In silico and in vitro Studies Evaluating the Promising Antiureolytic Activity of Schiff’s Base 4-(3-Hydroxybenzylideneamino)phenol and Its Amine Derivative

Urea is the most widely used nitrogen fertilizer worldwide. However, ammonia volatilization, resulting from applying urea to the soil surface, causes economic and environmental losses; thus, urease inhibitors have been developed to mitigate these losses. In this work, the anti-ureolytic activity of Schiff’s base 4-(3-hydroxybenzylideneamino) phenol (3B4) and its amine-derived (3B4a) was evaluated. The most promising urease inhibitor in soil was 3B4 (55.0 ± 3.9% inhibition), with comparable results to N-(butyl) thiophosphoric triamide (p = 0.659). In the in vitro analysis (Canavalia ensiformis), the results of anti-ureolytic activity were similar, 22.6 ± 6.9% for 3B4 and 24.2 ± 9.6% for 3B4a. Biophysical interaction studies were also carried out through molecular docking studies and molecular fluorescence spectroscopy. These studies showed that both substances are preferentially competitive inhibitors, with the interaction between 3B4a and urease forming a more stable complex. In the analysis by Fourier transform infrared spectroscopy, no interaction was observed when 3B4 or 3B4a was mixed with urea (1:1) for 48 h, providing evidence of compatibility. Thus, the Schiff base 3B4 and its corresponding amine 3B4a may represent potential additives for urea fertilization aiming to assist in the urease inhibition process.

Keywords:
urease; urea; urease inhibitors; Schiff bases; amine derivative; competitive inhibitors