Synthesis, Anti-Proliferative Activity and SAR studies of Novel 5-(3-Indolyl)-5H-Thiazolo[4,3-b][1,3,4]Thiadiazoles tethered with Steroid Moieties

Abo-Salem, Heba; El-kady, Dina; Abd-Elhalim, Mervat; Soliman, Ahmed; Ebaid, Manal; El-Sawy, Eslam

doi:10.21608/ejchem.2020.38975.2800

Synthesis, Anti-Proliferative Activity and SAR studies of Novel 5-(3-Indolyl)-5H-Thiazolo[4,3-b][1,3,4]Thiadiazoles tethered with Steroid Moieties

Document Type : Original Article

Authors

¹ Chemistry of Natural Compounds Department, National Research Centre, P.O. Box 12622 Dokki, Giza, Egypt

² Hormones Department, National Research Centre (NRC), El-Behoos St. 33, 12622Dokki-Giza, Egypt.

³ Drug Bioassay-Cell Culture Laboratory, Pharmacognosy Department, National Research Center (NRC), El-Behoos St. 33, 12622Dokki-Giza, Egypt

⁴ Chemistry of Natural Compounds Département, National Research Centre (NRC), El-Behoos St. 33, 12622Dokki-Giza, Egypt.

⁵ Chemistry of Natural Compounds Department, National Research Centre, 12611 Dokki, Giza, Egypt

10.21608/ejchem.2020.38975.2800

Abstract

A new series of the fused thiazolo[4,3-b]-1,3,4-thiadiazoles 2a-e have been synthesized via one-pot reaction of N-substituted indole-3-carboxaldehydes 1a-e with thioglycolic acid and thiosemicarbazide under grinding condition. Condensation reaction of 2a-e with acetylated epiandrosterone and progesterone afford the corresponding Schiff's bases 3a-e and 4a,b, respectively. Besides, the chloroacetylation of 2a-e in situ by chloroacetyl chloride yielded the chloroacetamides 5a-e. The reaction of 5a-e with 3-amino-pyrazolopyridine derivative 6 provided the goal 2-[(steroids)-2H-pyrazolo[3,4-b]pyridin-3-ylamino]-5-(indoles)-thiazolo[4,3-b][1,3,4]thiadiazol-2-yl]-acetamides 7a-e. The analytical and spectral data of the entire target compounds 3a-e, 4a,b and 7a-e were compatible with their structures. Compounds 3a-e, 4a,b, and 7a-e were selected to be screened in vitro against different cancer cell lines, namely A-549, HC-T116, MCF-7, and PC3 using MTT assay. The anti-proliferative activity results implied that compounds 3a-e, 4a, and 7e showed excellent growth inhibitory activity toward the human colon cancer cell (HCT-116) with IC50 value ranging from 7.25-38.92 μM/ml in comparison to the reference drug doxorubicin with IC50 of 48.02 μM/ml. Interestingly, compound 3e found to be the most active one towards A-549, HCT-116, and PC3 cancer cell lines with IC50 of 27.05, 12.69, and 24.61µM/ml in comparison with doxorubicin of IC50 39.74, 48.02, and 34.77µM/ml, respectively. In addition, molecular docking studies helped to rationalize the binding interaction of the most active compounds toward human colon cancer cell (HCT-116) 3a-e, 4a and 7a with the anti-apoptotic Bcl-2 and the result revealed that the docking of compounds was more potent compared co-crystalline ligand.

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