Crop chemicals, natural substances

Several of the top 20 pharmaceuticals in gross sales in 1992 were natural products or close derivatives thereof (eg. Mevacor, Ceclor). Of the top 20 crop chemicals in this same period, only one class of compounds, the pyrethroids, are based on a natural substance, the plant metabolite pyrethrin. Three active areas of chemistry have the potential to impact this situation within the next ten years the methoxyacrylate family of fungicides based upon the fungal metabolite, strobilurin Basta, a post-emergent broad-spectrum herbicide based upon the Streptomyces viridochromogenes metabolite phosphinothricylalanylalanine and avermectin, and its semi-synthetic derivatives, insecticides originating from Streptomyces avermitilis. 

A remedy is said to have selectivity if it can influence one kind of living cell without affecting others, even when these cells are close neighbours. Man has found many selective agents for treating his diseases and those of his farm animals and field crops. Most of the chemical substances that man uses in therapy differ from those evolved by nature, and yet are often related to them because both kinds may act on the same receptors. The substances employed by... 

---