Average final culture density (n = 3) as measured by optical density (OD) at 600 nm when Ibu-2 was inoculated in liquid MSM culture containing ibuprofen or its analogs [ipf, ibuprofen; paa, phenylacetic acid; 2ppa, 2-phenylpropionic acid; 3taa, 3-tolylacetic acid; 4taa, 4-tolylacetic acid; 2(4t)pa, 2-(4-tolyl)propionic acid]. The error bars represent standard deviations.