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

Treatment of rheumatoid arthritis with curcumin analog 3,5-bis(arylidene)-4-piperidone

Rheumatoid arthritis (RA) is an inflammatory disease. Curcumin can inhibit NF-κB and reduce the expression of inflammation-related genes. Aim: To evaluate the potential development of 6d in the clinical treatment of inflammatory diseases such as RA. Methods: Using a skeleton fusion strategy to synthesize curcumin analogues for 6d. This work evaluates anti-inflammatory activity by conducting anti-arthritis experiments (adjuvant-induced RA models) on rats. Western blot and ELISA were used to detect the expression of inflammatory-related proteins and cytokines. Molecular docking analysis confirmed the binding effect of 6d with active sites. Conclusion: 6d inhibits NF-κB has a protective effect on arthritis caused by RA.

Tumor killing by a dietary curcumin mono-carbonyl analog that works as a selective ROS generator via TrxR inhibition

In comparison with normal cells, cancer cells feature intrinsic oxidative stress, thereby being more vulnerable to further production of reactive oxygen species (ROS) by pro-oxidative anticancer agents (PAAs). However, PAAs also inevitably generate ROS in normal cells, resulting in their narrow therapeutic window and toxic side effects that greatly limit their clinical application. To develop PAAs that generate ROS selectively in cancer cells over in normal cells, we rationally designed three series of 21 dietary curcumin 5-carbon mono-carbonyl analogs differentiated by either placement of the cyclohexanone, piperidone, and methylpiperidone linkers, or introduction of electron-withdrawing trifluoromethyl and electron-donating methoxyl groups on its two aromatic rings in the ortho, meta, or para position to the linkers. From the designed molecules, 2c, characterized of the presence of the meta-CF₃-substituted mode and the piperidone linker, was identified as a potent selective ROS-generating agent, allowing its ability to kill selectively human non-small cell lung cancer NCI-H460 (IC₅₀ = 0.44 μM) over human normal lung MRC-5 cells with a selectivity index of 32.0. Additionally, it was more potent and selective than the conventional chemotherapeutic agents (5-fluorouracil and camptothecin) did. Mechanistical investigation reveals that by means of its Michael acceptor unit and structure characteristics as described above, 2c could covalently modify the Sec-498 residue of intracellular thioredoxin reductase (TrxR) to generate ROS selectively, resulting in ROS-dependent apoptosis and ferroptosis of NCI-H460 cells. Noticeably, 2c inhibited significantly the growth of NCI-H460 cell xenograft tumor in nude mice without obvious toxicity to liver and kidney. Together, this work highlights a practical strategy of targeting TrxR overexpressed in cancer cells to develop PAAs capable of generating ROS selectively, as evidenced by the example of 2c.

Anti-inflammatory activity of fluorine-substituted benzo[h]quinazoline-2-amine derivatives as NF-κB inhibitors

Excessive inflammation can cause loss of tissue or organ function, leading to a number of chronic diseases and sometimes even death. Traditional treatment strategies for inflammation have mainly involved steroidal and non-steroidal anti-inflammatory drugs, but both have increasingly prominent side effects. Nuclear factor kappa B (NF-κB) inhibitors with anti-inflammatory properties and low toxicity are a new therapeutic strategy for the treatment of inflammatory diseases. To obtain novel NF-κB inhibitors, a series of 3,4-dihydronaphthalen-1(2H)-one derivatives (DHNs 6a-s), 1,4,5,6-tetrahydrobenzo[h]quinazolin-2-amine derivatives (BQAs 7a-c) and 5,6-dihydrobenzo[h]quinazolin-2-amine derivatives (BQAs 8a-p) were designed and synthesized, and characterized by NMR and HRMS. By evaluating toxicity and anti-inflammatory properties, fluorine-substituted 8c showed more potential anti-inflammatory activity and lower toxicity. 8c significantly reduced the phosphorylation of IκBα and p65, thereby inhibiting the NF-κB signaling pathway. In addition, 8c markedly decreased reactive oxygen species (ROS) production and downregulated the expression of NOD-like receptor pyrin domain-containing protein 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC) and cysteine aspartate protein hydrolase-1 (caspase-1). Therefore, compound 8c is expected to be a candidate compound for NF-κB inhibition and deserves further research and development.

