Aluminium chelates

Boudet, A.-C., Cornard, J.-P., and Merlin, J.-C., Conformational and spectroscopic investigation of 3-hydroxyflavone-aluminium chelates, Spectrochim. Acta A, 56, 829, 2000. 

A quantum-corrected fluorescence spectrum of TC HC1 (11 mg/50 ml) in 0.05 N NaOH taken with a Perkin-Elmer spectrofluorometer LS 5 is given in Fig. 12. Various fluorimetric methods of determination of tetracycline antibiotics are reported in literature (116, 117, 118, 119, 120). TC can be dehydrated to ATC by heating in acid solutions and taking the advantage of the greater lipophilicity of ATC it is extracted at about pH 4 - 5 with chloroform and then the fluorescence of aluminium-chelate is measured (116, 121). 

Hyperparathyroidism and aluminium hydroxide lead to aluminium-related bone disease however, total parathyroidectomy does not lead to failure of aluminium mobilization after renal transplantation. This man had satisfactory graft function, and the aluminium excretion that was achieved by deferoxamine suggests that the renal transplant was not the limiting factor for the mobihzation of aluminium. The most likely explanation was that he developed adynamic bone through a combination of vitamin D deficiency, hypoparathyroidism, and aluminium deposition. Vitamin D supplementation failed to prevent the osteodystrophy on its own. When aluminium chelation therapy was used, bone healing occurred and his symptoms improved. 

Kontoghiorghes GJ. New concepts of iron and aluminium chelation therapy with oral LI (deferiprone) and other chelators. A review. Analyst 1995 120(3) 845-51. 

Kontoghiorghes, G.J. (1995) Comparative efficacy and toxicity of desferrioxamine, deferiprone and other iron and aluminium chelating drugs. Toxicol. Lett., SO. 1-18. 

Carminic acid, the active colourant principle of cochineal, is employed in the form of its derivatives, notably, the aluminium chelate which is obtained by semi-synthesis. 

Cochineal extract (Colour Index 75470, E 120)is the final alcohol-free material obtained after aqueous ethanolic extraction of the dried bodies of the female scale insect Dactylopius coccus Costa which lives on cacti such as Opuntia or Nopalea coccinellifera a species indigenous to Peru and Mexico, although also found in the Canary Islands. In practice a simpler procedure consists of aqueous alkaline extraction. The colourant principle is carminic acid which is more well-known in the form of carmine, an aluminium chelate of carminic acid, a material insoluble in water and stable on the acidic side. A uv spectrophotometric study has been made (ref. 21). Thin layer chromatography of cochineal has been examined on acetylated cellulose with the solvent system, ethyl acetate-tetrahydrofuran-water (6 35 47) in which the Rf was 0.94 (refs.22,23). The history of the chemistry of cochineal has been discussed (ref.24). 

Structural and Catalytic Properties of Amorphous Mesoporous AIPO4 Materials Prepared in the Presence of 2,4-Pentanedione and 2,5-Hexanedione as Aluminium Chelating Agents... 

The two faces of the double bond of the dienophile are now different because of the chiral centre they are diastereotopic, and the diene can distinguish between them. If we now do the Diels-Alder reaction in the presence of a Lewis acid, Et2AlCl, the aluminium chelates the oxygen atoms of the dienophile to form the rigid and reactive structure shown below. The isopropyl group is held in such a way that its steric bulk prevents the diene attacking that face of the prochiral alkene. The diene has no choice but to attack from above, and only one of the possible diastereoisomeric products is formed. 

Charnell method Addition of aluminium chelating agent ethanolamine or related compounds LTA, FAU... 

T. Yogo and H. Iwahara, Synthesis of polycrystalline alumina fiber with aluminium chelate precursor, J. Mater. Sci., 26.5292-5296 (1991). 

Use of aluminates is in its infancy and there is very little information available concerning the nature of the products and their effects other than that they are chemically modified alkoxy aluminium chelates. Their use is being pioneered by Kenrich Petrochemicals [81]. 

Carmine pigments are anthraquinone derivatives, which, unlike other anthraquinones, are of animal origin. Carmine (also known as Natural Red 4) is the term that describes the aluminium chelate of anthraquinone derivative carminic acid. The term cochineal... 

Bittar, E.E. Xiang, Z. Huang, Y.P. (1992) Citrate as an aluminium chelator and pwsitive effector of the sodium efflux in single batnade muscle fibers, Biodiim Biofdiys Acta, Vol. 1108, pp. 210-214. 

Experiments undertaken by a number of workers to assess the effects of organic acids on feldspar dissolution kinetics and the effects on aluminium chelation provide little solace for the proponents of the organic acid hypothesis. Only unrealistically large dicarboxylic acid concentrations present in low pH solutions have any significant impact on Al mobility. 

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