Synthesis And Bioactivities Of Hymexazol-amino Acid Derivatives

Hymexazol is a systemic fungicide, also a kind of soil disinfectant, and have good prevention effect to diseases aroused by fusarium, aphanomyces, pythium and corticium. Hymexazol is usually used as seed treatment or root-irrigation, can combine with the iron ions and aluminum ions in soil, aslo inhibit the germination of spores. Hymexazol can be absorbed by roots and transmit within the root system, and it can be resolved into two kinds of glucoside by plant metabolism and have the effect of physiological activity.Amino acids pesticides have the characteristic with low toxicity,high efficient, non-pollution, easily biodegradation, extensive raw material sources, etc. Therefore, the research proposed the concept that derived synthesis with hymexazol and amino acid, then obtain the hymexazol-amino acid derivatives, and determined the biological activity by growth rate control method.This research has synthesized26new compounds firstly that have not been reported. Bioassay results showed that these new compounds had apparent inhibitory activity to mycelial growth caused by the wheat gibberellic disease pathogen(Fuasrium graminearum Schw.),cotton Fusarium wilt pathogen(Fuasrium oxysporum f. sp. Vasinfectum (Atk.) Synder&Hansen), cotton red rot pathogen(Fusarium moniliforme Var. Intermedium Neish et Leggett). What’s more, the activity of partial derivatives is significantly higher than the Hymexazol’s activity. These new compounds have poor growth inhibitory activity to Rice blight pathogen(Rhizoctonia solaniKuhn) and walnut root rot pathogen(Fusarium oxysporum), but their activity was equal to Hymexazol’s.The respective50%effective concentration (EC50) of N-carbobenzoxy-alanine-hymexazol ester, N-carbobenzoxy-leucine-hymexazol ester, N-carbobenzoxy-proline-hymexazol ester, N-carbobenzoxy-phenylalanine-hymexazol ester and N-carbobenzoxy-menthionine-hymexazol ester to wheat scab are0.264mmol/L,0.245mmol/L,0.212mmol/L,0.225mmol/L and0.205mmol/L, but the50%effective concentration of hymexazol is0.338mmol/L. The respective50%effective concentration (EC50) of N-carbobenzoxy-proline-hymexazol ester, N-carbobenzoxy-phenylalanine-hymexazol ester and N-carbobenzoxy-menthionine-hymexazol ester to cotton Fusarium wilt pathogen are0.234mmol/L,0.277mmol/L and0.289mmol/L, but the50%effective concentration of hymexazol is0.479mmol/L. The respective50%effective concentration (EC50) of N-carbobenzoxy-valine-hymexazol ester, N-carbobenzoxy-leucine-hymexazol ester, N-carbobenzoxy-isoleucine-hymexazol ester and N-carbobenzoxy-proline-hymexazol ester to cotton red rot pathogen are0.061 mmol/L,0.058mmol/L,0.060mmol/L and0.041mmol/L, but the50%effective concentration of hymexazol is0.175mmol/L.The respective50%effective concentration of phthaloyl-glycine-hymexazol ester, phthaloyl-isoleucine-hymexazol ester, phthaloyl-phenylalanine-hymexazol ester and phthaloyl-tryptophan-hymexazol ester to wheat scab are0.104mmol/L,0.175mmol/L,0.128mmol/L and0.189mmol/L, but the50%effective concentration of hymexazol is0.302mmol/L. The respective50%effective concentration of phthaloyl-glycine-hymexazol ester, phthaloyl-alanine-hymexazol ester, phthaloyl-leucine-hymexazol ester, phthaloyl-isoleucine-hymexazol ester and phthaloyl-phenylalanine-hymexazol ester to cotton red rot pathogen are0.039mmol/L,0.101mmol/L,0.107mmol/L,0.082mmol/L and0.068mmol/L, but the50%effective concentration of hymexazol is0.175mmol/L.The trial results show that the new derivatives have the same biological activity as hymexazol, and the new derivatives have higher bioactivity than the others four pathogenic bacteria to cotton red pathogen. But while N-carbobenzoxy and phthaloyl protect amino acid, there have no effect on bioactivity of new derivatives.But, there is no regulary change of bioactivity between the different amino acid structure and the different pathogenic bacteria, and what kind of amino acid structure can improve the derivatives’s biological activity, it remains to be further research.