Weina She

The Thermomyces lanuginosus lipase (TLLs) was successfully immobilized within a novel hydrogel matrix through a two-step crosslinking method. TLLs were initially crosslinked through the Schiff base reaction by oxidized carboxymethyl cellulose (OCMC). The water-soluble OCMC@TLLs complex was subsequently crosslinked by carboxymethyl chitosan (CMCSH) in a microfluidic apparatus to form the CMCHS/OCMC@TLLs microspheres. The CD (Circular Dichroism, CD) and FT-IR (Fourier Transform infrared spectroscopy, FT-IR) spectra demonstrated that the crosslinking of TLLs with OCMC resulted in a less significant impact on their structure compared to that with glutaraldehyde. CMCHS/OCMC@TLLs showed decreased catalytic performance due to the mass transfer resistance, while its thermal stability was greatly improved. The CMCHS/OCMC@TLLs were used to catalyze the lauroylation of arbutin in tetrahydrofuran. After 12 h of reaction under optimal conditions, the yield of 6'-O-lauryl arbutin reached an impressive 92.12%. The prepared 6'-O-lauryl arbutin has high lipophilicity and exhibits similar tyrosinase inhibitory activity and higher antioxidant activity compared to its parent compound.

• Amino acid-catalyzed the functionalization of C(sp 3 )-H was conducted. • The addition of amino acids significantly improved the reaction efficiency. • The yield achieved 91.47 % after only 36 h of reaction. • The recycling experiment demonstrated that L-Leu exhibited excellent reusability. Using amino acids as catalysts, the addition reactions between four quinolone derivatives (2-methylquinoline, 2,4-dimethylquinoline, 2,6-dimethylquinoline, and 2,7-dimethylquinoline) and p -nitrobenzaldehyde ( p -NBA) were conducted, respectively. Thin layer chromatography (TLC), mass spectrometry (MS), and nuclear magnetic resonance (NMR) analysis confirmed that the functionalization reaction occurred exclusively on the methyl group at C-2 position of the quinoline ring. The addition of amino acids, particularly the L-leucine, significantly improved the reaction efficiency. By optimizing the conditions, the yield of 1-(4-nitrophenyl)-2-(quinoline-2-yl)ethane-1-ol ( IIIa ) achieved 91.47 % after only 36 h of reaction. The proposed catalytic mechanism suggested that amino acids mediated the electron transfer process via hydrogen bonding, which facilitated the rearrangement reaction of double bonds, and promoting the formation of enamine intermediates. The recycling experiments demonstrated that the L-Leu could be effectively recovered and reused solely through filtration, thereby enhancing the practical value of this method.