Synthesis and cytotoxic effect of a few N-heteroaryl enamino amides and dihydropyrimidinethiones on AGS and MCF-7 human cancer cell lines

Cytotoxic monastrol derivatives as adjective inhibitors of drug-resistant Eg5: a molecular dynamics perspective

The mitotic kinesin Eg5 is a motor protein involved in the formation of bipolar spindle and cell division. Eg5 is overexpressed in various cancer cells and Eg5 targeting agents are promising candidates for cancer therapy. Subsequent to the discovery of monastrol as a small-molecule Eg5 modulator, numerous inhibitors/modulators have been reported from which a few entered clinical trials. Mutagenic investigations specified declined sensitivity of Eg5 allosteric site to monastrol due to the occurrence of drug-resistant mutations in some cell cultures. Accordingly, identification of tight binders to the mutant Eg5 allosteric site is an invaluable strategy to devise more efficient Eg5 modulators. We have previously synthesized a few dihydropyrimidinethione (DHPMT)-based 5-carboxamide monastrol derivatives (1-5) with higher cytotoxicities against AGS (IC50 9.90-98.48 µM) and MCF-7 (IC50 15.20-149.13 µM) cancer cell lines than monastrol. Within a current study, a structural insight was offered into the binding mechanism of intended derivatives inside the mutant Eg5 loop5/α2/α3 allosteric pocket. Molecular docking of the DHPMT R and S-enantiomers unraveled top-scored Eg5 complexes. Molecular dynamics (MD) simulations were carried out on 5 superior complexes as (R)-2/D130V-Eg5, (R)-4/D130V-Eg5, (R)-5/D130V-Eg5, (R)-5/L214I-Eg5, (R)-5/R119L-Eg5, and the control groups monastrol/D130V-Eg5, monastrol/L214I-Eg5, monastrol/R119L-Eg5. Free energy calculations were conducted through conformational sampling of MD-driven binding trajectories. Our results provided structural details on probable interaction mechanism of the cytotoxic DHPMTs that are difficult to address experimentally. The outputs of the current study propose new monastrol derivatives as probable resistance-overwhelming Eg5 modulators.Communicated by Ramaswamy H. Sarma.

Synthesis and antileishmanial effect of a few cyclic and non-cyclic n-aryl enamino amide derivatives

Background and purpose

The prevalence of leishmaniasis is reported in more than 98 countries and Iran is one of the endemic areas. There is no vaccine for this disease and few effective drugs are available to treat it. Moreover, drug resistance to the disease is increasing. During the past decade, several in vitro and in vivo studies have been performed on dihydropyrimidine derivatives as antileishmanial agents.

Experimental approach

In the present project, a few 6-methyl-4-aryl-N-aryl dihydropyrimidinone/thiones (A7-A11) and N-heteroaryl-3-(para-methoxy benzyl) amino but-enamides (A1-A6) were synthesized, structurally characterized, and finally subjected to in vitro anti-leishmanial effect against Leishmania major promastigotes.

Findings / Results

Results of the study showed that compound A10, 4-(3-chlorophenyl)-6-methyl-N-phenyl- 2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxamide, exhibited superior anti-leishmanial effect with IC50 value of 52.67 µg/mL (more active than standard drug Glucantim® with IC50 71000 ± 390 µg/mL).

Conclusion and implications

It was demonstrated that some dihydropyrimidine thiones were able to inhibit Leishmania major promastigotes. Structure-activity relationship evaluations indicated that more electron-poor rings such as isoxazole afforded higher activity within A1-A6 series and in these derivatives, N-benzothiazole rings reinforced anti-leishmanial activity concerning thiazole. It was also observed that higher anti-parasite activities of A10 and A11 concerning A7-A9 might be related to the incorporation of the sulfur atom into C2 position, replacement of N-thiazole carboxamide by N-phenyl carboxamide on C5 position of dihydropyrimidine ring, and also replacement of para with meta-substituted phenyls within C4 of dihydropyrimidine ring. The results may help unveil new 4-aryl-5-carboxamide dihydropyrimidines as potential anti-leishmanial agents and their further structural modification toward more potent derivatives.

Synthesis and cytotoxicity evaluation of novel cyclic/non-cyclic N-aryl enamino amides against human cancer cell lines

Background and purpose:

Considering the undesirable consequences of prevalent cancer diseases, design and development of potent and selective anticancer chemotherapeutics is a major concern. Several studies have unraveled the potential of dihydropyrimidinone (DHPM) scaffold toward generating anticancer agents.

Experimental approach:

In the present work, a series of new dihydropyrimidinethiones (DHPMTs) along with a few acyclic enamino amides were synthesized and evaluated for their cytotoxic activity against human gastric (AGS), liver (Hep-G2), and breast (MCF-7) cancer cell lines.

Findings/Results:

Among the assessed compounds, one of the DHPMT derivatives (compounds, one of the DHPMT derivatives (compound 5: 4-(3- fluorophenyl)-6-methyl-N-phenyl-2-thioxo-1,2,3,4-ttrahydropyrimidine-5-carboxamide) exhibited superior cytotoxicity in all of the target cell lines (AGS, IC₅₀ 9.9 μM; MCF-7, IC₅₀ 15.2 μM; and Hep-G2, IC₅₀ 40.5 μM). Cytotoxicity assessments showed that non-cyclic enamino amides exhibited weaker activities when compared to cyclic analogues (DHPMs).

Conclusion and implications:

DHPMTs were better cytotoxic agents than non-cyclic enamino amides. Structure activity relationship studies guided us toward the design of DHPMT derivatives with OH and NH groups particularly on meta position of 4-phenyl ring and hydrophobic bulky substituents on carboxamide side chain within the structure. Possible interaction with the hydrophobic site(s) of the cellular target was supposed. The results of this study emphasized the potential role of DHPMTs and their optimized derivatives as privileged medicinal scaffolds to inhibit the growth of gastric, breast, and liver cancer cells.