The present invention provides compounds of Formula (I), and pharmaceutically acceptable salts, solvates, esters, prodrugs, tautomers, or isomers of said compounds), having general structure (I); wherein L, R1, R2, R3, R4, R5, and R6 area selected independently of each other and as defined herein. The present invention also provides compounds (and salts, solvates, esters, prodrugs, tautomers, and isomers) of Formulas II, III, IV, V, and VI, as defined herein. Also provided are pharmaceutical compositions, methods of preparing, and methods of using such compounds in the treatment and prophylaxis of a wide range of immune, autoimmune, and inflammatory diseases and conditions.