Patent ID: 7033541

Claim:
A compound having the general formula I wherein A 1 and A 2 are selected from the group consisting of carbon (═CH—) and nitrogen (═N—); D 1 and D 2 are selected from the group consisting of —OH, —SH and —NHR 1 groups, wherein R 1 is hydrogen, hydrophilic substituent, hydrophobic substituent or linker; X 1 and X 2 are selected from the group consisting of oxygen (═O), sulphur (═S) and ═NR 2 group, wherein R 2 is hydrogen, hydrophilic substituent, hydrophobic substituent or linker; X 3 is selected from the group consisting of oxygen (═O), sulphur (═S), ═NR 2 group and two singly bonded moieties, wherein both moieties are hydrogen or one moiety is hydrogen and the other moiety is selected from the group of hydrophilic substituent, hydrophobic substituent and linker; and R 1 –R 9 are selected from the group consisting of hydrogen, electron donating substituent, electron accepting substituent, hydrophilic substituent, hydrophobic substituent and linker, or R 3 and R 4 and/or R 6 and R 7 form together an aromatic or heteroaromatic, substituted or unsubstituted ring and the remaining moieties R 1 –R 9 are as defined above.