Patent ID: 8071626

Claim:
A chelating agent comprising (a) two or more pyridyl groups, wherein at least one of said two or more pyridyl groups is substituted with a trialkoxyphenyl group, wherein the alkoxy groups are same or different C1-C4 alkoxy groups, carboxyalkoxy groups or alkoxycarbonylalkoxy groups, and the pyridyl groups are i) tethered directly to each other to form a 2,2â€³-bipyridyl or 2,2â€³:6â€³,2â€³-terpyridyl group, respectively, or ii) tethered to each other via N-containing hydrocarbon chains; (b) at least two carboxylic acid or phosphonic acid groups, or esters or salts of said acid groups, attached to the pyridyl groups at ortho position either directly or via an N-containing hydrocarbon chain; and (c) a substituent A selected from the group consisting of isothiocyanate, haloacetamido, maleimido, dichlorotriazinylamino, pyridyldithio, thioester, aminooxy, hydrazide, amino, a polymerizing group, a carboxylic acid or acid halide or an active ester thereof, an amino acid residue â€”CH(NHR 1 )R 5 wherein R 1 is a transient protecting group and R 5 is a carboxylic acid, its salt, acid halide or an ester, and a group -E-Oâ€”PZâ€”Oâ€”R 4 , wherein one of the oxygen atoms optionally is replaced by sulfur Z is chloro or NR 2 R 3 , R 4 is a protecting group, R 2 and R 3 are alkyl groups, E is absent or is a radical of a purine base or a pyrimidine base, wherein said base is connected to the oxygen atom via either i) a hydrocarbon chain substituted with a protected hydroxyethyl group, or ii) a furan ring or pyrane ring; wherein: said substituent A is tethered to i) at least one of said two or more pyridyl groups, or ii) at least one of said hydrocarbon chains, either directly or via a linker x, wherein said linker x is formed from one to ten moieties, each moiety being selected from the group consisting of phenylene, alkylene containing 1-12 carbon atoms, ethynydiyl (â€”Câ‰¡Câ€”), ethylenediyl (â€”Câ•Câ€”), ether (â€”Oâ€”), thioether (â€”Sâ€”) amide (â€”COâ€”NHâ€”, â€”COâ€”NRâ€³â€”, NHâ€”CO and â€”NRâ€²'COâ€”), carbonyl (â€”COâ€”), ester (â€”COOâ€” and â€”OOCâ€”), disulfide (â€”SSâ€”), diaza (â€”Nâ•Nâ€”), and tertiary amine, wherein Râ€² represents an alkyl group containing less than 5 carbon atoms.