Results 81 to 90 of about 21,587 (210)

Racemization and Epimerization [PDF]

Science, 1971
W T, Smith, K A, Kvenvolden
openaire   +3 more sources

Human Proteoglycan Linkage Region Glycosyltransferases are Dimeric and Show Unexpected Specificities

Angewandte Chemie, Volume 138, Issue 3, 16 January 2026.
Non‐canonical glycopeptides of the proteoglycan linkage region are accessible by the enzymes B3GalT6 and GlcAT‐1 confirming a recently discovered rescue mode in glycosaminoglycan (GAG) biosynthesis. The crystal structure of B3GalT6 revealed a covalent dimer linked by a disulfide. Abstract We selected the N,O‐glycosylated proteoglycan bikunin as a model
Sascha Weidler, Ole Bundgaard, Markus Hessefort, Marisa Rädisch, Christopher Günther Franz Graf, Kevin Lam, Vanessa J. Neubauer, Johanna Eisenreich, Leonhard Köhler, Kelley W. Moremen, Catharina Steentoft, Henrik Clausen, Teng‐Yi Huang, Shang‐Cheng Hung, Clemens Steegborn, Michael Weyand, Carlo Unverzagt   +16 more
wiley   +2 more sources

8-epi-Salvinorin B: crystal structure and affinity at the κ opioid receptor

Beilstein Journal of Organic Chemistry, 2007
There have been many reports of epimerization of salvinorins at C-8 under basic conditions, but little evidence has been presented to establish the structure of these compounds.
Thomas A. Munro, Katharine K. Duncan, Richard J. Staples, Wei Xu, Lee-Yuan Liu-Chen, Cécile Béguin, William A. Carlezon Jr., Bruce M. Cohen   +7 more
doaj   +1 more source

Photoinduced, Chemoselective γ‐Alkylation of 2‐Silyloxyfurans With α‐Bromoketones: A Rapid Entry to Chiral ε‐Keto‐γ‐Butenolides

Chemistry – A European Journal, Volume 32, Issue 5, 2 February 2026.
A photoinduced, regio‐ and chemoselective γ‐alkylation of 2‐silyloxyfurans with a‐bromoketones was achieved by exploiting a photoredox catalytic process promoted by blue light. This approach provides practical and efficient access to chiral, ε‐ketobutenolides, in one step and high yields.
Debora Guazzetti, Luca Aimi, Enrico Marcantonio, Giovanni Maria Siciliano, Kelly Bugatti, Sara Dobani, Andrea Sartori, Lucia Battistini, Franca Zanardi, Claudio Curti   +9 more
wiley   +1 more source

Enantioselective Syntheses of Secondary Alkylboronates via Asymmetric Regioselective Reduction of 1,3‐Dienylboronates

Angewandte Chemie, Volume 138, Issue 3, 16 January 2026.
We report herein the development of catalytic asymmetric synthesis of secondary alkyl boronates. Under the optimal conditions, Cu‐catalyzed semi‐reduction of 1‐alkyl‐ or 1,3‐dialkyl‐substituted 1‐boryl‐1,3‐butadienes forms secondary alkyl boronates with excellent regioselectivities and enantioselectivities.
Wen‐Bin Cao, Lingfei Hu, Jiaming Liu, George Chen, Gang Lu, Ming Chen   +5 more
wiley   +2 more sources

Effect of bile acid oxazoline derivatives on microorganisms participating in 7 alpha-hydroxyl epimerization of primary bile acids.

Journal of Lipid Research, 1983
We tested bile acid oxazoline derivatives of chenodeoxycholic (CDC-OX), 7-ketolithocholic (7-KLC-OX), ursodeoxycholic (UDC-OX), and deoxycholic (DC-OX) as inhibitors of the 7-epimerization of the primary bile acids cholic acid (CA) and CDC in cultures of
I A Macdonald, J D Sutherland, B I Cohen, E H Mosbach   +3 more
doaj   +1 more source

Revised magnetostratigraphies confirm low sedimentation rates in Arctic Ocean cores [PDF]

, 1988
The general lack of an age-diagnostic biostratigraphy in the Neogene sediments of the abyssal Arctic Ocean has emphasized the importance of magnetostratigraphy in providing chronostratigraphic control in these sediments.
Kent, Dennis V., Witte, William K.
core   +2 more sources

All‐Round Talent: Unique Zinc Guanidine Catalyst Performs Efficiently in Synthesis and Chemical Recycling of (Bio)Polyesters

Advanced Science, Volume 13, Issue 8, 9 February 2026.
A new zinc hybrid guanidine catalyst [Zn{(R,R)TMGNMe2(1,2)ch}2](OTf)2 (C1) shows very high catalytic activity in the polymerization of cyclic esters and in the depolymerization of these polyesters. Using C1 in the ring‐opening polymerization of lactide and caprolactone under industrially relevant conditions, astonishing rate constants of the same order
Tabea Becker, Koki Takeuchi, Carolin Süßmuth, Frederico Boekhoff, Martin A. Schäfer, Shunsuke Kato, Alexander Hoffmann, Takashi Hayashi, Sonja Herres‐Pawlis   +8 more
wiley   +1 more source

Mono‐Materials Created by Engineering a Continuum of P3HB Stereomicrostructures in a One‐Step Catalytic Process

Angewandte Chemie, Volume 138, Issue 3, 16 January 2026.
Diastereomeric mixtures of diolide were polymerized to P3HB mono‐materials that behave like thermoplastics, thermoplastic elastomers, and pressure‐sensitive adhesives, which were then combined to create all‐P3HB mono‐material tapes. Abstract Multi‐material products that combine multiple complementary polymers can create products with desired ...
Ethan C. Quinn, Celine R. Parker, Maëlle T. Gace, Minjung Lee, Shu Xu, Ethan Poppen, Zhen Zhang, Deepak K. Barange, Meltem Urgun‐Demirtas, Nicholas Rorrer, Eugene Y.‐X. Chen   +10 more
wiley   +2 more sources

Acid-catalyzed Epimerization of Kobophenol A to Carasinol B

Molecules, 2008
The conversion from kobophenol A into carasinol B, two main chemicalconstituents of Caragana sinica, was confirmed by in vitro acid-catalyzed epimerization.The result provides important information about the biotransformation of kobophenol A inplants and
Changqi Hu, Gaolin Liang, Kejun Cheng
doaj   +1 more source