Novel Unsymmetric 3,5-Bis(benzylidene)-4-piperidones That Display Tumor-Selective Toxicity

Two series of novel unsymmetrical 3,5-bis(benzylidene)-4 piperidones 2a-f and 3a-e were designed as candidate antineoplastic agents. These compounds display potent cytotoxicity towards two colon cancers, as well as several oral squamous cell carcinomas. These compounds are less toxic to various non-malignant cells giving rise to large selectivity index (SI) figures. Many of the compounds are also cytotoxic towards CEM lymphoma and HL-60 leukemia cells. Representative compounds induced apoptotic cell death characterized by caspase-3 activation and subG1 accumulation in some OSCC cells, as well as the depolarization of the mitochondrial membrane potential in CEM cells. A further line of inquiry was directed to finding if the SI values are correlated with the atomic charges on the olefinic carbon atoms. The potential of these compounds as antineoplastic agents was enhanced by an ADME (absorption, distribution, metabolism, and excretion) evaluation of five lead molecules, which revealed no violations.

Cytotoxic Tumour-Selective 1,5-Diaryl-3-Oxo-1,4-Pentadienes Mounted on a Piperidine Ring

A series of 3,5-bis(benzylidene)-4-piperidones 2a–u were prepared as candidate cytotoxic agents. In general, the compounds are highly toxic to human gingival carcinoma (Ca9-22), human squamous carcinoma-2 (HSC-2) and human squamous carcinoma-4 (HSC-4) neoplasms, but less so towards non-malignant human gingival fibroblast (HGF), human periodontal ligament fibroblast (HPLF) and human pulp cells (HPC), thereby demonstrating tumour-selective toxicity. A further study revealed that most of the compounds in series 2 were more toxic to the human Colo-205 adenocarcinoma cell line (Colo-205), human HT29 colorectal adenocarcinoma cells (HT-29) and human CEM lymphoid cells (CEM) neoplasms than towards non-malignant human foreskin Hs27 fibroblast line (Hs27) cells. The potency of the cytotoxins towards the six malignant cell lines increased as the sigma and sigma star values of the aryl substituents rose. Attempts to condense various aryl aldehydes with 2,2,6,6-tetramethyl-4-piperidone led to the isolation of some 1,5-diaryl-1,4-pentadien-3-ones. The highest specificity for oral cancer cells was displayed by 2e and 2r. In the case of 2r, its selective toxicity exceeded that of doxorubicin and melphalan. The enones 2k, m, o have the highest SI values towards colon cancer and leukemic cells. Both 2e,r inhibited mitosis and increased the subG1 population (with a transient increase in G2/M phase cells). Slight activation of caspase-3, based on the cleavage of poly(ADP-ribose)polymerase (PARP) and procaspase 3, was detected.

Design, Synthesis and Tumour-Selective Toxicity of Novel 1-[3-{3,5-Bis(benzylidene)-4-oxo-1-piperidino}-3-oxopropyl]-4-piperidone Oximes and Related Quaternary Ammonium Salts

A novel series of 1-[3-{3,5-bis(benzylidene)-4-oxo-1-piperidino}-3-oxopropyl]-4-piperidone oximes 3a-h and related quaternary ammonium salts 4a-h were prepared as candidate antineoplastic agents. Evaluation against neoplastic Ca9-22, HSC-2 and HSC-4 cells revealed the compounds in series 3 and 4 to be potent cytotoxins with submicromolar CC50 values in virtually all cases. In contrast, the compounds were less cytocidal towards HGF, HPLF and HPC non-malignant cells revealing their tumour-selective toxicity. Quantitative structure-activity relationships revealed that, in general, both cytotoxic potency and selectivity index figures increased as the magnitude of the Hammett sigma values rose. In addition, 3a-h are cytotoxic towards a number of leukemic and colon cancer cells. 4b,c lowered the mitochondrial membrane potential in CEM cells, and 4d induced transient G2/M accumulation in Ca9-22 cells. Five compounds, namely 3c,d and 4c-e, were identified as lead molecules that have drug-like properties.

