Synthesis, in vitro antitumour activity, and molecular docking study of novel 2-substituted mercapto-3-(3,4,5-trimethoxybenzyl)-4(3H)-quinazolinone analogues

Figures & data

Figure 1. Structures of erlotinib, gefitinib, reported compounds A–D, and designed quinazoline derivatives E–H as antitumour agents.

Scheme 1. Synthesis of new quinazoline conjugates 1–20.

Table 1. Percentage growth inhibition (GI %) of in vitro subpanel tumour cell lines at 10 µM concentration.

	% Growth Inhibition (GI %)
Subpanel tumour cell lines	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	5-FU
Leukaemia
CCRF-CEM	12	–	–	24	–	17	–	–	–	–	–	–	21	14	23	–	–	65	–	57.1
K-562	27	nt	13	38	–	55	14	21	–	21	nt	–	37	30	29	15	12	92	nt	42.3
MOLT-4	12	17	–	51	–	54	–	32	11	12	–	–	38	51	39	22	–	82	–	43.1
PRMI-8226	30	–	–	42	–	72	–	14	–	–	–	–	33	26	17	13	–	61	–	41.4
SR	17	–	–	44	–	54	–	18	34	12	–	–	39	44	24	37	20	89	–	24.8
Non-small cell lung cancer
A549/ATCC	–	–	–	15	–	36	–	–	38	–	–	–	19	17	15	14	14	65	14	34.2
HOP-62	35	13	–	11	–	46	36	–	58	–	–	16	15	18	16	21	–	71	64	47.8
NCI-H226	26	13	12	37	13	L	–	12	43	34	–	12	18	21	23	27	21	30	21	69.5
HOP-92	–	–	–	24	–	61	–	42	61	–	–	–	36	45	40	41	43	56	39	50.6
NCI-H23	–	–	–	15	11	28	38	–	23	–	–	–	13	–	11	–	–	49	–	39.0
NCI-H322M	–	–	–	–	–	36	–	–	18	–	–	–	28	19	13	11	–	40	–	59.5
NCI-H460	–	–	–		–	83	–	–	43	–	–	–	–	–	–	–	–	87	20	13.0
NCI-H522	29	22	32	49	11	60	27	44	67	30	19	17	51	47	40	32	30	90	62	58.0
Colon cancer
COLO 205	–	–	–	27	–	–	–	–	–	–	–	–	–	–	–	–	–	75	–	40.2
HCC-2998	–	nt	–	–	–	–	–	–	–	–	–	–	–	–	–	–	–	14	21	>100
HCT-116	18	–	–	44	–	65	–	11	42	14	–	–	44	35	31	16	24	84	–	17.8
HCT-15	–	–	–	31	–	28	–	11	–	–	–	–	27	21	24	12	–	83	–	26.5
HT29	–	–	–	41	–	13	–	–	–	–	–	–	13	14	–	–	–	88	–	27.1
KM12	–	–	–	–	–	21	–	–	–	–	–	–	–	–	–	–	–	83	–	40.7
SW-620	–	–	–	12	–	23	–	–	–	–	–	–	–	–	–	–	–	77	–	50.1
CNS cancer
SF-268	–	–	14	–	–	44	13	15	46	–	–	18	23	20	19	12	–	50	18	59.0
SF-295	23	–	–	–	–	38	–		15	–	–		16	12	–	–	–	64	–	69.1
SF-539	13	–	–	–	–	L	–	22	34	–	–	–	14	16	16	–	–	75	42	>100
SNB-19	–	–	–	19	–	37	–		26	16	–	–	21	20	23	18	17	45	33	65.9
SNB-75	22	15	27	34	12	73	52	34	L	27	11	21	26	20	36	34	36	83	77	65.9
U251	–	–	–	–	–	25	–	–	48	–	–	–	12	–	–	–	–	62	14	50.3
Melanoma
LOX IMVI	–	–	–	13	–	44	–	–	–	–	–	–	12	–	–	–	–	56	–	30.4
MALME-3M	–	–	–	–	–	91	–	14	18	12	–	–	17	–	–	17	13	60	13	58.2
M14	–	–	–	14	–	26	–	–	–	–	–	–	14	–	–	11	–	94	–	–
MDA-MB-435	–	–	–	–	–	31	–	–	–	–	–	–	–	–	–	–	–	L	–	36.6
SK-MEL-2	–	–	–	25	–	19	–	–	25	–	–	–	19	19	17	–	–	L	15	95.5
SK-MEL-28	–	–	–	–	–	17	12	–	–	–	–	–	–	–	–	13	–	45	–	–
SK-MEL-5	20	–	–	15	–	51	11	13	–	–	–	–	12	16	18	20	18	88	21	33.7
UACC-257	–	–	–	–	–	27	–	–	–	–	–	–	–	–	–	15	13	41	13	19.5
UACC-62	25	–	–	32	–	37	15	26	16	23	14	–	31	24	32	27	26	64	21	39.7
Ovarian cancer
IGROV1	–	–	–	24	–	59	–	–	28	11	–	–	14	23	23	22	24	49	–	51.2
OVCAR-4	34	–	30	37	–	47	28	18	11	15	–	–	23	15	30	26	23	42	12	59.4
OVCAR-5	–	–	–	–	–	18	–	–	12	–	–	–	–	–	–	–	–	32	–	44.3
OVCAR-8	–	–	15	15	–	38	20	–	20	–	–	13	15	16	14	–	14	52	–	–
NCI/ADR-RES	22	–	–	22	–	49	–	17	–	–	–	–	19	17	14	–	–	83	–	47.6
SK-OV-3	–	–	–	–	–	32	13	–	49	–	–	–	–	–	–	–	–	73	43	77.5
Renal cancer
786-0	–	–	–	–	–	L	–		27	–	–	–	11	–	–	–	–	44	–	48.7
A498	–	–	–	–	18	59	–	13	38	20	12	–	36	37	29	29	–	79	–	>100
ACHN	19	–	13	15	–	82	17	20	67	–	–	–	16	19	15	15	18	52	13	39.3
CAKI-1	25	–	–	22	–	29	–	–	–	–	–	–	29	26	14	11	–	66	–	39.4
RXF 393	–	–	–	–	–	81	22	18	39	–	–	–	23	26	22	26	–	47	34	34.3
SN12C	20	–	12	31	–	29	–	21	18	12	–	–	28	18	25	18	16	50	15	54.0
TK-10	–	–	–	0	–	33	16	–	33	–	–	–	–	–	–	–	–	38	–	66.9
UO-31	41	32	16	48	27	83	20	27	20	25	28	13	52	47	46	49	31	53	17	41.3
Prostate cancer
PC-3	18	–	–	41	13	35	–	15	13	–	–	–	28	25	25	17	19	51	–	58.2
DU-145	–	–	–	–	–	34	–	–	–	–	–	–	–	–	–		–	42	–	35.5
Breast cancer
MCF7	–	–	–	21	–	23	13	–	–	–	–	–	16	–	13	11	18	85	17	11.5
MDA-MB-231/ATCC	25	14	11	36	13	51	14	27	42	19	–	19	36	35	37	37	30	54	35	78.1
HS 578T	–	–	13		–	93	13	–	52	–	–	–	20	14	12	20	–	43	22	>100
BT-549	–	–	–		–	25	–	11	35	–	–	–	19	–	–	12	–	52	30	37.8
T-47D	14	–	15	36	–	55	–	16	23	–	11	–	15	23	32	24	–	91	36	56.7
MDA-MB-468	30	–	–	24	–	53	15	–	28	16	–	12	–	12	15	48	38	99	61	–
MGI%	11	2	4	19	2	47	7	10	24	7	2	1	19	17	16	15	10	65	16
PCE	24/57	7/55	13/57	36/57	8/57	55/57	20/57	26/57	38/57	17/57	6/56	9/57	44/57	37/57	38/57	36/57	23/57	57/57	29/56	55/59

