Hydroxamic acids. III. Mass spectra of substituted hydroxamic acids and cyclic imides

1969 ◽  
Vol 22 (1) ◽  
pp. 175 ◽  
Author(s):  
JH Bowie ◽  
MTW Hearn ◽  
AD Ward

Aryl hydroxamic acid derivatives fragment in a diagnostic manner upon electron impact. A hydroxamic acid containing both styryl and benzyl substituents undergoes skeletal-rearrangement of the type ABC → AC+B. The mass spectra of the O- and N-acetyl derivatives of O- benzylhydroxamic acids are indistinguishable. M-CO2 fragments are again observed in the mass spectra of several substituted phthalimides.

1967 ◽  
Vol 20 (4) ◽  
pp. 689 ◽  
Author(s):  
JH Bowie ◽  
RG Cooks ◽  
P Jakobsen ◽  
S Lawesson ◽  
G Schroll

The mass spectra of representative series of simple alkyl acetoacetates, alkyl acetothioacetates, and some unsaturated esters derived from unsaturated alcohols or phenols are reported and discussed. The fragmentation schemes have been established by high resolution measurements, appropriate metastable ions, and by deuterium and 18O labelling. Many of the spectra show significant skeletal rearrangement fragments arising from either loss of carbon monoxide or carbon dioxide.


Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3941 ◽  
Author(s):  
Ozsváth ◽  
Bíró ◽  
Nagy ◽  
Buglyó ◽  
Sanna ◽  
...  

By using various techniques (pH-potentiometry, UV-Visible spectrophotometry, 1H and 17O-NMR, EPR, ESI-MS), first time in the literature, solution equilibrium study has been performed on complexes of dipeptide and tripeptide hydroxamic acids—AlaAlaNHOH, AlaAlaN(Me)OH, AlaGlyGlyNHOH, and AlaGlyGlyN(Me)OH—with 4d metals: the essential Mo(VI) and two half-sandwich type cations, [(η6-p-cym)Ru(H2O)3]2+ as well as [(η5-Cp*)Rh(H2O)3]2+, the latter two having potential importance in cancer therapy. The tripeptide derivatives have also been studied with some biologically important 3d metals, such as Fe(III), Ni(II), Cu(II), and Zn(II), in order to compare these new results with the corresponding previously obtained ones on dipeptide hydroxamic acids. Based on the outcomes, the effects of the type of metal ions, the coordination number, the number and types of donor atoms, and their relative positions to each other on the complexation have been evaluated in the present work. We hope that these collected results might be used when a new peptide-based hydroxamic acid molecule is planned with some purpose, e.g. to develop a potential metalloenzyme inhibitor.


ChemInform ◽  
2014 ◽  
Vol 45 (27) ◽  
pp. no-no
Author(s):  
Gavara Govinda Rajulu ◽  
Halehatty Seephya Bhojya Naik ◽  
Abhilash Viswanadhan ◽  
Jayaraman Thiruvengadam ◽  
Kondodiyil Rajesh ◽  
...  

1968 ◽  
Vol 21 (8) ◽  
pp. 2031 ◽  
Author(s):  
JH Bowie ◽  
SO Lawesson ◽  
BS Larse ◽  
GE Lewis ◽  
G Schroll

The negative-ion mass spectra of aromatic azoxy compounds, nitrones, and N-oxides exhibit pronounced molecular ions and simple fragmentation processes. No skeletal-rearrangement fragments are produced upon electron impact, in marked contrast to those exhibited in the positive-ion spectra of these compounds.


2014 ◽  
Vol 62 (2) ◽  
pp. 168-175 ◽  
Author(s):  
Gavara Govinda Rajulu ◽  
Halehatty Seephya Bhojya Naik ◽  
Abhilash Viswanadhan ◽  
Jayaraman Thiruvengadam ◽  
Kondodiyil Rajesh ◽  
...  

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