scholarly journals Effect of phenolic hydroxy group and type of acid on lignin acidolysis

2020 ◽  
Author(s):  
QIAOQIAO YE
Keyword(s):  
Hydroxy Group ◽  
Phenolic Hydroxy Group ◽  
Phenolic Hydroxy

scholarly journals Protein-bound glycogen is linked to tyrosine residues

1985 ◽  
Vol 229 (1) ◽  
pp. 269-272 ◽  
Author(s):  
M A Aon ◽  
J A Curtino
Keyword(s):  
Amino Acid ◽  
Hydroxy Group ◽  
Edman Degradation ◽  
Proteolytic Digestion ◽  
Phenolic Hydroxy Group ◽  
Radioactive Product ◽  
Tyrosine Residues ◽  
Phenolic Hydroxy

Tyrosine-glycogen obtained from retina proteoglycogen by exhaustive proteolytic digestion was radiolabelled with 125I. The 125I-labelled tyrosine-glycogen was degraded by amylolytic digestion to a very small radioactive product, which was identified as iodotyrosine by h.p.l.c. The amylolytic mixture used released glucose and maltose that were alpha-linked to the phenolic hydroxy group of p-nitrophenol. No free iodotyrosine was found before or after the intact [125I]iodotyrosine-glycogen was subjected to two cycles of the Edman degradation procedure. The linkage between protein and glycogen was alkali-stable. Therefore it is concluded that the protein-bound glycogen was O-glycosidically linked to the phenolic hydroxy group of tyrosine. The amino acid has not been heretofore found to be involved in the linkage of carbohydrates to proteins.

scholarly journals Cinnarizinium 3,5-dinitrosalicylate

2012 ◽  
Vol 68 (4) ◽  
pp. o1165-o1166 ◽  
Author(s):  
Alaloor S. Dayananda ◽  
Hemmige S. Yathirajan ◽  
Thomas Gerber ◽  
Eric Hosten ◽  
Richard Betz
Keyword(s):  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Hydroxy Group ◽  
Tertiary Amine ◽  
Title Compound ◽  
Chair Conformation ◽  
Acid Group ◽  
Carboxylic Acid Group ◽  
Phenolic Hydroxy Group ◽  
Phenolic Hydroxy

The title compound [systematic name: 4-diphenylmethyl-1-(3-phenylprop-2-en-1-yl)-piperazin-1-ium 2-carboxy-4,6-dinitrophenolate], C26H29N2+·C7H3N2O7−, is the dinitrosalicylate salt of a tertiary amine. Deprotonation of the carboxylic acid group occurred on the phenolic hydroxy group. The diazacyclohexane ring adopts a chair conformation. Intramolecular O—H...O and intermolecular C—H...O and N—H...O hydrogen bonds are observed. The N—H...O hydrogen bonds are bifurcated at the H atom and connect the cinnarizinium and 3,5-dinitrosalicylate ions together. Intermolecular C—H...O hydrogen bonds connect the components into layers perpendicular to the crystallographicaaxis.

scholarly journals Copper-Catalyzed Enantioselective Coupling between Allyl­boronates and Phosphates Using a Phenol–Carbene Chiral Ligand: Asymmetric Synthesis of Chiral Branched 1,5-Dienes

Synthesis ◽  
2018 ◽  
Vol 50 (11) ◽  
pp. 2235-2246 ◽  
Author(s):  
Hirohisa Ohmiya ◽  
Masaya Sawamura ◽  
Yuto Yasuda
Keyword(s):  
Asymmetric Synthesis ◽  
Hydroxy Group ◽  
Coupling Reaction ◽  
Copper Catalysis ◽  
Chiral Ligand ◽  
Phenolic Hydroxy Group ◽  
Earth Abundant ◽  
Low Toxicity ◽  
Stereogenic Center ◽  
Phenolic Hydroxy

Details of the Cu-catalyzed enantioselective allyl–allyl coupling reaction between allylboronates and (Z)-allylic phosphates using a new chiral N-heterocyclic carbene (NHC) ligand containing a phenolic hydroxy group are presented. The copper catalysis delivers enantio­enriched chiral 1,5-dienes with a tertiary stereogenic center. Compatibility with various functional groups and the use of earth-abundant and relatively low-toxicity copper as a metal are attractive features of this protocol. The utility of the chiral phenol–NHC ligand for enantioselective copper catalysis with organoboron compounds is demonstrated and enantiodiscrimination models are discussed.

scholarly journals Biochemical applications of chemically induced nuclear polarization in phenols, peptides, catecholamines and related molecules

1978 ◽  
Vol 173 (3) ◽  
pp. 993-996 ◽  
Author(s):  
K A Muszkat ◽  
M Weinstein ◽  
C Gilon
Keyword(s):  
Hydrogen Atom ◽  
Hydroxy Group ◽  
Nuclear Polarization ◽  
Hydrogen Atom Transfer ◽  
Atom Transfer ◽  
Dye Molecules ◽  
Phenolic Hydroxy Group ◽  
Chemically Induced ◽  
Photochemical Method ◽  
Phenolic Hydroxy

A photochemical method for producing proton nuclear polarization in phenolic biogenic molecules such as tyrosyl polypeptides and phenolic amines is described. The nuclear polarization is due to the reversible hydrogen-atom transfer from the phenolic hydroxy group to triplet photoexcited xanthene-dye molecules. Typical results obtained with insulin, catecholamines and other phenolic molecules are treated in detail.

The Heck Reaction of Protected Hydroxychromones: on route to Natural Products

2011 ◽  
Vol 64 (5) ◽  
pp. 647 ◽  
Author(s):  
Attila Vasas ◽  
Tamás Patonay ◽  
Krisztina Kónya ◽  
Artur M. S. Silva ◽  
José A. S. Cavaleiro
Keyword(s):  
Natural Products ◽  
Hydroxy Group ◽  
Heck Reaction ◽  
Protecting Group ◽  
Phenolic Hydroxy Group ◽  
Coupling Conditions ◽  
Naturally Occurring ◽  
Phenolic Hydroxy

The Heck reaction has been successfully extended to the bromochromones with an adjacent protected phenolic hydroxy group which offers a new methodology to various naturally occurring derivatives including tricyclic O-heterocycles. Phosphine-free coupling conditions are found to be effective. Surprisingly, the methoxymethyl protecting group is unstable in several cases but benzyl proved to be an ideal protecting group which could be selectively cleaved by boron trihalides in good yields.

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