937-34-8Relevant academic research and scientific papers
Aryl sulfotransferase from Haliangium ochraceum: A versatile tool for the sulfation of small molecules
Ayuso-Fernandez, Ivan,Galmes, Miquel A.,Bastida, Agatha,Garcia-Junceda, Eduardo
, p. 1059 - 1065 (2014/05/06)
Sulfation is an important molecular modification that regulates essential cellular processes and is also implicated in numerous pathological processes. The enzymes responsible for this reaction in living organisms are sulfotransferases. The gene Hoch-5094 from Haliangium ochraceum is annotated as a putative sulfotransferase. The arylsulfotransferase codified by this gene (HocAST) was expressed heterologously in E. coli and showed aryl sulfotransferase activity. Circular dichroism analysis of HocAST showed a main α/β secondary structure that agrees with the overall structure of other cytosolic sulfotransferases. Interestingly, HocAST was able to use both p-nitrophenyl sulfate and 3'-phosphoadenosine-5'-phosphosulfate (PAPS) as sulfuryl donors contrary to that of aryl sulfate sulfotransferase, which cannot use PAPS as a donor. Regarding the specificity towards the acceptor, HocAST has shown quite a wide scope and was able to accept several mono- and dihydroxylated phenols and other phosphorylated compounds as substrates. Sulfation variations: We prove experimentally that the gene Hoch-5094 from Haliangium ochraceum encodes for an aryl sulfotransferase. The codified enzyme, HocAST, may be a very versatile biocatalyst as it is able to use both p- nitrophenyl sulfate (p-NPS) and 3'-phosphoadenosine-5′-phosphosulfate (PAPS) as donors and transfer the sulfuryl group to several phenolic compounds and biologically relevant phosphorylated molecules. GTP(S)=Guanosine-5′- triphosphate(-5′-sulfate), BiPhOH= 4,4'-Biphenol, BiPhOS=4,4'-Biphenol 4-sulfate.
Human serum albumin and process for producing the same
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, (2008/06/13)
Human serum albumin obtained by gene manipulation techniques can be purified by treating recombinant human serum albumin with a hydrophobic chromatography carrier at pH of 2 to 5 and a salt concentration of 0.4 to 1 and exposing the carrier to a pH of 6 to 8 and a salt concentration of 0.01 to 0.3 M, or treating the culture supernatant with boric acid or a salt thereof at pH 8 to 11 for 1 to 10 hours and recovering the supernatant to thereby obtain human serum albumin which contains substantially no contaminants which are contained in the culture medium or contained in or secreted by the host microorganism, specifically free nonantigenic contaminants detectable by the phenol-sulfuric acid method, antigenic producer host-derived contaminants and pyrogen. The thus-obtained human serum albumin is of very high purity and free from various side effects attributed to the contaminants.
Reactions of sulfur trioxide with benzene derivatives containing a deactivating oxy substituent
Ansink, Harold R. W.,Cerfontain, Hans
, p. 215 - 221 (2007/10/02)
The reactions of phenyl acetate (2), (trifluoromethoxy)benzene (3), (difluoromethoxy)benzene (4), 4-(trifluoromethoxy)phenol (5), 4-(trifluoromethoxy)phenyl methanesulfonate (6), 4-(trifluoromethoxy)anisole (7) and 3-(trifluoromethoxy)anisole (8) with SO3 in nitromethane have been studied.Upon reaction with SO3, 2 yields 2-4-sulfonic acid (2-4-S); subsequently, transfer of the acetyl group takes place to yield the mixed anhydride of phenol-4-pyrosulfonic acid and acetic acid (9) or the corresponding hydrogen sulfate 10, depending on the amount of SO3 used.Reaction of the α-fluorinated anisoles 3 and 4 with SO3 leads to sulfonation at the 4-position only; however, on using both a high substrate concentration and an excess of SO3, some 2,4-S2 is formed with 4 but not with 3.On reaction of 5 with 0.8 mol-equiv of SO3 in C(2)H3NO2, the hydrogen sulfate derivative (5-O-S) is formed; at 100 deg C, some isomerization to 5-2-S occurs.Upon reaction with 4.0 mol-equiv of SO3, the initially formed hydrogen sulfate slowly yields the corresponding 2-sulfophenyl hydrogen sulfate (5-O,2-S2).On using 6.0 mol-equiv of SO3, the 5-O,2-S2 is slowly converted into 6-(trifluoromethoxy)benzo-1,3,2,4-dioxadithiin 2,2,4,4-tetraoxide (11).Reaction of 6 with either 0.9 or 3.0 mol-equiv of SO3, initially leads to insertion of sulfur trioxide in between the SO2CH3 and the adjacent O, yielding the 4-(trifluoromethoxy)phenyl methanepyrosulfonate 12.This species subsequently yields 13 and 14.Reaction of 7 with SO3 leads to sulfonation only at the 2-position; eventually some sulfodemethylation to yield 5-2-S takes place.Reaction of 8 with 1.0 mol-equiv of SO3 yields a 68:32 mixture of 8-4-S and 8-6-S.
