concentration of compound 2 (μM)	absorbance at 450 nm		
90	0.29	0.3014	0.3143
60	0.3894	0.3538	0.3529
40	0.3647	0.4028	0.3934
20	0.5427	0.5101	
10	0.5814	0.6423	0.5221
3.33	0.7153	0.7487	0.6506
1.11	0.7733	0.732	
positive control	0.7864	0.8351	0.8938
negative control	0.1454	0.1437	0.1514
