2-Amino-1,3,4-thiadiazole derivative (FABT) inhibits the extracellular signal-regulated kinase pathway and induces cell cycle arrest in human non-small lung carcinoma cells

Synthesis, molecular docking, and molecular dynamic simulation studies of new 1,3,4-thiadiazole derivatives as potential apoptosis inducers in A549 lung cancer cell line

1,3,4-Thiadiazoles are structures that are bioisosteres of 1,3,4-oxadiazole and pyrimidine ring, which are found in the structure of many drugs and anticancer active newly studied derivatives. In the past, high effect profiles have been observed in many molecules created, based on the anticancer effects of the 2-amino-1,3,4-thiadiazole (NSC 4728) molecule and acetazolamide molecules. Focusing on these molecules and evaluating them in terms of mechanistic effects, twelve new N-[5-((3,5-dichlorophenoxy) methyl]-1,3,4-thiadiazole derivatives (3a-3i) were synthesized and their biological activities were investigated in lung cancer cells. The anticancer effects of the compounds were evaluated on the A549 and L929 cell lines. Compound 3f, namely 2-[(5-chlorobenzotiyazol-2-yl)thio]-N-[5-[(3,5-dichlorophenoxy)methyl]-1,3,4-thiadiazol-2-yl]acetamide, showed better activity than cisplatin, exhibiting high inhibitory potency (IC50: <0.98 μg/mL) and selectivity against A549 cell line even at the lowest concentration tested. Compounds 3c, 3f, and 3h with the lowest IC50 values of the compounds exhibited an excellent percentage of apoptosis between 72.48 and 91.95% compared to cisplatin. The caspase-3 activation and mitochondrial membrane potential change of the aforementioned three compounds were also studied. Moreover, matrix metalloproteinase-9 (MMP-9) inhibition potential of all final compounds was also investigated and IC50 values for compounds 3b and 3g were identified as 154.23 and 107.28 µM. Molecular docking and molecular dynamic simulation studies for MMP-9 enzyme inhibition were realized on these compounds and the nitrogen atoms of amide and thiadiazole moieties' ascertained that they play a key role in chelating with Zn metal, at the same time, (thio)ether moieties allow conformational change resulting in the ligand can make more stable contacts.Communicated by Ramaswamy H. Sarma.

Synthesis, Anticancer Activity, and In Silico Studies of 5-(3-Bromophenyl)-N-aryl-4H-1,2,4-triazol-3-amine Analogs

In the current study, we described the synthesis of ten new 5-(3-Bromophenyl)-N-aryl-4H-1,2,4-triazol-3-amine analogs (4a-j), as well as their characterization, anticancer activity, molecular docking studies, ADME, and toxicity prediction. The title compounds (4a-j) were prepared in three steps, starting from substituted anilines in a satisfactory yield, followed by their characterization via spectroscopic techniques. The National Cancer Institute (NCI US) protocol was followed to test the compounds' (4a-j) anticancer activity against nine panels of 58 cancer cell lines at a concentration of 10-5 M, and growth percent (GP) as well as percent growth inhibition (PGI) were calculated. Some of the compounds demonstrated significant anticancer activity against a few cancer cell lines. The CNS cancer cell line SNB-75, which showed a PGI of 41.25 percent, was discovered to be the most sensitive cancer cell line to the tested compound 4e. The mean GP of compound 4i was found to be the most promising among the series of compounds. The five cancer cell lines that were found to be the most susceptible to compound 4i were SNB-75, UO-31, CCRF-CEM, EKVX, and OVCAR-5; these five cell lines showed PGIs of 38.94, 30.14, 26.92, 26.61, and 23.12 percent, respectively, at 10-5 M. The inhibition of tubulin is one of the primary molecular targets of many anticancer agents; hence, the compounds (4a-j) were further subjected to molecular docking studies looking at the tubulin-combretastatin A-4 binding site (PDB ID: 5LYJ) of tubulin. The binding affinities were found to be efficient, ranging from -6.502 to -8.341 kcal/mol, with two major electrostatic interactions observed: H-bond and halogen bond. Ligand 4i had a binding affinity of -8.149 kcal/mol with the tubulin-combretastatin A-4 binding site and displayed a H-bond interaction with the residue Asn258. The ADME and toxicity prediction studies for each compound were carried out using SwissADME and ProTox-II software. None of the compounds' ADME predictions showed that they violated Lipinski's rule of five. All of the compounds were also predicted to have LD50 values between 440 and 500 mg/kg, putting them all in class IV toxicity, according to the toxicity prediction. The current discovery could potentially open up the opportunity for further developments in cancer.

