Hodgkin, Dorothy Mary Crowfoot (1910–1994)

English biochemist who analysed the structure of penicillin, insulin, and vitamin B₁₂. Hodgkin was the first to use a computer to analyse the molecular structure of complex chemicals, and this enabled her to produce three-dimensional models. She was awarded the Nobel Prize for Chemistry in 1964 for her work in the crystallographic determination of the structures of biochemical compounds, notably penicillin and cyanocobalamin (vitamin B₁₂).

Hodgkin studied the structures of calciferol (vitamin D₂), lumisterol, and cholesterol iodide, the first complex organic molecule to be determined completely by the pioneering technique of X-ray crystallography, a physical analysis technique devised by Lawrence Bragg (1890–1971), and at the time used only to confirm formulas predicted by organic chemical techniques. She also used this technique to determine the structure of penicillin, insulin, and vitamin B₁₂.

Penicillin Hodgkin was born in Cairo and educated at Somerville College, Oxford. At Cambridge (1932–34) she worked on the development of X-ray crystallography and, returning to Oxford in 1934, began working on penicillin. After Howard Florey and Ernst Chain isolated penicillin from mould in 1939, chemists in Britain and the USA raced to determine its structure. Hodgkin's assertion that the core of penicillin consisted of a ring of three carbons and a nitrogen thought too unstable to exist, brought from Australian chemist John Cornforth the derisive comment, ‘If that's the formula of penicillin, I'll give up chemistry and grow mushrooms.’ But Hodgkin was right, and she went on to determine the structure of the antibiotic cephalosporin C.

Vitamin B12 In 1948 Hodgkin began her work on vitamin B12, a substance that proved to be far more complex than penicillin: the first X-ray diffraction pictures showed over 1,000 atoms, compared to penicillin's 39. It took Hodgkin and her co-workers eight years to solve.

Insulin The structure of insulin was to take much longer still; Hodgkin first saw the diffraction pattern made by insulin in 1935, but it was to take 34 years for her to determine its structure.

Honours In 1964 Hodgkin became the second woman to have ever received the Order of Merit (the first was Florence Nightingale) and – a committed socialist all her life – in 1987 she was awarded the Lenin Peace Prize. She was chancellor of Bristol University 1970–88 and helped found a Hodgkin scholarship for students from the developing world.