- Biotransformation of nicotinamide to nicotinyl hydroxamic acid at bench scale by amidase acyl transfer activity of Pseudomonas putida BR-1
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Acyl transfer activity of amidase of Pseudomonas putida BR-1 has been explored for the conversion of N-substituted aromatic amide (nicotinamide) and hydroxylamine to nicotinyl hydroxamic acid. Nicotinyl hydroxamic acid is an important pharmaceutical compound with enormous biomedical applications. P. putida BR-1 produces maximum amidase acyl transfer activity 138 U/mg dcm at 50 °C, with highest conversion (95%) of nicotinamide to nicotinyl hydroxamic acid. A bioprocess was developed for production of nicotinyl hydroxamic acid in batch reaction (final volume 1 L) by adding 200 mM nicotinamide and 1000 mM of hydroxylamine in 100 mM sodium phosphate buffer (pH 7.5) at 50 °C, using 20 U/ml acyl transfer activity resting cells of P. putida BR-1 in reaction mixture. From 1 L reaction mixture 16 g of nicotinyl hydroxamic acid was recovered with 32 g/L/h volumetric productivity. The amidase acyl transfer activity of P. putida BR-1 and the process developed in the present study are of industrial significance for the enzyme mediated production of nicotinyl hydroxamic acid.
- Bhatia, Ravi Kant,Bhatia, Shashi Kant,Mehta, Praveen Kumar,Bhalla, Tek Chand
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- Nicotinamide hydroxamic acid collecting agent as well as preparation method and application thereof
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The invention relates to the field of floatation reagents, in particular to a nicotinyl hydroximic acid collecting agent and a preparing method and application of the nicotinyl hydroximic acid collecting agent. The molecular formula of the nicotinyl hydroximic acid collecting agent is C6H6N2O2. The nicotinyl hydroximic acid collecting agent has a very high collecting capability on oxidized ore such as wolframite, scheelite, ilmenite and bastnaesite, water solubility of nicotinyl hydroximic acid is very good, the nicotinyl hydroximic acid can also be completely dissolved into water at the low temperature, adding operation is easy, and the cost of the reagent is low.
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Paragraph 0025-0028
(2020/02/17)
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- Photoinduced one-pot synthesis of hydroxamic acids from aldehydes through in-situ generated silver nanoclusters
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Hydroxamic acids have attracted significant attention due to their widespread use in applied chemistry. In this report, a modified Angeli–Rimini method has been achieved via the visible light-mediated catalytic transformation of a variety of heterocyclic, aromatic and aliphatic aldehydes 1a–j to their corresponding hydroxamic acids 2a–j in 81–93% yield. The unique ability of vitamin K3 as a photoredox catalyst to expedite the development of completely new reaction mechanisms and to enable the construction of challenging carbon–nitrogen bonds has been investigated. It is shown for the first time that the vitamin K3 and aldehyde are largely responsible for rapid in situ reduction of Ag+ ions to catalytic photoluminescent Ag nanoclusters that possess a bandgap energy of 2.87?eV and are less than 2 nm in size. A mechanism for this reaction has been proposed and is supported by UV–Vis, TEM, ESI/MS, FT-IR, 1H NMR and 13C NMR analyses. The investigated method utilizes readily available reagents and produces the hydroxamic acids in high yields without the formation of side products, making it simple, practical and cost-effective.
- Mohamed, Yasser M. A.,Attia, Yasser A.,Solum, Eirik Johansson
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p. 7173 - 7186
(2018/08/17)
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- An Experimental and Computational Approach to Understanding the Reactions of Acyl Nitroso Compounds in [4 + 2] Cycloadditions
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Catalytic aerobic oxidation of phenyl hydroxycarbamate 1 and 1-hydroxy-3-phenylurea 2 using CuCl2 and 2-ethyl-2-oxazoline in methanol gave acyl nitroso species in situ, which were trapped in nitroso-Diels-Alder (NDA) reactions with various dienes to afford the corresponding cycloadducts in high yields (90-98%). Competing ene products were also present for dienes containing both alkene π-bonds and allylic σ-bonds, and the ene yields are higher with 1 than with 2. The use of the chiral hydroxamic acid, (R)-1-hydroxy-3-(1-phenylethylurea) 3 (same conditions) gave NDA cycloadducts in high yields (97-99%) with no ene product from 2,3-dimethyl-1,3-butadiene. NDA cycloadducts were not obtained from other hydroxamic acid analogues [RCONHOH (R = PhCH2 4; Ph(CH2)2 5; Ph(CH2)3 6; Ph(CH2)4 7; Ph 8; 2-pyridyl 9; 3-pyridyl 10] with various dienes using copper-oxidation but rather were obtained using sodium periodate, resulting in variable NDA yields (13-51%) from hydroxamic acids 1-10 with cyclohexa-1,3-diene and 2,3-dimethyl-1,3-butadiene (several cycloadducts characterized by X-ray crystallography). The NDA and nitroso-ene reaction pathways of nitroso intermediates with dienes were mapped by DFT computations (B3LYP/6-31G), which showed that the acyl nitroso species are super-reactive and that activation energies in the NDA processes are lower than the isomerization barriers between some cis- and trans-butadienes.
