Design and Synthesis of Novel Derivatives of 4-(6-(4-Substituted Phenyl)-7H-[1,2,4] Triazolo[3,4-b][1,3,4]Thiadiazin-3- yl) Phenol as a Potent Inhibitor of Tubulin with Antitumor Activity

Kubba, Ammar A. Razzak Mahmood (Department of Pharmaceutical Chemistry, College of Pharmacy-University of Baghdad, Bab-Al-Mouadam-10001, Baghdad)
Shihab, Wurood Ahmed (Department of Pharmaceutical Chemistry-College of Pharmacy/University of Ashur, Al-waziriya, Baghdad/Iraq)
Al-Shawi, Nada Naji (Department of Pharmacology and Toxicology, College of Pharmacy-University of Baghdad, Bab-Al-Mouadam-10001, Baghdad/Iraq)
Jabir, Majid Shamki (Division of Biotechnology/ Department of Applied Science/University of Technology, Baghdad/Iraq)

INDONESIAN JOURNAL OF PHARMACY
Vol 31 No 2, 2020

A new series of 4-(6-(4-substituted phenyl)-7H[1,2,4] triazolo[3,4b][1,3,4]thiadiazin-3-yl) phenol was synthesized and explored for anti-tubulin activity  using in silico and in vitro assay models. The starting nucleus, ethyl-4-hydroxybenzoate was treated with hydrazine hydrated, and converted to 4-hydroxybenzohydrazide (1). Then, (1) was stirred with CS2 and KOH in dry EtOH  to afford 2-(4-. hydroxyl benzoyl)hydrazine-1-carbodithioate, as a potassium salt (2). Compound (2) was used directly and refluxed with hydrazine hydrate to yield a parent nucleus, 4-(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)phenol (3). The target compounds (4-7), were synthesized by refluxing compound (3) with various substituted phenacyl bromides  using  sodium acetate as  a abase, The new compounds (3-7) were characterized using different spectroscopic analysis  techniques including IR, and 1HNMR.  The anticipated  modes  of binding to α- tubulin were also investigated by means of a molecular docking experiment. The binding mode revealed good agreement with the in vitro work with binding energies of (-38.77 and  -37.50 kcal/ mol) for the most potent compounds 7 and 4, respectively. The effect of synthetic novel compounds on cancer cell lines proliferation was screened  by MTT assay. The ability of the synthetic compounds to induce apoptosis process was tested using acridine orange/ ethidium  bromide staining. The synthetic novel compounds exhibited potent inhibitory effects on the growth and viability of cancer cell lines SKOV-3 and AMJ-13 cells. They inhibited  the proliferation and growth  of cancer cell lines at low concentrations, with IC50 values ranging from10.44 to 19.67 µg/mL against SKOV-3 cells, and for AMJ-13 cells,  the IC50 values were11.35 to 20.52 µg/mL. The effect of  the synthetic compounds on  the cell growth, and proliferation of cancer cell lines was associated with increased apoptosis.Our results demonstrated that the target compounds inhibited cancer cell lines proliferation, with a mechanism of action parallel to that of other tubulin inhibitors