Crystal structure of (E)-7-fluoro-2-(3-fluorobenzylidene)-3,4-dihydronaphthalen-1(2H)-one, C17H12F2O1

C17H12F2O1, monoclinic, P 1 ‾ $P\overline{1}$ (no. 2), a = 7.3832(8) Å, b = 8.6467(9) Å, c = 11.3278(11) Å, α = 87.633(8)°, β = 88.022(8)°, γ = 65.364(10)°, V = 654.88(13) Å3, Z = 2, R gt (F) = 0.0369, wR ref (F 2) = 0.0987, T = 293(2) K.

Crystal structure of (E)-7-methoxy-2-((2-methoxypyridin-3-yl)methylene)-3,4-dihydronaphthalen-1 (2H)-one, C18H17NO3

C18H17NO3, triclinic, P 1 ‾ $P\overline{1}$ (no. 2), a = 7.4638(8) Å, b = 8.0392(8) Å, c = 12.6767(11) Å, α = 108.187(8)°, β = 94.029(7)°, γ = 95.071(8)°, V = 715.95(13) Å3, Z = 2, R gt (F) = 0.0573, wR ref (F 2) = 0.1460, T = 100.0(2) K.

Crystal structure of (E)-7-hydroxy-2-((6-methoxypyridin-3-yl)methylene)-3, 4-dihydronaphthalen-1(2H)-one, C17H15NO3

C17H15NO3, monoclinic, P21/n (no. 14), a = 4.3970(3) Å, b = 13.8942(8) Å, c = 22.0484(14) Å, β = 91.099(6)°, V = 1346.75(15), Z = 4, R gt (F) = 0.0412, wR ref (F 2) = 0.1003, T = 150 K.

Crystal structure of (E)-7-fluoro-2-(4-methoxy-2-(trifluoromethyl)benzylidene)-3,4-dihydronaphthalen-1(2H)-one, C19H14F4O2

C19H14F4O2, monoclinic, P21/c (no. 14), a = 11.8614(10) Å, b = 7.9148(6) Å, c = 16.7999(16) Å, β = 99.150(9)°, V = 1557.1(2) Å3, Z = 4, R gt (F) = 0.0446, wR ref (F 2) = 0.1150, T = 100 K.

Trifluoromethyl-substituted 3,5-bis(arylidene)-4-piperidones as potential anti-hepatoma and anti-inflammation agents by inhibiting NF-кB activation

Some methoxy-, hydroxyl-, pyridyl-, or fluoro-substituted 3,5-bis(arylidene)-4-piperidones (BAPs) could reduce inflammation and promote hepatoma cell apoptosis by inhibiting activation of NF-κB, especially after introduction of trifluoromethyl. Herein, a series of trifluoromethyl-substituted BAPs (4-30) were synthesised and the biological activities were evaluated. We successfully found the most potential 16, which contains three trifluoromethyl substituents and exhibits the best anti-tumour and anti-inflammatory activities. Preliminary mechanism research revealed that 16 could promote HepG2 cell apoptosis in a dose-dependent manner by down-regulating the expression of Bcl-2 and up-regulating the expression of Bax, C-caspase-3. Meanwhile, 16 inhibited activation of NF-κB by directly inhibiting the phosphorylation of p65 and IκBα induced by LPS, together with indirectly inhibiting MAPK pathway, thereby exhibiting both anti-hepatoma and anti-inflammatory activities. Molecular docking confirmed that 16 could bind to the active sites of Bcl-2, p65, and p38 reasonably. The above results suggested that 16 has enormous potential to be developed as a multifunctional agent for the clinical treatment of liver cancers and inflammatory diseases.