Synthesis and Anticancer Evaluation of 4-Chloro-2-((5-aryl-1,3,4-oxadiazol-2-yl)amino)phenol Analogues: An Insight into Experimental and Theoretical Studies

We report herein the synthesis, docking studies and biological evaluation of a series of new 4-chloro-2-((5-aryl-1,3,4-oxadiazol-2-yl)amino)phenol analogues (6a-h). The new compounds were designed based on the oxadiazole-linked aryl core of tubulin inhibitors of IMC-038525 and IMC-094332, prepared in five steps and further characterized via spectral analyses. The anticancer activity of the compounds was assessed against several cancer cell lines belonging to nine different panels as per National Cancer Institute (NCI US) protocol. 4-Chloro-2-((5-(3,4,5-trimethoxyphenyl)-1,3,4-oxadiazol-2-yl)amino)phenol (6h) demonstrated significant anticancer activity against SNB-19 (PGI = 65.12), NCI-H460 (PGI = 55.61), and SNB-75 (PGI = 54.68) at 10 µM. The compounds were subjected to molecular docking studies against the active site of the tubulin-combretastatin A4 complex (PDB ID: 5LYJ); they displayed efficient binding and ligand 4h (with docking score = -8.030 kcal/mol) lay within the hydrophobic cavity surrounded by important residues Leu252, Ala250, Leu248, Leu242, Cys241, Val238, Ile318, Ala317, and Ala316. Furthermore, the antibacterial activity of some of the compounds was found to be promising. 4-Chloro-2-((5-(4-nitrophenyl)-1,3,4-oxadiazol-2-yl)amino)phenol (6c) displayed the most promising antibacterial activity against both Gram-negative as well as Gram-positive bacteria with MICs of 8 µg/mL and a zone of inhibition ranging from 17.0 ± 0.40 to 17.0 ± 0.15 mm at 200 µg/mL; however, the standard drug ciprofloxacin exhibited antibacterial activity with MIC values of 4 µg/mL.

Design, Synthesis, ADME, and Anticancer Studies of Newer N-Aryl-5-(3,4,5-Trifluorophenyl)-1,3,4-Oxadiazol-2-Amines: An Insight into Experimental and Theoretical Investigations

In continuance of our investigation into the anticancer activity of oxadiazoles, we report here the preparation of 10 new 1,3,4-oxadiazole analogues using the scaffold hopping technique. We have prepared the oxadiazoles having a common pharmacophoric structure (oxadiazole linked aryl nucleus) as seen in the reported anticancer agents IMC-038525 (tubulin inhibitor), IMC-094332 (tubulin inhibitor), and FATB (isosteric replacement of the S of thiadiazole with the O of oxadiazole). All of the oxadiazole analogues were predicted for their absorption, distribution, metabolism, and excretion (ADME) profiles and toxicity studies. All of the compounds were found to follow Lipinski's rule of 5 with a safe toxicity profile (Class IV compound) against immunotoxicity, mutagenicity, and toxicity. All of the compounds were synthesized and characterized using spectral data, followed by their anticancer activity tested in a single-dose assay at 10 μM as reported by the National Cancer Institute (NCI US) Protocol against nearly 59 cancer cell lines obtained from nine panels, including non-small-cell lung, ovarian, breast, central nervous system (CNS), colon, leukemia, prostate, and cancer melanoma. N-(2,4-Dimethylphenyl)-5-(3,4,5-trifluorophenyl)-1,3,4-oxadiazol-2-amine (6h) displayed significant anticancer activity against SNB-19, OVCAR-8, and NCI-H40 with percent growth inhibitions (PGIs) of 86.61, 85.26, and 75.99 and moderate anticancer activity against HOP-92, SNB-75, ACHN, NCI/ADR-RES, 786-O, A549/ATCC, HCT-116, MDA-MB-231, and SF-295 with PGIs of 67.55, 65.46, 59.09, 59.02, 57.88, 56.88, 56.53, 56.4, and 51.88, respectively. The compound 6h also registered better anticancer activity than Imatinib against CNS, ovarian, renal, breast, prostate, and melanoma cancers with average PGIs of 56.18, 40.41, 36.36, 27.61, 22.61, and 10.33, respectively. Molecular docking against tubulin, one of the appealing cancer targets, demonstrated an efficient binding within the binding site of combretastatin A4. The ligand 6h (docking score = -8.144 kcal/mol) interacted π-cationically with the residue Lys352 (with the oxadiazole ring). Furthermore, molecular dynamic (MD) simulation studies in complex with the tubulin-combretastatin A4 protein and ligand 6h were performed to examine the dynamic stability and conformational behavior.

