Discovery of ARD-2585 as an Exceptionally Potent and Orally Active PROTAC Degrader of Androgen Receptor for the Treatment of Advanced Prostate Cancer.

We report herein the discovery of exceptionally potent and orally bioavailable PROTAC AR degraders with ARD-2585 being the most promising compound. ARD-2585 achieves DC50 values of ≤0.1 nM in the VCaP cell line with AR gene amplification and in the LNCaP cell line carrying an AR mutation. It potently inhibits cell growth with IC50 values of 1.5 and 16.2 nM in the VCaP and LNCaP cell lines, respectively, and achieves excellent pharmacokinetics and 51% of oral bioavailability in mice. It is more efficacious than enzalutamide in inhibition of VCaP tumor growth and does not cause any sign of toxicity in mice. ARD-2585 is a promising AR degrader for extensive investigations for the treatment of advanced prostate cancer.

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.

Dispiropyrrolidine tethered piperidone heterocyclic hybrids with broad-spectrum antifungal activity against Candida albicans and Cryptococcus neoformans.

Invasive fungal infections along with rising incidence of resistance to antifungal drugs pose increasing threat to immunocompromised individuals, including cancer patients. In this study, we examined the antifungal activity of dispiropyrrolidine tethered piperidone heterocyclic hybrids. Results indicate that compounds 5a and 6i have demonstrated a potent antifungal effect on multiple fungal strains, including Candida albicans, without exhibiting cytotoxicity to mammalian cells. Furthermore, these two compounds exhibited significant inhibition on Candida albicans hyphae and biofilm development that surpasses the FDA-approved antifungal drug currently used for treatment. Taken together, our results suggest that 5a and 6i are promising candidates for development into new antifungal drugs.

Synthesis of novel 4-Boc-piperidone chalcones and evaluation of their cytotoxic activity against highly-metastatic cancer cells.

In this study, six curcuminoids containing a tert-butoxycarbonyl (Boc) piperidone core were successfully synthesized, five of them are novel compounds reported here for the first time. These compounds were prepared through an aldolic condensation by adding tetrahydropyranyl-protected benzaldehydes or substituted benzaldehyde to a reaction mixture containing 4-Boc-piperidone and lithium hydroxide in an alcoholic solvent. A 44-94% yield was obtained supporting the developed methodology as a good strategy for the synthesis of 4-Boc-piperidone chalcones. Cytotoxic activity against LoVo and COLO 205 human colorectal cell lines was observed at GI50 values that range from 0.84 to 34.7 µg/mL, while in PC3 and 22RV1 human prostate cancer cell lines, GI50 values ranging from 17.1 to 22.9 µg/mL were obtained. Results from biochemical assays suggest that the cytotoxicity of the 4-Boc-piperidone chalcones can be linked to their ability to induce apoptosis, decrease the activity of NFκB and cellular proliferation. Our findings strongly support the potential of Boc-piperidone chalcones as novel cytotoxic agents against highly-metastatic cancer cells.

NFBTA: A Potent Cytotoxic Agent against Glioblastoma.

Piplartine (PPL), also known as piperlongumine, is a biologically active alkaloid extracted from the Piper genus which has been found to have highly effective anticancer activity against several tumor cell lines. This study investigates in detail the antitumoral potential of a PPL analogue; (E)-N-(4-fluorobenzyl)-3-(3,4,5-trimethoxyphenyl) acrylamide (NFBTA). The anticancer potential of NFBTA on the glioblastoma multiforme (GBM) cell line (U87MG) was determined by 3-(4,5-dimethyl-2-thia-zolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT), and lactate dehydrogenase (LDH) release analysis, and the selectivity index (SI) was calculated. To detect cell apoptosis, fluorescent staining via flow cytometry and Hoechst 33258 staining were performed. Oxidative alterations were assessed via colorimetric measurement methods. Alterations in expressions of key genes related to carcinogenesis were determined. Additionally, in terms of NFBTA cytotoxic, oxidative, and genotoxic damage potential, the biosafety of this novel agent was evaluated in cultured human whole blood cells. Cell viability analyses revealed that NFBTA exhibited strong cytotoxic activity in cultured U87MG cells, with high selectivity and inhibitory activity in apoptotic processes, as well as potential for altering the principal molecular genetic responses in U87MG cell growth. Molecular docking studies strongly suggested a plausible anti-proliferative mechanism for NBFTA. The results of the experimental in vitro human glioblastoma model and computational approach revealed promising cytotoxic activity for NFBTA, helping to orient further studies evaluating its antitumor profile for safe and effective therapeutic applications.

Novel Curcumin Inspired Antineoplastic 1-Sulfonyl-4-Piperidones: Design, Synthesis and Molecular Modeling Studies.

