Chemo-enzymatic, regioselective synthesis of dihydropyrimidinone-fused β-amino alcohols and their anti-inflammatory and antioxidant activity evaluation

A highly regioselective and efficient method has been developed for synthesizing novel β-amino alcohols fused with dihydropyrimidin-2-one. This method utilizes the enzyme Novozyme-435 to catalyze the reaction between epoxides and various aliphatic amines in acetonitrile. Novozyme-435 outperformed other catalysts, including Porcine Pancreatic Lipase (PPL), Pseudomonas aeruginosa lipase (PAL), and Candida rugosa lipase (CRL). This process yielded two series of β-amino alcohols (compounds 8a-h and 9a-h), whose structures were confirmed through IR, NMR (¹H,¹³C), and HRMS analyses. The anti-inflammatory and antioxidant properties of these compounds were evaluated, revealing mild to moderate inhibition of TNF-α-induced ICAM-1 expression in primary human endothelial cells, with compounds 9a and 9c showing approximately 60% inhibition. Antioxidant activity, assessed using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, indicated that compounds 9a, 9b, 9c, and 9 g had the superior activity than others. This study highlights the potential of these β-amino alcohols fused with dihydropyrimidin-2-one as anti-inflammatory and antioxidant agents.