Sulfonation of anisole, phenol, toluene and related alkyl and alkoxy derivatives with SO3. The influence of the solvent system on the reactivity and the sulfonic acid product distribution
Ansink, Harold R. W.,Cerfontain, Hans
, p. 183 - 187 (2007/10/02)
The reactions of anisole (1), phenol (2), the alkoxy- and alkylphenyl ethers 3-11, toluene (12) and the o-dialkylbenzenes 13-15 with sulfur trioxide in dichloromethane or trichlorofluoromethane have been studied.Our results have been compared with those obtained with the same substrates upon reaction with SO3 in nitromethane and dioxane.We show that ortho substitution is enhanced for sterically unhindered phenyl ethers and phenols due to complex formation between SO3 and the C(sp2)-bonded oxygen when dichloromethane is used as solvent instead of nitromethane or dioxane.This is mainly as a result of intramolecular SO3 transfer from the oxygen to the ortho carbon and subsequent conversion of the resulting ?-complex into the ortho sulfonic acid.
Intramolecular Catalysis of Sulphate Diester Hydrolysis by One and Two Carboxy Groups. The Hydrolysis of Aryl 2-Carboxyphenyl Sulphates
Drummond, Jeremy N.,Kirby, Anthony J.
, p. 579 - 584 (2007/10/02)
The hydrolysis of aryl 2-carboxyphenyl (salicyl) sulphates is subject to efficient nucleophilic catalysis by the neighbouring carboxylate group.The intermediate cyclic acyl sulphate can be trapped with hydroxylamine.The reaction of disalicyl sulphate is further catalysed by the second carboxy group, acting, rather inefficiently, as a general acid.
Sulfonation of three Symmetrical 2,6-Dialkylphenols, 2,6-Dichlorophenol, Phenol, and 2,6-Dimethylanisole. Sulfation and Sulfonation Product Distribution and Mechanisms
Cerfontain, Hans,Koeberg-Telder, Ankie,Lambrechts, Hans J.A.,de Wit, Peter
, p. 4917 - 4923 (2007/10/02)
The sulfonation of four symmetrically substituted 2,6-disubstituted phenols, phenol, 2,6-dimethylanisole with SO3 in aprotic solvents was studied.With the phenols the initial product is the phenyl hydrogen sulfate, which is slowly converted into the phenolsulfonic acids via O-desulfonation and subsequent C-sulfonation if the phenol is in excess and via C-sulfonation and subsequent O-desulfonation if the SO3 is in excess.The ratio of partial rate factors for 3- and 4-sulfonation (f3/f4) for 2,6-dimethylphenol (1) in nitromethan strongly decreases on replacing the methyl groups by i-Pr, t-Bu (steric effects), and Cl (electronic effects).The strong increase of f3/f4 on increasing the SO3:1 ratio from 0.9 to 6.0 is ascribed to increasing sulfonation of the phenyl hydrogensulfate for which because of steric inhibition of resonance f3/f4 is higher (3.9) than that of the phenol 1 (0.01) and of 2,6-dimethylanisole (5) (0.01).The protic sulfonation of 1 and 5 in concentrated sulfuric acid was also studied.The large variations in f3/f4 with increasing sulfuric acid concentration are discussed in terms of steric inhibition of resonance for the entities undergoing sulfonation, viz., 1, its hydrogen sulfate, and 5 by the various sulfonating entities in the sulfuric acid range 75 - 107 percent H2SO4.
