Molecules

Novel pyrrole-based derivatives were synthesized in high purity and yields (52–89%), with 17i and 17j displaying selective MAO-B inhibition (50–60%), comparable to Selegiline, and negligible MAO-A activity. In rat brain subcellular fractions, both compounds showed low intrinsic neurotoxicity at 100 μM while exerting significant neuroprotective and antioxidant effects under 6-OHDA, t-BuOOH, and Fe²⁺/ascorbate-induced stress. Mechanistic studies indicate dual protection via reactive oxygen species scavenging and preservation of reduced glutathione, with mitochondria and microsomes being the most responsive compartments. The performed in silico analysis revealed no general toxicity alerts, though hydrazine groups classify the compounds as contact allergens, and the furan ring in 17i poses hepatotoxic and carcinogenic risks. Metabolic predictions suggest ester hydrolysis at the pyrrole ring as the main biotransformation pathway. Overall, 17i and 17j are promising lead compounds for developing therapeutics targeting oxidative stress-related neurodegenerative diseases, such as Parkinson’s and Alzheimer’s, supporting further in vivo studies.

This study aimed to produce the hydrolysates of Xuanwei ham bone using enzymatic hydrolysis assisted by microwave and ultrasound pretreatment. A back propagation artificial neural network (BP-ANN) model was utilized to predict the optimal conditions, which involved 15 W/g bone for 15 min of ultrasound pretreatment and 5 W/g bone for 30 min of microwave pretreatment, achieving the highest degree of hydrolysis (DH). The model predicted a DH of 27.69, closely aligning with the experimentally measured actual DH of 28.33. DPPH radical scavenging and TBARS demonstrated that hydrolysates prepared by ultrasound combined microwave pretreatment (UMH) exhibited the highest antioxidant activity and significantly inhibited lipid oxidation. GC-MS analysis revealed that the UMH showed removal of bitter volatile flavor compounds, such as o-Cresol and m-Cresol, the retention of aromatic volatile compounds, such as 2-pentylfuran, formation of new aromatic volatile compounds such as 3-methylbutanal, and the reduction in certain aldehyde and ketone compounds. Pearson correlation analysis elucidated that the reduction in aldehyde and ketone compounds was positively linked to the enhanced antioxidant capacity of UMH. The results obtained hold substantial significance for enhancing the added value of Xuanwei ham within the food industry.

^‡ These authors contributed equally to this work [...]