A compound having the structural formula: wherein: R 1 is -H, unsubstituted or substituted alkyl, unsubstituted or substituted alkenyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted non-aromatic heterocyclyl, substituted or unsubstituted aromatic heterocyclyl, substituted or unsubstituted heterocyclylalkyl, - COR 11 , -C(O)OR 11 , -C(O)NR 11 R 12 , -C=NR 11 , -CN, -OR 11 , -OC(O)R 11 , -NR 11 R 12 , - NR 11 C(O)R 12 , -NO 2 , -N=CR 11 R 12 or -halogen; preferably C 1 -C 10 alkyl, more preferably - methyl, -ethyl, -propyl or -butyl, such as t -butyl, most preferred -methyl; R 2 and R 3 are independently selected from the group consisting of: -methyl, -ethyl, -phenyl, acetoxymethyl (AM), pivaloyloxymethyl (POM), or R 2 and R 3 jointly form a structure selected from the group consisting of: and wherein R 4 is -H or -alkyl, preferably -methyl; R 5 is -H or -alkyl, preferably -methyl or t -butyl; R 6 is -H, -alkyl, or -CH 2 (CO)OCH 3 ; R 7 is -H, -alkyl or -halogen; R 8 is -H, -alkyl, preferably t -butyl; R 9 is -H, -alkyl, preferably -methyl or t -butyl; R 10 is -H, -alkyl, preferably -methyl or t -butyl; R 11 and R 12 are each independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted aryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, or halogen; or a pharmaceutically acceptable salt or solvate thereof. R 1 is -H, unsubstituted or substituted alkyl, unsubstituted or substituted alkenyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted non-aromatic heterocyclyl, substituted or unsubstituted aromatic heterocyclyl, substituted or unsubstituted heterocyclylalkyl, - COR 11 , -C(O)OR 11 , -C(O)NR 11 R 12 , -C=NR 11 , -CN, -OR 11 , -OC(O)R 11 , -NR 11 R 12 , - NR 11 C(O)R 12 , -NO 2 , -N=CR 11 R 12 or -halogen; preferably C 1 -C 10 alkyl, more preferably - methyl, -ethyl, -propyl or -butyl, such as t -butyl, most preferred -methyl; R 2 and R 3 are independently selected from the group consisting of: -methyl, -ethyl, -phenyl, acetoxymethyl (AM), pivaloyloxymethyl (POM), or R 2 and R 3 jointly form a structure selected from the group consisting of: and wherein R 4 is -H or -alkyl, preferably -methyl; R 5 is -H or -alkyl, preferably -methyl or t -butyl; R 6 is -H, -alkyl, or -CH 2 (CO)OCH 3 ; R 7 is -H, -alkyl or -halogen; R 8 is -H, -alkyl, preferably t -butyl; R 9 is -H, -alkyl, preferably -methyl or t -butyl; R 10 is -H, -alkyl, preferably -methyl or t -butyl; R 11 and R 12 are each independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted aryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, or halogen; R 4 is -H or -alkyl, preferably -methyl; R 5 is -H or -alkyl, preferably -methyl or t -butyl; R 6 is -H, -alkyl, or -CH 2 (CO)OCH 3 ; R 7 is -H, -alkyl or -halogen; R 8 is -H, -alkyl, preferably t -butyl; R 9 is -H, -alkyl, preferably -methyl or t -butyl; R 10 is -H, -alkyl, preferably -methyl or t -butyl; R 11 and R 12 are each independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted aryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, or halogen; <EOS>