highlighted recently by Prof. Jürg Gertsch in a Planta Medica special issue (vide infra).

Otto Sticher’s research focused on the isolation, structure elucidation and biological screening of natural products from medicinal plants and cyanobacteria, as well as on quality control of herbal drugs, phytopharmaceuticals and ethnobotany. He was a specialist in the phytochemistry of Ginkgo biloba and Panax ginseng, among other herbal medicines, as well as the natural product classes iridoids and saponins. In his laboratory the “PRISMA” Model for computer-aided HPLC mobile phase optimization was developed. Otto Sticher was the main author of the later editions of one of the leading German textbooks “Pharmakognosie / Phytopharmazie”, first published in 1963 by E. Steinegger und R. Hänsel, which so far has been published in an 10th edition (2015). An influential review on natural product isolation published by the Royal Society of Chemistry came out in 2008. In 2014 Prof. Sticher was honored by a special issue of Journal of Natural Products, and in 2021, a special issue in Planta Medica on the occasion of his 85th birthday was dedicated to him.

With quotes from former PhD students, postdocs, visiting scientists and colleagues we want to highlight his many contributions to science and his impact he has had on all of us:

“I am grateful for getting to know Otto, and, indebted having the chance to work with him for more than twenty years. I was fortunate to work under Otto’s leadership, which had in time turned into prolific collaborative research. My initial and virtual experiences with the scientific world turned out to be a real lifetime experience, when I got to find out about the work of Otto.” (Ihsan Çaliş, Near East University, Nicosia)

“After a postdoctoral stay at Columbia University in New York, I felt the need to go back to my country. At this period, I had no contact with Otto but I was attracted by the modern research on medicinal plants he was conducting. I wrote him a letter asking for a job in his laboratory. He had no open position but created one: “Oberassistent”. Thus, I could join his group. The integration into the research was not difficult as my field was natural product chemistry. But as a chemist, I was especially challenged to teach the practical lessons, which included microscopical analyses for pharmacy students. But I liked the modern teaching approach of Otto as the pharmacognosy course was based on the active principles of plants and not on the botanical classification, as before. I spent 2 1/2 years in Zürich and could publish a couple of papers with Otto and learn many things. Then I was appointed professor of pharmacognosy at University of Lausanne. Without the stay at Otto’s lab and without his help, I could not obtain this new position. I owe my career to Otto. Thank you, I shall never forget that.” (Kurt Hostettmann, formerly University of Geneva)

“I was privileged to spend nearly six months on sabbatical as a Gastprofessor in Otto’s laboratory in Zurich in 1990, and this has very positively influenced me for the remainder of my working life. He was a model of academic excellence in our field of scientific inquiry. Otto very kindly served as an Editorial Board Member of the Journal of Natural Products from 1994–2003, and he attended many of the meetings of this group held in conjunction with the annual meetings of the American Society of Pharmacognosy. It was always refreshing and enlightening to talk to Otto and Miriam whenever they came to the United States.” (Douglas Kinghorn, University of Ohio)

“In 1974 Otto Sticher was open for – at that time – practically unknown technology of HPLC and gave me the chance to promote RP-HPLC in the analyses of medicinal plants. The strategy was very successful. His open mind to support progress in science as well as young researchers motivated PhD students and co-workers to be successful in many fields. For me, a nearly 50 year-long friendship ended physically, but not mentally.” (Beat Meier, Zurich University of Applied Sciences and SMGP)

“It has been such a wonderful experience to have had Otto’s support especially during my early years as a postdoctoral researcher. His openness to collaborating on ethnopharmacological projects and his enthusiasm for the research projects in México has been a motivation for me. He was a man of few words, but also one who quietly pushed for overcoming academic boundaries. I will also remember him as a great ambassador for excellent and precise science.” (Michael Heinrich, UCL School of Pharmacy, University College London)

“I am grateful for getting to know Otto as a teacher, mentor, and friend. He was always a gracious and friendly person. He was also a model scholar, very knowledgeable, dedicated and yet humble. One of my favorite memories is our plant collection trip to Papua New Guinea. We spent the days in the field collecting plants. Otto took part in all the hard work (cutting down trees, collecting leaves, etc.) and seemed to really enjoy it despite the tropical heat. In the evenings me, Otto and Miriam spent time talking about science and life in general over a cold drink – wonderful memories.” (Jimmy Orjala, University of Illinois at Chicago)

