Biological and synthetic receptors for three different types of pest s
pecies have been compared: valinomycin and calix[4]crown ethers for K, urease and metallomacrocycles for urea, and phosphate binding protei
ns and synthetic anion receptors for different anions. The symbiosis o
f synthetic and biological receptors is demonstrated for transesterifi
cation reactions of amino acid esters by alpha-chymotrypsin in organic
solvents in the presence of crown ethers.