Table 5. Inhibition Rate of Formation of S-Methyl Derivative 17 After Incubation of 8 With Different Salicylate Derivatives in Rat’s and Monkey’s Blood.

co-incubated compound	concentration [mM]	inhibition percentage in rat’s blood [%]	inhibition percentage in monkey’s blood [%]
sulfasalazine	0.2	8	12
	1.0	42	80
olsalazine	0.05	15	a
	0.5	42	37
5-ASA (mesalamine)	0.2	28	51
	1.0	91	81
N-Ac-5-ASA	0.2	a	45
	1.0	32	94

^aReduction of formation was not relevant. Result presented were obtained with one single incubation in the two different species.