Crystal structure of (E)-2-((2-methoxy-3-pyridyl)methylene)-7-fluoro-3,4-dihydronaphthalen-1(2H)-one, C17H14FNO2

C17H14FNO2, monoclinic, P21/c (no. 14), a = 14.0279(13) Å, b = 7.0527(5) Å, c = 14.4150(16) Å, β = 113.165(12)°, V = 1311.2(2) Å3, Z = 4, Rgt (F) = 0.0524, wRref (F 2) = 0.1358, T = 100 K.

Potential anti-neuroinflammatory NF-кB inhibitors based on 3,4-dihydronaphthalen-1(2H)-one derivatives

Nuclear factor kappa B (NF-кB) inhibition represents a new therapeutic strategy for the treatment of neuroinflammatory diseases. In this study, a series of 3,4-dihydronaphthalen-1(2H)-one (DHN; 6a-n, 7a-c) derivatives were synthesised and characterised by NMR and HRMS. We assessed the toxicity and anti-neuroinflammatory properties of these compounds and found that 6m showed the greatest anti-neuroinflammatory properties, with relatively low toxicity. Specifically, 6m significantly reduced reactive oxygen species production, down-regulated the expression of NOD-like receptor pyrin domain-containing protein 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC), and caspase-1 and prevented lipopolysaccharide-stimulated BV2 microglia cells polarisation towards an M1 phenotype. Furthermore, 6m significantly decreased IκBα and NF-кB p65 phosphorylation, thus inhibiting the NF-кB signalling pathway. This suggests that 6m may be explored as a functional anti-neuroinflammatory agent for the treatment of inflammatory diseases in the central nervous system, such as multiple sclerosis, traumatic brain injury, stroke and spinal cord injury.

Highlights on Steroidal Arylidene Derivatives as a Source of Pharmacologically Active Compounds: A Review

Steroids constitute a unique class of chemical compounds, playing an important role in physiopathological processes, and have high pharmacological interest. Additionally, steroids have been associated with a relatively low toxicity and high bioavailability. Nowadays, multiple steroidal derivatives are clinically available for the treatment of numerous diseases. Moreover, different structural modifications on their skeleton have been explored, aiming to develop compounds with new and improved pharmacological properties. Thus, steroidal arylidene derivatives emerged as a relevant example of these modifications. This family of compounds has been mainly described as 17β-hydroxysteroid dehydrogenase type 1 and aromatase inhibitors, as well as neuroprotective and anticancer agents. Besides, due to their straightforward preparation and intrinsic chemical reactivity, steroidal arylidene derivatives are important synthetic intermediates for the preparation of other compounds, particularly bearing heterocyclic systems. In fact, starting from arylidenesteroids, it was possible to develop bioactive steroidal pyrazolines, pyrazoles, pyrimidines, pyridines, spiro-pyrrolidines, amongst others. Most of these products have also been studied as anti-inflammatory and anticancer agents, as well as 5α-reductase and aromatase inhibitors. This work aims to provide a comprehensive overview of steroidal arylidene derivatives described in the literature, highlighting their bioactivities and importance as synthetic intermediates for other pharmacologically active compounds.

Crystal structure of (E)-2-(3,5-bis(trifluoromethyl)benzylidene)-7-methoxy-3,4-dihydronaphthalen- 1(2H)-one, C20H14F6O2

C 20 H 14 F 6 O 2 ${\text{C}}_{20}{\text{H}}_{14}{\text{F}}_{6}{\text{O}}_{2}$ , monoclinic, P21/c (no. 14), a = 14.791(2) Å, b = 8.5303(9) Å, c = 15.531(3) Å, β = 115.474(19)°, V = 1769.1(5) Å3, Z = 4, R g t ${R}_{gt}$ (F) = 0.0574, w   R ref $w\,{R}_{\text{ref}}$ (F 2) = 0.1451, T = 100 K.

