scholarly journals Interaction of dopamine β-mono-oxygenase with substituted imidazoles and pyrazoles. Catalysis and inhibition

1987 ◽  
Vol 242 (1) ◽  
pp. 227-233 ◽  
Author(s):  
S R Sirimanne ◽  
H H Herman ◽  
S W May
Keyword(s):  
Steric Effect ◽  
Alkyl Chain ◽  
Imidazole Ring ◽  
Amino Group ◽  
O2 Consumption ◽  
Methyl Substituent ◽  
Kinetic Behaviour ◽  
Substrate Analogues ◽  
Active Substrate ◽  
Terminal Amino

The interaction of dopamine beta-mono-oxygenase (DBM) with substrate analogues possessing either imidazole or pyrazole functionalities at the alkyl chain terminus was investigated. 1-(4-Hydroxybenzyl)imidazole (4-HOBI) is an active substrate for DBM, and it exhibits the expected ascorbate- and fumarate-dependencies and normal kinetic behaviour at concentrations up to 10 mM. 4-Hydroxybenzaldehyde was identified as the product formed from 4-HOBI on the basis of h.p.l.c. and g.c.-m.s. analysis, and its formation exhibits the expected 1:1 stoichiometry with O2 consumption. The 4-HOBI/DBM reaction is kinetically comparable with other DBM activities, and 4-HOBI is the first substrate analogue yet reported that exhibits substantial activity though lacking a terminal amino group. Introduction of a methyl substituent at the 2-position of the imidazole ring abolishes substrate activity, probably through a steric effect. 1-(4-Hydroxybenzyl)pyrazole, where imidazole is replaced by the isomeric pyrazole moiety, is a potent DBM inhibitor, and not a substrate. These results represent the first report of an active heterocyclic substrate or inhibitor for this enzyme, and establish the basis for the design of new classes of DBM substrates and inhibitors.

scholarly journals New Histamine-Related Five-Membered N-Heterocycle Derivatives as Carbonic Anhydrase I Activators

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 545
Author(s):  
Niccolò Chiaramonte ◽  
Alessio Gabellini ◽  
Andrea Angeli ◽  
Gianluca Bartolucci ◽  
Laura Braconi ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Imidazole Ring ◽  
Aliphatic Chain ◽  
Amino Group ◽  
Carbonic Anhydrase I ◽  
Terminal Amino ◽  
Human Carbonic Anhydrase ◽  
New Compounds ◽  
Related Compounds ◽  
Micromolar Range

A series of histamine (HST)-related compounds were synthesized and tested for their activating properties on five physiologically relevant human Carbonic Anhydrase (hCA) isoforms (I, II, Va, VII and XIII). The imidazole ring of HST was replaced with different 5-membered heterocycles and the length of the aliphatic chain was varied. For the most interesting compounds some modifications on the terminal amino group were also performed. The most sensitive isoform to activation was hCA I (KA values in the low micromolar range), but surprisingly none of the new compounds displayed activity on hCA II. Some derivatives (1, 3a and 22) displayed an interesting selectivity for activating hCA I over hCA II, Va, VII and XIII.

Reaction of metallic nitrilotriacetates with histamine

1969 ◽  
Vol 47 (8) ◽  
pp. 1269-1273 ◽  
Author(s):  
A. L. Beauchamp ◽  
J. Israeli ◽  
H. Saulnier
Keyword(s):  
Potentiometric Titration ◽  
Formation Constants ◽  
Amino Group ◽  
Mixed Complex ◽  
Ph Values ◽  
Titration Curves ◽  
Terminal Amino ◽  
Complex Ion

Cu(II), Ni(II), Co(II), and Zn(II) nitrilotriacetates (MeX−) react with histamine nitrate (LH+) to form a protonated mixed complex MeXLH where the metal appears to be bound only to the tertiary imidazolic nitrogen of histaminium ion. At higher pH values the proton dissociates to yield a mixed complex ion MeXL− in which both the imidazolic nitrogen and the terminal amino group are coordinated. The formation constants of these species were calculated from the potentiometric titration curves.

Synthesis of three Salmonella epitopes for biosensor studies of carbohydrate–antibody interactions

2002 ◽  
Vol 80 (8) ◽  
pp. 1131-1140 ◽  
Author(s):  
Henry N Yu ◽  
Chang-Chun Ling ◽  
David R Bundle
Keyword(s):  
Key Words ◽  
Self Assembled Monolayers ◽  
Antigenic Determinants ◽  
Amino Group ◽  
Assembled Monolayers ◽  
Construction Of Self ◽  
Terminal Amino ◽  
Salmonella Serotypes ◽  
O Antigens ◽  
Antibody Interactions

Disaccharides 1-3 corresponding to the antigenic determinants of Salmonella serotypes A, B, and D1 were synthesized in a form suited for use in biosensors. The disaccharide determinants each contain a unique 3,6-dideoxyhexose, namely abequose (3,6-dideoxy-D-xylo-hexose), paratose (3,6-dideoxy-D-ribohexose), and tyvelose (3,6-dideoxy-D-arabino-hexose), are α-linked to the 3-position of D-mannopyranose. The disaccharides were further derivatized with a linear aglycon that has a terminal amino group, and can be readily coupled to pertinent chains carrying a terminal thiol for the construction of self-assembled monolayers (SAMs). Efficient routes that employed a single 3,6-dideoxygenation step were developed for the synthesis of paratoside 15 and tyveloside 22.Key words: Salmonella O-antigens, lipopolysaccharide, abequose, paratose, tyvelose, 3,6-dideoxyhexose, deoxygenation, glycoside tethers, immobilization via pentenyl glycosides.

