Results 251 to 260 of about 53,376 (301)
Some of the next articles are maybe not open access.
Hexahelicenophanes and Their Racemization
Angewandte Chemie International Edition, 1998A drastic increase in the rate of racemization is found for the bridged hexahelicenophanes 1 (n=8, 10) relative to the unsubstituted parent [6]helicene. This unexpected result occurs from steric interactions between the polymethylenedioxy chains and the terminal rings, which causes the energy of the ground state to be raised and that of the transition ...
Herbert, Meier +2 more
openaire +2 more sources
Racemic and Quasi‐Racemic X‐ray Structures of Cyclic Disulfide‐Rich Peptide Drug Scaffolds [PDF]
Angewandte Chemie - International Edition, 2014 Cyclic disulfide-rich peptides have exceptional stability and are promising frameworks for drug design. We were interested in obtaining X-ray structures of these peptides to assist in drug design applications, but disulfide-rich peptides can be ...
Conan K Wang +2 more
exaly +3 more sources
A Synthesis of Racemic Thalidomide
Synthetic Communications, 2003AbstractFor Abstract see ChemInform Abstract in Full Text.
Meng‐Yang Chang +2 more
openaire +1 more source
On the Racemization of Chiral Imidazolines
The Journal of Organic Chemistry, 2008Racemization of chiral imidazolines with base has been studied for the first time following an unexpected finding in the synthesis of chiral imidazoline ligands. Amine bases do not cause racemization. Strong inorganic bases can induce racemization, yet this occurs only when the nitrogen is unsubstituted, in agreement with a symmetry-allowed thermal ...
Carl A, Busacca +8 more
openaire +2 more sources
Bioequivalence of Racemic Drugs
The Journal of Clinical Pharmacology, 1992Although pharmacokinetic and pharmacodynamic differences between the enantiomers of a chiral drug have been known or suspected for many years, racemate drugs have frequently been developed and approved without clinical pharmacologic consideration of their chiral components.
S G, Nerurkar, S V, Dighe, R L, Williams
openaire +2 more sources
Enzymatic Resolution of Racemates Contaminated by Racemic Product
Biocatalysis, 1994Enzyme-catalyzed kinetic resolution is sometimes performed starting with substrate already containing small amounts of the racemic product. Then the determination of the enantiomeric ratio may be seriously disturbed when this parameter is calculated from the degree of conversion and the enantiomeric excess of either the substrate or the product (Chen ...
A. Wolff +2 more
openaire +1 more source
Resolution of racemic gossypol
Journal of Ethnopharmacology, 1987Treating racemic gossypol with chiral amine (S)-1-methylphenethyl amine gave the expected pair of diastereomeric amino condensates in which the binaphthyl nuclei racemized during further treatment. Acetylation was applied to avoid the change. On acetylation, 7 products were separated.
L, Huang, D K, Zheng, Y K, Si
openaire +2 more sources
Resolution of racemic gossypol
Journal of the Chemical Society, Chemical Communications, 1985Racemic gossypol, a potential antifertility agent has been resolved through its derivatives with chiral 1-methylphen-ethylamine into (+)- and (–)-gossypol.
D K, Zheng +4 more
openaire +2 more sources
Enzymic Racemization of Allantoin
The Journal of Biochemistry, 1978Allantoin racemase was isolated from cells of Candida utilis, and purified by chromatography on columns of DEAE-cellulose and Sephadex G-100. Using this purified enzyme, the racemization of allantoin in deuterium oxide was investigated. Polarimetric and PMR spectroscopic analyses showed that racemization of allantoin by the enzyme proceeded in ...
I, Okumura, T, Yamamoto
openaire +2 more sources
Racemic Protein Crystallography
Annual Review of Biophysics, 2012Although natural proteins are chiral and are all of one “handedness,” their mirror image forms can be prepared by chemical synthesis. This opens up new opportunities for protein crystallography. A racemic mixture of the enantiomeric forms of a protein molecule can crystallize in ways that natural proteins cannot.
Todd O, Yeates, Stephen B H, Kent
openaire +2 more sources