Design, synthesis, and docking studies of quinazoline analogues bearing aryl semicarbazone scaffolds as potent EGFR inhibitors

Article abstract of DOI:10.1016/j.bmc.2017.04.001

Two series of quinazoline derivatives bearing aryl semicarbazone scaffolds (9a–o and 10a–o) were designed, synthesized and evaluated for the IC₅₀ values against four cancer cell lines (A549, HepG2, MCF-7 and PC-3). The selected compound 9o was further evaluated for the inhibitory activity against EGFR kinases. Four of the compounds showed excellent cytotoxicity activity and selectivity with the IC₅₀ values in single-digit μM to nanomole range. Two of them are equal to more active than positive control afatinib against one or more cell lines. The most promising compound 9o showed the best activity against A549, HepG2, MCF-7 and PC-3 cancer cell lines and EGFR kinase, with the IC₅₀ values of 1.32?±?0.38?μM, 0.07?±?0.01?μM, 0.91?±?0.29?μM and 4.89?±?0.69?μM, which were equal to more active than afatinib (1.40?±?0.83?μM, 1.33?±?1.28?μM, 2.63?±?1.06?μM and 3.96?±?0.59?μM), respectively. Activity of the most promising compound 9o (IC₅₀ 56?nM) against EGFR kinase was slightly lower to the positive compound afatinib (IC₅₀ 1.6?nM) but more active than reference staurosporine (IC₅₀ 238?nM). The result of flow cytometry, with the dose of compound 9o increasing, which indicated the compound 9o could induce remarkable apoptosis of A549 and cells in a dose dependent manner. Structure–activity relationships (SARs) and docking studies indicated that replacement of the cinnamamide group by aryl semicarbazone scaffolds slightly decreased the anti-tumor activity. The results suggested that hydroxy substitution at C-4 had a significant impact on the activity and replacement of the tetrahydrofuran group by methyl moiety was not beneficial for the activity.

Full text of DOI:10.1016/j.bmc.2017.04.001

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Accepted Manuscript
Design, synthesis, and docking studies of quinazoline analogues bearing aryl
semicarbazone scaffolds as potent EGFR inhibitors
Yuanbiao Tu, Caolin Wang, Shan Xu, Zhou Lan, Wei Li, Jiaqian Han,
Yuanzhang Zhou, Pengwu Zheng, Wufu Zhu
PII:
S0968-0896(17)30148-7
DOI:
http://dx.doi.org/10.1016/j.bmc.2017.04.001
BMC 13668
Reference:
Bioorganic & Medicinal Chemistry
To appear in:
Received Date:
Revised Date:
Accepted Date:
23 January 2017
9 March 2017
1 April 2017
Please cite this article as: Tu, Y., Wang, C., Xu, S., Lan, Z., Li, W., Han, J., Zhou, Y., Zheng, P., Zhu, W., Design,
synthesis, and docking studies of quinazoline analogues bearing aryl semicarbazone scaffolds as potent EGFR
inhibitors, Bioorganic & Medicinal Chemistry (2017), doi: http://dx.doi.org/10.1016/j.bmc.2017.04.001
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Design, synthesis, and docking studies of quinazoline analogues bearing aryl semicarbazone scaffolds as potent
EGFR inhibitors
Yuanbiao Tu1,†, Caolin Wang1,†, Shan Xu1∗, Zhou Lan1, Wei Li2, Jiaqian Han,Yuanzhang Zhou1, Pengwu Zheng1, Wufu
Zhu1*
1 School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang 330013, P. R. China.
2Key Laboratory of Jiangxi Province Natural Active Pharmaceutical Ingredients, College of Chemistry and Biology En
gineering, Yichun University, Yichun 336000, China
*Correspondence author.
Tel/Fax: +86 791 8380-2393;
E-mail address: zhuwf@jxstnu.edu.cn, zhuwufu-1122@163.com (W. Zhu), shanxu9891@126.com (S. Xu).
Two series of quinazoline derivatives bearing aryl semicarbazone scaffolds (9a–o and 10a–o) were designed,
synthesized and evaluated for the IC50 values against four cancer cell lines (A549, HepG2, MCF-7 and PC-3). The
selected compound 9o was further evaluated for the inhibitory activity against EGFR kinases. Four of the compounds
showed excellent cytotoxicity activity and selectivity with the IC50 values in single-digit ꢀM to nanomole range. Two of
them are equal to more active than positive control afatinib against one or more cell lines. The most promising
compound 9o showed the best activity against A549, HepG2, MCF-7 and PC-3 cancer cell lines and EGFR kinase, with
the IC50 values of 1.32 0.38 ꢀM, 0.07 0.01 ꢀM, 0.91 0.29 ꢀM and 4.89 0.69 ꢀM, which were equal to more
active than afatinib (1.40 0.83 ꢀM, 1.33 1.28 ꢀM, 2.63 1.06 ꢀM and 3.96 0.59 ꢀM), respectively. Activity of the
most promising compound 9o (IC50 56 nM) against EGFR kinase was slightly lower to the positive compound afatinib
(IC50 1.6 nM) but more active than reference staurosporine (IC50 238 nM). The result of flow cytometry, with the dose
of compound 9o increasing, which indicated the compound 9o could induce remarkable apoptosis of A549 and cells in a
dose dependent manner. Structure–activity relationships (SARs) and docking studies indicated that replacement of the
cinnamamide group by aryl semicarbazone scaffolds slightly decreased the anti-tumor activity. The results suggested
that hydroxy substitution at C-4 had a significant impact on the activity and replacement of the tetrahydrofuran group
by methyl moiety was not beneficial for the activity.
Key words: Quinazoline ; aryl semicarbazone scaffolds; Synthesis; Docking; anti-tumor activity
† These authors contribute equally to this work
∗
Corresponding author. Tel./fax: +86 791 83802393.
E-mail address:zhuwf@jxstnu.edu.cn, zhuwufu-1122@163.com (W. Zhu), shanxu9891@126.com (S. Xu).
1

