Design, synthesis, anticancer activity and cytotoxicity of novel 4-piperidone/cyclohexanone derivatives

Diarylpentanoids with antitumor activity: A critical review of structure-activity relationship studies

Diarypentanoids are commonly considered as monocarbonyl analogues of curcumin. Since the discovery of this compound in 1962, twenty one diarylpentanoids have been isolated and almost 600 synthetic analogues with antitumor activity have been synthesized. This review reports the exploitation of diarylpentanoids to develop curcumin analogues with improved antitumor activity over the last two decades. The mechanism of action and structure-activity relationship (SAR) studies are also highlighted. More importantly, structural features for the antitumor activity that may guide the design of new and more effective diarylpentanoids are also proposed.

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.

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.

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.

Synthesis, crystal structures and anti-inflammatory activity of four 3,5-bis(arylidene)-N-benzenesulfonyl-4-piperidone derivatives

3,5-Bis(arylidene)-4-piperidone (BAP) derivatives display good antitumour and anti-inflammatory activities because of their double α,β-unsaturated ketone structural characteristics. If N-benzenesulfonyl substituents are introduced into BAPs, the configuration of the BAPs would change significantly and their anti-inflammatory activities should improve. Four N-benzenesulfonyl BAPs, namely (3E,5E)-1-(4-methylbenzenesulfonyl)-3,5-bis[4-(trifluoromethyl)benzylidene]piperidin-4-one dichloromethane monosolvate, C₂₈H₂₁F₆NO₃S·CH₂Cl₂, (4), (3E,5E)-1-(4-fluorobenzenesulfonyl)-3,5-bis[4-(trifluoromethyl)benzylidene]piperidin-4-one, C₂₇H₁₈F₇NO₃S, (5), (3E,5E)-1-(4-nitrobenzenesulfonyl)-3,5-bis[4-(trifluoromethyl)benzylidene]piperidin-4-one, C₂₇H₁₈F₆N₂O₅S, (6), and (3E,5E)-1-(4-cyanobenzenesulfonyl)-3,5-bis[4-(trifluoromethyl)benzylidene]piperidin-4-one dichloromethane monosolvate, C₂₈H₁₈F₆N₂O₃S·CH₂Cl₂, (7), were prepared by Claisen-Schmidt condensation and N-sulfonylation. They were characterized by NMR, FT-IR and HRMS (high resolution mass spectrometry). Single-crystal structure analysis reveals that the two 4-(trifluoromethyl)phenyl rings on both sides of the piperidone ring in (4)-(7) adopt an E stereochemistry of the olefinic double bonds. Molecules of both (4) and (6) are connected by hydrogen bonds into one-dimensional chains. In (5) and (7), pairs of adjacent molecules embrace through intermolecular hydrogen bonds to form a bimolecular combination, which are further extended into a two-dimensional sheet. The anti-inflammatory activity data reveal that (4)-(7) significantly inhibit LPS-induced interleukin (IL-6) and tumour necrosis factor (TNF-α) secretion. Most importantly, (6) and (7), with strong electron-withdrawing substituents, display more potential inhibitory effects than (4) and (5).

Novel asymmetric 3,5-bis(arylidene)piperidin-4-one derivatives: synthesis, crystal structures and cytotoxicity

3,5-Bis(arylidene)piperidin-4-one derivatives (BAPs) display good antitumour activity because of their double α,β-unsaturated ketone structural characteristics. Reported BAPs have generally been symmetric and asymmetric BAPs have been little documented. Three asymmetric BAPs, namely (5E)-3-(4-tert-butylbenzylidene)-5-(4-fluorobenzylidene)-1-methylpiperidin-4-one, C₂₄H₂₆FNO, (5), (5E)-3-(4-tert-butylbenzylidene)-5-(3,5-dimethoxybenzylidene)-1-methylpiperidin-4-one, C₂₆H₃₁NO₃, (6), and (5E)-3-{3-[(E)-(2,3-dihydroxybenzylidene)amino]benzylidene}-5-(2-fluorobenzylidene)-1-methylpiperidin-4-one, C₂₇H₂₃FN₂O₃, (12), were generated by Claisen-Schmidt condensation. They are characterized by NMR and FT-IR spectroscopies, and elemental analysis. Single-crystal structure analysis reveals that the two arylidene rings on both sides of the BAP structures adopt an E stereochemistry of the olefinic double bonds and the compounds are E,E isomers. Molecules of (5) and (12) generate one-dimensional chains through intermolecular hydrogen bonds, while compound (6) generates a two-dimensional network through hydrogen bonds. Preliminary cytotoxicities toward human liver hepatocellular carcinoma cell line (HepG2), human acute mononuclear granulocyte leukaemia (THP-1) and human normal hepatical cell line (LO2) were evaluated.

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.