Optical diagnostic agents for diagnosis of neurodegenerative diseases by means of near infrared radiation (NIR radiation)

A compound of formula I

• Fm(—A1)(—Bn)(—Wo) (I)
• in which
• A is a biomolecule that binds to β-amyloid-plaques,
• B is a dye that binds to β-amyloid-plaques,
• W is a hydrophilic, low-molecular structural element that binds to β-amyloid-plaques,
• m stands for number 1 or 2, or provided that n and o mean 0, m stands for an integer 3-20,
• l and n, independently of one another, stand for number 0, 1 or 2,
• o stands for an integer 0, 1, 2, 3 or 4, provided that the sum of l, n and o≧1, and
• F is a dye-signal molecule, which has at least one absorption maximum in the range of 600 to 1200 nm, which is
• (a) a cyanine dye of formula V
• in which
• p means an integer 2 or 3,
• X and Y, independently of one another, stand for O, S, —CH═CH— or C(CH3)2,
• R19 and R20, independently of one another, represent a radical —COOE1, —CONE1E2, —NHCOE1, —NHCONHE1, —NE1E2, —OE1, —OSO3H, —SO3H, —E1, wherein E1 and E2, independently of one another, stand for a hydrogen atom, a saturated or unsaturated, branched or straight-chain C1-C50 alkyl chain, wherein the chain or portions of this chain optionally forms one or more aromatic or saturated cyclic C5-C6 units or bicyclic C10 units, and wherein the C1-C50 alkyl chain is interrupted by 0 to 15 oxygen atoms and/or by 0 to 3 carbonyl groups and/or is substituted with 0 to 5 hydroxy groups, provided that E1 and E2 are not hydrogen atoms at the same time, and R20 is not a hydrogen atom,and R21 and R22, independently of one another, stand for a radical —E1 with the above-indicated meaning, for a C1-C4 sulfoalkyl chain
• or R19, R20, R21, R22, E1 or E2 binds to A, B or W,
• (b) a cyanine dye of formula VI
• in which
• p, X, Y, R21 and R22 have the above-indicated meaning and,
• R23 stands for —OE3, —COOE3, —CONHE3, —CONH(CH2)1-6—NHE3, —CONH(CH2)1-6—OE3, —CONH(CH2)1-6—COOE3 or —CONH(CH2)1-6—CONHE3, in which
• E3 stands for a mono-, oligo- or polysaccharide with at least one radical —OSO3Hx, or
• (c) an oxonol dye of formula VII
• in which
• p, R19 and R20 have the above-indicated meaning, and
• R24 and R25, independently of one another, stand for a phenyl ring that is substituted in one to three places with a hydroxy, carboxy, sulfate, sulfonate, alkyl or alkoxy or carboxylic acid ester radical, or a physiologically compatible salt thereof.