A compound having the structure of Formula I or pharmaceutically suitable salts thereof, wherein L is O or S; R 8 is H, Cl, F, Br, OH, NH 2, 1-3C alkyl, amino-1-3C alkyl, aminocyclopropyl, OCH 3, OCH 2 CH 3, cyclopropyl, CH 2 cyclopropyl, CH 2 Cl, CHCl 2, CCl 3, CH 2 CH 2 Cl, CH 2 Br, CHBr 2, CH 2 F, CHF 2, CF 3, CH 2 CH 2 F, CH 2 CHF 2, CH 2 CF 3, NHNH 2, NHOH, NHNHCH 3, NHOCH 3, NHCD 3, SCH 3, or NHCOH. X, Y and Z are independently selected from the group consisting of N, CR X, CR Y, and CR Z, provided that no more than two of X, Y and Z are N, wherein R X is H, CH 3, Cl, Br, or F; wherein R Y is H, CH 3, CHF 2, CF 3, CN, CH 2 CH 3, Cl, Br, or F; wherein R Z is H, CH 3, Cl, Br, or F. R 2 is a 6-membered aryl or heteroaryl ring containing 0-3 O, S, or N heteroatoms, optionally substituted with 0-3 substituents selected from: a substituent selected from the group consisting of OH, CO 2 H, CN, NH 2, Br, Cl, F, SO 3 H, SO 2 NH 2, SO 2 CH 3, SOCH 3, NHOH, NHOCH 3 and NO 2; or an optionally substituted Cl-15 hydrocarbyl residue containing 0-5 O, S, or N heteroatoms, optionally substituted with OH, CN, =O, NH 2, NHOH, =NOH, =NNH 2, =NOCH 3, Br, F, Cl, SO 3 H, or NO 2, wherein 2 adjacent substituents on R 2 may form one or more fused rings with the 6-membered aryl or heteroaryl ring; wherein the 6-membered aryl or heteroaryl ring of R 2 has a CH at the positions immediately adjacent the position where R 2 attaches to L; R 4 is: H; an optionally substituted OR a; an optionally substituted secondary or tertiary amine attached to the C Ring through the secondary or tertiary amine N; or an optionally substituted 5-10 membered unsaturated cyclic or heterocyclic residue containing 0-3 N, O or S heteroatoms; wherein the optional substituent is 0-3 substituents; wherein R a is a 5-6 membered aryl or heteroaryl containing 0-3 O, S, or N heteroatoms optionally substituted with 0-3 substituents; wherein the optional substituent is 0-3 substituents selected from the group consisting of OH, NO, CO 2 H, CN, NH 2, Br, Cl, F, SO 3 H and NO 2 or is a C1-15 hydrocarbyl residue containing 0-5 O, S or N heteroatoms optionally substituted with OH, CN, =O, NH 2, =NOH, =NNH 2, =NOCH 3, Br, F, Cl, SO 3 H, or NO 2; and wherein the term alkyl includes straight- and branched-chain and cyclic monovalent substituents. L is O or S; R 8 is H, Cl, F, Br, OH, NH 2, 1-3C alkyl, amino-1-3C alkyl, aminocyclopropyl, OCH 3, OCH 2 CH 3, cyclopropyl, CH 2 cyclopropyl, CH 2 Cl, CHCl 2, CCl 3, CH 2 CH 2 Cl, CH 2 Br, CHBr 2, CH 2 F, CHF 2, CF 3, CH 2 CH 2 F, CH 2 CHF 2, CH 2 CF 3, NHNH 2, NHOH, NHNHCH 3, NHOCH 3, NHCD 3, SCH 3, or NHCOH. X, Y and Z are independently selected from the group consisting of N, CR X, CR Y, and CR Z, provided that no more than two of X, Y and Z are N, wherein R X is H, CH 3, Cl, Br, or F; wherein R Y is H, CH 3, CHF 2, CF 3, CN, CH 2 CH 3, Cl, Br, or F; wherein R Z is H, CH 3, Cl, Br, or F. R 2 is a 6-membered aryl or heteroaryl ring containing 0-3 O, S, or N heteroatoms, optionally substituted with 0-3 substituents selected from: a substituent selected from the group consisting of OH, CO 2 H, CN, NH 2, Br, Cl, F, SO 3 H, SO 2 NH 2, SO 2 CH 3, SOCH 3, NHOH, NHOCH 3 and NO 2; or an optionally substituted Cl-15 hydrocarbyl residue containing 0-5 O, S, or N heteroatoms, optionally substituted with OH, CN, =O, NH 2, NHOH, =NOH, =NNH 2, =NOCH 3, Br, F, Cl, SO 3 H, or NO 2, wherein 2 adjacent substituents on R 2 may form one or more fused rings with the 6-membered aryl or heteroaryl ring; wherein the 6-membered aryl or heteroaryl ring of R 2 has a CH at the positions immediately adjacent the position where R 2 attaches to L; R 4 is: H; an optionally substituted OR a; an optionally substituted secondary or tertiary amine attached to the C Ring through the secondary or tertiary amine N; or an optionally substituted 5-10 membered unsaturated cyclic or heterocyclic residue containing 0-3 N, O or S heteroatoms; wherein the optional substituent is 0-3 substituents; wherein R a is a 5-6 membered aryl or heteroaryl containing 0-3 O, S, or N heteroatoms optionally substituted with 0-3 substituents; wherein the optional substituent is 0-3 substituents selected from the group consisting of OH, NO, CO 2 H, CN, NH 2, Br, Cl, F, SO 3 H and NO 2 or is a C1-15 hydrocarbyl residue containing 0-5 O, S or N heteroatoms optionally substituted with OH, CN, =O, NH 2, =NOH, =NNH 2, =NOCH 3, Br, F, Cl, SO 3 H, or NO 2; and wherein the term alkyl includes straight- and branched-chain and cyclic monovalent substituents. H; an optionally substituted OR a; an optionally substituted secondary or tertiary amine attached to the C Ring through the secondary or tertiary amine N; or an optionally substituted 5-10 membered unsaturated cyclic or heterocyclic residue containing 0-3 N, O or S heteroatoms; wherein the optional substituent is 0-3 substituents; wherein R a is a 5-6 membered aryl or heteroaryl containing 0-3 O, S, or N heteroatoms optionally substituted with 0-3 substituents; wherein the optional substituent is 0-3 substituents selected from the group consisting of OH, NO, CO 2 H, CN, NH 2, Br, Cl, F, SO 3 H and NO 2 or is a C1-15 hydrocarbyl residue containing 0-5 O, S or N heteroatoms optionally substituted with OH, CN, =O, NH 2, =NOH, =NNH 2, =NOCH 3, Br, F, Cl, SO 3 H, or NO 2; and wherein the term alkyl includes straight- and branched-chain and cyclic monovalent substituents.