Synthesis and Anticancer Activity of Thiadiazole Containing Thiourea, Benzothiazole and Imidazo[2,1-b][1,3,4]thiadiazole Scaffolds

BACKGROUND

A great array of nitrogen-containing heterocyclic rings were being extensively explored for their functional versatility in the field of medicine, especially in anticancer research. 1,3,4- thiadiazole is one of such heterocyclic rings with promising anticancer activity against several cancer cell lines, inhibiting diverse biological targets.

INTRODUCTION

The 1,3,4-thiadiazole, when equipped with other heterocyclic scaffolds, has displayed enhanced anticancer properties. The thiourea, benzothiazole, imidazo[2,1,b][1,3,4]-thiadiazoles are such potential scaffolds with promising anticancer activity.

METHODS

A new series of 5-substituted-1,3,4-thiadiazoles linked with phenyl thiourea, benzothiazole and 2,6-disubstituted imidazo[2,1-b][1,3,4]thiadiazole derivatives were synthesized and tested for invitro anticancer activity on various cancer cell lines.

RESULTS

The National Cancer Institute's preliminary anticancer screening results showed compounds 4b and 5b having potent antileukemic activity. Compound 4b selectively showed 32 percent lethality on Human Leukemia-60 cell line. The docking studies of the derivatives on aromatase enzyme (Protein Data Bank: 3S7S) have shown reversible interactions at the active site with good docking scores comparable to Letrozole and Exemestane. Furthermore, the selected derivatives were tested for anticancer activity on HeLa cell line based on the molecular docking studies.

CONCLUSION

Compounds 4b and 5b showed effective inhibition equivalent to Letrozole. These preliminary biological screening studies have given positive anticancer activity for these new classes of derivatives. An additional research study like the mechanism of action of the anticancer activity of this new class of compounds is necessary. These groundwork studies illuminate a future pathway for research of this class of compounds enabling the discovery of potent antitumor agents.

Design, synthesis and biological evaluation of novel 1,3,4-thiadiazole derivatives as anti-glioblastoma agents targeting the AKT pathway

In spite of progress in understanding biology of glioblastoma (GBM), this tumor remains incurable with a median survival rate of 15 months. Previous studies have shown that 2-(4-fluorophenyloamino)-5-(2,4-dihydroxyphenyl)-1,3,4-thiadiazole (FPDT) and 2-(3-chlorophenyloamino)-5-(2,4-dihydroxyphenyl)-1,3,4-thiadiazole (CPDT) diminished viability of cancer cell lines of different origin. In the current study, we have examined activity of these compounds in several GBM cell lines and patient-derived GBM cells. We have also designed, synthesized and evaluated anti-GBM activity of novel 1,3,4-thiadiazole derivatives containing additional Cl or CH₂CH₃ substitute at C5-position of 2,4-dihydroxyphenyl. The tested compounds presented a considerable cytotoxicity against all GBM cell lines examined as well as patient-derived GBM cells. They were 15-110 times more potent than temozolomide, the first-line chemotherapeutic agent for GBM. Notably, in anticancer concentrations three of the derivatives were not toxic to human astrocytes. FPDT appeared to be the most promising compound with IC₅₀ values between 45 μM and 68 μM for GBM cells and >100 μM for astrocytes. It augmented activity of temozolomide and inhibited proliferation migration and invasion of GBM cells. Treatment with FPDT diminished phosphorylation level of GSK3β and AKT. Pretreatment with PDGF-BB, an AKT activator, partially protected cells from death caused by FPDT, indicating that FPDT-mediated decrease in cell viability is causatively related to the inhibition of the AKT pathway.

