Figure 1.

SQ109 is a gametocyte-targeting compound. (A) IC₅₀ for parent compound SQ109/1 on asexual parasites (ABS), immature-stage gametocytes (IGc, stage II/III), or late-stage gametocytes (LGc, stage IV/V), under 48 h drug pressure. IC₅₀ ABS: 1.58 ± 0.2 μM; IC₅₀ IGc: 0.38 ± 0.10 μM; IC₅₀ LGc: 0.14 ± 0.03 μM; ** P < 0.01 indicates IGc and LGc vs ABS. (B) Chemical structure and summary of the designed structure–activity relationships (SAR-1, SAR-2 and SAR-3) around SQ109/1. Data are from >2 independent biological repeats, mean ± SE indicated, unpaired Student’s t-test applied.