Mn(III)TBAP is a cell-permeable SOD mimic. At a concentration of 30 µM, it decreases the doubling time of SOD-null E. coli. by 2-fold.[1]
Reference:
[1]. Faulkner, K.M., Liochev, S.I., and Fridovich, I. Stable Mn(III) porphyrins mimic superoxide dismutase in vitro and substitute for it in vivo. J. Biol. Chem. 269(38), 23471-23476 (1994).