Design, synthesis and anticancer activity of some novel thioureido-benzenesulfonamides incorporated biologically active moieties

Synthesis and Biological Importance of 2-(thio)ureabenzothiazoles

The (thio)urea and benzothiazole (BT) derivatives have been shown to have a broad spectrum of biological activities. These groups, when bonded, result in the 2-(thio)ureabenzothizoles (TBT and UBT), which could favor the physicochemical and biological properties. UBTs and TBTs are compounds of great importance in medicinal chemistry. For instance, Frentizole is a UBT derivative used for the treatment of rheumatoid arthritis and systemic lupus erythematosus. The UBTs Bentaluron and Bethabenthiazuron are commercial fungicides used as wood preservatives and herbicides in winter corn crops. On these bases, we prepared this bibliography review, which covers chemical aspects of UBTs and TBTs as potential therapeutic agents as well as their studies on the mechanisms of a variety of pharmacological activities. This work covers synthetic methodologies from 1935 to nowadays, highlighting the most recent approaches to afford UBTs and TBTs with a variety of substituents as illustrated in 42 schemes and 13 figures and concluded with 187 references. In addition, this interesting review is designed on chemical reactions of 2-aminobenzothiazoles (2ABTs) with (thio)phosgenes, iso(thio)cyanates, 1,1′-(thio)carbonyldiimidazoles [(T)CDI]s, (thio)carbamoyl chlorides, and carbon disulfide. This topic will provide information of utility for medicinal chemists dedicated to the design and synthesis of this class of compounds to be tested with respect to their biological activities and be proposed as new pharmacophores.

Investigation of the Mechanisms of Cytotoxic Activity of 1,3-Disubstituted Thiourea Derivatives

Substituted thiourea derivatives possess confirmed cytotoxic activity towards cancer but also normal cells. To develop new selective antitumor agents, a series of 3-(trifluoromethyl)phenylthiourea analogs were synthesized, and their cytotoxicity was evaluated in vitro against the cell line panel. Compounds 1-5, 8, and 9 were highly cytotoxic against human colon (SW480, SW620) and prostate (PC3) cancer cells, and leukemia K-562 cell lines (IC₅₀ ≤ 10 µM), with favorable selectivity over normal HaCaT cells. The derivatives exerted better growth inhibitory profiles towards selected tumor cells than the reference cisplatin. Compounds incorporating 3,4-dichloro- (2) and 4-CF₃-phenyl (8) substituents displayed the highest activity (IC₅₀ from 1.5 to 8.9 µM). The mechanisms of cytotoxic action of the most effective thioureas 1-3, 8, and 9 were studied, including the trypan blue exclusion test of cell viability, interleukin-6, and apoptosis assessments. Compounds reduced all cancerous cell numbers (especially SW480 and SW620) by 20-93%. Derivatives 2 and 8 diminished the viability of SW620 cells by 45-58%. Thioureas 1, 2, and 8 exerted strong pro-apoptotic activity. Compound 2 induced late apoptosis in both colon cancer cell lines (95-99%) and in K-562 cells (73%). All derivatives acted as inhibitors of IL-6 levels in both SW480 and SW620 cells, decreasing its secretion by 23-63%.

Synthesis and biological evaluation of new coumarin derivatives as cytotoxic agents

New coumarin derivatives 9a-f, 10a-e, and 11a-f were synthesized and evaluated for their cytotoxic activity against a human breast cancer cell line (MCF-7). All compounds exhibited good activity in the nanomolar range, using doxorubicin and erlotinib as positive controls. The most active compound 9d with IC₅₀ of 21 nM was tested against the HCT-116, HepG-2, A549, and SGC-7901 cell lines, with IC₅₀ values of 0.021, 0.170, 0.028, and 0.11 µM, respectively. Compound 9d was further investigated for its ability to suppress the expression of epidermal growth factor receptor (EGFR). Compound 9d decreased the concentration of EGFR by 87%, using erlotinib as a positive control. A docking study revealed similar or higher scores than for erlotinib and similar binding poses providing interactions with the hinge region of the tyrosine kinase (TK). Besides the effect on expression, this in silico investigation predicts the possibility of direct binding between the new coumarin derivatives and the EGFR TK. Moreover, computational calculation for ADME properties for the most active compounds 9d, 9e, 10c, and 11c revealed the expected high gastrointestinal tract absorption, moderate water solubility with no central nervous system toxicity, and druglikeness.

