1687-60-1Relevant academic research and scientific papers
14N Quadrupole Double Resonance in Some Substituted Hydroxamic Acids
Ruiqin, Wang,Xiaolan, Yu,Zhenye, Feng,Haq, Mian M. I.,Khurshid, Muhammed M. P.,et al.
, p. 114 - 120 (1989)
14N quadrupole coupling constants and asymmetry parameters have been measured in a number of hydroxamic acids by double-resonance field-cycling techniques based on either irradiation in zero magnetic field or cross relaxation.The compounds all display high asymmetry parameters.Those in which this quantity is greater than 0.9 show remarkable line shapes for the two lower 14N frequencies (νy, νz) in their irradiation spectra.They are explained in terms of a thermal-mixing mechanism, which generates polarization of the 1H dipolar levels when these nearly degenerate frequencies are strongly irradiated in zero field, and then subsequently modified by level crossing when the sample is returned to high field to measure the remaining 1H signal.Ab initio SCF-MO calculations of the 14N quadrupole tensor in a group of molecules at the orientation found in crystals of acetohydroxamic acid hemihydrate and oxalodihydroxamic acid are in reasonable agreement with experiment and predict that in all the hydroxamic acids studied the maximum principal component is negative and closely parallel to the direction of the 2p? orbital.
Hydroxamic acids: synthesis and adjuvant activity in combinatorial anticancer therapy
Fedorov,Fadeev,Eremeev,Konovalova,Bogdanov,Tatyanenko,Sashenkova,Mishchenko
, p. 801 - 805 (2016)
Monoand disubstituted N-hydroxyamides of dicarboxylic acids were prepared by reaction of dicarboxylic acids or acid anhydrides with hydroxylamine. The use of these compounds in combinatorial cytostatic therapy of implanted tumors with cisplatin or cyclophosphamide totally inhibits metastasis formation in B16 melanoma and Lewis lung carcinoma, and resulted in 100% survival of leukemic animals.
Experimental and computational studies on hydroxamic acids as environmental friendly chelating corrosion inhibitors for mild steel in aqueous acidic medium
Al Fantazi, Akram,Asatkar, Ashish,Ebenso, Eno E.,Hussain, Chaudhery Mustansar,Khan, Fahmida,Verma, Chandrabhan,Verma, Dakeshwar Kumar
, (2020)
In the present study, three hydroxamic acids (HAs) namely acetohydroxamic acid (AHA), benzohydroxamic acid (BHA) and oxalohydroxamic acid (OHA) were synthesized, characterized and used as inhibitors for mild steel corrosion in1 M HCl using chemical, electrochemical, surface and computational methods. Results of the studies show that the HAs act as effective corrosion inhibitors and their inhibition efficiencies follow the order: OHA (96.37%) > BHA (95.69%) > AHA (93.29%). EIS study showed that studied HAs act as interface type inhibitors. Polarization study revealed that HAs demonstrate mixed-type corrosion inhibitors characteristics and adsorb on the active sites of metallic surface. Adsorption of HAs on metal-1 M HCl interfaces followed the Langmuir adsorption isotherm model. Surface morphological analyses of inhibited and uninhibited metallic surface were carried out using SEM-EDX and XRD methods. DFT analyses showed that studied compounds act as chelating type of ligands. Effect of Keto-enol tautomerism and different possible conformational isomers on metallic corrosion inhibition was demonstrated. The conformational isomers in which >C=O and –OH (hydroxyl) groups present in same side behave as chelating ligands and form relatively more stable complex than that of conformational isomers in which >C=O and –OH groups present in opposite side. Experimental and DFT studies complimented each other well.
Hydroxamic acids as a novel family of serine racemase inhibitors: Mechanistic analysis reveals different modes of interaction with the pyridoxal-5′-phosphate cofactor
Hoffman, Hillary E.,Jirásková, Jana,Cígler, Petr,?anda, Miloslav,Schraml, Jan,Konvalinka, Jan
experimental part, p. 6032 - 6041 (2010/03/24)
Mammalian serine racemase (SR) is a pyridoxal-5′-phosphate (PLP) dependent enzyme responsible for the biosynthesis of the neurotransmitter D-serine, which activates N-methyl-D-aspartate (NMDA) receptors in the CNS. Aberrant regulation of NMDA receptor signaling has been implicated in a variety of neuropathologies, and inhibitors of SR would therefore be a worthwhile tool for further investigation or treatment of such conditions. Here, we identify a series of small aliphatic hydroxamic acids (HAs) that act as potent SR inhibitors. However, specificity studies showed that some of these HAs can act as nonspecific inhibitors of PLP-dependent enzymes. We employed NMR, MS, and UV/vis spectroscopic techniques to reveal that the nonspecific effect is likely due to irreversible interaction of the HA moiety with PLP to form aldoxime species. We also characterize L-aspartic acid β-hydroxamate as a competitive and selective SR inhibitor that could be used as a scaffold for further inhibitor development. 2009 American Chemical Society.
A comparison between the acid-catalysed reactions of some dihydroxamic acids, monohydroxamic acids and desferal
Ghosh, Kallol K.,Patle, Shyam Kumar,Sharma, Pokhraj,Rajput, Surendra Kumar
, p. 283 - 290 (2007/10/03)
A kinetic study on the hydrolysis of some dihydroxamic acids HOHNOC-(CH2)n-CONHOH (n = 0, oxalo, [ODHA]; n = 1 malono [MDHA]; and n = 2, succino, [SDHA] dihydroxamic acids) in aqueous mineral acids is reported. A comparison of the kinetic data with those from the hydrolysis of simple monohydroxamic acid, (acetohydroxamic acid [AHA] CH3CONHOH, benzohydroxamic acid [BHA] C6H5CONHOH) and the natural trihydroxamate-based siderophore desferal (DFB) revealed that the hydrolytic stability sequence of the compounds is generally: BHA > ODHA > MDHA > DFB > AHA > SDHA. An excess acidity analysis reveals that the reaction involving a pre-equilibrium protonation was followed by a rate determining A-2 type nucleophilic attack of water molecule on the protonated substrate. An attempt has been made to study protonation equilibria.
