The invention provides alpha -mimetic structure of formula (I) wherein A is -(C=O)-CHR3-, or -(C=O), B is N-R3- or -CHR6-, D is -(C=O)-(CHR7)- or - (C=O) Eis -(ZR8)- or (C=O), G is -(XR9)n-, -(CHR10)-(NR6)-, -(C=O)-(XR12)-, -(C=N-W-R1)-, -(C=O)-, X-(C=O)-R13, X-(C=O)-NR13R14, X-(SO2)-R13, or X-(C=O)-OR13, Wis -Y(C=O)-, -(C=O)NH-, -(SO2)-, -CHR14, (C=O)-(NR15)-, substituted orunsubstituted oxadiazole, substituted or unsubstituted triazole, substitutedor unsubstituted thiadiazole, substituted or unsubstituted 4,5 dihydrooxazole,substituted or unsubstituted 4,5 dihydrothiazole, substituted or unsubstituted4,5 dihydroimidazole, or nothing, Y is oxygen or sulfur, X and Z isindependently nitrogen or CH, n=0 or 1； and R1 R2, R3, R4, R5, R6, R7, R8, R9R10, R11, R12, R13, R14, and R15 are the same or different and independentlyselected from an amino acid side chain moiety or derivative thereof, theremainder of the molecule, a linker and a solid support, and stereoisomers,salts, and prodrugs thereof, provided that where B is CHR6 and W is -Y(C=O)-, -(C=O)NH-, -(SO2), -CHR14, or (C=O)-(NR15)-, G cannot be CHR9, NR9, (C=O)-CHR12, (C=O)-NR12, or no atom at all. Additionally, the invention providesmethods wherein .alpha.-mimetic compounds are used to treat cancer stem cells .