Cytotoxic Properties of 1,3,4-Thiadiazole Derivatives-A Review

During recent years, small molecules containing five-member heterocyclic moieties have become the subject of considerable growing interest for designing new antitumor agents. One of them is 1,3,4-thiadiazole. This study is an attempt to collect the 1,3,4-thiadiazole and its derivatives, which can be considered as potential anticancer agents, reported in the literature in the last ten years.

ESIPT-Related Origin of Dual Fluorescence in the Selected Model 1,3,4-Thiadiazole Derivatives

In our previous work, we discussed the emergence of the dual fluorescence phenomenon in selected compounds from the group of 1,3,4-thiadiazoles. The results obtained in a number of experimental studies, supported by [TD]DFT calculations, clearly indicated that the phenomenon of dual fluorescence stemmed from an overlap of several factors, including the correct conformation of the analyzed molecule and, very significantly in this context, aggregation effects. Where those two conditions were met, we could observe the phenomenon of intermolecular charge transfer (CT) and the emergence of electronic states responsible for long wave emissions. However, in light of the new studies presented in this paper, we were able, for the first time, to provide a specific theory for the effect of dual fluorescence observed in the analyzed group of 1,3,4-thiadiazoles. We present the results of spectroscopic measurements conducted for two selected analogues from the 1,3,4-thiadiazole group, both in polar and non-polar solvents, which clearly evidence (as we have already suspected in the past, albeit have not shown in publications to date) the possibility of processes related to emission from the tautomer formed in the process of excited state intramolecular proton transfer, which is responsible for the long-wavelength emissions observed in the selected analogues. The presented results obtained with the use of UV-Vis, fluorescence (stationary and time-resolved), FTIR, and Raman spectroscopy, as well as from calculations of dipole moment changes between the ground and excited state with the use of two derivatives with different structures of the resorcylic system, corroborated our standing hypothesis. At the same time, they excluded the presence of ground state keto forms of the analyzed analogues unless necessitated by the structure of the molecule itself. In this case, aggregation factors enhance the observed effects related to the dual fluorescence of the analyzed compounds (by way of AIE-aggregated induced emissions).

Thiadiazole derivatives as anticancer agents

In spite of substantial progress made toward understanding cancer pathogenesis, this disease remains one of the leading causes of mortality. Thus, there is an urgent need to develop novel, more effective anticancer therapeutics. Thiadiazole ring is a versatile scaffold widely studied in medicinal chemistry. Mesoionic character of this ring allows thiadiazole-containing compounds to cross cellular membrane and interact strongly with biological targets. Consequently, these compounds exert a broad spectrum of biological activities. This review presents the current state of knowledge on thiadiazole derivatives that demonstrate in vitro and/or in vivo efficacy across the cancer models with an emphasis on targets of action. The influence of the substituent on the compounds' activity is depicted. Furthermore, the results from clinical trials assessing thiadiazole-containing drugs in cancer patients are summarized.

The origin of the longer wavelength emission in 2-(4-fluorophenylamino)-5-(2,4-dihydroxybenzeno)-1,3,4-thiadiazole and its analogue 2-phenylamino-5-(2-hydroxybenzono)-1,3,4-thiadiazole† ‡

In aqueous solution, 2-(4-fluorophenylamino)-5-(2,4-dihydroxybenzeno)-1,3,4-thiadiazole (FABT) was found to emit dual emission and the longer wavelength emission was assigned to the combination of aggregation and conformational change. In a number of molecules that possess an intramolecular hydrogen bond between the proton donor and the acceptor, the longer wavelength emission is often observed due to the emission from the tautomer formed by excited state intramolecular proton transfer (ESIPT). Therefore, an analogue of FABT, 2-phenylamino-5-(2-hydroxybenzono)-1,3,4-thiadiazole (PHBT), was synthesized to determine the origin of the longer wavelength emission. The luminescence of PHBT and its methoxy derivatives was studied and compared with that of FABT. Theoretical calculations were also performed on both FABT and PHBT. Based on the experimental and theoretical investigations, the nonexistence of the keto tautomer in the ground state and the origin of the longer wavelength emission are divulged.

