Table 2. IC₅₀ Values of NBD-Aa-Triterpene Conjugates 1–12 on Three Cancer Cell Lines.

compound	B16-F10a	HT-29a	HepG2a
OA	106.4 ± 3.7	429.9 ± 0.7	211.8 ± 0.5
MA	36.2 ± 2.5	32.2 ± 3.8	99.2 ± 5.5
BO	52.2 ± 0.9	67.1 ± 3.2	38.7 ± 1.7
BM	19.0 ± 0.2	15.3 ± 0.5	17.0 ± 0.0
1	2.4 ± 0.1	19.5 ± 0.1	12.5 ± 0.1
2	4.9 ± 0.4	6.6 ± 0.1	13.9 ± 0.6
3	76.6 ± 3.7	63.3 ± 2.4	74.3 ± 0.7
4	96.4 ± 0.9	120.7 ± 4.0	91.2 ± 2.3
5	136.8 ± 2.0	105.4 ± 1.2	95.7 ± 3.4
6	39.5 ± 0.8	45.2 ± 0.9	98.5 ± 0.8
7	74.2 ± 2.2	95.9 ± 2.2	71.6 ± 1.7
8	96.8 ± 1.8	122.8 ± 1.7	95.3 ± 0.7
9	101.1 ± 0.9	113.0 ± 4.4	84.5 ± 0.4
10	107.7 ± 0.4	109.8 ± 5.2	122.8 ± 0.9
11	92.3 ± 1.5	100.9 ± 1.1	82.7 ± 2.5
12	80.8 ± 0.9	108.3 ± 3.8	80.9 ± 1.1

^aThe IC₅₀ values (μM) were calculated by considering untreated control cells as 100% viability. Cell viability was analyzed using the MTT assay, as described in the Experimental Section.