PCE: positive cytotoxic effect; the ratio between the number of cell lines with percentage growth inhibition >10% and total number of cell lines. MGI%: mean growth inhibition percentage; nt = not tested; L= >100%

Table 2. Median growth inhibitory (GI₅₀, μM), total growth inhibitory (TGI, μM), and median lethal (LC₅₀, μM) concentrations of compounds 7 and 19 on in vitro subpanel tumour cell lines.

	Subpanel tumour cell lines
Compd.	Activity	Leukaemia	NSC lung cancer	Colon cancer	CNS cancer	Melanoma	Ovarian cancer	Renal cancer	Prostate cancer	Breast cancer	MG-MID^a
7	GI50	68.28	8.11	30.82	4.33	12.26	8.86	5.76	17.40	5.30	17.90
	TGI	^b	40.56	85.81	15.28	57.06	37.30	30.41	^b	30.46	55.20
	LC50	^b	80.22	89.76	46.10	78.12	80.95	64.80	^b	84.75	80.52
19	GI50	4.57	8.95	5.47	4.62	5.25	8.07	6.62	9.03	4.47	6.33
	TGI	93.44	63.45	73.35	63.85	49.74	56.50	65.06	^b	70.50	70.65
	LC50	^b	96.36	88.55	64.62	^b	92.75	^b	^b	^b	93.58
5-FU	GI50	15.10	^b	8.40	72.10	70.60	61.40	45.60	22.70	76.40	18.60
	TGI	^b	^b	^b	^b	^b	^b	^b	^b	^b	^b
	LC50	^b	^b	^b	^b	^b	^b	^b	^b	^b	^b

^a Full panel mean-graph midpoint (μM).

^b Compounds showed values >100 μM.

Table 3. GI₅₀ values (μM) of compounds 7 and 19 compared with those of erlotinib, gefitinib, and 5-FU on in vitro subpanel tumour cell lines.