“On my first day as senior assistant at ETH, Otto asked me into his office. Because I was a bit unsure and everything was new, I asked him how I should best deal with the doctoral students. He just said: ‘Always be there for everyone, offer your help, try to be fair and always be a role model.’ Otto and his working group gave me six years in Zurich, which both personally and scientifically are among the best of my life.” (Jörg Heilmann, University of Regensburg)

“Otto Sticher’s research career always had a strong focus towards analytical quality of herbal medicinal products. He contributed many scientific publications in this field. His achievements made him a highly esteemed and respected scientist and promoter in the phytopharmaceutical industry.” (Clemens Erdelmeier, formerly Fa. W. Schwabe Karlsruhe, Germany)

“I have experienced Otto Sticher as a very sharp mind, who was interested in all parts of his science in great depth and detail. I have supported his group with NMR expertise on establishing structures of the isolated natural products, and the often required sophisticated NMR methods to pin down their structure. He would go carefully through spectra and arguments to check whether he would agree on the proposed structure. He was really taking the necessary time to do that, and I am sure we will find very few if any errors in the published structures.” (Oliver Zerbe, University of Zurich)

“Working at ETH with Prof. Sticher was a great milestone in my career. He was a dedicated scientist, and his contributions to Phytochemistry will live long. I fondly remember ’Kaffeerunde’ that he always attended even when busy with his work. He was a humble mentor and encouraged all of us to do our best.” (Ikhlas A Khan, University of Mississippi)

“Otto Sticher was a very open-minded, fair and friendly person, and a humble, exceptionally knowledgeable scientist. I learned from him being perfect and correct, and enjoyed the freedom he gave to his students. He was a great supervisor who recognized, valued, and supported talent. The door of his extremely tidy and pleasant office was always open, we could just knock and get in, he always had time for us. Those years I spent in his lab as a PhD student were not only the happiest times of my academic life, but also opened new horizons in my career. I enjoyed the famous pharmacobotanical excursions with him and students and very much and made me fall fell in love with (Swiss) mountains forever.” (Deniz Tasdemir, GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel)

“I am incredibly grateful to Otto for opening the doors of the renowned ETH Zurich to ethnopharmacology and ethnobotany. It was in the summer of 1990 when, at my audition for a PhD position, he agreed without hesitation to supervise a first ethnopharmacological-phytochemical dissertation including field studies in Mexico. The foundations were laid for many more interdisciplinary dissertations in collaboration with Michael Heinrich. Amazingly, already at the GA congress in 2000 in Zurich, Otto gave broad space to ethnopharmacology and this event became a great joint congress between the GA and the International Society for Ethnopharmacology. The legacy of Prof Carl Hartwich (1855–1917) came to light during the move of the institute in 1992. Together with his wife Miriam, he made this valuable collection accessible to the public, an important piece of pharmacy history. It remains an unforgettable effort to recover this pharmacognostic treasure. During my time at ETH and in the following years, his curiosity in new aspects of phytochemistry always enchanted me. This includes Miriam’s and Otto’s visit to my places of fieldwork in México, and their visit during my postdoc time in Kenya. It was always an honor to host him for exciting scientific and friendly discussions. All these are wonderful memories, and without doubt he leaves a huge gap.” (Barbara Frei Haller, ETH Zürich)

“At a time when pharmacy was moving increasingly in a direction of a narrow, discipline-specific field, Otto tried to bring together natural product chemists, botanists, pharmacologists, even ethnologists. Without his generosity, openness, and freedom for PhD students I could have not pursued an interdisciplinary career and I am deeply grateful to him. I have fond memories about personal conversations during travels to congresses all over the world. I will never forget Otto and Miriam at the occasion of their intrepid visit during my fieldwork in the upper Orinoco, an event which made us friends for life.” (Jürg Gertsch, University of Bern)

“Honest, fair and providing guidance and support whenever needed – this is how I will remember Prof. Sticher. With his very well-structured lectures he established a solid scientific basis of pharmacognosy in his students. And later being one of his postgraduates, I valued not only the excellent equipment and resources in his department, but even more the inspiring working environment he created.” (Eva Hoberg-Scholz, Switzerland)

