Design, Synthesis, Anticancer Evaluation, Enzymatic Assays, and a Molecular Modeling Study of Novel Pyrazole-Indole Hybrids

Ashraf S Hassan; Gaber O Moustafa; Hanem M Awad; Eman S Nossier; Mohamed F Mady

doi:10.1021/acsomega.1c01604

Design, Synthesis, Anticancer Evaluation, Enzymatic Assays, and a Molecular Modeling Study of Novel Pyrazole-Indole Hybrids

ACS Omega. 2021 Apr 29;6(18):12361-12374. doi: 10.1021/acsomega.1c01604. eCollection 2021 May 11.

Authors

Ashraf S Hassan¹, Gaber O Moustafa², Hanem M Awad³, Eman S Nossier⁴, Mohamed F Mady^{5

6}

Affiliations

¹ Organometallic and Organometalloid Chemistry Department, National Research Centre, Dokki, Cairo 12622, Egypt.
² Peptide Chemistry Department, National Research Centre, Dokki, Cairo 12622, Egypt.
³ Department of Tanning Materials and Leather Technology, National Research Centre, Dokki, Cairo 12622, Egypt.
⁴ Department of Pharmaceutical Chemistry, Faculty of Pharmacy (Girls), Al-Azhar University, Cairo 11754, Egypt.
⁵ Department of Chemistry, Bioscience and Environmental Engineering, Faculty of Science and Technology, University of Stavanger, N-4036 Stavanger, Norway.
⁶ Green Chemistry Department, National Research Centre, Dokki, Cairo 12622, Egypt.

Abstract

The molecular hybridization concept has recently emerged as a powerful approach in drug discovery. A series of novel indole derivatives linked to the pyrazole moiety were designed and developed via a molecular hybridization protocol as antitumor agents. The target compounds (5a-j and 7a-e) were prepared by the reaction of 5-aminopyrazoles (1a-e) with N-substituted isatin (4a,b) and 1H-indole-3-carbaldehyde (6), respectively. All products were characterized via several analytical and spectroscopic techniques. Compounds (5a-j and 7a-e) were screened for their cytotoxicity activities in vitro against four human cancer types [human colorectal carcinoma (HCT-116), human breast adenocarcinoma (MCF-7), human liver carcinoma (HepG2), and human lung carcinoma (A549)] using the MTT assay. The obtained results showed that the newly synthesized compounds displayed good-to-excellent antitumor activity. For example, 5-((1H-indol-3-yl)methyleneamino)-N-phenyl-3-(phenylamino)-1H-pyrazole-4-carboxamide (7a) and 5-((1H-indol-3-yl)methyleneamino)-3-(phenylamino)-N-(4-methylphenyl)-1H-pyrazole-4-carboxamide (7b) provided excellent anticancer inhibition performance against the HepG2 cancer cell line with IC₅₀ values of 6.1 ± 1.9 and 7.9 ± 1.9 μM, respectively, compared to the standard reference drug, doxorubicin (IC₅₀ = 24.7 ± 3.2 μM). The two powerful anticancer compounds (7a and 7b) were further subjected to cell cycle analysis and apoptosis investigation in HepG2 using flow cytometry. We have also studied the enzymatic assay of these two compounds against some enzymes, namely, caspase-3, Bcl-2, Bax, and CDK-2. Interestingly, the molecular docking study revealed that compounds 7a and 7b could well embed in the active pocket of the CDK-2 enzyme via different interactions. Overall, the prepared pyrazole-indole hybrids (7a and 7b) can be proposed as strong anticancer candidate drugs against various cancer cell lines.