scholarly journals An acylation-Finkelstein approach to radioiodination of bioactives: The role of amide group anchimeric assistance

2018 ◽  
Vol 31 (7) ◽  
pp. e3835 ◽  
Author(s):  
Richard Fjellaksel ◽  
Damir Dugalic ◽  
Taye B. Demissie ◽  
Patrick J. Riss ◽  
Ole-Kristian Hjelstuen ◽  
...  
Keyword(s):  
Amide Group ◽  
Anchimeric Assistance

Computational DFT Investigation of Vicinal Amide Group Anchimeric Assistance in Ether Cleavage

2008 ◽  
Vol 73 (6) ◽  
pp. 2066-2073 ◽  
Author(s):  
Matteo Calvaresi ◽  
Samuele Rinaldi ◽  
Antonio Arcelli ◽  
Marco Garavelli
Keyword(s):  
Amide Group ◽  
Ether Cleavage ◽  
Anchimeric Assistance

Conformation of 3-acetamido-3,6-dideoxyhexopyranosides: Circular dichroism study

1979 ◽  
Vol 44 (1) ◽  
pp. 174-182 ◽  
Author(s):  
Slavomír Bystrický ◽  
Ivo Frič ◽  
Jan Staněk ◽  
Karel Čapek ◽  
Jiří Jarý ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Spatial Orientation ◽  
Amide Group ◽  
Cd Spectra ◽  
Pyranose Ring ◽  
Cotton Effects ◽  
Circular Dichroïsm

CD spectra of 15 stereoisomeric methyl 3-acetamido-3,6-dideoxyhexopyranosides were measured in methanol, 2,2,2-trifluoroethanol and acetonitrile. The data have been applied for estimation of probable conformations. The factor determining signs of the observed Cotton effects seems to be the spatial orientation of the acetamido group with respect to the pyranose ring. The possible role of a non-planar amide group is also discussed.

The 9-decalyl and related cations. IV. Generation of cis- and trans-2-t-Butyl-9-decalyl cations through σ-routes by acetolysis

1978 ◽  
Vol 31 (4) ◽  
pp. 835 ◽  
Author(s):  
GE Gream ◽  
MH Laffer ◽  
AK Serelis
Keyword(s):  
Ion Pairs ◽  
Ring Expansion ◽  
Ion Pair ◽  
Membered Ring ◽  
Boat Conformation ◽  
Proton Abstraction ◽  
Conformational Interconversion ◽  
Anchimeric Assistance ◽  
Cis And Trans

The synthesis and solvolytic behaviour (in buffered acetic acid) of cis- and trans-9-t-butylspiro[4,5]-dec-6-yl p-toluenesulfonate (5) and (6) are described. The two compounds solvolyse with anchimeric assistance and undergo ring expansion with complete stereospecificity; the cis- and trans-esters yield trans- and cis-2-t-butyl-9-decalyl cation (8) and (7), respectively. To account for the stereospecificity, it is proposed that (6) must solvolyse through a boat conformation of the six-membered ring. Ring contraction (c. 8%), with the formation of the 1-(3'-t-butylcyclopentyl)cyclopentyl cation (presumably trans (36)), also takes place in the acetolysis of (6). ��� The possible role of ion-pairs in the reactions of (5) and (6) is examined. It is concluded that the anion in an ion-pair might be involved in olefin formation only when it (the anion) is ideally located for proton abstraction in the initially formed ion-pair (or that formed by conformational interconversion of the cationic moiety).

The role of carbohydrate in the glycoenzyme invertase of Neurospora crassa

1977 ◽  
Vol 55 (3) ◽  
pp. 249-256 ◽  
Author(s):  
Yuji Tashiro ◽  
John R. Trevithick
Keyword(s):  
Neurospora Crassa ◽  
Low Temperatures ◽  
Tertiary Structure ◽  
Sodium Periodate ◽  
Heat Stability ◽  
Amide Group ◽  
Glycosidic Bonds ◽  
Carbohydrate Chains

Data obtained concerning the carbohydrate moieties of the glycoenzyme invertase (EC 3.2.1.26, β-D-fructofuranoside fructohydrolase) from Neurospora crassa were consistent with a linkage of some carbohydrate chains by O-glycosidic bonds to serine and threonine residues; the possibility of N-glycosylamine linkage of some of the carbohydrate to the amide group of asparagine is also indicated. The invertase was remarkably stable on storage at low temperatures. Oxidation of the carbohydrate residues in the enzyme by sodium periodate markedly affected the heat-stability of the enzyme. It is suggested that the carbohydrate moieties function as stabilizers of the tertiary structure of the glycoenzyme.

Self-Association of Nicotinamide in Aqueous-Solution: N.M.R. Studies of Nicotinamide and the Mono- and Di-methyl-Substituted Amide Analogs

1993 ◽  
Vol 46 (3) ◽  
pp. 377 ◽  
Author(s):  
WN Charman ◽  
CSC Lai ◽  
DJ Craik ◽  
BC Finnin ◽  
BL Reed
Keyword(s):  
Aqueous Solution ◽  
Lattice Relaxation ◽  
Amide Group ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Self Association ◽  
13C Chemical Shift ◽  
Associated Species ◽  
Monosubstituted Derivative

The concentration-dependent self-association of nicotinamide in solution has been studied by 1H and 13C n.m.r. spectroscopy, attendant relaxation time measurements, and osmometric techniques. N-Methylnicotinamide and N,N- dimethylnicotinamide were also studied to evaluate the role of the amide group in the association process. The osmometric studies indicated that the dimethyl -substituted analogue underwent little (if any) self-association, whereas nicotinamide and N- methylnicotinamide did self-associate. The concentration-dependent 1H and 13C chemical shift profiles of nicotinamide and the monosubstituted analogue indicated that the association involved the amide group and did not occur through stacking of the pyridine rings. Spin lattice relaxation (T1) studies indicated that the T1( ortho C)/T1( para C) ratio of nicotinamide decreased with increasing concentration, and that loss of a preferred axis of rotation had occurred due to formation of a large associated species. The T1 ratios of either substituted amide analogue were not concentration-dependent. The extent of self-association of the monosubstituted derivative was insufficient to affect the measured T1 ratios. These data indicate that the self-association of nicotinamide in aqueous solution occurs primarily through interamide hydrogen bonding.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management

The power of norms to sway fused group members

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam
Keyword(s):  
Evolutionary Anthropology ◽  
Normative Systems ◽  
Violent Extremism ◽  
Identity Fusion ◽  
Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

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