- Chaiyaveij, Duangduan,Batsanov, Andrei S.,Fox, Mark A.,Marder, Todd B.,Whiting, Andrew
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p. 9518 - 9534
(2015/10/12)
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- HISTONE DEACETYLASE INHIBITORS AND METHODS OF USE THEREOF
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The present invention provides novel compounds for inhibiting histone deacetylases, and pharmaceutically acceptable salts and derivatives thereof. The present invention further provides methods for treating disorders regulated by histone deacetylase activity (e.g., proliferative diseases, cancer, inflammatory diseases, protozoal infections, hair loss, etc.) comprising administering a therapeutically effective amount of a compound of the invention to a subject in need thereof. The present invention also provides methods for preparing compounds of the invention.
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Page/Page column 46
(2012/09/10)
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- Iron(III) tris(pyridinehydroxamate)s and related nickel(II) and zinc(II) complexes: Potential platforms for the design of novel heterodimetallic supramolecular assemblies
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The reaction of 3- and 4-pyhaH (pyhaH = pyridinehydroxamic acid) with hydrated metal salts (FeIII, NiII, ZnII) in aqueous solution affords tris(pyridinehydroxamate)s in the case of Fe III and bis(pyridinehydroxamate)s in the case of ZnII and NiII in both the solid state and in solution. These metal pyridinehydroxamates that have the hydroxamato moiety coordinated in an O,O′-bidentate fashion all contain free pyridine nitrogen donor atoms that might allow them to be used as building blocks in the construction of pyridinehydroxamato-bridged supramolecular assemblies. The crystal and molecular structures of the two novel FeIII tris(pyridinehydroxamate) building blocks [FeIII(3-pyha)3]·5.125H2O (1a) and [FeIII(4-pyha)3]·5.5H2O (2a) are found to have different packing systems despite the similar nature of the two complexes. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Mulcahy, Clodagh,Krot, Krystyna A.,Griffith, Darren M.,Suponitsky, Kyrill Yu.,Starikova, Zoya A.,Marmion, Celine J.
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p. 1373 - 1380
(2008/02/06)
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- Synthesis, characterisation and speciation studies of heterobimetallic pyridinehydroxamate-bridged Pt(II)/M(II) complexes (M = Cu, Ni, Zn). Crystal structure of a novel heterobimetallic 3-pyridinehydroxamate-bridged Pt(II)/Cu(II) wave-like coordination polymer
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The reaction of cis-[Pt(NH3)2(3-pyhaH) 2]2+ (3-pyhaH = 3-pyridinehydroxamic acid) and cis-[Pt(NH3)2(4-pyhaH)2]2+ (4-pyhaH = 4-pyridinehydroxamic acid) with Cu(II), Ni(II) or Zn(II) in aqueous solution affords novel heterobimetallic pyridinehydroxamate-bridged complexes, {cis-[Pt(NH3)2(μ-3-pyha)M(μ-3-pyha)]·SO 4·xH2O}n and {cis-[Pt(NH 3)2-(μ-4-pyha)M(μ-4-pyha)]·SO 4·xH2O}n respectively. The crystal and molecular structure of one of these, {cis-[Pt-(NH3) 2(μ-3-pyha)Cu(μ-3-pyha)]SO4·8H 2O}n 3a, has been determined and was found to be a novel heterobimetallic wave-like coordination polymer, the structure of which contains interlinked pyridinehydroxamate-bridged repeating units of Pt(II) and Cu(II) ions in slightly distorted square-planar N4 and O4 coordination environments respectively and extensive hydrogen-bonding through the Pt ammines and the deprotonated hydroxamate O and via the O of the SO 42- counterions and the H(N) of the hydroxamate moiety. Spectrophotometric and speciation studies on the other heterobimetallic systems confirm that very similar species are being formed in solution and based on elemental analysis and spectroscopic results analogous complexes are formed in the solid-state. In this paper, we report the first examples of coordination polymers incorporating both Pt(II)/Cu(II), Pt(II)/Ni(II) and Pt(II)/Zn(II) and containing pyridinehydroxamic acids as bridging scaffolds. The Royal Society of Chemistry 2005.
- Mulcahy, Clodagh,Dolgushin, Fedor M.,Krot, Krystyna A.,Griffith, Darren,Marmion, Celine J.
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p. 1993 - 1998
(2007/10/03)
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- Cephalosporin antibiotics
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Cephalosporin antibiotics represented by the formula STR1 wherein R is hydrogen, C1 -C4 alkyl or a carboxy substituted alkyl group; R1 is H or C1 -C4 alkyl; n is 0, 1 or 2; and A and A' independently are hydrogen, C1 -C4 alkyl or allyl; and pharmaceutically acceptable salts thereof are broad spectrum antibiotics useful in the treatment of gram positive and gram negative infections of mammals.
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