Design, Synthesis and Bioevaluation of NovelN-Substituted-3,5-Bis(Arylidene)-4-piperidone Derivatives as Cytotoxic and Antitumor Agents with Fluorescent Properties

Discovery of new pyridine heterocyclic hybrids; design, synthesis, dynamic simulations, and in vitro and in vivo breast cancer biological assays

Pyridine is a nitrogen bearing heterocyclic scaffold that shows a wide range of biological activities. The pyridine nucleus has become an interesting target for medicinal chemistry researchers worldwide. Several pyridine derivatives exhibited good anticancer effects against diverse cell lines. Therefore, to explore new anticancer pyridine entities, novel pyridine derivatives were designed and synthesized and evaluated for their anticancer abilities in vitro and in vivo. All of the target compounds were evaluated against three different human cancer cell lines (Huh-7, A549 and MCF-7) via MTT assay. Most of the compounds exhibited significant cytotoxic activities. Compounds 3a, 3b, 5a and 5b showed superior antiproliferative activities to Taxol. Where, compound 3b showed IC₅₀ values of 6.54, 15.54 and 6.13 μM compared to Taxol (6.68, 38.05, 12.32 μM) against Huh-7, A549 and MCF-7, respectively. Also, tubulin polymerization assay was carried out. The most potent compounds 3a, 3b, 5a and 5b could significantly inhibit tubulin polymerization with IC₅₀ values of 15.6, 4.03, 6.06 and 12.61 μM, respectively. Compound 3b exhibited the highest tubulin polymerization inhibitory effect with an IC₅₀ value of 4.03 μM compared to combretastatin (A-4) (1.64 μM). Molecular modeling studies of the designed compounds confirmed that most of the compounds made the essential binding interactions compared to the reference compound which assisted in the prediction of the structure requirements for the detected anticancer activity. Finally, in vivo studies showed that compound 3b could significantly inhibit breast cancer.

Crystal structure of (3E,5E)-1-(4-cyanobenzenesulfonyl)-3,5-bis(3-fluorobenzylidene)piperidin-4-one-dichloromethane (1/1), C27H20Cl2F2N2O3S

C27H20Cl2F2N2O3S, triclinic, P 1 ‾ $P‾{1}$ (no. 2), a = 8.7887(4) Å, b = 11.2517(6) Å, c = 13.7609(7) Å, α = 74.962(4)°, β = 81.084(4)°, γ = 71.259(4)°, V = 1240.68(11) Å3, Z = 2, R gt (F) = 0.0582, wR ref (F 2) = 0.1543, T = 100.0(1) K.

Crystal structure of (3E,5E)-3,5-bis(4-fluorobenzylidene)-1-((4-trifluoromethyl)benzenesulfonyl)piperidin-4-one, C26H18F5NO3S

C26H18F5NO3S, triclinic, P 1 ‾ $P‾{1}$ (no. 2), a = 7.8831(4) Å, b = 11.9591(7) Å, c = 13.3258(7) Å, α = 69.072(5)°, β = 88.556(4)°, γ = 73.730(5)°, V = 1122.48(11) Å3, Z = 2, R gt (F) = 0.0507, wR ref (F 2) = 0.1216, T = 100.0(1) K.

Hydroxyl-substituted double Schiff-base condensed 4-piperidone/cyclohexanones as potential anticancer agents with biological evaluation

Novel hydroxyl-substituted double Schiff-base 4-piperidone/cyclohexanone derivatives, 3a-e, 4a-e, 5a-d, and 6a-c, were synthesized and fully characterized by 1H NMR, IR and elemental analysis. The cytotoxicity against human carcinoma cell lines A549, SGC7901, HePG2, HeLa, K562, THP-1 and non-malignant LO2 cell lines were evaluated. The results showed 4-piperidinone derivatives displayed better cytotoxicity than cyclohexanone derivatives, especially for 3,4,5-trihydroxyphenyl-substituted BAP 5c. The western blot and flow cytometry results proved 5c can effectively promote cell apoptosis through up-regulating Bax protein and down-regulating Bcl-2 protein expression. Molecular docking modes showed that 5c could reasonably bind to the active site of Bcl-2 protein through strong intermolecular hydrogen bonds and significant hydrophobic effect. In vivo, 5c can effectively suppress the growth of HepG2 xenografts without apparent body weight changes. This study indicates that 5c can be a potential anticancer agent for early treatment of liver cancers.

