This has just come in from Rothamsted Research:
MICHAEL ELLIOTT, CBE, DSc, FRS
Michael Elliott, who has died aged 83, was the chemist responsible for leading a team of scientists in the discovery and development of modern synthetic pyrethroids, a class of insecticides highly effective against major pests of public health and agricultural importance, and also exceptionally benign to the environment. Thirty years after their introduction, they still constitute a substantial proportion of the total insecticide market; the synthetic pyrethroids reached at least 20% of global insecticide sales during this time and have made a significant contribution to the UK economy.
Pyrethrum, a natural product of chrysanthemum (Tanacetum = chrysanthemum cinerariifolium) flowers, had long been known to have insecticidal properties. The natural product has very low mammalian toxicity, rapid knockdown of flying insects and negligible persistence. After work to identify the most active components of the natural extract, Elliott turned to synthesising analogues, some of which were sufficiently active to justify support by the National Research Development Corporation (which later became the British Technology Group). They had the foresight to support a programme of work at Rothamsted to prepare and test related compounds. Elliott was justifiably convinced that pyrethroids act by a lock and key mechanism, and spent many hours manipulating molecular models ("playing", in the eyes of less trusting colleagues), seeking to identify compounds that should be synthesised to probe the shape of the lock. By 1967, the multi-disciplinary team had synthesised pyrethroids such as resmethrin and bioresmethrin having much greater activity than the natural products, whilst retaining other favourable properties. Then, by 1974, the team had discovered a second set of compounds, notably permethrin, cypermethrin and deltamethrin, with increased persistence because of resistance to degradation by light and air, yet without diminishing their susceptibility to degradation by birds, mammals and soil microflora, thus making them suitable for use in agriculture. At the time, deltamethrin was the most active insecticide known. Sabbaticals at the Division of Entomology, University of California, Berkeley, in 1969 and 1974 contributed to knowledge of pyrethroid metabolism. With the problems of DDT becoming apparent, the invention of these pyrethroids was a timely development. In the 1980s, pyrethroid sales were in excess of 20% of the global insecticide market. The Elliott pyrethroids constituted two thirds of this total, and even today account for one third, worth over US$500M per annum. They continue to find new applications, the most notable recent example being their use in sprays and bednets in Africa, which has resulted in a substantial reduction in the incidence of malaria.
Michael Elliott was born in London on September 30th, 1924 and educated at University College, Southampton, and King's College, London. There, his Ph.D. work was on the synthesis of the natural pyrethrins, generating an interest that would dominate his scientific career. In 1948, he was appointed Scientific Officer in the Insecticides and Fungicides Department at Rothamsted Experimental Station, Hertfordshire, to study relationships between molecular structure and biological activity. The two sets of new compounds discovered by the team earned Queen's Awards for Technological Achievement for Rothamsted in 1976 and 1980. In 1979, he was elected to Fellowship of the Royal Society of London and was appointed Commander of the Order of the British Empire in 1982. In acknowledgement of his pioneering work on the synthetic pyrethroids, he received numerous national and international awards including the highly prestigious Royal Society Mullard Award, given in recognition of outstanding contributions to the advancement of science or technology leading directly to national prosperity in the United Kingdom. By the time he retired in 1984, he had risen to the position of Deputy Chief Scientific Officer (Individual Merit), Head of Department and Deputy Director. In 1996, he was elected a Foreign Associate of the National Academy of Sciences, United States of America.
He was popular with his colleagues, acknowledging their contribution in public whenever he could. His tenacity and ability to recognise serendipitous occurrences were always well recognised. He was a gifted photographer whose work frequently demonstrated his sense of humour, as did his ability to mimic foreign visiting scientists, which very nearly got him into trouble on several occasions. In retirement, Elliott continued to take an active interest in research at Rothamsted and elsewhere, and his advice was eagerly sought. He was a devoted family man, married for 57 years to Margaret and sharing a love of photography, travel, music, cars, and good food and wine. He leaves two daughters, Karen and Fiona, and four grandchildren.