Structure-based drug design and biological evaluation of 2-acetamidobenzothiazole derivative as EGFR kinase inhibitor

Figures & data

Scheme 1. Reaction conditions and reagents: (i) chloroacetyl chloride, CCl₄, 12 h, 61%; (ii) hydrazine hydrate, C₂H₅OH, reflux, 14h, 58%; (iii) diethyl ethoxymethylenemalonate, anhydrous K₂CO₃, CH₃CN, reflux, 12h, 45%.

Table 1. Percentages of enzymatic inhibition exerted by compound 4 on 11 human protein and lipid kinases.

% Kinase inhibition
	Tyrosine kinases contain SH2 Domain		Tyrosine kinases contain SH2 and SH3 Domains				Other human protein or lipid kinases
Compounds	TYK2	LCK	JAK3	ABL-1	BTK	LYN	Cyclin D1	MEK1	mTOR	AKT1	EGFR
4	9.2	43.3	9.1	11.7	8.1	18.7	23.7	15.7	54.3	25.0	94.4
Staurosporine	99.6	99.5	99.8	99.5	99.7	99.8	100.1	99.7	nt	99.3	97.8
LY294002	nt	nt	nt	nt	nt	nt	nt	nt	81.3	nt	nt

Bold underlined value represents the best result. % Activity in each enzyme is the mean of two different readings. Test compound was used in a single dose concentration of 100 µM. Reference compounds were used in a single dose concentration of 20 µM. % Inhibition was calculated after subtraction of the activity of DMSO. nt, Indicates compound not tested against enzyme.

Table 2. GI₅₀ values (µM) of compound 4 and erlotinib over cell lines of non-small lung cancer, colon cancer and breast cancer subpanels.

	GI50
Subpanel tumor cell lines	Compound 4	Erlotinib
Non-small lung cancer
A549/ATCC	1.31	10
HOP-62	0.353	15.8
HOP-92	0.196	3.98
NCI-H226	1.43	39.8
NCI-H23	1.09	31.6
NCI-H460	1.72	6.3
NCI-H522^a	0.0573	1.00
Colon cancer
COLO 205	1.53	50.1
HCC-2998	2.11	79.4
HCT-116	1.38	6.31
HCT-15	1.44	3.98
HT29	0.353	63.10
SW-620	1.69	79.4
Breast cancer
MCF-7	1.36	100
MDA-MB-231	0.317	6.31
HS 578T	1.71	6.31
BT-549	1.27	31.6
MDA-MB-468	0.56	0.126
T-47D	1.32	3.98

The cell lines overexpressing EGFR in each tumor subpanel and their GI₅₀ values are bold and underlined.

Figure 1. 2D Interaction of compound 4 with the binding site of EGFR-TK. Dashed lines represent hydrogen bonds. Hydrophobic interactions are shown by green solid lines.

Figure 2. Kinase profile assay of compound 4 against different human protein and lipid kinases.

Figure 3. % Inhibition expressed by compound 4 at a single-dose concentration of 10 µM over the selected cancer cell lines.