Karger Gazette No 71> Swiss Pioneers in Science and Medicine


	No. 71 Swiss Pioneers in Science and Medicine

The Fruits of Labor: The First Industrial Synthesis of Vitamin C Tadeus Reichstein (1897–1996)	© istockphoto.com/Martin McCarthy

The industrial production of vitamin C was a crucial step in the fight against malnutrition. But it was only possible because of the demise of a humble fruit fly.

D. Paterson

In 1934 a preparation of vitamin C called Redoxon was launched onto the market by Hoffmann-La Roche, a Swiss pharmaceutical company. Redoxon was ground breaking for being the first industrially synthesized vitamin C to be sold to the public. Its production was based on a revolutionary process developed by Tadeus Reichstein, a Polish-born chemist working at the Swiss Federal Institute of Technology in Zürich.

Vitamin C – also known as ascorbic acid – is an essential nutrient, being an antioxidant and also critical to the production of collagen, the main protein in connective tissues. Most animals and plants are able to synthesize vitamin C from glucose but, in a curious evolutionary twist, humans lost one of the enzymes necessary for this process and so must obtain the vitamin from their diet. The shortcomings of this evolutionary strategy only really became apparent when humans set out on long sea voyages with no access to fresh foods, and found that they rather frequently died of scurvy.

Although the curative effects of fresh fruits and vegetables were known as early as the 16th century, it was not until 1932 that the 'antiscorbutic factor' now called vitamin C was isolated and linked to scurvy in laboratories headed by Albert Szent-Györgyi and Charles Glen King.

Once news of the discovery broke, a number of research groups began looking at ways to synthesize vitamin C on a large scale. Among those interested was Tadeus Reichstein. The tricky step in making vitamin C from glucose was converting sorbitol, a reduction product of glucose, to L-sorbose, a sugar. Reichstein knew that so-called sorbose bacteria could carry out this transformation, but he could not get his hands on a culture that carried out the process efficiently. Drawing inspiration from a 19th century publication by Gabriel Bertrand, a French chemist, Reichstein set out to catch some wild bacteria using half-a-dozen glasses filled with an acidic mixture containing red wine, vinegar, yeast and sorbitol. After leaving these glasses outside for a few days, Reichstein returned to discover a Drosophila fly had drowned in this unpleasant brew. From one of its legs, long sorbose crystals were growing. Reichstein was able to isolate the Drosophila-borne bacteria and put them to work making sorbose. Soon after, his team had the remaining steps worked out and the first industrial process for creating vitamin C was born.

Although Reichstein received the patent for the production process – which still bears his name – his work was not recognized as widely as it could have been. In 1937, the Nobel committee awarded the Prize in Chemistry to Walter Haworth, a British competitor of Reichstein, partly in recognition of his work on vitamin C. Haworth's team in Birmingham had been the first to make crystals of the levo form of ascorbic acid (the isomer that is found in nature) through a painstaking 11-step process. However, Reichstein's method was more suitable for industrial production.

Tadeus Reichstein at work in his laboratory
Photo by Gotthard Schuh. © Fotostiftung Schweiz

In her 1999 piece on Reichstein in the Biographical Memoirs of Fellows of the Royal Society, Miriam Rothschild, a British entomologist and personal friend of Reichstein, was astonished that he did not receive greater recognition. She wrote: 'Many people were surprised at the fact that Tadeus did not receive the Nobel Prize for the synthesis of vitamin C, or at least shared the honor with Szent-Györgyi and perhaps Oppenauer [one of Reichstein's PhD students]. It was recognized that the work had laid the foundation stone for the modern bridge spanning organic chemistry and medicine.'
However, Reichstein was to receive recognition from the Nobel committee when, in 1950, it awarded him – together with Edward Kendall and Philip Hench – the Prize in Physiology or Medicine for his later work on the structure and functions of adrenal cortex hormones, chiefly the isolation of cortisone.

Further Reading

Rothschild M: Tadeus Reichstein. 20 July 1987–1 August 1996: Elected For.Mem.R.S. 1952. Biogr Mems Fell R Soc 1999;45:449–467.

Nobel Lectures, Physiology or Medicine 1942-1962. Amsterdam, Elsevier, 1964.

David Paterson is an editor of the Karger Gazette