BACKGROUND: Curcumin is a well-known example of plant origin exhibiting promising diverse biological properties such as, anti-inflammatory and antitumor as well as poor pharmacokinetic/pharmacodynamic properties. This is why effective agents based on its chemical scaffold were explored. METHODS: A set of 3,5-bis(ylidene)-1-(alkylsulfonyl)piperidin-4-ones were synthesized in excellent yield (80- 96%) through dehydrohalogenation reaction of 3,5-bis(ylidene)-4-piperidinones with the corresponding alkane sulfonyl chloride in the presence of triethylamine. Antiproliferative properties of the synthesized compounds (dienone/curcumin inspired analogues) were studied by the standard MTT technique. RESULTS: Most of the synthesized compounds revealed antiproliferative properties against HCT116 (colon) and A431 (skin/squamous) cancer cell lines with IC50 values at sub-micromolar level. Compound 36 also exhibited potency against MCF7 (breast) and A549 (lung) cancer cell lines (IC50 = 2.23, 4.27µM, respectively) higher than that of the reference standards (IC50 = 3.15, 5.93µM for 5-fluorouracil and doxorubicin against MCF7 and A549 cell lines, respectively). Cytotoxic properties of the synthesized compounds against non-cancer RPE1 cell line supported the safety profile of the effective agents against normal cells. Molecular modeling (3Dpharmacophore and 2D-QSAR) studies validated the observed bio-properties and explained the parameters governing activity. Inhibitory properties of compounds 27 and 29 (representative examples of the promising antiproliferative agents synthesized) supported their mode of action against topoisomerase IIα. CONCLUSION: The synthesized scaffold is a promising antitumor agent (with special selectivity against colon and skin/squamous cancer cell lines) so, it can be considered for further investigation and development of highly effective hits/leads based on the computational models obtained.

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.

A novel cereblon modulator for targeted protein degradation.

Immunomodulatory drugs (IMiDs) exert anti-myeloma activity by binding to the protein cereblon (CRBN) and subsequently degrading IKZF1/3. Recently, their ability to recruit E3 ubiquitin ligase has been used in the proteolysis targeting chimera (PROTAC) technology. Herein, we design and synthesize a novel IMiD analog TD-106 that induces the degradation of IKZF1/3 and inhibits the proliferation of multiple myeloma cells in vitro as well as in vivo. Moreover, we demonstrate that TD-428, which comprises TD-106 linked to a BET inhibitor, JQ1 efficiently induce BET protein degradation in the prostate cancer cell line 22Rv1. Consequently, cell proliferation is inhibited due to suppressed C-MYC transcription. These results, therefore, firmly suggest that the newly synthesized IMiD analog, TD-106, is a novel CRBN modulator that can be used for targeted protein degradation.

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,ß-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).

The development of piperidinones as potent MDM2-P53 protein-protein interaction inhibitors for cancer therapy.

In tumor cells, p53 is always inactivated due to the mutation or deletion of TP53 gene or inhibited by the overexpressed MDM2. Small-molecule induced restoring of p53 function by blocking MDM2-p53 protein-protein interactions has been highly pursued as an attractive therapeutic strategy for cancer therapy. To date, a large number of small-molecule inhibitors have been identified based on the compact and well-defined MDM2-p53 interactions, of which SAR405838, MK-8242, DS-3032b, NVP-CGM097, RG7112, HDM201, RG7388, ALRN-6924 and AMG 232 are undergoing clinical assessment at different phases for cancer therapy. This review is focused on the discovery and development of piperidinone-based MDM2-p53 inhibitors for cancer therapy, including the identification of hit compounds, hit-to-lead optimizations, binding models of ligands in the active site of MDM2, metabolic studies, and preclinical data of advanced piperidinone-based MDM2-p53 inhibitors. Additionally, acquired resistance of MDM2 inhibitors and potential toxicity toward normal tissues are briefly discussed.

Epithelial cell adhesion efficacy of a novel peptide identified by panning on a smooth titanium surface.

Epithelial attachment via the basal lamina on the tooth surface provides an important structural defence mechanism against bacterial invasion in combating periodontal disease. However, when considering dental implants, strong epithelial attachment does not exist throughout the titanium-soft tissue interface, making soft tissues more susceptible to peri-implant disease. This study introduced a novel synthetic peptide (A10) to enhance epithelial attachment. A10 was identified from a bacterial peptide display library and synthesized. A10 and protease-activated receptor 4-activating peptide (PAR4-AP, positive control) were immobilized on commercially pure titanium. The peptide-treated titanium showed high epithelial cell migration ability during incubation in platelet-rich plasma. We confirmed the development of dense and expanded BL (stained by Ln5) with pericellular junctions (stained by ZO1) on the peptide-treated titanium surface. In an adhesion assay of epithelial cells on A10-treated titanium, PAR4-AP-treated titanium, bovine root and non-treated titanium, A10-treated titanium and PAR4-AP-treated titanium showed significantly stronger adhesion than non-treated titanium. PAR4-AP-treated titanium showed significantly higher inflammatory cytokine release than non-treated titanium. There was no significant difference in inflammatory cytokine release between A10-treated and non-treated titanium. These results indicated that A10 could induce the adhesion and migration of epithelial cells with low inflammatory cytokine release. This novel peptide has a potentially useful application that could improve clinical outcomes with titanium implants and abutments by reducing or preventing peri-implant disease.

