FIG 2.

Heme crystallization inhibition by quinine, quinidine, and their derivatives. Only the compound HEQD appreciably inhibited heme crystallization similarly to quinine and quinidine after 16 h. Two to five independent experiments were completed for each compound with each concentration in triplicate per experiment, reported with the corresponding standard errors of the means. Mean IC₅₀s calculated for all compounds in the order listed in graph were 16.3, 16.0, 208, 59.3, 24.0, and 155 μM, respectively.