Table 2.

In vitro anti-inflammatory activities of compounds 19, 21, 26, and 31.

Compound	iNOS (IC50, µM)	NF-κB (IC50, µM)
19 a	26.4 ± 5.3	NA b
21	22.4 ± 2.4	122.3 ± 20.3
26	0.24 ± 0.03	132.1 ± 3.4
31	17.4 ± 1.3	47.0 ± 6.7
Parthenolide	0.72 ± 0.08	3.83 ± 0.60

^a Obtained from a commercial source. ^b Not active at the highest test concentration of 87.9 μM (50 µg/mL).