Titanium biological function

Although these cations and anions are indispensable, excessive amounts of them are toxic, so that it is important that their concentrations are regulated, either by mechanisms existing in the animal or by externally imposed controls. There are also several kinds of metal ions found in Nature which do not appear to serve any useful biological function but which are highly toxic if they are absorbed into the body. These include arsenic and the environmental pollutants lead, cadmium and mercury ions. Most of the remaining metals occur as inert species such as the aluminosilicates and titanium dioxide that are poorly absorbed, if at all, by plants and animals, or are present in only trace amounts and have little physiological effect. 

Ogawa A, Akatsuka R, Tamauchi H, Hio K, Kanematsu H (2011) Influence of nickel-titanium alloy components on biological functions. BMC Proc 5 79... 

Trimethylsilyloxy)furan can also be used as a functionalized silyl enol ether for the asymmetric catalytic aldol-type reaction. Figadere has reported that the reaction of aliphatic aldehydes with the siloxyfuran catalyzed by BINOL-derived titanium complex provides the diastereomeric mixtures with high enantioselectivity (Sch. 42) [107], The addition reaction proceeds at the y position of the siloxyfuran to give butenolides of biological and synthetic importance. 

There have been recent reports on photochemical systems from a number of laboratories that use colloidal particles incorporating titanium and ruthenium which can split water and produce hydrogen and oxygen. Experimental problems still exist with such systems, but they are the first reports of purely chemical systems that appear as if they might function. The only system which actually does function in visible light on a continuous basis is the biological system (Fig.2). In... 

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