Thiosemicarbazone complexes of copper(II): structural and biological studies

The nature of metal complexes of heterocyclic thiosemicarbazones reported in the literature through 1989 have been reviewed with an emphasis on variations in stoichiometry and stereochemistry. A brief introduction is followed by a survey of the biological activity of the uncomplexed thiosemicarbazones. Next is a section on the chemical nature of thiosemicarbazones including a discussion of preparative methods, modes of coordination and isomerism. This is followed by a discussion of structural information and biological activity of the iron(III), iron(II), copper(II), cobalt(III), cobalt(II) and nickel(II) complexes of heterocyclic thiosemicarbazones. Short sections on the biological activity of other chelating thiosemicarbazones and metal complexes are also included.

Structural and physical correlations in the biological properties of transition metal heterocyclic thiosemicarbazone and S -alkyldithiocarbazate complexes

http://www.jsps.org/alumni/documents/JohnFossey20101129.pdf

Boronic acid building blocks: tools for self assembly.

Influence of borate complexation on the electrophoretic behavior of carbohydrates in capillary electrophoresis

The antiradical activity of caffeic acid (1), dihydrocaffeic acid (5), and their corresponding n-alkyl esters was evaluated by using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH(*)) method Dihydrocaffeic acid (5) was the most potent compound, having an antiradical effect higher than that of (+/-)-alpha-tocopherol, whereas caffeic acid (1) was less efficient Esterification of the carboxyl group of dihydrocaffeic acid (5) had a dramatic effect on its antiradical potency, but similar effects were not observed for caffeic acid (1) derivatives The n-alkyl esters of both phenolic series had similar potencies, and their antiradical activities were independent of the alkyl chain length Dose-dependent scavenger effects were found in both series Acid-base properties of the compounds, evaluated by using potentiometry and spectrophotometry, showed that the catechol moiety had pK(a2) and pK(a3) values of 9 24-902 and 1138-1099 in the dihydrocaffeic series and 848-824 and 1138-1107 in the caffeic series, respectively Antiradical activity and pK(a) values of the compounds were not related

https://bdigital.ufp.pt/bitstream/10284/8322/1/J.%20Agric.%20Food%20Chem.%202000.pdf

Phenolic acids and derivatives: studies on the relationship among structure, radical scavenging activity, and physicochemical parameters.

Copper complexes of pyridine 2-aldehyde and 2-acetylpyridine thiosemicarbazones

A study of the complexes of borate ions and some cyclitols using 11B-n.m.r. spectroscopy

Borate complexation with pentitols: a study by 11B-N.M.R. spectroscopy and MNDO semi-empirical LCAO-MO calculations

Boric acid complexes of phenolic acids

The complexation between boric acid and the three phenolic carboxylic acids, 3,4-dihydroxybenzoic, caffeic and chlorogenic acids, has been examined spectroscopically and this has established that a 1 : 1 complex is formed in each case. With the first two acids, there is also evidence of a 2 : 1 complex being formed at high acid to B ratios. Equilibrium constants have been calculated from 11 B NMR spectra of mixtures for the equation for the formation of the 1 : 1 complex: B+H 2 A − = BA 2− +H 3 O + . Conditions in which aerial oxidation of the organic acids occurs have been studied by ESR and UV spectroscopy. The presence of boron stabilizes the acids towards oxidation to free radicals and also retards the rate at which the radicals, when formed, are oxidized further to semiquinones.

Colin F. Bell

Papers

Copper complexes of pyridine 2-aldehyde and 2-acetylpyridine thiosemicarbazones

A study of the complexes of borate ions and some cyclitols using 11B-n.m.r. spectroscopy

Borate complexation with pentitols: a study by 11B-N.M.R. spectroscopy and MNDO semi-empirical LCAO-MO calculations

Boric acid complexes of phenolic acids

Boric Acid Complexes of Phenolic Acids.