Investigation of the chemical and optical properties of halogen-substituted N-methyl-4-piperidone curcumin analogs by density functional theory calculations

Halogen-substituted N-methyl-4-piperidone curcumin analog compounds were studied for their molecular structure, molecular vibration analysis, natural bond orbital, ultraviolet spectra, molecular reactivity analysis, and nonlinear optical properties. The molecules in interest were the (3E,5E)-3,5-dibenzylidene-1-methylpiperidin-4-one along with its substituted halogen (X = F- or Cl- or Br-) at the ortho, meta and para position in the phenyl ring. The calculated geometrical parameters at B3LYP/6-311++G(d,p) were in good agreement with the available experimental XRD data. Using the frequency calculations, the molecular vibrational modes have been analyzed. Meanwhile, the hyperconjugative stabilization energies have been calculated using NBO analysis to address the donor and acceptor in the hyperconjugation. The calculated UV spectra at TD-CAM-B3LYP/6-311++G(d,p) show strong absorption around 300 to 320 nm which corresponds to the absorption in the UV-A and UV-B region. From molecular electrostatic potential surface, CO moiety is one of the electronegative regions in the compounds where the CX moiety is the other electronegative region of the compounds. Fluoro-substituted compounds are the compounds with the most electronegativity while bromo-substituted compounds are the compounds with the least electronegativity. Calculations of average local ionization energy surfaces have been performed to obtain information related to the local reactivity of the molecules where the phenyl becomes less reactive after the substitution. The calculated first hyperpolarizability is 6 to 17 times larger than urea, the standard nonlinear optic material. These findings imply that all of the molecules considered have potential to be applied as active sunscreen material or nonlinear optic material.

Potential multifunctional agents with anti-hepatoma and anti-inflammation properties by inhibiting NF-кB activation

Inhibition of NF-κB signalling has been demonstrated as a therapeutic option in treating inflammatory diseases and cancers. Herein, we synthesized novel dissymmetric 3,5-bis(arylidene)-4-piperidones (BAPs, 83-102) and characterized fully. MTT and ELISA assay were performed to screen the anti-hepatoma and anti-inflammation properties. 96 showed the most potential bioactivity. 96 could promote HepG2 apoptosis through up-regulating the expression of C-Caspase-3 and Bax, down-regulating the expression of Bcl-2, while markedly inhibit LPS or TNF-α-induced activation of NF-κB through both inhibiting the phosphorylation of IκBα and p65, and preventing the p65 nuclear translocation to exhibit both anti-hepatoma and anti-inflammatory activities. Molecular docking verified that simulated 96 can effectively bond to the active site of Bcl-2 and NF-κB/p65 proteins. 96 inhibited xenografts growth by reducing the expression of TNF-α and Bcl-2 in the tumour tissue. This study suggested that 96 could be developed as a potential multifunctional agent for treatment of inflammatory diseases and cancers.

Crystal structure of (3E,5E)-3,5-bis(4-cyanobenzylidene)-1-((4-fluorophenyl)sulfonyl)piperidin-4-one, C27H18FN3O3S

C27H18FN3O3S, monoclinic, P21/c (no. 14), a = 8.091(6) Å, b = 42.84(3) Å, c = 7.096(6) Å, β = 107.806(10)°, V = 2342(3) Å3, Z = 4, R gt(F) = 0.0616, wR ref(F 2) = 0.1321, T = 173(2) K.

Synthesis, antiproliferative activity and 2D-QSAR study of some 8-alkyl-2,4-bisbenzylidene-3-nortropinones

AIM

Colon cancer is the third leading cause of death worldwide; therefore, there is a need for an effective therapy with lower side effects.

METHODS

A series of 8-alkyl-2,4-bisbenzylidene-3-nortropinones 3 & 14-39 was prepared via Claisen-Schmidt condensation of 8-alkyl-3-nortropinones 11-13 with different aromatic aldehydes. The target compounds were screened for their antiproliferative activity.

RESULTS

Most of the prepared compounds showed promising antiproliferative activity against many of 60 National Cancer Institute cell lines at 10 μM. Furthermore, 8-ethyl-2,4-bis(3,4-dimethoxybenzylidene)-8-nortropin-3-one 29 and its 3,4,5-trimethoxy analog 30 were the most active compounds against HCT116 cell line with IC₅₀ values 0.01 and 0.46 μM, respectively. Using CODESSA-Pro software, a significant 2D-quantitative structure-activity relationship (QSAR) model was obtained.

CONCLUSION

The 8-Alkyl-2,4-bisbenzylidene-8-azabicyclo[3.2.1]octan-3-one represents an interesting core for further structural optimization to obtain more promising hits.

