The application of pesticides is critical during the growth of high-quality grape for wine making. However, pesticide residues have significant influence on the wine flavor. In this study, gas chromatography-mass spectrometry (GC-MS) was performed and the obtained datasets were analyzed with multivariate statistical methods to investigate changes in flavor substances in wine during fermentation. The principal component analysis (PCA) score plot showed significant differences in the metabolites of wine treated with various pesticides. In trials using five pesticides (hexaconazole, difenoconazole, flutriafol, tebuconazole, and propiconazole), more than 86 metabolites were changed. Most of these metabolites were natural flavor compounds, like carbohydrates, amino acids, and short-chain fatty acids and their derivatives, which essentially define the appearance, aroma, flavor, and taste of the wine. Moreover, the five pesticides added to grape pulp exhibited different effects on the metabolic pathways, involving mainly alanine, aspartate and glutamate metabolism, butanoate metabolism, arginine, and proline metabolism. The results of this study will provide new insight into the potential impact of pesticide residues on the metabolites and sensory profile of wine during fermentation.

Epilepsy is a chronic disease caused by sudden abnormal discharge of brain neurons, leading to transient brain dysfunction. Levetiracetam, developed by the UCB company in Belgium, is an effective drug for the treatment of epilepsy. (S)‐Methyl 2‐chlorobutanoate is an important chiral building block of levetiracetam, which has attracted a great deal of attention. In this study, a strain of lipase‐produced Acinetobacter sp. zjutfet‐1 was screened from soil samples. At optimized conditions for fermentation and biocatalysis, the bacterial lipase exhibited high catalytic activity for hydrolysis and stereoselectivity toward racemic methyl 2‐chlorobutanoate. When the enzymatic reaction was carried out in 6% of racemic substrate, the enantiomeric excess (e.e.s) reached more than 95%, with a yield of over 86%. Therefore, this lipase can efficiently resolve racemic methyl 2‐chlorobutanoate and obtain (S)‐methyl 2‐chlorobutanoate, which presents great potential in the industrial production of levetiracetam.