Fig. 1

Biologically active quinolones. The 4(1H)-quinolone scaffold 1, the fluoroquinolone ciprofloxacin active against TB (ref. 20), the endochin analogue EQ-300 and the quinoline O-carbonate prodrug ELQ-337 active against malaria (refs. 23,24), and ELQ-271 active against toxoplasmosis (ref. 27). Activity of decoquinate 2 against Mtb is unrecorded, but is active against malaria (refs. 31,32) and toxoplasmosis (ref. 33). Activities of the quinolones in vitro against Mtb, Pf and Tg are given. Pf 3D7 and D6 are chloroquine (CQ)-sensitive, W2 and Dd2 are CQ-resistant strains