Boraei ATA, Ghabbour HA, Gomaa MS, El Ashry ESH, Barakat A. Synthesis and Anti-Proliferative Assessment of Triazolo-Thiadiazepine and Triazolo-Thiadiazine Scaffolds.
Molecules 2019;
24:molecules24244471. [PMID:
31817609 PMCID:
PMC6943432 DOI:
10.3390/molecules24244471]
[Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 11/29/2019] [Accepted: 12/04/2019] [Indexed: 11/16/2022] Open
Abstract
A series of triazolo-thiadiazepines 4a–k were synthesized with excellent yields using dehydrated PTSA as a catalyst in toluene. Two triazolo-thiadiazines were obtained; 8a was formed directly by reflux in ethanol, whereas, PTSA promoted the formation of 8b. The molecular structure of the formed triazolo-thiadiazepines is identical to the imine-form 4a–k and not the enamine-tautomer 6a–k. The structures of the newly synthesized triazolo-thiadiazepines 4a–k and triazolo-thiadiazines 8a–b were elucidated using NMR (1H, and 13C), 2D NMR, HRMS, and X-ray single crystal. Furthermore, 4a was deduced using X-ray single crystal diffraction analysis. These new thiadiazepine hits represent an optimized series of previously synthesized indole-triazole derivatives for the inhibition of EGFR. The cytotoxicity activity against two cancer cell lines including human liver cancer (HEPG-2) and breast cancer (MCF-7) was promising, with IC50 between 12.9 to 44.6 µg/mL and 14.7 to 48.7 µg/mL for the tested cancer cell lines respectively, compared to doxorubicin (IC50 4.0 µg/mL). Docking studies revealed that the thiadiazepine scaffold presented a suitable anchor, allowing good interaction of the various binding groups with the enzyme binding regions and sub-pockets.
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