Piperlongumine (piplartine) as a lead compound for anticancer agents - Synthesis and properties of analogues: A mini-review.

Piperlongumine, also known as piplartine, is an amide alkaloid of Piper longum L. (long piper), a medical plant known from Ayurvedic medicine. Although was discovered well over fifty years ago, its pharmacological properties have been uncovered in the past decade. In particular, piperlongumine has been most extensively studied as a potential anticancer agent. Piperlongumine has exhibited cytotoxicity against a broad spectrum of human cancer cell lines, as well as demonstrated antitumor activity in rodents. Piperlongumine has also been found to be a proapoptotic, anti-invasive, antiangiogenic agent and synergize with modern chemotherapeutic agents. Because of its clinical potential, several studies were undertaken to obtain piperlongumine analogues, which have exhibited more potent activity or more appropriate drug-like parameters. In this review, the synthesis of piperlongumine analogues and piperlongumine-based hybrid compounds, as well as their anticancer properties and the molecular basis for their activity are explored. General structure-activity relationship conclusions are drawn and directions for the future research are indicated.

Multicomponent Domino Synthesis, Anticancer Activity and Molecular Modeling Simulation of Complex Dispirooxindolopyrrolidines.

A series of spirooxindolopyrrolidine fused N-styrylpiperidone heterocyclic hybrids has been synthesized in excellent yield via a domino multicomponent protocol that involves one-pot three component 1,3-dipolar cycloaddition and concomitant enamine reactions performed in an inexpensive ionic liquid, namely 1-butyl-3-methylimidazolium bromide ([bmim]Br). Compounds thus synthesized were evaluated for their cytotoxicity against U-937 tumor cells. Interestingly; compounds 5i and 5m exhibited a better cytotoxicity than the anticancer drug bleomycin. In addition; the effect of the synthesized compounds on the nuclear morphology of U937 FaDu cells revealed that treatment with compounds 5a⁻m led to their apoptotic cell death.

Halogenated Bis(methoxybenzylidene)-4-piperidone Curcuminoids with Improved Anticancer Activity.

A series of readily available curcuminoids with a halogenated bis(4-methoxy/4,5-dimethoxybenzylidene)-4-piperidone structure were prepared and analyzed for their cytotoxic impact on eight human cancer cell lines of five different entities. The known 3,4,5-trimethoxybenzylidene curcuminoid 2 a and the new bis-(3-bromophenyl) and bis-(3,5-dibromophenyl) derivatives 3 c and 3 d proved to be more strongly antiproliferative than the known curcuminoid EF24 against six of these cell lines. Compounds 2 a and 3 c caused a distinct increase of reactive oxygen species, which eventually elicited apoptosis in 518A2 melanoma cells. Compound 2 a arrested 518A2 melanoma cells in G1 phase of the cell cycle and had no effect on the expression of pro-metastatic matrix metalloproteinases MMP-2 and MMP-9, whereas 3 c led to an accumulation of 518A2 cells in the G2 /M phase and to a downregulation of MMP-2 expression. In addition, treatment with 2 a and 3 c resulted in significant inhibition of colony formation in HCT116 cells. Both 2 a and 3 c showed antiangiogenic activity, for example, by inhibiting the formation of sub-intestinal veins (SIV) in zebrafish embryos. Compound 3 c was also well tolerated by mice and inhibited the growth of HCT116 colon cancer xenografts.

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 anti-tumor activity of EF24 analogues as IKKß inhibitors.

EF24 is an IKKß inhibitor (IC50: 72 µM) containing various anti-tumor activities. In this study, a series of EF24 analogs targeting IKKß were designed and synthesized. Several IKKß inhibitors with better activities than EF24 were screened out and B3 showed best IKKß inhibitory (IC50: 6.6 µM). Molecular docking and dynamic simulation experiments further confirmed this inhibitory effect. B3 obviously suppressed the viability of Hela229, A549, SGC-7901 and MGC-803 cells. Then, in SGC-7901 and MGC-803 cells, B3 blocked the NF-κB signal pathway by inhibiting IKKß phosphorylation, and followed arrested the cell cycle at G2/M phase by suppressing the Cyclin B1 and Cdc2 p34 expression, induced the cell apoptosis by down-regulating Bcl-2 protein and up-regulating cleaved-caspase3. Moreover, B3 significantly reduced tumor growth and suppressed the IKKß-NF-κB signal pathway in SGC-7901 xenograft model. In total, this study present a potential IKKß inhibitor as anti-tumor precursor.

