The molecule is a hydroxy monocarboxylic acid anion that is the conjugate base of SN-38 carboxylic acid, obtained from the deprotonation of the carboxy group. It is the major microspecies at pH 7.3. It is a conjugate base of a SN-38 carboxylic acid.
(2S)-2-[12-ethyl-2-hydroxy-8-(hydroxymethyl)-9-oxo-11H-indolizino[1,2-b]quinolin-7-yl]-2-hydroxybutanoate