Dados do Trabalho

Título

EXPLORING NEW UREASE INHIBITORS FOR AGRICULTURAL APPLICATIONS: FROM NATURAL TO SYNTHETIC SOURCES

Resumo

Urea is one of the most widely used nitrogen (N) fertilizers globally. However, when urea is applied to the soil surface, the activity of extracellular soil ureases can lead to N losses through ammonia volatilization. To mitigate these N losses, urease inhibitors like NBPT have been employed. This study aimed to discover new urease inhibitors of agricultural significance from both natural and synthetic sources. These inhibitors were sought to be more stable and/or cost-effective compared to NBPT. Several substances were screened for their inhibitory potential against Jack bean urease and the production of ammonium in different Brazilian soils. These substances included pyroligneous acids derived from black wattle (EPAN), coconut (EPCC), and eucalyptus (EPEU), a benzylisothiocyanate (MFC) extracted from horseradish tree, 26 Biginelli adducts, and 12 imines. The concentrations (v/v) necessary to inhibit the urease by 50% (IC50) in vitro for EPCC, EPAN, and EPEU were 0.2 %, 0.3 %, and 0.5 % respectively. The highest potency showed by EPCC is consistent with its higher levels of phenols and humic substances, well-known urease inhibitors. MFC (50% inhibition) was as efficient as the NBPT regarding the inhibition of ureases from a Red Latossolo/Udox. The Biginelli adducts 2A7 and 2D2 (IC50 = 3.2 mM) were the most efficient among the Biginelli adducts on ureases present in a clayey dystrophic Red Latossolo. Both BAs are very stable at temperatures as high as 200 oC. The imines 4, 5, and 6 showed outstanding IC50 values towards ureases from a clayey dystrophic Red Latossolo (27.5-233.9 µM). None of them impaired the germination of lettuce and millet seeds or the seedling’s growth. Notably, imines 4 and 5 stimulated the root growth of L. sativa while 5 also stimulated the millet’s growth. The natural and synthetic compounds tested led us to identify lead urease inhibitors for the development of urea-based fertilizer formulations of increased efficiency.

Palavras-chave

Urease inhibitors; Natural and synthetic compounds; plant growth; soil ureases

Instituição financiadora

FAPEMIG, CNPq, and CAPES

Agradecimentos

PRPq-UFMG, PPG Biologia Vegetal-UFMG, and PPG Química-UFMG