| abstract |
The invention features novel peptide derivatives called Reversins, and provides for their use in a method of reducing the activity of the multi-drug transporter protein MDR1 in order to overcome multidrug resistance in a mammal. The peptide derivatives are of the formula (I) X1n-X2-X3(X4)n-X5, wherein n is 0 or 1, and each n is the same or different; X1 is BOC, BOC-Asu, Z-Asu, benzyloxycarbonyl, Glu(OBzl)-OBzl, Trp-OMe, Trp-Phe-OMe, Phe-Trp-OMe, Phe-Phe-OtBu, Trp-Trp-OtBu, indoloacetyl, benzoyl, an alkylamine of 1-4 carbons, dibenzylamide, tryptamide, 1-amino-adamantine, aminomethylcyclohexane, indoline, phenylethylamide or dicyclohexylamide; X2 is Glu(OBzl), Asp(OBzl), succinyl, O,O-dibenzoyltartaroyl, diphenoyl, muconyl, Thx, Cpa, Asu, Nal, Pen, Phg, Dbt, Lys(BOC), Lys(Z), Cys(Bzl), Thr(Bzl), Glu(OtBu), tert.-Leu, Leu, Nle, Pro, Phe, Tyr(Bzl), or Ser(Bal); X3 is Asp, Asu, Lys, Glu, Trp, Thx, Cpa, Nal, Pen, Phg, Dbt, Glu(OtBu), tert.-Leu, Leu, Nle, Pro, Tyr, Phe, or Tyr(Bzl); X4 is BOC-Glu(OBzl), Glu(OBzl), Asu, OBzl, Bzl, BOC, BOC-Lys(BOC), Z-Glu(OtBu), Asp(OBzl), Asp(OBz)-OBzl, benzyloxycarbonyl, O-(cyclo-hexyl), fluorenylmethyl ester, Glu(OtBu), Glu(OtBu)-OBzl, 1-amino-adamantine, aminomethylcyclohexane, indoline, phenylethylamide, or dicyclohexylamide; and X5 is OMe, OBzl, OtBu, Phe-OMe, -O-(cyclohexyl), Trp-OMe, (chlorophenyl)-isobutylamide, fluorenylmethyl ester, ONp, 1-aminoadamantane, aminomethylcyclohexane, indoline, phenylethylamide, or dicyclohexylamide. |