中文摘要：

使用脲酶抑制剂能够降低脲酶的活性，减缓尿素的水解，是提高尿素利用率的有效途径。以天然产物棉酚为原料，通过N-取代基苯胺对其进行化学改性制备高效脲酶抑制剂苯胺棉酚席夫碱（Gos-H），氨基苯甲酸棉酚席夫碱（Gos-COOH）和氨基苯磺酸棉酚席夫碱（Gos-SO3H），并探究其抑制土壤氨挥发的效果。结果表明，棉酚及其衍生物均有较强的脲酶抑制活性。其对刀豆脲酶的抑制IC50值分别如下：Gos，2．61×10^5mol·L^-1；Gos-H，9．93×10^-5mol·L^-1；Gos-COOH，1．49×10^-4mol·L^-1和Gos-SO3H，1．85×10^-4mol·L^-1。抑制土壤氨挥发的IC50值分别为：Gos，5．74×10^-5mol·L^-1；Gos-H，3．47×10^-5mol·L^-1；Gos-COOH，2．27×10^-5mol·L^-1和Gos-So3H，1．75×10^-5mol·L^-1。总体来说，改性引入的含O基团能够增加棉酚席夫碱的抑制能力。

英文摘要：

Urease inhibitors are key factors to increase the efficiency of urea usage through reducing urease activity. In order to find novel urease inhibitors, phenylgossypol Schiffbase （Gos-H）, benzoyloxy gossypol Schiffbase （Gos-COOH）, and sulfonatephenyl gossypol Schiffbase （Gos-SO3H） were synthesized through chemical modification from natural resource gossypol and their inhibitory effects on urease were studied. These compounds were applied to the red clay soil and the reduction of ammonia volatilization losses from urea with urease was determined. It was showed that gossypol and its derivatives had an excellent performance on inhibiting urease IC50 values of gossypol and its derivatives to jack bean urease were： Gos, 2.61×10^-5 mol·L^-1; Gos-H, 9.93×10^-5 mol·L^-1; Gos-COOH, 1.49×10^-4mol·L^-1, and Gos-SO3H, 1.85×10^-4mol·L^-1. Schiffbases served as inhibitors for minimizing the ammonia volatilization losses from the red clay soil and their IC50 values were： Gos, 5.74×10^-5 mol·L^-1; Gos-H, 3.47×10^-5 mol·L^-1; Gos-COOH, 2.27×10^-5 mol·L^-1, and Gos-SO3H, 1.75×10^-5 mol·L^-1. In conclusion, the inhibition of Schiffbases was enhanced by the O-group modification from chemical treatments.