News: In Memoriam: Wolfgang Pfleiderer (1927-2018)

Wolfgang Pfleiderer, professor emeritus of chemistry at the University of Konstanz, sadly passed away in January. He was known as an outstanding scientist in heterocyclic chemistry as well as in the field of nucleosides, nucleotides and nucleic acids.                                                                                                    

Wolfgang Pfleiderer was born on July 22, 1927 in Esslingen am Neckar. Still in school, he was conscripted to the army, when in April 1945 he was severely wounded and lost his left arm and right thumb. Sheer willpower allowed him to finish school in 1946 where he studied chemistry. He earned a Masters degree in chemistry and a Ph.D., both from the University of Stuttgart under the supervision of Professor Hellmut Bredereck. In 1957. Later he did his habilitat at the same university on investigations in the field of pteridine chemistry, to which he remained loyal during his whole career. After his postdoctoral studies at Princeton University with Professor E.C. Taylor, he became an assistant professor in Stuttgart and moved to the University of Konstanz in 1967, where he then became full professor at the newly founded university. There he established, together with his colleagues, a modern curriculum for chemistry students.

Wolfgang Pfleiderer was visiting professor at Arizona State University (1963), Australian National University (1965), University of Osaka (1977), University of Bagdad (1980, 1990), University of Strathclyde (1980). He has an honorary degree of Trinity College Dublin and received an International Award of Heterocyclic Chemistry (1991), the Frederic Gowland Hopkins Award for Pteridine Chemistry (1993) and a Life Achievement Award from the German Nucleic Acids Society (2017). He published 586 articles in international peer reviewed journals from 1953 to 2015, the first in 1953 (Synthesen in der Purinreihe, II. Mitteil. Über die Einwirkung von Essigsäureanhydrid auf Harnsäure in Berichte der deutschen chemischen Gesellschaft), and finally in 2015, (Pteridines part CXXI: protection of (6R)-5,6,7,8-tetrahydro-L-biopterin in Australian J. Chem.), in total, eight books and many patents.

His main focus during his life-long career was pursuing the organic and physico-chemistry of nitrogen heterocycles with a special emphasis on pteridines, purines and pyrimidines. As part of this, he studied the influence of structure on tautomerism, spectra and pKa, photochemistry and electrochemistry. As he himself would often admit, one of his hobbies were the natural pteridines. Striking examples are his outstanding work on the isolation, purification and structural determination of erythropterin, drosopterin, isodrosopterin, aurodrosopterin, euglenapterin and limipterin. This work was published in the leading journals of that time (Chem. Ber. 1992, 1978; Liebigs Ann. Chem. 1986; Helv. Chim. Acta 1993, 1995).

Wolfgang Pfleiderer developed new methods for the synthesis of pteridine nucleosides with fluorescent properties, which were later used as fluorescent probes in nucleic acids. He is recognized for his work in the field of phosphotriester and phosphoramidite chemistry to improve solid and solution phase nucleic acids synthesis. He introduced a universal protecting group strategy (i.e. p-nitrophenylethyl) for oligonucleotide synthesis and has applied this principles to other fields of organic synthesis. He became interested in the development of photolabile protecting groups for the combinatorial synthesis of oligonucleotides on chips.

His advice was often sought by many colleagues, and he was generous with samples of his vast collection of compounds and in sharing his deep knowledge. A large number of collaborations all over the world yielded many joint publications. With Professor Robert Suhadolnik, Temple University, Philadelphia, he worked for 30 years on the biochemistry and biology of 2’-5’-oligoadenylates, involved in the mechanism of inducing an antiviral state in cells. He worked out structure activity relationships by synthesizing many modified 2’-5’-adenylates (modified at the base, sugar, and/or phosphate moieties) in larger quantities by solution phase chemistry.

Wolfgang Pfleiderer trained many Ph.D. students during his career, many postdoctoral fellows worked with him in Konstanz. He was German editor of the J. Heterocyclic Chemistry. He founded the first nucleoside and nucleic acids society in continental Europe which later became part of the International Society of Nucleoside, Nucleotides and Nucleic Acids. He was president of the International Society of Heterocyclic Chemistry, the International Society of Pteridinology and the International Society of Nucleic Acids Chemistry. He organized the International Symposium on Pteridines and Folates in Stuttgart 1962, Konstanz 1975 and Berchtesgaden 1997, as well as the International Roundtable in Konstanz in 1986.

Wolfgang Pfleiderer was recognized as a passionate and creative chemist, with a high level of curiosity and productivity, who enjoyed working on the the bench himself until 2016. As a person, he was a very generous man. His wife Cornelia predeceased him in 2016, and he leaves behind a daughter and two sons.