CCDC no.: 2016723

Crystal structure of (E)-2-(4-fluoro-3-(trifluoromethyl)benzylidene)-7-methoxy-3,4-dihydronaphthalen-1(2H)-one, C19H14F4O2

C 19 H 14 F 4 O 2 ${\text{C}}_{19}{\text{H}}_{14}{\text{F}}_{4}{\text{O}}_{2}$ , triclinic, P 1 ‾ $P‾{1}$ (no. 2), a = 8.1539(7) Å, b = 8.8584(6) Å, c = 11.8025(9) Å, α = 73.186(7)°, β = 76.184(7)°, γ = 69.512(7)°, V = 755.39(11) Å3, Z = 2, R g t ${R}_{gt}$ (F) = 0.0436, w R ref $w{R}_{\text{ref}}$ (F 2) = 0.0965, T = 100 K.

Crystal structure of (3E,5E)-3,5-bis-4-methoxy-3-(trifluoromethyl)benzylidene)-1-methylpiperidin-4-one, C24H21F6NO3

C24H21F6NO3, monoclinic, P21/c (no. 14), a = 16.6493(9) Å, b = 15.3005(8) Å, c = 8.8554(5) Å, β = 99.746(6)°, V = 2223.3(2) Å3, Z = 4, R gt (F) = 0.0444, wR ref (F 2) = 0.1094, T = 100 K.

Discovery of novel NF-кB inhibitor based on scaffold hopping: 1,4,5,6,7,8-hexahydropyrido[4,3-d]pyrimidine

NF-κB is a key signaling pathway molecule linking hepatoma and chronic inflammation. Inhibition of NF-κB activation can alleviate inflammation, and promote hepatoma cell apoptosis. In this study, a series of fluoro-substituted 1,4,5,6,7,8-hexahydropyrido[4,3-d]pyrimidines (PPMs, 31-57) were synthesized from 3,5-bis(arylidene)-4-piperidones (BAPs, 4-30) based on scaffold hopping. We successfully discovered the most potent 43 substituted by electron-withdrawing substitutes (3-F and 4-CF₃) exhibited less toxicity and higher anti-inflammatory activity. Preliminary mechanistic studies revealed that 43 induced dose-dependent cell apoptosis at cell and protein level, while inhibited NF-κB activation by suppressing LPS-induced phosphorylation levels of p65, IκBα and Akt, and by indirectly suppressing MAPK signaling, and by inhibiting the nuclear translocation of NF-κB induced by TNF-α or LPS. Docking analysis verified simulated 43 could reasonably bind to the active site of Bcl-2, p65 and p38 proteins. This compound, as a novel NF-κB inhibitor, also demonstrated both anti-inflammatory and anti-hepatoma activities, warranting its further development as a potential multifunctional agent for the clinical treatment of liver cancers and inflammatory diseases.

Crystal structure and anti-inflammatory activity of (3E,5E)-1-((4-chlorophenyl)sulfonyl)-3,5-bis(4-fluorobenzylidene)piperidin-4-one-dichloromethane (1/1), C26H20Cl3F2NO3S

C26H20Cl3F2NO3S, triclinic, P1̄ (no. 2), a = 8.6281(7) Å, b = 11.3695(9) Å, c = 14.3529(11) Å, α = 68.166(7)°, β = 80.707(7)°, γ = 71.169(7)°, V = 1235.65(19) Å3, Z = 2, R gt(F) = 0.0564, wR ref(F 2) = 0.1376, T = 100.00(10) K.