“When I was an undergraduate student in pharmacy, Otto’s lectures in pharmacognosy aroused my interest for the field and encouraged me to pursue a career in pharmaceutical biology.” (Matthias Hamburger, University of Basel)

“Since my early days of pharmacognosy, I have been fascinated by Otto Sticher’s generosity and dedication to pharmacognosy. He has always been a role model of academic excellence and achieved immortality not only for his family and friends, but for all natural product researchers.” (Judith M. Rollinger, University of Vienna)

“For so many people he was not only a gracious, friendly person, but a model for what a humble scholar should be.” (Thomas W. Baumann)

“I thank Otto Sticher for his openness and support of my “Mayan project”. The field work in Mexiko and the research in the lab at ETH was my best time of my life. I had a wonderful time with him and Miriam Sticher during their visit in Yucatan” (Anita Ankli)

“I remember him as a very generous person and scientist. The trust he had in us students was an additional motivation.” (Marco Leonti, University of Cagliari)

“Aside from Otto Sticher’s many scientific achievements, he managed to create a work environment where everyone could thrive. As graduate students we had creative freedom and generous resources to advance our research. But most importantly, we were offered an environment, where friendships were established for life. Meeting Otto and Miriam at conferences and during their visit to Chicago was always a sweet reminder of the four very special years I had in Zurich.” (Birgit Jaki, University of Illinois at Chicago)

“From Otto Sticher, one could learn the precision required for the pursuit of exact science. His publications were solid to the core, and his way of doing science defied the utility-oriented spirit of the times. Paradoxically and sadly, he was not able to prevent the dissolution of the once world-renowned pharmacognosy at ETH Zurich into the ubiquitously spreading ‘molecular sciences’. I am grateful for the working atmosphere under Prof. Sticher and his instinct for bringing together extraordinary people, a constellation from which – even after subtracting all scientific connotations – lasting friendships grew up.” (Wolfgang Schühly, University of Graz)

“I am grateful and fortunate to have worked for a short time in his laboratory. I remember him as a generous and humble person.” (Anastasia Karioti, University of Thessaloniki)

“Otto was the prototypical pharmacognosist: rooted in the ethnobotany of medicinal plants, keen to advance knowledge about their underlying complex chemistry, and a scientist working at the forefront of natural products research. Foremost, Otto always had a supportive attitude and interacting with him was very pleasant.” (Guido Pauli, University of Illinois at Chicago)

“I was very fortunate and grateful to have the opportunity to work for such a generous, direct, and fair person, learned a lot about phytochemistry in the four years of my Ph. D study in Mr. Sticher’s group, the best time of my life. His silent and peaceful attitude motivated me, showing his trust on us.’’ (Pınar Akbay Irmak, Switzerland)

“Otto Sticher will be sadly missed for his life-long promotion of pharmacognosy and phytochemistry through his teaching and key work on antibacterial and cytotoxic agents from plant and marine sources. The personal loss is more acute because these essential elements of the pharmaceutical sciences are being neglected in some quarters, not least the UK.” (Alexander (Sandy) T. Florence, UCL School of Pharmacy, University College London)

“I remember numerous stimulating and even controversial conversations about the value and meaning of pharmacy with Otto, of whom I was a colleague at ETH between 1991 and 2002. He was always concerned about the self-confidence and independence of pharmaceutical sciences that do not lean on either medicine or chemistry. Interdisciplinarity was something natural and characteristic to pharmacy which Otto and considered as one of the assets of pharmaceutical research, a point on which we always agreed.” (Gerd Folkers, ETH Zurich)

“Otto Sticher nourished my enthusiasm for phytochemistry and phytotherapy, and this has shaped my entire career. I enjoyed four rich and inspiring years in his group, and I am most grateful for this wonderful time.” (Beatrix Falch, ETH Zurich)

As reflected by these personal recollections, Otto Sticher will be remembered as a scholar in a class of his own. His scientific contributions were prodigious in quality and quantity. As mentor and friend to many scientists in the field of natural product research he will remain with us after his passing. Several of his former PhD students have become professors. The human and academic legacy of Otto Sticher will live on, and he will be missed in person but not in our intellectual work. His vision and personality remain an inspiration to all of us.

The thoughts of us all go to his beloved wife and family.

His former PhD students, postdocs, colleagues, and in name of the GA board