Abstract:

The contact toxicity of 11 synthetic polyacetylenes was tested to newly hatched Periplaneta americana larvae with the method of drug film. The results showed these compounds, 1-t-butyl-4-hydroxymethyldiacetylene, 1-benzyl-4-methyldiacetylene and di-ethyl-2-propargylthiophosphate caused high mortality of over 70% to the larvae at 20 μg/cm² The LC₅₀ of 1-benzyl-4-methyl diacetylene and di-ethyl-2-propargyl thiophosphate was 3.91 μg/cm² and 1.50 μg/cm², respectively. The effect on AChE of the insect indicated that 1-t-butyl-4-hydroxymethyldiacetylene, 1-phenyl-4-o-nitrophenyl-diacetylene and di-ethyl-2-propargylthiophosphate inhibited its activity, and the inhibition rate was 12.00%, 27.24% and 62.22%, respectively. To ATPase, 1-t-butyl-4-hydroxymethyl diacetylene and di-ethyl-2-propargyl thiophosphate inhibited the activity of Na⁺K⁺ATPase, and the inhibition rate was 44.55% and 31.44%, respectively; but 1-phenyl-4-(3,4methylenedioxy)-phenyl-diacetylene and 1-phenyl-4-m-nitrophenyl-diacetylene enhanced the activity of the enzyme, and the activation rate was 24.98% and 20.61%; 1-t-butyl-4-hydroxymethyl-diacetylene,1-phenyl-4-p-methoxyphenyldiacetylene and 1-phenyl-4-o-nitrophenyl-diacetylene inhibited the activity of Ca²⁺Mg²⁺ATPase, and the inhibition rate was 49.02%, 38.53% and 35.32%, respectively; but other compounds enhanced activity of the enzyme, among them the highest activity was observed with 1-phenyl-4-(3,4-methylenedioxy)-phenyl-diacetylene, and the activation rate was 81.12%.

Key words: Polyacetylenes, Periplaneta americana, contact toxicity, AChE, Na⁺K⁺ATPase, Ca²⁺Mg²⁺ATPase