Results 151 to 160 of about 19,944 (197)

Examples of diastereomers

Journal of Chemical Education, 1984
Using right- and left-handed doors as examples of familiar objects that exhibit enantiomerism.
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Synthesis and chiroptical characterization of prostacyclin diastereomers

Prostaglandins, 1980
In the mercuri- and halo-cyclizations of PGF2 alpha methyl ester and its 11,15-bis(alpha- ethoxyethyl)-ether (or other protected forms) the exo-PGI1 derivative predominates independent of reagent and degree of protection of the PGF2 alpha sample used. Diastereomerically pure samples of exo- and endo-PGI1 and prostacycline (PGI2) were prepared.
, De Biswanath, N H, Andersen, R M, Ippolito, C H, Wilson, W D, Johnson   +4 more
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Stereochemistry of the Roridins. Diastereomers of Roridin E

Journal of Natural Products, 1999
A careful investigation of cultures of Myrothecium verrucaria has shown that this fungus produces all four roridin E isomers (3a-d), diastereomeric at the C-6' and C-13' centers. The stereochemistries at these centers were established by a combination of X-ray crystallographic analysis, NMR spectroscopy, and chemical transformations.
B B, Jarvis, S, Wang
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Diastereomers of Neopterin and Biopterin in Human Urine

Biological Chemistry Hoppe-Seyler, 1992
A new pteridine compound, named umanopterin, was isolated from human urine both of cancer patients and non-cancer controls. The structure was confirmed to be 2-amino-4(3H)-oxo-6-[(1'R,2'R)-1',2',3'-trihydroxypropyl]pteridine , a diastereomer of neopterin.
S, Ogiwara, T, Nagatsu, R, Teradaira, K, Fujita, T, Sugimoto   +4 more
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Synthesis of a Diastereomer of the Marine Macrolide Lytophilippine A

Organic Letters, 2019
The synthesis of a diastereomer of lytophilippine A required 22 longest linear steps using known building blocks. Cross-metathesis/asymmetric aldol addition and regioselective esterification/ring-closing metathesis served as efficient combi tools for scaffold construction.
André Klüppel, Annika Gille, Ceren Ester Karayel, Martin Hiersemann   +3 more
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Permeation of Membranes by Ribose and Its Diastereomers

Journal of the American Chemical Society, 2009
It was recently found that ribose permeates membranes an order of magnitude faster than its diastereomers arabinose and xylose (Sacerdote, M. G.; Szostak, J. W. Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 6004). On this basis it was hypothesized that differences in membrane permeability to aldopentoses provide a mechanism for preferential delivery of ...
Chenyu, Wei, Andrew, Pohorille
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Rotamers or Diastereomers? An Overlooked NMR Solution

The Journal of Organic Chemistry, 2012
The existence of rotamers in a solution of analyte complicates (1)H NMR analysis, especially when the presence of diastereomers is also possible. Organic chemists have often responded to this problem by conducting variable-temperature (VT) NMR experiments, changing NMR solvents, or adding complexing agents.
Dennis X, Hu, Peter, Grice, Steven V, Ley   +2 more
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The Synthesis of Both Diastereomers of 5′-Methylhomoaristeromycin

Nucleosides, Nucleotides and Nucleic Acids, 2016
The preparation of the C-5' diastereomers of 5'-homoaristeromycin has been achieved in 6 steps beginning with readily available (3aR,6aR)-2,2-dimethyl-2H,3aH,4H,6aH-cyclopenta[1,3]dioxol-4-one in a Michael reaction employing chiral Evans N-acyloxazolidinones that served to direct the requisite side chain stereochemistry.
Wei, Ye, Stewart W, Schneller
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Emerging trends in the characterization of oligonucleotide diastereomers

Journal of Chromatography A
Chemical modifications have enabled the use of oligonucleotides as therapeutic drugs. However, they also complicate their analytical characterization. Phosphorothioate (PS)-modified oligonucleotides exist as complex mixtures of diastereomers. Health authorities have emphasized the need for suitable state-of-the-art methods to provide, at a minimum, an ...
Alexandre Goyon, Daniel Ngoc Nguyen, Kelly Zhang   +2 more
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Thermal properties of isomalt: A diastereomer mixture

Journal of Thermal Analysis and Calorimetry, 2002
Isomalt, a commercial sugar alcohol widely used as a sweetener, is approximately a 1:1 mixture of two diastereomers, α-D-glucopyranosyl-1-6-mannitol (GPM) and α-D-glucopyranosyl-1-6-sorbitol (GPS). A calorimetric investigation has been carried out on mixtures of isomalt with GPS, in the (molar) composition range 0 ...
BORDE B., CESARO, ATTILIO
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