Crystal structure and anti-inflammatory activity of (3E,5E)-3,5-bis(4-fluorobenzylidene)-1-((4-fluorophenyl)sulfonyl)piperidin-4-one-dichloromethane (1/1), C26H20Cl2F3NO3S

C26H20Cl2F3NO3S, triclinic, P1̄ (no. 2), a = 8.5616(4) Å, b = 11.6052(6) Å, c = 14.1451(8) Å, α = 66.617(6)°, β = 82.391(4)°, γ = 69.072(4)°, V = 1204.85(12) Å3, Z = 2, R gt(F) = 0.0460, wR ref(F 2) = 0.1206, T = 100.00(10) K.

Crystal structure and anti-inflammatory activity of (3E,5E)-1-((4-chlorophenyl)sulfonyl)-3-(pyridin-4-ylmethylene)-5-(2-(trifluoromethyl)benzylidene)piperidin-4-one, C25H18ClF3N2O3S

C25H18ClF3N2O3S, monoclinic, P21/n (no. 14), a = 9.9087(5) Å, b = 21.7843(10) Å, c = 10.2512(6) Å, β = 94.749(5)°, V = 2205.2(2) Å3, Z = 4, R gt(F) = 0.0448, wR ref(F 2) = 0.1028, T = 100 K.

Crystal structure and anti-inflammatory activity of (3E,5E)-1-((4-bromophenyl)sulfonyl)-3-(pyridin-4-ylmethylene)-5-(2-(trifluoromethyl)benzylidene)piperidin-4-one, C25H18BrF3N2O3S

C25H18BrF3N2O3S, monoclinic, P21/n (no. 14), a = 9.9295(11) Å, b = 21.755(2) Å, c = 10.2358(11) Å, β = 95.022(10)°, V = 2202.6(4) Å3, Z = 4, R gt(F) = 0.0373, wR ref(F 2) = 0.0795, T = 100(1) K.

Crystal structure and anti-inflammatory activity of (3E,5E)-3-(2-fluorobenzylidene)-1-((4-fluorophenyl)sulfonyl)-5-(pyridin-3-ylmethylene)piperidin-4-one, C24H18F2N2O3S

C24H18F2N2O3S, monoclinic, P21/c (no. 14), a = 15.180(5) Å, b = 10.221(3) Å, c = 13.556(4) Å, β = 106.628(4)°, V = 2015.3(10) Å3, Z = 4, R gt(F) = 0.0530, wR ref(F 2) = 0.1342, T = 173(2) 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.

Crystal structure of (3E,5E)-1-((4-fluorophenyl)sulfonyl)-3,5-bis(3-nitrobenzylidene)piperidin-4-one — dichloromethane (2/1), C51H38Cl2F2N6O14S2

C51H38Cl2F2N6O14S2, triclinic, P1̄ (no. 2), a = 11.8987(6) Å, b = 14.0939(8) Å, c = 16.1915(9) Å, α = 67.590(5)°, β = 75.402(5)°, γ = 77.522(4)°, V = 2407.3(2) Å3, Z = 2, Rgt(F) = 0.0584, wRref(F2) = 0.1645, T = 100.0(1) K.

Crystal structure and anti-inflammatory activity of (3E,5E)-3-(2-fluorobenzylidene)-1-((4-acetamidophenyl)sulfonyl)-5-(pyridin-3-ylmethylene)piperidin-4-one-methanol-hydrate (2/1/1), C53H50F2N6O10S2

C53H50F2N6O10S2, monoclinic, P21/n (no. 14), a = 15.088(5) Å, b = 23.560(9) Å, c = 15.401(6) Å, β = 112.254(5)°, V = 5067(3) Å3, Z = 4, R gt(F) = 0.0509, wR ref(F 2) = 0.1336, T = 298(2) K.

