The biosynthesis of folic acidVI. Enzymatic conversion of carbon atom 8 of guanosine triphosphate to formic acid

1966 ◽  
Vol 117 (1) ◽  
pp. 275-278 ◽  
Author(s):  
A BURG ◽  
G BROWN
Keyword(s):  
Carbon Atom ◽  
Formic Acid ◽  
Enzymatic Conversion ◽  
Guanosine Triphosphate

scholarly journals Theoretical kinetic study of the formic acid catalyzed Criegee intermediate isomerization: multistructural anharmonicity and atmospheric implications

2018 ◽  
Vol 20 (16) ◽  
pp. 10806-10814 ◽  
Author(s):  
M. Monge-Palacios ◽  
Matti P. Rissanen ◽  
Zhandong Wang ◽  
S. Mani Sarathy
Keyword(s):  
Carbon Atom ◽  
Formic Acid ◽  
Kinetic Study ◽  
Theoretical Study ◽  
Isomerization Reaction ◽  
Hydrogen Shift ◽  
Acid Catalyzed ◽  
Double Hydrogen

We performed a theoretical study on the double hydrogen shift isomerization reaction of a six carbon atom Criegee intermediate (C6-CI), catalyzed by formic acid (HCOOH), to produce vinylhydroperoxide (VHP), C6-CI + HCOOH → VHP + HCOOH.

scholarly journals Guanosine triphosphate cyclohydrolase activity in rat tissues

1984 ◽  
Vol 217 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Z Bellahsene ◽  
J L Dhondt ◽  
J P Farriaux
Keyword(s):  
Formic Acid ◽  
Gel Filtration ◽  
Maximal Activity ◽  
Rat Tissues ◽  
Synthetase Activity ◽  
Guanosine Triphosphate ◽  
Heat Treated ◽  
Liver Homogenates ◽  
Acid Release ◽  
Reduced Forms

The GTP cyclohydrolase activity of rat tissues has been studied by means of the measurement of formic acid release and neopterin synthesis from GTP. After gel filtration of a 45%-satd.-(NH4)2SO4 fraction of liver homogenates, three enzyme fractions were separated and named A1, A2 and A3 according to the order of their elution. Fractions A1 and A3 displayed an 8-formyl-GTP deformylase activity; no proof of cyclized product has yet been established. This activity was heat-labile and required Mg2+ for maximal activity. Fraction A2 displayed a ‘neopterin-synthetase’ activity, with dihydroneopterin triphosphate and formic acid formed in stochiometric amounts. Fraction A1 isolated from heat-treated homogenates also produced dihydroneopterin triphosphate. Neopterin synthetase activity in fractions A1 and A2 was heat-resistant and inhibited by Mg2+. In liver the A2 fraction represented 70-75% of the neopterin synthetase capacity and was inhibited by reduced pterines (sepiapterin, dihydrobiopterin and tetrahydrobiopterin) and to a lesser extent by reduced forms of folic acid. In kidney and brain, fraction A1 and A3 GTP 8-formylhydrolase activities were found in significant amounts, in contrast with the neopterin synthetase activity, which was low and appeared to be confined to the A1 fraction.

The removal of the 32-carbon atom as formic acid in cholesterol biosynthesis

1972 ◽  
pp. 383 ◽  
Author(s):  
K. Alexander ◽  
M. Akhtar ◽  
R. B. Boar ◽  
J. F. McGhie ◽  
D. H. R. Barton
Keyword(s):  
Carbon Atom ◽  
Formic Acid ◽  
Cholesterol Biosynthesis

scholarly journals Electrochemically driven efficient enzymatic conversion of CO2 to formic acid with artificial cofactors

2021 ◽  
Vol 52 ◽  
pp. 101679
Author(s):  
Zhibo Zhang ◽  
Tudor Vasiliu ◽  
Fangfang Li ◽  
Aatto Laaksonen ◽  
Francesca Mocci ◽  
...  
Keyword(s):  
Formic Acid ◽  
Enzymatic Conversion

Synthesis and conformations of α-aminoadipyl- and glycyl-α-aminoadipylthiazepine sulfoxides

1981 ◽  
Vol 59 (2) ◽  
pp. 406-421 ◽  
Author(s):  
Saul Wolfe ◽  
Raymond John Bowers ◽  
Syed Khaqan Hasan ◽  
Peter Michael Kazmaier
Keyword(s):  
Hydrogen Bond ◽  
Carbon Atom ◽  
Formic Acid ◽  
Chair Conformation ◽  
Membered Ring ◽  
Amide Proton ◽  
Penicillin Biosynthesis ◽  
Boat Conformation ◽  
Internal Hydrogen Bond ◽  
Twist Boat

The title compounds, having the R-absolute configurations at sulfur, and labelled with 14C at carbons 5, 6, and 7 of the seven-membered ring, have been synthesized by condensation of isotopically labelled 3D-benzhydryloxycarbonyl-6L-amino-2,2-dimethyl-5-oxoperhydro-1,4-thiazepine with N-Boc- and α-benzhydryl-protected L-α-aminoadipic acid and glycyl-L-α-aminoadipic acid, followed by oxidation with m-chloroperoxybenzoic acid and complete deprotection with formic acid. The conformations of the sulfoxides, and related thiazepines and thiazepine sulfoxides, have been examined by 1Hmr spectroscopy. All thiazepines, and the two title sulfoxides, appear to exist in a twist boat conformation. Most other sulfoxides exist in a chair conformation, which is stabilized by an internal hydrogen bond between the sulfinyl oxygen and the amide proton at C6; when this hydrogen bond is not present, both chair and twist boat conformations may be observable. The title compounds are of interest as possible intermediates in penicillin biosynthesis from glycyl-δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine (GACV) or ACV, according to a new theory, which deals, in particular, with the stereochemical course of the biosynthesis at the beta (β) carbon atom of valine.

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