Carbon-13 chemical shifts of the carbonyl group. V. Observation of a deuterium isotope effect using carbon-13 field-frequency lock

1967 ◽  
Vol 71 (7) ◽  
pp. 2160-2164 ◽  
Author(s):  
Gary E. Maciel ◽  
Paul D. Ellis ◽  
Donald C. Hofer
Keyword(s):  
Carbonyl Group ◽  
Isotope Effect ◽  
Chemical Shifts ◽  
Deuterium Isotope Effect ◽  
Field Frequency ◽  
Group V

The Mechanism of The Microbial Hydroxylation of Steroids. Part 1. The C-21 Hydroxylation of Progesterone by Aspergillusniger ATCC 9142

1975 ◽  
Vol 53 (6) ◽  
pp. 845-854 ◽  
Author(s):  
Herbert L. Holland ◽  
Barbara J. Auret
Keyword(s):  
Hydrogen Bond ◽  
Carbonyl Group ◽  
Isotope Effect ◽  
Enol Form ◽  
Deuterium Isotope Effect ◽  
Rate Determining Step ◽  
Microbial Hydroxylation ◽  
Hydroxylation Reaction ◽  
Microbial C

The mechanism of the C-21 hydroxylation of progesterone (1a) by Aspergillusniger ATCC 9142 to give 11-deoxycorticosterone (1b) has been studied by the use of progesterone derivatives and of C-21 deuterium labelled progesterones. The requirement of the C-21 hydroxylase system for a C-20 carbonyl group is demonstrated and the possibility of the involvement of this group, in the C-20,21 enol form, in the C-21 hydroxylation reaction has been discussed. However, on the basis of the observed deuterium isotope effect (KH/KD = 1.25), a mechanism for the microbial C-21 hydroxylation reaction is proposed in which the rate-determining step is the direct insertion of oxygen into a C-21 carbon–hydrogen bond and not one involving enolization of the C-20 carbonyl.In addition, C-11α and C-15β hydroxylation of both 20α- and 20β-hydroxypregn-4-ene-3-one (2a and 2b) by A. niger has been observed.

Studies Based on Deuterium Isotope Effect on13C Chemical Shifts

ChemInform ◽  
2005 ◽  
Vol 36 (3) ◽  
Author(s):  
T. Dziembowska ◽  
P. E. Hansen ◽  
Z. Rozwadowski
Keyword(s):  
Isotope Effect ◽  
Chemical Shifts ◽  
Deuterium Isotope Effect

Deuterium Isotope Effect on Shifts of 13C Magnetic Resonance Signals of Sugars: Signal Assignment Studies

1974 ◽  
Vol 52 (3) ◽  
pp. 458-461 ◽  
Author(s):  
Philip A. J. Gorin
Keyword(s):  
Magnetic Resonance ◽  
Isotope Effect ◽  
Chemical Shifts ◽  
Deuterium Isotope Effect ◽  
Signal Assignment

The 13C chemical shifts of nuclei in several sugars undergo an isotope effect 0 to −0.10 p.p.m when a proton in the β position is substituted by a deuteron. The effect may be used for signal assignments in crowded spectra if it is taken into account that lower values are observed for 13C nuclei which are attached to more electronegative groups. The β effect coupled with the elimination of the α-carbon signal have been used to assign signals in c.m.r. spectra of the α- and β-anomers of D-glucose, D-mannose, D-allose, and D-galactose.

Deuterium isotope effect on 1H and 13C chemical shifts of intramolecularly hydrogen bonded perylenequinones

1997 ◽  
pp. 2013-2021 ◽  
Author(s):  
Stefania Mazzini ◽  
Lucio Merlini ◽  
Rosanna Mondelli ◽  
Gianluca Nasini ◽  
Enzio Ragg ◽  
...  
Keyword(s):  
Isotope Effect ◽  
Chemical Shifts ◽  
Deuterium Isotope Effect ◽  
13C Chemical Shifts ◽  
Hydrogen Bonded
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