Mechanistic investigations on substituted benzene sulphonamides as apoptosis inducing anticancer agents

In an approach to develop potent cytotoxic compounds with targeted action, a systematic methodology was employed to design and initially synthesize parent compounds A1, A8, A13 and A14 followed by synthesis of further analogs of A1 (A2-A7) and A8 (A9-A12) with characterization by IR, NMR, mass and elemental techniques. These compounds were evaluated for their in vitro anti-proliferative activities against DU-145, MCF-7, HCT-15, HT-29 cell lines and apoptosis inducing potential via various mechanistic studies. Compounds A2, A9, A10 exhibited significant cytotoxic activities compared to their parent compounds and standard drug 5-fluorouracil. Compound A2 displayed superior cytotoxicity with IC50 values less than 1 µM in most of the tested cell lines. Further, compound A2 also induced apoptosis in DU-145 cells as exemplified from DAPI staining, Annexin V-FITC assay, ROS generation and mitochondrial membrane alteration studies. The above studies depict the synthesized compound A2 as potent anticancer agent with the ability to induce apoptosis in prostate cancerous cells.

Disubstituted 4-Chloro-3-nitrophenylthiourea Derivatives: Antimicrobial and Cytotoxic Studies

4-Chloro-3-nitrophenylthioureas 1–30 were synthesized and tested for their antimicrobial and cytotoxic activities. Compounds exhibited high to moderate antistaphylococcal activity against both standard and clinical strains (MIC values 2–64 μg/mL). Among them derivatives with electron-donating alkyl substituents at the phenyl ring were the most promising. Moreover, compounds 1–6 and 8–19 were cytotoxic against MT-4 cells and various other cell lines derived from human hematological tumors (CC₅₀ ≤ 10 μM). The influence of derivatives 11, 13 and 25 on viability, mortality and the growth rate of immortalized human keratinocytes (HaCaT) was observed.

Metal-free, base promoted sp2 C-H functionalization in the sulfonamidation of 1,4-naphthoquinones

A novel, metal-free, base promoted sp2 C-H functionalization in the sulfonamidation of 1,4-naphthoquinones via a [3 + 2] cycloaddition reaction using sulfonyl azides under mild reaction conditions is reported. In this straightforward atom- and step-economical protocol, the active alkene moiety of quinone undergoes a thermal azide-alkene [3 + 2] cycloaddition followed by proton abstraction, ring opening and elimination of a nitrogen molecule to form sulfonamidation products in good yield and all the synthesized sulfonamidation derivatives exhibit good absorption and emission characteristics. In addition, the electrochemical properties of both 1,4-naphthoquinone and menadione sulfonamidation derivatives are studied and significant redox potentials are observed. Other important features of this methodology are readily accessible and easy to handle starting materials, milder conditions, reaction with a wide range of substrates and shorter reaction times with good yields.

A comparative study of the metal binding behavior of alanine based bis-thiourea isomers

Two new symmetrical bis-thiourea, 2,2′-[{(terephthaloylbis(azanediyl)bis(carbonothioyl) bis(azanediyl)}dipropanoic acid] (1A) and 3,3′-[{(terephthaloylbis(azanediyl)bis (carbonothioyl)bis(azanediyl)} dipropanoic acid] (1B) were synthesized by the reaction of terephthaloyl chloride with α- and β-alanine in good yields. Their binding properties were investigated with various metal cations using UV–Vis titration experiments. Both isomers exhibited effective binding with Ag⁺, Cu²⁺, Hg²⁺, Pb²⁺, Fe²⁺ and Fe³⁺ cations. However, in the presence of other cations, such as Na⁺, Ni²⁺, Co²⁺, Cd²⁺, Zn²⁺, Mn²⁺, Mg²⁺, Ca²⁺, Sn²⁺, Al³⁺, and anions tetrabutylammonium Cl⁻ and H₂PO₄⁻, no interaction occurred. Both isomers displayed similar trends towards binding with metal cations.

Synthesis, carbonic anhydrase I and II inhibition studies of the 1,3,5-trisubstituted-pyrazolines

4-(3-(4-Substituted-phenyl)-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl) benzenesulfonamides (9-16) were successfully synthesized and their chemical structures were confirmed by ¹H NMR, ¹³C NMR, and HRMS spectra. Carbonic anhydrase I and II inhibitory effects of the compounds were investigated. K_i values of the compounds were in the range of 316.7 ± 9.6-533.1 ± 187.8 nM towards hCA I and 412.5 ± 115.4-624.6 ± 168.2 nM towards hCA II isoenzymes. While K_i values of the reference compound Acetazolamide were 278.8 ± 44.3 nM and 293.4 ± 46.4 nM towards hCA I and hCA II izoenzymes, respectively. Compound 14 with bromine and compound 13 with fluorine substituents can be considered as the leader compounds of the series because of the lowest K_i values in series to make further detailed carbonic anhydrase inhibiton studies.