Table 4. Cross-Resistance Profile of Complexes 5–16, Oxaliplatin, and Doxorubicin^a.

	IC50 (μM) ± S.D.
compound	LoVo	LoVo OXP	RF	LoVo MDR	RF
5 [(PTA)2Cu(L1)][PF6]	2.4 ± 0.3	1.8 ± 0.5	0.8	1.6 ± 0.7	0.7
6 [(PPh3)2Cu(L1)][PF6]	1.4 ± 0.4	1.1 ± 0.3	0.8	1.2 ± 0.4	0.9
7 [(L1)CuCl2]	1.8 ± 0.5	1.7 ± 0.6	0.9	1.0 ± 0.4	0.6
8 [(PTA)2Cu(L3)]PF6	0.9 ± 0.1	0.7 ± 0.2	0.8	0.7 ± 0.3	0.9
9 [(PPh3)2Cu(L3)]PF6	0.20 ± 0.05	0.30 ± 0.04	1.5	0.10 ± 0.03	0.5
10 [(L3)CuCl2]	0.6 ± 0.1	0.7 ± 0.1	1.0	0.8 ± 0.2	1.3
11 [(PTA)2Cu(L2)][PF6]	2.8 ± 0.7	2.2 ± 0.9	0.8	2.5 ± 0.4	0.9
12 [(PPh3)2Cu(L2)][PF6]	2.2 ± 0.4	1.6 ± 0.3	0.7	1.7 ± 0.6	0.8
13 [(L2)CuCl2]	2.8 ± 0.7	2.1 ± 0.6	0.8	2.0 ± 0.5	0.7
14 [(PTA)2Cu(L4)]PF6	0.4 ± 0.1	0.7 ± 0.1	1.8	0.7 ± 0.2	1.0
15 [(PPh3)2Cu(L4)]PF6	0.20 ± 0.02	0.20 ± 0.03	1.0	0.10 ± 0.01	0.5
16 [(L4)CuCl2]	0.8 ± 0.1	0.9 ± 0.3	1.1	1.1 ± 0.3	1.4
oxaliplatin	1.5 ± 0.6	19.6 ± 1.9	13.1
doxorubicin	1.1 ± 0.5			19.4 ± 2.2	17.4

^aCells (5 × 10³ mL^–1) were treated for 72 h with the tested compounds. Cell viability was measured by means of an MTT test. IC₅₀ values were calculated using the 4-PL logistic model (P < 0.05). S.D. = standard deviation. RF = IC₅₀ (resistant cells)/IC₅₀ (wild-type cells).