Lemon Juice as a Biocatalyst Under Ultrasound Irradiation: Synthesis and Pharmacological Evaluation of 2-amino 1,3,4-thiadiazoles

BACKGROUND

The 2-amino 1,3,4-thiadiazole framework has attracted considerable interest because of its prevalence in compounds possessing a wide range of pharmacological properties including anticancer/antitumor activities. Though a number of methods have been reported for the synthesis of this class of compounds, some of them are not straightforward, inexpensive and environmentally friendly.

OBJECTIVE

To synthesize 2-amino-1,3,4-thiadiazole derivatives that could act as potential anticancer agents.

METHODS

The use of lemon juice as an inexpensive and readily available biocatalyst was explored in the synthesis of 2-amino 1,3,4-thiadiazole derivatives. Accordingly, a convenient method has been developed for the rapid synthesis of this class of compounds under a mild and non-hazardous reaction condition in good yields. The methodology involved the reaction of various acid hydrazides with TMSNCS in the presence of lemon juice in PEG-400 at room temperature (25-30ºC) under ultrasound irradiation. These compounds were assessed for their cytotoxic properties against two different metastatic breast cancer cell lines e.g., MDAMB-231 and MCF-7 and subsequently against SIRT1.

RESULTS

The 2-amino 1,3,4-thiadiazole derivatives 3a, 3i, 3j and 3l showed promising growth inhibition of MDAMB- 231 and MCF-7 cell lines and SIRT1 inhibition in vitro. Indeed, 3i was found to be a potent inhibitor of SIRT1.

CONCLUSION

An ultrasound-assisted method facilitated by lemon juice has been developed to synthesize 2-amino- 1,3,4-thiadiazole derivatives that could act as potential anticancer agents.

Synergistic antifungal interactions of amphotericin B with 4-(5-methyl-1,3,4-thiadiazole-2-yl) benzene-1,3-diol

Amphotericin B (AmB) is a very potent antifungal drug with very rare resistance among clinical isolates. Treatment with the AmB formulations available currently is associated with severe side effects. A promising strategy to minimize the toxicity of AmB is reducing its dose by combination therapy with other antifungals, showing synergistic interactions. Therefore, substances that display synergistic interactions with AmB are still being searched for. Screening tests carried out on several dozen of synthetic 1,3,4-thiadiazole derivatives allowed selection of a compound called 4-(5-methyl-1,3,4-thiadiazole-2-yl) benzene-1,3-diol (abbreviated as C1), which shows strong synergistic interaction with AmB and low toxicity towards human cells. The aim of the present study was to investigate the type of in vitro antifungal interactions of the C1 compound with AmB against fungal clinical isolates differing in susceptibility. The results presented in the present paper indicate that the C1 derivative shows strong synergistic interaction with AmB, which allows the use of a dozen to several dozen times lower AmB concentration necessary for 100% inhibition of the growth of pathogenic fungi in vitro. Synergistic interactions were noted for all tested strains, including strains with reduced sensitivity to AmB and azole-resistant isolates. These observations give hope for the possibility of application of the AmB - C1 combinatory therapy in the treatment of fungal infections.

Synthesis and Anticancer Activity of New ((Furan-2-yl)-1,3,4-thiadiazolyl)-1,3,4-oxadiazole Acyclic Sugar Derivatives

New sugar hydrazones incorporating furan and/or 1,3,4-thiadiazole ring systems were synthesized by reaction of the corresponding hydrazide with different aldose sugars. Heterocyclization of the formed hydrazones afforded the derived acyclic nucleoside analogues possessing the 1,3,4-oxadiazoline as modified nucleobase via acetylation followed by the heterocyclization process. The anticancer activity of the synthesized compounds was studied against human liver carcinoma cell (HepG-2) and at human normal retina pigmented epithelium cells (RPE-1). High activities were revealed by compounds 3, 12 and 14 with IC₅₀ values near to that of the reference drug doxorubicin.

