Insecticides biological agents

Biological agents such as Bacillus thuringensis, BT, has been coming to the fore as a forest insecticide, as more has been learned about its use. Attention is now being given also to the viruses such as the polyhedrosis virus of the tussock moth. 

Plant secondary compounds play an important role in industry and medicine. Many industries are based on flavoring agents and perfumes, rubber, and naval stores. Several secondary compounds are physiologically active, which results in their use as insecticides, medicinal agents, or biological probes or tools. Plant compounds that are toxic to man and domestic livestock are widespread and may be responsible not only for accidental but also for chronic poisoning by common foods such as cassava, sago, lima, and fava beans. 

Many organosulfur compounds undergo biological oxidation at the sulfur atom to yield products which have pronounced physiological activity or serve as intermediates in generating bioactive compounds. Three examples are the lachrymating agent in onions ( ) (1), the oxo intermediate ( ) in metabolic desulfuration of phosphorothionate insecticides to form potent cholinesterase inhibitors (2), and the sulfoxides QJ produced on metabolism of thiocarbamate herbicides (3). 

Unsaturated 5(4//)-oxazolones have also been used as intermediates to prepare analogues with diverse biological activities. For example, the oxazolone derived from 4-biphenylcarboxaldehyde is a synthetic precursor of the antiinflammatory agent 4-biphenylacetic acid." In addition, 2-substituted oxazolones derived from 2-thioarylbenzaldehydes are starting materials for the preparation of dibenzothie-pine derivatives that are useful to treat schizophrenia." Other oxazolones have been used as intermediates to prepare insecticides and acaricides." ... 

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