Leonidas Zervas

Leonidas Zervas (Λεωνίδας Ζέρβας, ; 21 May 1902 – 10 July 1980) was a Greek organic chemist who made seminal contributions in peptide chemical synthesis.

Zervas was born in 1902 in the rural town of Megalopolis in Arcadia, southern Greece.

He was the first of 7 children of lawyer and parliamentarian Theodoros Zervas with Vasiliki Zerva (née Gyftaki).

After finishing secondary education at the local Gymnasion of Kalamata in 1918, he went to study Chemistry at the University of Athens.

Before finishing his studies there, he moved to Berlin in 1921 where he graduated with a degree in chemistry from the University of Berlin in 1924.

Under the supervision of Max Bergmann, he finished his doctoral thesis on the reactions of amino acids with aldehydes and was awarded his Dr. rer. nat. from the University of Berlin in 1926.

He proceeded to work with Bergmann in the Kaiser Wilhelm Institute for Leather Research in Dresden, of which Bergmann was the founder and director.

From 1926 to 1929 Zervas was a research associate and eventually rose to head of the organic chemistry division and vice-director of the institute (1929–1934).

It was at this period that the two men developed the Bergmann-Zervas oligopeptide synthesis which brought them international fame within academic circles.

In 1930, he married Hildegard Lange, and they remained together until his death.

Together with his mentor Max Bergmann they laid the foundations for the field in 1932 with their major discovery, the Bergmann-Zervas carboxybenzoxy oligopeptide synthesis which remained unsurpassed in utility for the next two decades.

The carboxybenzyl protecting group he discovered is often abbreviated Z in his honour.

Throughout his life Zervas also served in many important posts, including President of the Academy of Athens or briefly Minister of Industry of Greece.

He received numerous awards and honours during his life and posthumously, such as Foreign Member of the USSR Academy of Sciences or the first Max Bergmann golden medal.

Zervas, by that point a close personal friend of Bergmann, decided to follow the latter to the US in 1934 after Bergmann emigrated from Nazi Germany in 1933 under pressure due to his Jewish origin.

In New York, Zervas spent 3 years as lecturer and researcher at the Rockefeller Institute for Medical Research.

After his Berlin, Dresden and New York years, Zervas decided to return to Greece in 1937.

He was immediately appointed full Professor of Organic Chemistry and Biochemistry at the Aristotle University of Thessaloniki in recognition of his distinguished international work.

He stayed in this position until 1939, when he was invited to the Professorship of Organic Chemistry at the University of Athens and also appointed director of the Laboratory of Organic Chemistry of the same institution.

He continued conducting research, despite the severe limitations he often faced from the lack of equipment and funding.

Concurrent to research, Zervas taught organic chemistry, oversaw the laboratory and guided many generations of young chemists as doctoral advisor for the 29 years he held the post at the University of Athens.

During the Axis occupation of Greece Zervas played an active part in the Greek Resistance as a member of EDES; he was imprisoned twice, first by the Italian and then by the German occupying forces, and his laboratory was destroyed.

Following the liberation of Greece, Zervas managed to secure a small part of the American postwar aid for repairs in the University of Athens and the Athens Polytechnic, and thus rebuilt his laboratory in 1948–1951.

In the following years, guided by a sense of personal and professional duty, Zervas voluntarily took on a variety of responsibilities within the Greek state.

At his own insistence, he never got paid for these posts and kept receiving only his professorial salary.

In response, the Academy of Athens of which Zervas had been a member since 1956 elected him as its president in 1970.

The democratic ideals of Zervas made him a target of the military junta established in 1967, which removed him from his position in the University of Athens in 1968 after almost three decades of dedicated research and teaching.

Some notable positions he held in chronological order until 1968 include:

After his term as President of the Academy, Zervas retired in 1971.

With the restoration of democracy in 1974, Zervas was able to contribute once more to research and educational policy.

As previously, refusing to take a salary for these positions, he served a second time as the President of the Greek Atomic Energy Commission (1974–1975) and then as the President of the National Hellenic Research Foundation (1975–1979).

Zervas had suffered from periodic issues with respiratory health throughout his adult life, but in his final years the situation deteriorated.

The extended use of phosgene in his research has been implicated as the cause of this chronic pulmonary disease.

He showed perseverance and a pleasant attitude despite his health issues, continuing to attend meetings of the Academy of Athens until the very end of his life.

This came in the summer of 1980 after an acute pulmonary episode, which lasted three weeks before he died at the age of 78.

The enduring contributions of Zervas were made together with Bergmann and involved the first successful synthesis of substantial length oligopeptides.

They achieved this using the carboxybenzyl amine protecting group for the masking of the N-terminus of the growing oligopeptide chain to which amino acid residues are added in a serial manner.

The carboxybenzyl group discovered by Zervas is introduced by reaction with benzyl chloroformate, originally in aqueous sodium carbonate solution at 0 °C:

The protecting group is abbreviated Cbz or, in honour of Zervas, simply Z.

The typical route for deprotection involves hydrogenolysis under mild conditions e.g. with hydrogen gas and a catalyst such as palladium on charcoal.