Studies of alkyl side chains on PQS. Comparisons of congeners with PQS. (A) Target 10AF, all molecules studied at 12.5 μg/mL. C1-PQS, C3-PQS, C5-PQS, C9-PQS, PQS respectively, are p > 0.05, p < 0.01, p < 0.05, p < 0.05, p < 0.001 compared to control. DMSO control results same as ethanol control shown. C1-PQS, C3-PQS, C5-PQS, C9-PQS are all p < 0.001 compared to PQS. (B) Target 10AF, all molecules studied at 1.56 μg/mL; separate plates, so data is referent to controls on each plate. DMSO controls shown, were same as ethanol and RPMI controls. C1-PQS, C3-PQS, C5-PQS, C9-PQS, PQS respectively, are p > 0.05 (actual boost above control), p < 0.01, p < 0.05, p < 0.05, p < 0.001 compared to control. C1-PQS, C3-PQS, C5-PQS, C9-PQS are p < 0.001, p < 0.001, p < 0.01, p < 0.01, respectively, compared to inhibition by PQS. (C) Target Af293, all molecules studied at 1.56 μg/mL. Shown are DMSO control same as ethanol control. C1-PQS, C3-PQS, C5-PQS, C9-PQS, PQS respectively, are p > 0.05 (actual boost above control), p > 0.05, p < 0.05, p < 0.001, p < 0.001 respectively, compared to control. C1-PQS, C3-PQS, C5-PQS, C9-PQS are all less inhibitory than PQS (p < 0.001).