1.D.58 The Anion Transporting Prodigiosene (Prodigiosene) Family
Analogues of the tripyrrolic natural product prodigiosin bearing an additional methyl and a carbonyl group at the C-ring have been synthesised and evaluated (Rastogi et al. 2013). In vitro anticancer activity screening and the study of modes of action (transmembrane transport of chloride anions) showed that the presence of the methyl group is not detrimental to activity. Although the presence of an ester conjugated to the prodigiosene C-ring seems to decrease both the pKa and chloride transport efficiency compared to the natural product, these analogues still exhibit a high rate of chloride transport. All analogues exhibit good in vitro anticancer activity and reduced toxicity compared to the natural product (Rastogi et al. 2013).