Histone deacetylase inhibitors and uses thereof are provided that have the general formula wherein R1, R2, R3 and R4 are each independently selected from the group consisting of hydrogen, a substituted or unsubstituted straight chained C1-12 alkyl, C2-12 aminoalkyl or C2-12 oxaalkyl, and a substituted and unsubstituted 3, 4, 5, 6, 7 or 8 membered ring, with the proviso that R3 and R4 are not both hydrogen;R5 is selected from the group consisting of a carbonyl, a substituted or unsubstituted C1-3 alkyl, a substituted or unsubstituted —C1-3 alkyl-C(O), a substituted or unsubstituted —C(O)—C1-3 alkyl, and a substituted or unsubstituted —C(O)C(O)C1-3 alkyl;M is a substituent capable of complexing with a protein metal ion; andL is a substituent comprising a chain of 3-12 atoms connecting the M substituent to the carbon atom alpha to the L substituent.