Subpanel tumour cell lines			GI50 (μM)
	7	19	Erlotinib	Gefitinib	5-FU
Leukaemia
CCRF-CEM	4.91	>100	15.84	5.01	31.62
HL-60(TB(	3.57	>100	5.01	5.01	19.95
MOLT-4	7.38	>100	5.01	3.98	12.58
RPMI-8226	4.00	22.90	5.01	1.58	5.01
SR	3.01	18.05	6.30	3.16	3.98
Non-small cell lung cancer
A549/ATCC	6.33	4.66	7.94	7.94	1.99
HOP-62	4.36	3.10	12.58	10.00	19.95
HOP-92	5.70	2.26	6.30	7.94	>100
NCI-H226	14.60	4.00	6.30	15.84	>100
NCI-H23	6.87	16.5	19.95	15.84	12.58
NCI-H322M	23.00	19.1	0.05	0.08	19.95
NCI-H460	4.19	10.4	5.01	6.30	1.00
NCI-H522	6.55	4.89	1.00	6.30	39.81
Colon cancer
COLO 205	5.32	73.20	31.62	6.30	nt
HCC-2998	13.00	26.60	79.34	10.00	nt
HCT-116	3.76	4.04	5.01	7.94	nt
HCT-15	2.47	17.00	3.16	5.01	nt
KM12	3.98	32.30	63.09	7.94	nt
SW-620	4.31	31.80	5.01	7.94	nt
CNS cancer
SF-268	7.13	6.62	19.95	7.94	nt
SF-295	4.36	5.55	15.84	1.99	nt
SF-539	2.86	2.29	12.58	10.00	nt
SNB-19	6.00	6.80	3.98	12.58	nt
SNB-75	2.06	1.58	12.58	6.30	nt
U251	5.34	3.14	19.95	10.00	79.43
Melanoma
LOX IMVI	7.05	13.50	5.01	7.94	6.30
M14	2.23	16.50	6.30	5.01	50.11
MDA-MB-435	1.15	22.80	15.84	3.16	10.00
SK-MEL-2	2.82	15.20	12.58	12.58	>100
SK-MEL-28	6.69	11.40	31.62	0.31	50.11
SK-MEL-5	2.85	6.38	15.84	3.98	12.58
UACC-257	16.30	6.04	100	6.30	>100
UACC-62	2.92	6.29	1.25	5.01	12.58
Ovarian cancer
IGROV1	13.20	19.00	0.25	0.20	15.84
OVCAR-3	4.23	7.86	3.16	5.01	25.11
OVCAR-4	10.80	3.01	19.95	7.94	79.43
OVCAR-5	9.38	14.80	19.95	10.00	>100
OVCAR-8	10.00	4.82	7.94	10.00	19.95
NCI/ADR-RES	3.59	8.37	6.30	12.58	39.81
SK-OV-3	5.34	4.20	0.39	0.63	>100
Renal cancer
786-0	5.10	3.37	5.01	7.94	12.58
A498	4.05	2.42	1.58	0.40	10.00
ACHN	8.09	3.15	0.15	0.20	10.00
CAKI-1	5.46	11.30	0.10	0.16	5.01
RXF 393	5.31	2.59	6.30	5.01	50.11
SN12C	8.10	16.90	6.3	6.30	25.11
TK-10	11.00	2.63	0.10	0.10	>100
UO-31	5.90	3.75	1.99	1.25	5.01
Prostate cancer
PC-3	10.80	16.70	50.11	0.79	5.11
DU-145	7.27	18.10	1.58	2.51	50.11
Breast cancer
MCF7	3.46	8.97	100	10.00	1.99
MDA-MB-231/ATCC	5.36	3.08	1.99	12.58	>100
HS 578T	5.24	3.95	6.30	10.00	>100
BT-549	4.90	6.42	39.81	7.94	100
T-47D	5.52	2.16	3.16	6.30	79.43
MDA-MB-468	2.35	7.22	0.20	0.01	31.62

nt: not tested.

Figure 2. Three-dimensional (3D) interactions of erlotinib (upper panel), compounds 19 (middle panel) and 7 (lower panel) with the receptor pocket of EGFR kinase. Hydrogen bonds are shown with a green line.

Table 4. Results of the docking of compounds 7 and 19 into EGFR (pdb: 1m17), in comparison to the co-crystallised ligand (erlotinib).

Ligand no.	No. of HBs^a	Atoms in H-bonding in the ligand	Atoms in H-bonding in protein	Length^b (Å)
7	4	O of 3,4,5-timethoxyphenyl	NH of Lys^721	2.65, 2.82
		O of quinazoline-4-one	HOH^10 linked to Thr^766	2.70
		O of carbonyl anilide	NH of Gly^772	2.74
19	6	O of 3,4,5-timethoxyphenyl	NH of Lys^721	2.70, 2.71
		O of quinazoline-4-one	HOH^10 linked to Thr^766	2.75
		O of carbonyl anilide	NH of Gly^772	2.90
		O of carbonyl anilide	SH of Cys^773	3.26
		Ar-H of quinazoline	O of Pro^770	3.04
Erlotinib	4	N1 of quinazoline	NH of Met^769	2.90
		N3 of quinazoline	HOH^10 linked to Th^r766	2.83
		Ar-H of quinazoline	NH of Leu^768	3.42
		6-ring of anilino group	NH of Lys^721	4.58

^a HBs: hydrogen bonds;

^b Length among acceptor and donner atoms in angstrom (Å).