Synthesis and Evaluation of a Series of 1,3,4-Thiadiazole Derivatives as Potential Anticancer Agents

BACKGROUND AND METHODS

In an attempt to develop potent antitumor agents, the synthesis of a series of N-(6-substituted benzothiazol-2-yl)-2-[(5-(arylamino)-1,3,4-thiadiazol-2-yl)thio]acetamides (1-14) was described and their cytotoxic effects on A549 human lung adenocarcinoma, MCF-7 human breast adenocarcinoma, HepG2 human hepatocellular carcinoma and NIH/3T3 mouse embryonic fibroblast cell lines were investigated using MTT assay.

RESULTS

Phenyl-substituted compounds (8-14) were found to be more effective than naphthyl-substituted compounds (1-7) on cancer cells. Compounds 8, 9, 10, 12, 13 and 14 were identified as the most potent anticancer agents on MCF-7 and HepG2 cell lines and therefore their effects on DNA synthesis and apoptosis/necrosis in MCF-7 cell line were evaluated. Among these compounds, N-(6-methoxybenzothiazol-2-yl)-2-[(5- (phenylamino)-1,3,4-thiadiazol-2-yl)thio]acetamide (13) was the most selective anticancer agent against MCF-7 and HepG2 cell lines with a SI value of 100. On the other hand, compounds 8, 9, 10, 12, 13 and 14 inhibited DNA synthesis in MCF-7 cell line in a dose-dependent manner. Flow cytometric analyses clearly indicated that the compounds showed significant anticancer activity against MCF-7 cell line via the induction of apoptosis dose dependently.

CONCLUSION

According to in vitro assays, compounds 8, 9, 10, 12, 13 and 14 stand out as promising candidates for further studies.

Utility of 5-(furan-2-yl)-3-(p-tolyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide in the synthesis of heterocyclic compounds with antimicrobial activity

Background

Pyrazolines show different biological activities. In recent years, interest in the chemistry of hydrazonoyl halides has been renewed. 1,3,4-Thiadiazoles are one of the most common heterocyclic pharmacophores with a wide range of biological activities.

Results

Ethyl 2-(5-(furan-2-yl)-3-(p-tolyl)-4,5-dihydro-1H-pyrazol-1-yl)-4-methyl-thiazole-5-carboxylate, 2-(5-(furan-2-yl)-3-(p-tolyl)-4,5-dihydro-1H-pyrazol-1-yl)thiazol-4(5H)-one, and 1-(2-(5-(furan-2-yl)-3-(p-tolyl)-4,5-dihydro-1H-pyrazol-1-yl)-4-methylthiazol-5-yl)ethan-1-one were synthesized from the reaction of 5-(furan-2-yl)-3-(p-tolyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide with different halogenated compounds. Thiazole, 1,3,4-thiadiazole and pyrano[2,3-d]thiazole derivatives were also synthesized. The structures of the newly synthesized compounds were elucidated based on elemental analysis, spectral data, and alternative synthetic routes whenever possible. Additionally, the newly synthesized compounds were screened for antimicrobial activity against various microorganisms.

Conclusions

A new series of novel functionalized 1,3,4-thiadiazoles, 1,3-thiazoles, and pyrazoline-containing moieties were synthesized using hydrazonoyl halides as precursors and evaluated for their in vitro antibacterial, and antifungal activities. The antimicrobial results of the examined compounds revealed promising results and some derivatives have activities similar to the references used.

Electronic supplementary material

The online version of this article (10.1186/s13065-019-0566-y) contains supplementary material, which is available to authorized users.

Comprehensive Study on Thiadiazole-Based Anticancer Agents Inducing Cell Cycle Arrest and Apoptosis/Necrosis Through Suppression of Akt Activity in Lung Adenocarcinoma and Glioma Cells

Objectives

Akt is considered as an attractive target for anticancer drug discovery and development and therefore extensive efforts have been devoted to the discovery of new potent anticancer agents targeting Akt.

Materials and Methods

Due to the importance of thiadiazoles for anticancer drug discovery, herein eight 1,3,4-thiadiazole derivatives were investigated for their cytotoxic effects on C6 rat glioma and A549 human lung adenocarcinoma cell lines using the MTT assay. The effects of the most promising anticancer agents on apoptosis, caspase-3 activation, mitochondrial membrane potential, and cell cycle arrest were determined on a BD FACSAria (I) flow cytometer. Akt activity was measured in the C6 and A549 cell lines using an ELISA colorimetric method. Schrödinger's Maestro molecular modeling package was used to explore the possible binding modes of compounds 3 and 8 in the active site of Akt enzyme (PDB code: 3OW4).

