Abstract: Novel mono- and dihydroxy phenylethylamine derivatives useful in treating melanoma are provided having the formulae (Ia, Ib or Ic). In the above formulae, Ra is hydrogen or —COORb, Rb is hydrogen or C1-6 alkyl; Re and Re independently represent hydrogen and hydroxy, Rf is hydrogen, C1–4? alkyl or halogen, X is —CHOH—, —CH2-oxygen or sulphur, m is zero or 1, W is oxygen or sulphur, and —ODrug, —NHDrug and —N(Drug)2 each represent a residue of a therapeutically active agent. The above compounds are prodrugs which are inactive until metabolised by enzymes expressed by host melanoma cells.

Abstract: Novel mono- and dihydroxy phenylethylamine derivatives useful in treating melanoma are provided having the formulae (Ia, Ib or Ic). In the above formulae, Ra is hydrogen or —COORb, Rb is hydrogen or C1-6 alkyl; Re and Re independently represent hydrogen and hydroxy, Rf is hydrogen, C1-4? alkyl or halogen, X is —CHOH—, —CH2-oxygen or sulphur, m is zero or 1, W is oxygen or sulphur, and —ODrug, —NHDrug and —N(Drug)2 each represent a residue of a therapeutically active agent. The above compounds are prodrugs which are inactive until metabolised by enzymes expressed by host melanoma cells. The invention allows a greater amount of active agent to be used while reducing systemic side effects.

Abstract: Novel pro-drugs and assay reagents are provided which are useful as therapeutic agents especially for delivery and targetting therapeutically active agents to melanoma cells. The pro-drugs and assay reagents are substrates for tyrosinase and may be represented by the formula TyrX—B—ThrAg*. The compounds of formula TyrX—B—ThrAg* are capable of releasing a therapeutically active agent or assayable substance (ThrAg) at a desired location. TyrX— being a residue of an optionally substituted tyrosine analogue.