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1 Introduction
EGFR, distributed in epithelial cells, fibroblasts, glial cells, keratinocytes and other surfaces of cell of
mammals, is a vital tyrosine kinase receptor of the epidermal growth factor receptor family which plays a critical
role in vital cellular processes and in various cancers, including proliferation, differentiation, migration, apoptosis,
and angiogenesis[1]. Overexpression of EGFR has been reported in different tumors[2]. Therefore, developing
potent EGFR inhibitors is one of the research hotspots for the treatment of human cancer[3].
In recent years, many quinazoline derivatives with excellent anti-tumor activity have been reported, such as
afatinib (BIBW-2992)[4-6], gefinitib[7-8], LP-7[9], 1[10] and 2[11] (The structures of them are shown in Fig.1). Among
them, afatinib, which is a powerful, irreversible tyrosine kinase inhibitor of EGFR, with IC50 value (half-maximal
inhibitory concentration) of 0.5 nM, exhibits potent anti-tumor activity against non small-cell lung cancer
(NSCLC), and was approved by the FDA for the treatment of patients with metastatic NSCLC in 2013[12]
.
In this study, we devoted to synthesize two series of novel potent anti-tumor inhibitors bearing a common
aryl semicarbazone scaffolds. In our previous work, Compound 1 showed the best activity against EGFR
kinase[10], with the IC50 value of 3.6 nM while it showed unsatisfactory results in vivo and solubility in our later
work. It was reported that compound 2 is a excellent anti-tumor inhibitor which possessed remarkable cytotoxicity
and high selectivity due to bearing semicarbazone moiety with 2-hydroxy-3-allylphenyl group[11]. Inspired by 1
and 2, We decided to keep quinazoline skeleton as a privileged scaffold and introduc aryl semicarbazone scaffolds
to hope provided more nitrogen atoms combined with the receptor to see if α, β-unsaturated amide part is
necessary for activity against EGFR kinase. In addition, aryl semicarbazone scaffolds can provide more nitrogen
to improve solubility. Therefore, we synthesized the first series compounds (9a-o). Moreover, inspired by gefitinib,
the small molecule tetrahydrofuran was substituted with methyl group to obtain the second series compounds
(10a-o). Furthermore, various substituents were introduced with the purpose of exploring the influence of
substituents and screening compounds after improved pharmacokinetic on anti-tumor activity by regulating the
electronic or steric effect at the aryl ring. As a result, two novel quinazoline derivatives bearing aryl
semicarbazone scaffolds with different substituents at aryl ring (9a-o and 10a-o) were designed and synthesized.
The structures of target compounds are shown in Fig.1. The design strategy for all target compounds is shown in
Figure 2.
2

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Herein we disclose the design, synthesis and anti-tumor activity against A549 (human lung cancer), HepG2
(human liver cancer), MCF-7 (human breast cancer) and PC-3 (human prostate cancer) cancer cell lines, EGFR
kinases of novel quinazoline analogues. Moreover, docking studies was presented in this paper as well.
Fig. 1. Structures of EGFR inhibitors based on the quinazoline scaffold, 2 and the designed compounds
Fig. 2. Structures and design strategy for target compounds 9a-o and 10a-o.
2. Chemistry
The structures and preparation of target compounds 9a–o and 10a–o are described in Scheme 1. The key
intermediates 6a and 6b were synthesized from commercially available 2-amino-4-fluorobenzoic acid through six
steps which was reported in our previously research[10]. 6a, 6b were further treated with phenyl chloroformate in
1,4-dioxane in the presence of DIPEA to give the corresponding intermediates7a and 7b. In the following step, 7a,
3