Results

N-(4-Chlorophenyl)-2-[(5-((4-nitrophenyl)amino)-1,3,4-thiadiazol-2-yl)thio]acetamide (3) and N-(6-nitrobenzothiazol-2-yl)-2-[(5-((4- nitrophenyl)amino)-1,3,4-thiadiazol-2-yl)thio]acetamide (8) induced apoptosis and cell cycle arrest in the C6 cell line through inhibition of Akt activity (92.36% and 86.52%, respectively). The docking results of compounds 3 and 8 indicated that π-π interactions, H bonds, and salt-bridge formation were responsible for the observed Akt inhibitory activity.

Conclusion

According to in vitro and docking studies, compounds 3 and 8 stand out as promising antiglioma agents.

5-(Thiophen-2-yl)-1,3,4-thiadiazole derivatives: synthesis, molecular docking and in vitro cytotoxicity evaluation as potential anticancer agents

Background

Nowadays, cancer is an important public health problem in all countries. Limitations of current chemotherapy for neoplastic diseases such as severe adverse reactions and tumor resistance to the chemotherapeutic drugs have been led to a temptation for focusing on the discovery and development of new compounds with potential anticancer activity. The importance of thiophene and thiadiazole rings as scaffolds present in a wide range of therapeutic agents has been well reported and has driven the synthesis of a large number of novel antitumor agents.

Methods

A series of new 1,3,4-thiadiazoles were synthesized by heterocyclization of N-(4-nitrophenyl)thiophene-2-carbohydrazonoyl chloride with a variety of hydrazine-carbodithioate derivatives. The mechanisms of these reactions were discussed and the structure of the new products was elucidated via spectral data and elemental analysis. All the new synthesized compounds were investigated for in vitro activities against human hepatocellular carcinoma (HepG-2) and human lung cancer (A-549) cell lines compared with cisplatin standard anticancer drug. Moreover, molecular docking using MOE 2014.09 software was also carried out for the high potent compound 20b with the binding site of dihydrofolate reductase (DHFR, PDB ID (3NU0)).

Results

The results showed that compound 20b has promising activities against HepG-2 and A-549 cell lines (IC50 value of 4.37±0.7 and 8.03±0.5 μM, respectively) and the results of molecular docking supported the biological activity with total binding energy equals −1.6 E (Kcal/mol).

Conclusion

Overall, we synthesized a new series of 1,3,4-thiadiazoles as potential antitumor agents against HepG-2 and A-549 cell lines.

Design, Synthesis, and Biological Evaluation of Novel 1,3,4-Thiadiazole Derivatives as Potential Antitumor Agents against Chronic Myelogenous Leukemia: Striking Effect of Nitrothiazole Moiety

In an attempt to develop potent antitumor agents, new 1,3,4-thiadiazole derivatives were synthesized and evaluated for their cytotoxic effects on multiple human cancer cell lines, including the K562 chronic myelogenous leukemia cell line that expresses the Bcr-Abl tyrosine kinase. N-(5-Nitrothiazol-2-yl)-2-((5-((4-(trifluoromethyl)phenyl)amino)-1,3,4-thiadiazol-2-yl)thio)acetamide (2) inhibited the Abl protein kinase with an IC₅₀ value of 7.4 µM and showed selective activity against the Bcr-Abl positive K562 cell line. Furthermore, a Bcr-Abl-compound 2 molecular modelling simulation highlighted the anchoring role of the nitrothiazole moiety in bonding and hydrophobic interaction with the key amino acid residues. These results provide promising starting points for further development of novel kinase inhibitors.

