Table 2.

In vitro COX-1/COX-2 inhibition (IC₅₀, μmol/L), selectivity index, ulcerogenic evaluation for compounds 18–21, and standard agents.

Compd.	COX-1a COX-2a		COX-2 selectivityb	Ulcer index
18	4.52	0.42	10.76	1.22
19	6.74	0.62	10.87	3.02
20	4.52	0.52	8.69	2.60
21	7.86	0.86	9.14	2.61
Celecoxib	7.23	0.84	8.61	2.93
Ibuprofen	‒	‒	‒	20.25

^aThe result (IC₅₀, μmol/L) is the mean of three determinations acquired using a COX fluorescent inhibitor screening assay kit (Cayman Chemical, MI, USA).

^bCOX-2 selectivity index (COX-1 IC₅₀/COX-2 IC₅₀).