Photogeneration of Superoxide Anion upon Illumination of Purines and Pyrimidines in the Presence of Riboflavin: Structure-activity Relationships

1980 ◽  
Vol 43 (1) ◽  
pp. 19-20 ◽  
Author(s):  
MALGORZATA KORYCKA-DAHL ◽  
THOMAS RICHARDSON
Keyword(s):  
Superoxide Dismutase ◽  
Superoxide Anion ◽  
Orotic Acid ◽  
Imidazole Ring ◽  
Fluorescent Light ◽  
Carboxyl Group ◽  
Amino Group ◽  
Structure Activity ◽  
Related Compounds ◽  
Purines And Pyrimidines

Photogenerated superoxide anion might be involved in the oxidative deterioration of foods. For this reason, purines, pyrimidines and related compounds were illuminated with fluorescent light in the presence of riboflavin to examine their capacity to photogenerate superoxide anion (measured from suppression of its reduction of nitro blue tetrazolium by superoxide dismutase). Superoxide anion was photogenerated in the presence of guanine, xanthine, 6-thioguanine, thymine, uracil, 6-methyl uracil, orotic acid and 5- as well as 6-amino uracil but not in the presence of 24 other related compounds examined. Replacing the oxygen at the 6-position of guanine with sulfur or attachment of an amino group to the 5- or 6-carbon of uracil greatly increased superoxide anion generation as compared to guanine and uracil, respectively. The attachment of a carboxyl group at the 6-position of uracil augmented superoxide anion photogeneration to a much smaller extent and thymine and 6-methyl uracil did not yield any more superoxide anion than did uracil. In general, only those compounds which had an oxo group at the 6-position of purines or the 4-position of pyrimidines, and either an oxo or an amino group in the 2-position of either ring served as substrates for photogeneration of superoxide anion. Additionally, presence of purines and pyrimidines in an enol and/or amino form and an unsubstituted imidazole ring for purines were required for photogeneration of superoxide anion.

scholarly journals Analysis of crystalline and solution states of ligand-free spermidine N-acetyltransferase (SpeG) from Escherichia coli

2019 ◽  
Vol 75 (6) ◽  
pp. 545-553 ◽  
Author(s):  
Ekaterina V. Filippova ◽  
Steven Weigand ◽  
Olga Kiryukhina ◽  
Alan J. Wolfe ◽  
Wayne F. Anderson
Keyword(s):  
Escherichia Coli ◽  
Vibrio Cholerae ◽  
Crystal Structures ◽  
Coenzyme A ◽  
Amino Group ◽  
Acetyl Coenzyme A ◽  
E Coli ◽  
Ligand Free ◽  
Acetyl Group ◽  
Terminal Amino

Spermidine N-acetyltransferase (SpeG) transfers an acetyl group from acetyl-coenzyme A to an N-terminal amino group of intracellular spermidine. This acetylation inactivates spermidine, reducing the polyamine toxicity that tends to occur under certain chemical and physical stresses. The structure of the SpeG protein from Vibrio cholerae has been characterized: while the monomer possesses a structural fold similar to those of other Gcn5-related N-acetyltransferase superfamily members, its dodecameric structure remains exceptional. In this paper, structural analyses of SpeG isolated from Escherichia coli are described. Like V. cholerae SpeG, E. coli SpeG forms dodecamers, as revealed by two crystal structures of the ligand-free E. coli SpeG dodecamer determined at 1.75 and 2.9 Å resolution. Although both V. cholerae SpeG and E. coli SpeG can adopt an asymmetric open dodecameric state, solution analysis showed that the oligomeric composition of ligand-free E. coli SpeG differs from that of ligand-free V. cholerae SpeG. Based on these data, it is proposed that the equilibrium balance of SpeG oligomers in the absence of ligands differs from one species to another and thus might be important for SpeG function.

Reaction between Glucose and the Terminal Amino Group of Lysine

Nature ◽  
1951 ◽  
Vol 168 (4278) ◽  
pp. 744-745 ◽  
Author(s):  
R. S. HANNAN ◽  
C. H. LEA
Keyword(s):  
Amino Group ◽  
Terminal Amino

scholarly journals Primaquine derivatives: Modifications of the terminal amino group

2019 ◽  
Vol 182 ◽  
pp. 111640 ◽  
Author(s):  
Branka Zorc ◽  
Ivana Perković ◽  
Kristina Pavić ◽  
Zrinka Rajić ◽  
Maja Beus
Keyword(s):  
Amino Group ◽  
Terminal Amino
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