Proteasome activity enhancing compounds

A compound having the Formula (IV):

• or a pharmaceutically acceptable salt, solvate, clathrate or prodrug thereof;
• wherein
• Z is an optionally substituted N-heterocyclic;
• R1 and R2 are each independently selected from hydrogen and optionally substituted C1-C10 alkyl;
• R3f is selected from the group consisting of hydrogen, optionally substituted C1-C10 alkyl, optionally substituted C2-C10 alkenyl, optionally substituted C2-C10 alkynyl, optionally substituted C3-C12 cycloalkyl, optionally substituted C3-C12 cycloalkenyl, optionally substituted aryl, halo, N3, ORc, NRdRd, C(O)ORc, NO2, CN, C(O)Rc, C(O)C(O)Rc, C(O)NRdRd, NRdC(O)Rc, NRdS(O)nRc, N(Rd)C(O)ORc, NRdC(O)C(O)Rc, NRdC(O)NRdRd, NRdS(O)nNRdRd, NRdS(O)nRc, S(O)nRc, S(O)nNRdRd, OC(O)ORc(C═NRd)Rc, OC(O)Rc, optionally substituted heterocyclic and optionally substituted heteroaryl;
• each of R3b and R3c is independently selected from the group consisting of hydrogen, optionally substituted C1-C10 alkyl, optionally substituted C2-C10 alkenyl, optionally substituted C2-C10 alkynyl, optionally substituted C3-C12 cycloalkyl, optionally substituted C3-C12 cycloalkenyl, optionally substituted aryl, halo, N3, ORc, NRdRd, C(O)ORc, NO2, CN, C(O)Rc, C(O)C(O)Rc, C(O)NRdRd, NRdC(O)Rc, NRdS(O)nRc, N(Rd)C(O)ORc, NRdC(O)C(O)Rc, NRdC(O)NRdRd, NRdS(O)nNRdRd, NRdS(O)nRc, S(O)nRc, S(O)nNRdRd, OC(O)ORc(C═NRd)Rc, OC(O)Rc, optionally substituted heterocyclic and optionally substituted heteroaryl;
• and
• Rg is selected from the group consisting of hydrogen, optionally substituted C1-C10 alkyl, optionally substituted C2-C10alkenyl, optionally substituted C2-C10 alkynyl, optionally substituted C3-C12 cycloalkyl, optionally substituted C3-C12 cycloalkenyl, optionally substituted aryl, halo, N3, ORc, NRdRd, C(O)ORc, NO2, CN, C(O)Rc, C(O)C(O)Rc, C(O)NRdRd, NRdC(O)Rc, NRdS(O)nRc, N(Rd)C(O)ORc, NRdC(O)C(O)Rc, NRdC(O)NRdRd, NRdS(O)nNRdRd, NRdS(O)nRc, S(O)nRc, S(O)nNRdRd, OC(O)ORc(C═NRd)Rc, OC(O)Rc, optionally substituted heterocyclic and optionally substituted heteroaryl;
• Rj is optionally substituted C1-C4 alkyl;
• each Rc is independently selected from the group consisting of hydrogen, optionally substituted C1-C10 alkyl, optionally substituted C2-C10 alkenyl, optionally substituted C2-C10 alkynyl, optionally substituted C3-C12 cycloalkyl, optionally substituted C3-C12 cycloalkenyl, optionally substituted heterocyclic, optionally substituted aryl, and optionally substituted heteroaryl;
• each Rd is independently selected from the group consisting of hydrogen, optionally substituted C1-C10 alkyl, optionally substituted C2-C10 alkenyl, optionally substituted C2-C10 alkynyl, optionally substituted C1-C10 alkoxy, optionally substituted C3-C12 cycloalkyl, optionally substituted C3-C12 cycloalkenyl, optionally substituted heterocyclic, optionally substituted aryl, and optionally substituted heteroaryl;
• or two geminal Rd groups are taken together with the nitrogen atom to which they are attached to form an optionally substituted heterocyclic or an optionally substituted heteroaryl;
• and
• each n is independently, 1or 2.