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The use of immobilized alcohol dehydrogenases (ADHs) offers numerous advantages, especially in the reaction conditions required by industrial applications. Looking for more efficient and cost-effective methods of ADH immobilization, in this study we explored silica-based supports as an alternative to the use of functionalized polymeric resins. Three commercially available ADHs were immobilized by adsorption and covalent bond formation. The obtained supported biocatalysts were applied for the bioreduction of acetophenone and some derivatives with good yields and excellent enantioselectivity. The important intermediate (S)-1-[3,5-bis(trifluoromethyl)phenyl]ethanol was obtained with a high enantiomeric excess (>99%) by using the highest performing immobilized ADH sample. The reusability of this biocatalyst was investigated in a flow system for five consecutive runs; the experiments showed that the biocatalyst could be recycled without a loss of activity and enantioselectivity. Finally, cross-linking with the glutaraldehyde of the supported biocatalyst was also carried out to prevent the leaching of the enzyme during the catalytic reactions. [ABSTRACT FROM AUTHOR]

Both enantiomers of 1‐(3,5‐bis(trifluoromethyl)phenyl)‐ethanol (BTPE) constitute important building‐blocks for the synthesis of active pharmaceuticals ingredients (APIs). The reduction of 3',5'‐bis(trifluoromethyl)acetophenone (BTAP) performed with soluble and immobilized ketoreductases (KREDs) can be considered as one of the most efficient routes to produce enantiopure BTPE. In the present work, a commercial KRED was employed as biocatalyst after undergoing immobilization processes and it proved to be extremely efficient in the asymmetric synthesis of (S)‐BTPE. The immobilization was studied on a set of different commercially available supports. The best results were obtained with samples immobilized via covalent interaction on short chain amino‐functionalized support. Two reaction parameters, temperature, and solvent were optimized in the biocatalytic reduction of BTAP in batch conditions. A 90 : 10 (v/v) 2‐propanol (IPA): water solvent system and 30 °C proved to be the best reaction conditions in terms of substrate conversion and easy recovery of the product by simple solvent evaporation. Biotransformations were then performed in a flow system under optimized reaction conditions obtaining with most samples complete conversion after 24 hours and excellent enantiomeric excess (>99.9 %). Finally, the reusability of the immobilized biocatalyst was successfully tested in five consecutive reaction cycles, demonstrating the potential of this approach. [ABSTRACT FROM AUTHOR]

To date, studies focusing on oral health in obese adolescents have provided controversial data. The aim of this cross-sectional study was to investigate systemic and oral health parameters in eutrophic and overweight/obese adolescents. In total, 100 adolescents, mean aged 13.33 ± 2.04 years, were divided into two groups: 59 overweight/obese adolescents in the study group (SG) and 41 eutrophic-weight adolescents in the control group (CG). Chi-squared and Fisher exact tests were performed to compare dichotomous and categorical variables between the two groups. The subjects in the SG (mean aged 13.21 ± 2.21) reported a body mass index (BMI) of 29.05 ± 4.09 kg/m2, corresponding to over 95° percentile for both genders, and the subjects in the CG (mean aged 13.49 ± 1.77) reported a BMI of 18.26 ± 4.81 kg/m2, corresponding to 25° percentile for both genders. In the SG, the serum level of 25-hydroxy-vitamin D was significantly lower (p-value < 0.001), whereas fasting blood glucose (p = 0.006), waist circumference, and hip circumference were significantly higher (p-value < 0.001). Plaque Index (PI), Plaque Control Record (PCR), Oral Hygiene Index (OHI), Gingival Index (GI), and Gingival bleeding index (GBI) depicted a significantly worse level of oral health in the SG. Moreover, the number of subjects with caries was significantly higher in the SG. Nutritional and physical activity status according to the Mediterranean Diet Quality Index for children and teenagers (KIDMED test) and the International Physical Activity Questionnaire (IPAQ-Adolescent) were reported to be significanlty better in the CG. In light of our results, obesity and poor oral health coexist in a cohort of adolescents. A screening of oral health status should be considered in obese subjects to focus resources on therapeutic interventions aiming at improving oral health. [ABSTRACT FROM AUTHOR]

In recent years, the immobilization of palladium nanoparticles on solid supports to prepare active and stable catalytic systems has been deeply investigated. Compared to inorganic materials, naturally occurring organic solids are inexpensive, available and abundant. Moreover, the surface of these solids is fully covered by chelating groups which can stabilize the metal nanoparticles. In the present review, we have focused our attention on natural biomaterials-supported metal catalysts applied to the formation of C–C bonds by Mizoroki–Heck, Suzuki–Miyaura and Sonogashira reactions. A systematic approach based on the nature of the organic matrix will be followed: (i) metal catalysts supported on cellulose; (ii) metal catalysts supported on starch; (iii) metal catalysts supported on pectin; (iv) metal catalysts supported on agarose; (v) metal catalysts supported on chitosan; (vi) metal catalysts supported on proteins and enzymes. We will emphasize the effective heterogeneity and recyclability of each catalyst, specifying which studies were carried out to evaluate these aspects. [ABSTRACT FROM AUTHOR]

Four racemic iminoflavan derivatives were synthesized by simple condensation at C‐4 position of flavanone. All new compounds were characterized by using ultraviolet‐visible, infrared, and nuclear magnetic resonance spectroscopic techniques. A chiral chromatographic analysis of racemic mixtures was performed by direct chiral high‐performance liquid chromatography using Chiralcel® OD‐H as chiral stationary phase, and online‐coupled with electronic circular dichroism detector. The correlation of experimental electronic circular dichroism traces with quantum chemical electronic circular dichroism calculations run with time‐dependent density functional theory made it possible to elucidate the absolute configuration for each enantiomer, and to establish the elution order. [ABSTRACT FROM AUTHOR]