Patent ID: 7625930

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 the same or different, and the pyridyl groups are i) tethered directly to each other to form a 2,2′-bipyridyl or 2,2′:6′,2″-terpyridyl group, respectively, or ii) tethered to each other via hydrocarbon chains, wherein said hydrocarbon chains contain no heteroatoms other than N; (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 a hydrocarbon chain, wherein said hydrocarbon chain contains no heteroatoms other than N; 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 —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-O—PZ-O—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 (—C≡C—), ethylenediyl (—C═C—), ether (—O—), thioether (—S—) amide (—CO—NH—, —CO—NR′—, NH—CO and —NR′—CO—), carbonyl (—CO—), ester (—COO—and —OOC—), disulfide (—SS—), diaza (—N═N—), and tertiary amine, wherein R′ represents an alkyl group containing less than 5 carbon atoms.