New highly potent 2-substituted (20S)-1 alpha,25-dihydroxy-19-norvitamin D(3) analogs with elongated side chain were prepared by Wittig-Horner coupling of A-ring phosphine oxide with the corresponding protected (20S)-25-hydroxy Grundmann's ketones. Biologic evaluation in vitro and in vivo of the synthesized compounds was accomplished. All the synthesized vitamins possessing a 25-hydroxylated saturated side chain were slightly less active (3-5X) than 1 alpha,25-dihydroxyvitamin D(3) in binding to the porcine intestinal vitamin D receptor and significantly more potent (12-150X) in causing differentiation of HL-60 cells. In vivo, 2-methylene-26,27-dihomo and 2 alpha-methyl-26,27-dimethylene analogs were at least 10 times more active, and 2 alpha-methyl-26,27-dihomo compound at least 5 times more active than the vitamin D hormone both in stimulating intestinal calcium transport and bone calcium mobilization (serum calcium increase). It was also established that a 260 pmol dose of the corresponding 2 beta-methyl analogs had a similar effect on intestinal calcium transport and a much more pronounced effect on bone calcium mobilization as the same dose of 1 alpha,25-dihydroxyvitamin D(3).
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http://dx.doi.org/10.1016/s0039-128x(01)00156-8 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
National Experimental Teaching Demonstration Center for Materials Science and Engineering, School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing 100191, China.
Marine biofouling negatively impacts marine industries and ship navigation. However, current coatings are based on a single antifouling mechanism, which is insufficient to cope with the complex and ever-changing marine environment. Herein, multifunctional antifouling coatings were developed using a material system containing perfluoropolyether and caprolactone chains.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States.
Bottlebrush block polymers, characterized by densely grafted side chains extending from a backbone, have recently garnered significant attention. A particularly attractive feature is the accessibility of ordered morphologies with domain spacings exceeding several hundred nanometers, a capability that is challenging to achieve with linear polymers. These large morphologies make bottlebrush block polymers promising for various applications, such as photonic crystals.
View Article and Find Full Text PDFJ Am Soc Mass Spectrom
January 2025
Department of Physics and Astronomy, Aarhus University, Aarhus 8000, Denmark.
Förster resonance energy transfer (FRET) is becoming a valuable technique in gas-phase structural biology for identifying local structural motifs and conformations of biological molecules, such as peptides and proteins. This method involves labeling the biomolecule with two dyes, a donor dye and an acceptor dye, that are commonly charged rhodamines. Here we examine how different amino acid (AA) methyl esters linked to the dye via amide linkages can influence the dye transition energy and, consequently, the energy-transfer efficiency, using cryogenic ion fluorescence spectroscopy.
View Article and Find Full Text PDFACS Omega
December 2024
Department of Chemistry and Materials Science, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu 215000, P. R. China.
Spiro architectures with π-conjugation have improved thermal stability and stronger photosensitivity, making them potentially useful for organic optoelectronic devices. Our recent work has demonstrated the synthetic chemistry of a novel thiophene oligomer combining 2,7-dihydrooxepine and dispiro structure and derived it into A-D-A-type compounds. The optical spectroscopy and electrochemical characteristics were investigated.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Henan Normal University School of Chemistry and Chemical Engineering, Chemistry, CHINA.
ADP-ribosylation is a complex post-translational modification involved in key physiological processes and associated with various health and disease states. The growing interest in ADP-ribosylation necessitates straightforward and efficient synthetic methods for the preparation of ADP-ribosylated peptides/proteins. In this study, we report a facile reaction between nicotinamide adenine dinucleotide (NAD+) and alcohols promoted by a combination of ionic liquids, yielding up to 94% with α:β ratios ranging from 88:12 to 99:1 and a switchable configuration selectivity.
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