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, crystal structures and anti-inflammatory activity of fluorine-substituted 1,4,5,6-tetrahydrobenzo[h]quinazolin-2-amine derivatives

Two fluorine-substituted 1,4,5,6-tetrahydrobenzo[h]quinazolin-2-amine (BQA) derivatives, namely 2-amino-4-(2-fluorophenyl)-9-methoxy-1,4,5,6-tetrahydrobenzo[h]quinazolin-3-ium chloride, (8), and 2-amino-4-(4-fluorophenyl)-9-methoxy-1,4,5,6-tetrahydrobenzo[h]quinazolin-3-ium chloride, (9), both C₁₉H₁₉FN₃O⁺·Cl^-, were generated by Michael addition reactions between guanidine hydrochloride and the α,β-unsaturated ketones (E)-2-(2-fluorobenzylidene)-7-methoxy-3,4-dihydronaphthalen-1(2H)-one, C₁₈H₁₅FO₂, (6), and (E)-2-(4-fluorobenzylidene)-7-methoxy-3,4-dihydronaphthalen-1(2H)-one, (7). Because both sides of α,β-unsaturated ketones (6) or (7) can be attacked by guanidine, we obtained a pair of isomers in (8) and (9). Single-crystal X-ray diffraction indicates that each isomer has a chiral C atom and both (8) and (9) crystallize in the achiral space group P2₁/c. The chloride ion, as a hydrogen-bond acceptor, plays an important role in the formation of multiple hydrogen bonds. Thus, adjacent molecules are connected through intermolecular hydrogen bonds to generate a banded structure. Furthermore, these bands are linked into an interesting 3D network via hydrogen bonds and π-π interactions. Fortunately, the solubilities of (8) and (9) were distinctly improved and can exceed 50 mg ml^-1 in water or PBS buffer system (pH 7.4) at room temperature. In addition, the results of an investigation of anti-inflammatory activity show that (8) and (9), with o- and p-fluoro substituents, respectively, display more potential for inhibitory effects on LPS-induced NO secretion than starting ketones (6) and (7).

Crystal structure of (3E,5E)-3,5-bis(3-nitrobenzylidene)-1-((4-(trifluoromethyl)phenyl)sulfonyl)piperidin-4-one — dichloromethane (2/1), C53H38Cl2F6N6O14S2

C53H38Cl2F6N6O14S2, triclinic, P1̄ (no. 2), a = 12.1975(6) Å, b = 13.9973(7) Å, c = 16.3818(10) Å, α = 69.365(5)°, β = 76.620(5)°, γ = 77.292(4)°, V = 2516.8(3) Å3, Z = 2, R gt(F) = 0.0540, wR ref(F 2) = 0.1413, T = 100.02(10) K.

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.

Dissymmetric pyridyl-substituted 3,5-bis(arylidene)-4-piperidones as anti-hepatoma agents by inhibiting NF-κB pathway activation

To get new anti-hepatoma agents with anti-inflammatory activity and hypotoxicity, a series of dissymmetric pyridyl-substituted 3,5-bis(arylidene)-4-piperidones (BAPs, 25-82) were designed and synthesized. Many of them exhibited potential anti-hepatoma properties against human hepatocellular carcinoma cell lines (HepG2, QGY-7703, SMMC-7721) and hypotoxicity for human normal heptical cell line (HHL-5, LO2), and prominently inhibited lipopolysaccharides (LPS) induced IL-6, TNF-α secretion to exert its anti-inflammatory effect. Combining the data of cytotoxicity, cytocompatibility and anti-inflammatory activity, 3-pyridyl and -CF₃ substituted 67 may be the potential anti-hepatoma agent. 67 effectively promoted cell apoptosis through up-regulating cleaved caspase-3 and Bax expression and down-regulating Bcl-2 expression. Furthermore, 67 prominently inhibited NF-κB pathway activation by blocking the phosphorylation of IκBα, p65 and the nuclear translocation of NF-κB induced by TNF-α and LPS. In addition, 67 could reasonably bind to the active site of Bcl-2 and NF-κB/p65 protein proved by Molecular docking analyses. Moreover, 67 significantly suppressed the growth and inflammatory response of HepG2 xenografts in nude mice and was relatively nontoxic to mice. These results suggest that 67 may be effective and hypotoxicity anti-hepatoma agent for the clinical treatment of liver 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.