Crystal structure of 4-((E)-((E)-5-(2-fluorobenzylidene)-1-((4-fluorophenyl)sulfonyl)-4-oxopiperidin-3-ylidene)methyl)benzonitrile, C26H18F2N2O3S

C26H18F2N2O3S, monoclinic, P21/c (no. 14), a = 8.412(3) Å, b = 22.056(8) Å, c = 12.125(4) Å, β = 102.316(5)°, V = 2198.0(14) Å3, Z = 4, R gt(F) = 0.0475, wR ref(F 2) = 0.1156, T = 173(2) K.

Novel dissymmetric 3,5-bis(arylidene)-4-piperidones as potential antitumor agents with biological evaluation in vitro and in vivo

Thirty-five novel dissymmetric 3,5-bis(arylidene)-4-piperidone derivatives (BAPs, 6a-h, 7a-h, 8a-g, 9a-g, 10a-e) were synthesized and evaluated the cytotoxicity. BAPs 6d, 7h, 8g, 9g demonstrated the most potentially inhibitory activities against HepG2 and THP-1 but lower cytotoxicity toward LO2. In vitro, 6d, 7h, 8g, 9g can effectively up-regulate BAX expression, down-regulate Bcl-2 expression in HepG2 cell. They could reasonably bind to the active site of Bcl-2 protein proved by molecular docking modes. The most active BAP 6d induced HepG2 cells apoptosis in a dose-dependent manner by flow cytometrey. The cellular uptake of HepG2 cells showed 6d mainly accumulated into the nuclei by confocal laser scanning microscopy (CLSM). In vivo, 6d suppressed the growth of HepG2 xenografts in nude mice and relatively nontoxic to mice. These results suggest that 6d could be therapeutically beneficial as potential therapeutic agent for the early clinical treatment of liver cancers.

Synthesis and fluorescence studies of novel bisarylmethylidene derivatives of 2-methoxy-2-methyl-1,3-dioxan-5-one

The first general procedure is described for the synthesis of novel bisarylmethylidenes of 2-methoxy-2-methyl-1,3-dioxan-5-one 1. Thus, several derivatives of 3 are obtained rapidly in high yields by reacting 1 with different aldehydes in the presence of catalytic quantities of pyrrolidine in EtOH at room temperature. Upon completion of the reactions, products are obtained directly by spontaneous precipitation avoiding time consuming and expensive chromatographic separations. All products were characterized by proton and carbon NMR spectroscopy methods, and in one case, the proposed structure was elucidated by X-ray crystallography, confirming the Z stereochemistry for the olefinic C=C bonds. Due to showing different colours in solid and solution states, products were studied for their photophysical properties as well.

Synthesis, Anticancer Activity and Cytotoxicity of Novel Double Schiff-Base Condensed α,β-Unsaturated Keto Derivatives

Five double Schiff-base condensed α,β-unsaturated keto derivatives, as curcumin analogues, were synthesised in three steps. Cyclohexanone, or N-methyl-4-pyridone, and 3-nitrobenzaldehyde (2 equiv.) were subjected to Claisen-Schmidt condensation under acid conditions to yield tricyclic dinitro compounds which were reduced to the corresponding diamines and then derivatised at their amino groups with 1-aryl(alkyl)-butan-1,3-diones (MeCOCH2COR). Anticancer activities of the five compounds against four human carcinoma cell lines and their cytotoxicities for LO2 cell lines were evaluated by the MTT method. All compounds showed moderate anticancer activity and low cytotoxicity. The single N-methyl-4-piperidinone-derived compound that was synthesised displayed the highest anticancer activity toward THP-1 and the lowest cytotoxicity.

Synthesis, Antiproliferative, and Multidrug Resistance Reversal Activities of Heterocyclic α,β-Unsaturated Carbonyl Compounds

A series of heterocyclic α,β-unsaturated carbonyl compounds (1a-1d, 2a-2d, 3a-3d, 4a-3d, and 5a-5d) with 1,5-diaryl-3-oxo-1,4-pentadienyl pharmacophore were synthesized for the development of anticancer and multidrug resistance reverting agents. The antiproliferative activities were tested against nine human cancer cell lines. Approximately 73% of the IC50 values were below 5 μm, while 35% of these figures were submicromolar, and compounds 3a-3d with 4-trifluoro methyl in the arylidene benzene rings were the most potent, since their IC50 values are between 0.06 and 3.09 μm against all cancer cell lines employed. Meanwhile, their multidrug resistance reversal properties and cellular uptake were further examined. The data displayed that all of these compounds could reverse multidrug resistance, particularly, compounds 3a and 4a demonstrated both potent multidrug resistance reverting properties and strong antiproliferative activities, which can be taken as leading molecules for further research of dual effect agents in tumor chemotherapy.