A compound having a structure represented by formula wherein R 1 is H, unsubstituted or substituted C 1 -C 10 alkyl, unsubstituted or substituted C 2 -C 10 alkenyl, unsubstituted or substituted C 2 -C 10 alkynyl, unsubstituted or substituted aryl, unsubstituted or substituted heteroaryl, unsubstituted or substituted (CH 2) 1-2 O(C 1 -C 10 alkyl), unsubstituted or substituted (CH 2) 1-2 O(C 2 -C 10 alkenyl), unsubstituted or substituted (CH 2) 1-2 O(C 2 -C 10 alkynyl), (CH 2) 1-2 OC(=O)(C 1 -C 10 alkyl), unsubstituted or substituted (CH 2) 1-2 OC(=O)(C 2 -C 10 alkenyl), unsubstituted or substituted (CH 2) 1-2 OC(=O)(C 2 -C 10 alkynyl), unsubstituted or substituted C(-O)(C 1 -C 10 alkyl), unsubstituted or substituted C(-O)(C 2 -C 10 alkenyl), unsubstituted or substituted C(=O)(C 2 -C 10 alkynyl), unsubstituted or substituted cycloaliphatic, unsubstituted or substituted heterocycloaliphatic, unsubstituted or substituted arylalkyl, or unsubstituted or substituted alkylaryl; R 2 is H, unsubstituted or substituted C 1 -C 10 alkyl, unsubstituted or substituted C 2 -C 10 alkenyl, unsubstituted or substituted C 2 -C 10 alkynyl, unsubstituted or substituted aryl, unsubstituted or substituted heteroaryl, unsubstituted or substituted (CH 2) 1-2 O(C 1 -C 10 alkyl), unsubstituted or substituted (CH 2) 1-2 O(C 2 -C 10 alkenyl), unsubstituted or substituted (CH 2) 1-2 O(C 2 -C 10 alkynyl), (CH 2) 1-2 OC(=O)(C 1 -C 10 alkyl), unsubstituted or substituted (CH 2) 1-2 OC(=O)(C 2 -C 10 alkenyl), unsubstituted or substituted (CH 2) 1-2 OC(=O)(C 2 -C 10 alkynyl), unsubstituted or substituted C(=O)(C 1 -C 10 alkyl), unsubstituted or substituted C(=O)(C 2 -C 10 alkenyl), unsubstituted or substituted C(=O)(C 2 -C 10 alkynyl), unsubstituted or substituted cycloaliphatic, unsubstituted or substituted heterocycloaliphatic, unsubstituted or substituted arylalkyl, unsubstituted or substituted alkylaryl, or wherein each R 2a is independently H, NH 2, NHMe, Cl, F, Me, Et, or CN; R 3a and R 3b are independently H, C 1 -C 5 alkyl, CH 2 (C 5 -C 6 cycloalkyl), CH 2 C 6 H 5, C 6 H 5, or CH 2 CH 2 OH; R 4 is or wherein R 4a is H or C 1 -C 3 alkyl; and Y is H, OH, Cl, F, CN, Me, Et, NO 2, or NH 2; R 5 is H, C 1 -C 5 alkyl, C 2 -C 5 alkenyl, C 2 -C 5 alkynyl, CO(C 1 -C 5 alkyl), CO(C 2 -C 5 alkenyl), or CO(C 2 -C 5 alkynyl); W is O or S; and n is 0, 1, or 2; or a pharmaceutically acceptable salt thereof. R 1 is H, unsubstituted or substituted C 1 -C 10 alkyl, unsubstituted or substituted C 2 -C 10 alkenyl, unsubstituted or substituted C 2 -C 10 alkynyl, unsubstituted or substituted aryl, unsubstituted or substituted heteroaryl, unsubstituted or substituted (CH 2) 1-2 O(C 1 -C 10 alkyl), unsubstituted or substituted (CH 2) 1-2 O(C 2 -C 10 alkenyl), unsubstituted or substituted (CH 2) 1-2 O(C 2 -C 10 alkynyl), (CH 2) 1-2 OC(=O)(C 1 -C 10 alkyl), unsubstituted or substituted (CH 2) 1-2 OC(=O)(C 2 -C 10 alkenyl), unsubstituted or substituted (CH 2) 1-2 OC(=O)(C 2 -C 10 alkynyl), unsubstituted or substituted C(-O)(C 1 -C 10 alkyl), unsubstituted or substituted C(-O)(C 2 -C 10 alkenyl), unsubstituted or substituted C(=O)(C 2 -C 10 alkynyl), unsubstituted or substituted cycloaliphatic, unsubstituted or substituted heterocycloaliphatic, unsubstituted or substituted arylalkyl, or unsubstituted or substituted alkylaryl; R 2 is H, unsubstituted or substituted C 1 -C 10 alkyl, unsubstituted or substituted C 2 -C 10 alkenyl, unsubstituted or substituted C 2 -C 10 alkynyl, unsubstituted or substituted aryl, unsubstituted or substituted heteroaryl, unsubstituted or substituted (CH 2) 1-2 O(C 1 -C 10 alkyl), unsubstituted or substituted (CH 2) 1-2 O(C 2 -C 10 alkenyl), unsubstituted or substituted (CH 2) 1-2 O(C 2 -C 10 alkynyl), (CH 2) 1-2 OC(=O)(C 1 -C 10 alkyl), unsubstituted or substituted (CH 2) 1-2 OC(=O)(C 2 -C 10 alkenyl), unsubstituted or substituted (CH 2) 1-2 OC(=O)(C 2 -C 10 alkynyl), unsubstituted or substituted C(=O)(C 1 -C 10 alkyl), unsubstituted or substituted C(=O)(C 2 -C 10 alkenyl), unsubstituted or substituted C(=O)(C 2 -C 10 alkynyl), unsubstituted or substituted cycloaliphatic, unsubstituted or substituted heterocycloaliphatic, unsubstituted or substituted arylalkyl, unsubstituted or substituted alkylaryl, or wherein each R 2a is independently H, NH 2, NHMe, Cl, F, Me, Et, or CN; R 3a and R 3b are independently H, C 1 -C 5 alkyl, CH 2 (C 5 -C 6 cycloalkyl), CH 2 C 6 H 5, C 6 H 5, or CH 2 CH 2 OH; R 4 is or wherein R 4a is H or C 1 -C 3 alkyl; and Y is H, OH, Cl, F, CN, Me, Et, NO 2, or NH 2; R 5 is H, C 1 -C 5 alkyl, C 2 -C 5 alkenyl, C 2 -C 5 alkynyl, CO(C 1 -C 5 alkyl), CO(C 2 -C 5 alkenyl), or CO(C 2 -C 5 alkynyl); W is O or S; and n is 0, 1, or 2;