With respect to the hydrolysis (deacylation) of Z-D(L)-amino acid esters (N-(benzyloxycarbonyl)-D(L)-amino acid p-nitrophenyl esters) mediated by alpha-, beta- and gamma-cyclodextrins (CyDs), a remarkably high enantioselectivity (L/D=9.0) was observed for the deacylation of Ala substrate with gamma-CyD. The kinetic results on the basis of the Michaelis-Menten principle indicate that the enantioselectivity should be mainly originated in the deacylation process of substrates following the formation of gamma-CyD-substrate (1 : 1) complexes. The computer modeling (molecular mechanics) studies on the inclusion complexes are also described.
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http://dx.doi.org/10.1248/cpb.50.1283 | DOI Listing |
Carbohydr Res
January 2025
Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Campus Scientifico E. Mattei, via Ca' Le Suore 2, 61029, Urbino, PU, Italy. Electronic address:
Cinnamic Acid Sugar Ester Derivatives (CASEDs) are a class of natural compounds that exhibit several interesting biological activities. However, to date, no examples of their use in sunscreen formulations have been reported. Here, we describe the synthesis of a series of novel cinnamic acid esters of glucose (4a-g), ribose (4h) and lactose (4i) starting from the respective acetals 3.
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January 2025
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
Multicomponent reactions (MCRs), highly sought-after methods to produce atom-, step-, and energy-economic organic syntheses, have been developed extensively. However, catalytic asymmetric MCRs, especially those involving radical species, remain largely unexplored owing to the difficulty in stereoselectively regulating the extraordinarily high reactivity of open-shell radical species. Herein, we report a conceptually novel catalytic asymmetric three-component radical cascade reaction of readily accessible glycine esters, α-bromo carbonyl compounds and 2-vinylcyclopropyl ketones via synergistic photoredox/Brønsted acid catalysis, in which three sequential C-C (σ/π/σ) bond-forming events occurred through a radical addition/ring-opening/radical-radical coupling protocol, affording an array of valuable enantioenriched unnatural α-amino acid derivatives bearing two contiguous stereogenic centers and an alkene moiety in moderate to good yield with high diastereoselectivity, excellent enantioselectivity and good -dominated geometry under mild reaction conditions.
View Article and Find Full Text PDFACS Omega
January 2025
School of Ecology and Environment, Renmin University of China, No.59 Zhongguancun Street, Beijing 100872, China.
Hydrothermal liquefaction (HTL) is a promising technology for converting wet biomass to liquid fuels. However, the biocrude yield and quality in this process are unsatisfactory without catalysts. Herein, a Ru/ZrO-SiO catalyst was prepared with the NaBH reducing method for the HTL of .
View Article and Find Full Text PDFHeliyon
January 2025
Institute of Metal Research (IMR), Chinese Academy of Science, Wenhua Road, Shenyang, China.
Recently, researchers have used silver nanoparticles (AgNPs) coupled with humic acid (HA) as antimicrobial agents. Herein, AgNPs were prepared and coupled with humic acid for their antimicrobial activities. The as-prepared AgNPs coupled with humic acid (HA) were characterized by an atomic force microscope (AFM), X-ray powder diffraction (XRD), zeta potential, zeta sizer, Fourier-transform infrared (FT-IR) spectroscopy, and UV-VIS spectrophotometer.
View Article and Find Full Text PDFAdv Mater
January 2025
School of Materials Science and Engineering, Chongqing University of Technology, Chongqing, 400054, China.
Polymeric room temperature phosphorescence (RTP) materials have been well developed and utilized in various fields. However, their fast thermo- and moisture-quenching behavior highly limit their applications in certain harsh environments. Therefore, the preparation of materials with thermo- and moisture-resistant phosphorescence is greatly attractive.
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