Design, synthesis, biological evaluation, and docking study of 4-isochromanone hybrids bearing N-benzyl pyridinium moiety as dual binding site acetylcholinesterase inhibitors (part II).

A series of novel 4-isochromanone compounds bearing N-benzyl pyridinium moiety were designed and synthesized as acetylcholinesterase (AChE) inhibitors. The biological evaluation showed that most of the target compounds exhibited potent inhibitory activities against AChE. Among them, compound 1q possessed the strongest anti-AChE activity with an IC50 value of 0.15 nm and high AChE/BuChE selectivity (SI > 5,000). Moreover, compound 1q had low toxicity in normal nerve cells and was relatively stable in rat plasma. Together, the current finding may provide a new approach for the discovery of novel anti-Alzheimer's disease agents.

3,5-Bis(3-dimethylaminomethyl-4-hydroxybenzylidene)-4-piperidone and related compounds induce glutathione oxidation and mitochondria-mediated cell death in HCT-116 colon cancer cells.

This study aims at investigating the cytotoxicity and some of the modes of action of 3,5-bis(3-dimethylamino-4-hydroxybenzylidene)-4-piperidone trihydrochloride 3 and two related compounds 2 (which lacks the dimethylaminomethyl groups) and 4 (which has an additional dimethylaminoethyl substituent in both aryl rings) in order to ascertain the contribution of dimethylaminoethyl substituent to bioactivity. The bioactivities of 2-4 were compared with curcumin 5. Both 2 and 3 displayed submicromolar GI50 values towards HCT-116 cells and were significantly more potent than 4, 5 and 5-fluorouracil (5-FU). All of the compounds displayed greater toxicity towards HCT-116 cells than human CRL-1790 non-malignant colon cells. In HCT-116 cells, the compounds 2, 3 and 5 increased the ratio of oxidised to reduced glutathione and destabilized the mitochondrial membrane potential. Both 2 and 5 produced an increase in mitochondrial superoxide and a burst in intracellular reactive oxygen species in HCT 116 cells. In addition, 2 and 4 stimulated respiration in rat liver mitochondria while 2 and 5 induced mitochondrial swelling. The results suggest that 2 and 5 cause oxidation or cross-linking of the thiols which control the mitochondrial permeability transition.

Design, synthesis, and biological evaluation of novel EF24 and EF31 analogs as potential IκB kinase ß inhibitors for the treatment of pancreatic cancer.

Given the important role that inhibitory kappa B (IκB) kinase ß (IKKß) plays in pancreatic cancer (PC) development and progression, inhibitors targeting IKKß are believed to be increasingly popular as novel anti-PC therapies. Two synthetic molecules, named EF24 and EF31, exhibited favorable potential in terms of inhibition of both IKKß activity and PC cell proliferation. Aiming to enhance their cellular efficacy and to analyze their structure-activity relationship, four series of EF24 and EF31 analogs were designed and synthesized. Through kinase activity and vitality screening of cancer cells, D6 displayed excellent inhibition of both IKKß activity and PC cell proliferation. Additionally, multiple biological evaluations showed that D6 was directly bound to IKKß and significantly suppressed the activation of the IKKß/nuclear factor κB pathway induced by tumor necrosis factor-α, as well as effectively inducing cancer cell apoptosis. Moreover, molecular docking and molecular dynamics simulation analysis indicated that the dominant force between D6 and IKKß comprised hydrophobic interactions. In conclusion, D6 may be a promising therapeutic agent for PC treatment and it also provides a structural lead for the design of novel IKKß inhibitors.

The Therapeutic Potential of Migrastatin-Core Analogs for the Treatment of Metastatic Cancer.

Tumor metastasis is a complex process in which cells detach from the primary tumor and colonize a distant organ. Metastasis is also the main process responsible for cancer-related death. Despite the enormous efforts made to unravel the metastatic process, there is no effective therapy, and patients with metastatic tumors have poor prognosis. In this regard, there is an urgent need for new therapeutic tools for the treatment of this disease. Small molecules with the capacity to reduce cell migration could be used to treat metastasis. Migrastatin-core analogs are naturally inspired macrocycles that inhibit pathological cell migration and are able to reduce metastasis in animal models. Migrastatin analogs can be synthesized from a common advanced intermediate. Herein we present a review of the synthetic approaches that can be used to prepare this key intermediate, together with a review of the biological activity of migrastatin-core analogs and current hypotheses concerning their mechanism of action.