Synthesis and Evaluation of New Oxadiazole, Thiadiazole, and Triazole Derivatives as Potential Anticancer Agents Targeting MMP-9

Matrix metalloproteinases (MMPs) are important proteases involved in tumor progression including angiogenesis, tissue invasion, and migration. Therefore, MMPs have been reported as potential diagnostic and prognostic biomarkers in many types of cancer. New oxadiazole, thiadiazole, and triazole derivatives were synthesized and evaluated for their anticancer effects on A549 human lung adenocarcinoma and C6 rat glioma cell lines. In order to examine the relationship between their anticancer activity and MMP-9, the compounds were evaluated for their inhibitory effects on MMPs. N-(1,3-Benzodioxol-5-ylmethyl)-2-{[5-(((5,6,7,8-tetrahydronaphthalen-2-yl)oxy)methyl)-1,3,4-oxadiazol-2-yl]thio}acetamide (8) and N-(1,3-benzodioxol-5-ylmethyl)-2-[(5-phenyl-1,3,4-oxadiazol-2-yl)thio]acetamide (9) revealed promising cytotoxic effects on A549 and C6 cell lines similar to cisplatin without causing any toxicity towards NIH/3T3 mouse embryonic fibroblast cell line. Compounds 8 and 9 were also the most effective MMP-9 inhibitors in this series. Moreover, docking studies pointed out that compounds 8 and 9 had good affinity to the active site of the MMP-9 enzyme. The molecular docking and in vitro studies suggest that the MMP-9 inhibitory effects of compounds 8 and 9 may play an important role in lung adenocarcinoma and glioma treatment.

Synthesis and Antimicrobial Activity of Some New Thiadiazoles, Thioamides, 5-Arylazothiazoles and Pyrimido[4,5-d][1,2,4]triazolo[4,3-a]pyrimidines

A novel series of 1,3,4-thiadiazoles, 5-arylazothiazoles and hexahydropyrimido-[4,5-d][1,2,4]triazolo[4,3-a]pyrimidines were synthesized via reaction of hydrazonoyl halides with each of alkyl carbothioates, carbothioamides and 7-thioxo-5,6,7,8-tetrahydropyrimido-[4,5-d]pyrimidine-2,4(1H,3H)-diones in the presence of triethylamine. The structures of the newly synthesized compounds were established based on their spectral data, elemental analyses and alternative synthetic routes whenever possible. Also, the newly synthesized compounds were screened for their antimicrobial activity against various microorganisms.

Synthesis and antiproliferative activity of some N'-substituted 2,4-dihydroxybenzothiohydrazides

The paper shows that new N'-substituted 2,4-dihydroxybenzocarbothiohydrazides are able to inhibit the in vitro proliferation of human tumor cell lines. The compounds were prepared by the reaction of sulfinylbis[(2,4-dihydroxyphenyl)methanethione] (STB) or its analogs with the hydrazines. The panel of N'-substitution included aryl, pyridinyl and pyrimidinyl rings. The highest antiproliferative activity for N'-(4-(4-chlorophenyl)-6-(trifluoromethyl)pyrimidin-2-yl)-5-ethyl-2,4-dihydroxybenzothiohydrazide (5b) was found. The antiproliferative potency of some compounds was similar to that of cisplatin. Analogs with the Et substituent on benzenediol moiety displayed higher potency than with the unsubstituted one. The influence of N'-substitution on antiproliferative activity of compounds was discussed.

New derivative of 2-(2,4-dihydroxyphenyl)thieno-1,3-thiazin-4-one (BChTT) elicits antiproliferative effect via p38-mediated cell cycle arrest in cancer cells

2-(2,4-Dihydroxyphenyl)thieno-1,3-thiazin-4-ones are a group of new compounds with potential anticancer activity. This type of derivatives was poorly investigated in the area of synthesis and biological activities. In the present study the antiproliferative action of the most active derivative BChTT was described. The aim of biological evaluation was to investigate the ability of the compound to inhibit cancer cell proliferation and identify mechanism involved in its action on the molecular level. BChTT inhibited the proliferation of lung cancer A549, colon cancer HT-29 and glioma C6 cells in the concentration-dependent manner. It was not toxic to normal cells including skin fibroblasts, hepatocytes and oligodendrocytes in the antiproliferative concentrations. BChTT decreased the DNA synthesis in the treated cancer cells and induced cell cycle arrest in the G0/G1 phase. Moreover, the ability of the compound to activate p38 kinase and decrease cyclin D1 expression was estimated. Participation of p38 kinase in the antiproliferative action of the compound was confirmed by the analysis of BChTT activity in the cells with the p38 silenced gene. The obtained results may suggest the ability of the tested derivative to inhibit cancer cells proliferation by induction of p38-mediated cyclin D1 downregulation.