| pyrethrins | <chemical> The active insecticidal constituent of pyrethrum flowers. Pyrethrin I is the pyretholone ester of chrysanthemummonocarboxylic acid and pyrethrin II is the pyretholone ester of chrysanthemumdicarboxylic acid monomethyl ester. Pharmacological action: insecticide, botanical. (12 Dec 1998) |
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