scholarly journals Aldehydes or dicarbonyls in non-enzymic glycosylation of proteins

1985 ◽  
Vol 226 (2) ◽  
pp. 385-389 ◽  
Author(s):  
H T Beswick ◽  
J J Harding
Keyword(s):  
Schiff Base ◽  
Mass Spectroscopy ◽  
Fast Atom Bombardment ◽  
Protein Glycosylation ◽  
Amino Groups ◽  
Open Chain ◽  
Autoxidation Product ◽  
Alpha Crystallin ◽  
Glycosylation Reaction ◽  
Chain Aldehyde

The non-enzymic post-translational glycosylation of certain proteins has been implicated in the production of diabetic sequelae. In the present paper the possibility that it is not the glucose aldehyde that binds to proteins but a dicarbonyl autoxidation product is investigated. Earlier experiments may not have distinguished between these two possibilities. The rate of binding of 2-deoxyglucose (a non-autoxidizable sugar) to lens alpha-crystallin is compared with that of glucose (an autoxidizable sugar). The stabilized Schiff-base adducts was investigated by using proton n.m.r. and fast-atom-bombardment mass spectroscopy to distinguish whether they are the product of aldehyde or dicarbonyl addition. We conclude that it is the open-chain aldehyde of glucose that binds initially to amino groups and that there is no participation of dicarbonyl autoxidation products in the initial non-enzymic protein glycosylation reaction.

scholarly journals Synthesis, Characterization, and Electrochemical Behaviour of Cobalt(II) and Nickel(II) Complexes with N2O2 Chelating Ligand 4,4′-(Biphenyl-4,4′-diyldinitrilo)dipentan-2-one

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Lakhdar Sibous ◽  
Embarek Bentouhami ◽  
Mustayeen Ahmed Khan
Keyword(s):  
Schiff Base ◽  
Mass Spectroscopy ◽  
Elemental Analysis ◽  
Electrochemical Behaviour ◽  
Absolute Ethanol ◽  
Molar Ratio ◽  
H Nmr ◽  
Chelating Ligand ◽  
Metal Ligand

4,4′-Diaminobiphenyl reacts with 2,4-pentanedione in absolute ethanol in a molar ratio 1 : 2 to form mainly the product of [1 + 2] condensation, 4,4′-(biphenyl-4,4′-diyldinitrilo)dipentan-2-one (H2L). The Schiff base was used as tetradentate chelating ligand to coordinate CoII and NiII chlorides leading to complexes where the ratio of metal ligand was found to be 2 : 1 or 2 : 2. All the synthesized products were characterized by elemental analysis, infrared, electronic, and mass spectroscopy, 1H NMR, and DSC. The electrochemical behaviour of the ligand and its complexes in DMF is also investigated.

Investigation of the effect of ring size on the product distribution for the Schiff base reaction of 2-acetylcycloalkanones with diamino alkanes

1995 ◽  
Vol 73 (1) ◽  
pp. 16-21 ◽  
Author(s):  
Raul G. Enriquez ◽  
Juan M. Fernandez-G ◽  
Ismael Leon ◽  
William F. Reynolds ◽  
Ji.-Ping Yang ◽  
...  
Keyword(s):  
Schiff Base ◽  
Condensation Reaction ◽  
2D Nmr ◽  
Product Distribution ◽  
Major Product ◽  
Ring Size ◽  
Amino Group ◽  
Amino Groups ◽  
Similar Product ◽  
Acetyl Group

The Schiff base condensation reaction of 1,2-diaminoethane with a series of 2-acetylcycloalkanones (from cyclopentanone to cyclooctanone) has been investigated and the products characterized by two-dimensional nuclear magnetic resonance. The site of attack of the amino groups, i.e., ring ketone or acetyl ketone, is determined primarily by ring size. 2-Acetylcyclohexanone yields two products in ca. 9:1 ratio, the major product where the two amino groups attack at the ring ketones of two different cyclohexanone molecules, and the minor product where one amino group attacks one ring carbonyl of one cyclohexanone while the second amino group attacks the acetyl group of another. 2-Acetylcyclopentanone yields all three possible products with the major product involving attack at the acetyl groups of two different cyclopentanones. The corresponding reactions for 2-acetylcycloheptanone and 2-acetylcyclooctanone each give a single product corresponding to attack at the acetyl groups of two different cycloalkanones. Similar product distributions are observed for the reactions of the different 2-acetylcycloalkanones with 1,4-diaminobutane. Keywords: Schiff base reactions, diketones, 2D NMR.

Synthesis and Characterisation of Macrocyclic Copper(II) Complexes Containing N3O4 Donor Sets

2008 ◽  
Vol 2008 (10) ◽  
pp. 587-588 ◽  
Author(s):  
Hassan Keypour ◽  
Ahmad Ali Dehghani-Firouzabadi ◽  
Maryam Shayesteh ◽  
Sadegh Salehzadeh
Keyword(s):  
Schiff Base ◽  
Mass Spectroscopy ◽  
Elemental Analysis ◽  
Schiff Base Complexes ◽  
Macrocyclic Schiff Base ◽  
Formation Of Complexes ◽  
Template Reaction

Two new macrocyclic Schiff-base complexes of Cu(II) have been prepared by the template reaction of 2,6-bis (2-formylphenoxymethyl)pyridine with 1,2-bis(2′-aminophenoxy)benzene [L1] or with 1,2-bis(2′-aminophenoxy)-4-tert-butylbenzene [L2] in the presence of Cu(II) perchlorate. The amines used have low flexibility and therefore the formation of complexes was very difficult. The synthesised 23-membered, heptadentate N3O4 complexes were characterised by elemental analysis, IR, and FAB-mass spectroscopy.

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