The natural product pseudopyronine B (2) and the
methyl ether of pseudopyronine A (12) exhibited activity
against the InhA enzyme with IC50 values of 3.8 and 2.9 mg/
mL, respectively. There was no apparent correlation, however,
between the ability to inhibit the InhA enzyme and whole organism
(M. tuberculosis) activity for most of the remaining
synthetic compounds.