His many national and international awards included the Royal Society Mullard award. In 1979, Elliott was made a fellow of the Royal Society and was appointed CBE in 1982. The two sets of new compounds discovered by the team earned Queen's awards for technological achievement for Rothamsted in 19. In 1948, he was appointed scientific officer in the insecticides and fungicides department at Rothamsted to study relationships between molecular structure and biological activity. There, his PhD work was on the synthesis of the natural pyrethrins, generating an interest that would dominate his scientific career. 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.Įlliott was born in London and educated at Skinners county school in Tunbridge Wells University College, Southampton and King's College London. Even today, they account for one third, worth over £250m per annum. With the popularly perceived problems of DDT usage, the invention of these pyrethroids was a timely development.īy the mid-1980s, pyrethroid sales were in excess of 20% of the global insecticide market, with the Elliott compounds constituting two thirds of this total, subscribing substantially to the UK economy through patent rights. Sabbaticals at the division of entomology, University of California, Berkeley, in 19 contributed to knowledge of pyrethroid metabolism. At the time, deltamethrin was the most active insecticide known. The impact of these compounds was such that the first year's commercial production of bioresmethrin (14 tonnes) was shipped to Australia to protect their stored grain harvest of 14m tonnes.īy 1974, the team had discovered a second set of compounds, notably permethrin, cypermethrin and deltamethrin, with increased persistence due to 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. By 1967, the multidisciplinary team had synthesised pyrethroids such as resmethrin and bioresmethrin, more active than the natural products while retaining other favourable properties. They had the foresight to support a programme of work at the Rothamsted Experimental Station at Harpenden, Hertfordshire, to prepare and test related compounds in return for patent rights.Įlliott 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. 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). It has very low mammalian toxicity, rapid knockdown of flying insects and negligible persistence. Pyrethrum extract, a natural product of chrysanthemum flowers, had long been known to have insecticidal properties. Thirty years after their introduction, they still constitute a substantial proportion of the total insecticide market. 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.
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