Design and synthesis of novel tetrabromophthalimide derivatives as potential tubulin inhibitors endowed with apoptotic induction for cancer treatment.

Although various approaches exist for treating cancer, chemotherapy continues to hold a prominent role in the management of this disease. Besides, microtubules serve as a vital component of the cellular skeleton, playing a pivotal role in the process of cell division making it an attractive target for cancer treatment. Hence, the scope of this work was adapted to design and synthesize new anti-tubulin tetrabromophthalimide hybrids (3-17) with colchicine binding site (CBS) inhibitory potential. The conducted in vitro studies showed that compound 16 displayed the lowest IC50 values (11.46 µM) at the FaDu cancer cell lines, whereas compound 17 exhibited the lowest IC50 value (13.62 µM) at the PC3 cancer cell line. However, compound 7b exhibited the lowest IC50 value (11.45 µM) at the MDA-MB-468 cancer cell line. Moreover, compound 17 was observed to be the superior antitumor candidate against all three tested cancer cell lines (MDA-MB-468, PC3, and FaDu) with IC50 values of 17.22, 13.15, and 13.62 µM, respectively. In addition, compound 17 showed a well-established upregulation of apoptotic markers (Caspases 3, 7, 8, and 9, Bax, and P53). Moreover, compound 17 induced downregulation of the antiapoptotic markers (MMP2, MMP9, and BCL-2). Furthermore, the colchicine binding site inhibition assay showed that compounds 15a and 17 exhibited particularly significant inhibitory potentials, with IC50 values of 23.07 and 4.25 µM, respectively, compared to colchicine, which had an IC50 value of 3.89 µM. Additionally, cell cycle analysis was conducted, showing that compound 17 could prompt cell cycle arrest at both the G0-G1 and G2-M phases. On the other hand, a molecular docking approach was applied to investigate the binding interactions of the examined candidates compared to colchicine towards CBS of the ß-tubulin subunit. Thus, the synthesized tetrabromophthalimide hybrids can be regarded as outstanding anticancer candidates with significant apoptotic activity.

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.

Proteolysis Targeting Chimera (PROTAC) for Macrophage Migration Inhibitory Factor (MIF) Has Anti-Proliferative Activity in Lung Cancer Cells.

Macrophage migration inhibitory factor (MIF) is involved in protein-protein interactions that play key roles in inflammation and cancer. Current strategies to develop small molecule modulators of MIF functions are mainly restricted to the MIF tautomerase active site. Here, we use this site to develop proteolysis targeting chimera (PROTAC) in order to eliminate MIF from its protein-protein interaction network. We report the first potent MIF-directed PROTAC, denoted MD13, which induced almost complete MIF degradation at low micromolar concentrations with a DC50 around 100 nM in A549 cells. MD13 suppresses the proliferation of A549 cells, which can be explained by deactivation of the MAPK pathway and subsequent induction of cell cycle arrest at the G2/M phase. MD13 also exhibits antiproliferative effect in a 3D tumor spheroid model. In conclusion, we describe the first MIF-directed PROTAC (MD13) as a research tool, which also demonstrates the potential of PROTACs in cancer therapy.

Discovery of a new series of PI3K-δ inhibitors from Virtual Screening.

PI3K-δ mediates key immune cell signaling pathways and is a target of interest for treatment of oncological and immunological disorders. Here we describe the discovery and optimization of a novel series of PI3K-δ selective inhibitors. We first identified hits containing an isoindolinone scaffold using a combined ligand- and receptor-based virtual screening workflow, and then improved potency and selectivity guided by structural data and modeling. Careful optimization of molecular properties led to compounds with improved permeability and pharmacokinetic profile, and high potency in a whole blood assay.

Design and Synthesis of EZH2-Based PROTACs to Degrade the PRC2 Complex for Targeting the Noncatalytic Activity of EZH2.

EZH2 mediates both PRC2-dependent gene silencing via catalyzing H3K27me3 and PRC2-independent transcriptional activation in various cancers. Given its oncogenic role in cancers, EZH2 has constituted a compelling target for anticancer therapy. However, current EZH2 inhibitors only target its methyltransferase activity to downregulate H3K27me3 levels and show limited efficacy because of inadequate suppression of the EZH2 oncogenic activity. Therefore, therapeutic strategies to completely block the oncogenic activity of EZH2 are urgently needed. Herein, we report a series of EZH2-targeted proteolysis targeting chimeras (PROTACs) that induce proteasomal degradation of PRC2 components, including EZH2, EED, SUZ12, and RbAp48. Preliminary assessment identified E7 as the most active PROTAC molecule, which decreased PRC2 subunits and H3K27me2/3 levels in various cancer cells. Furthermore, E7 strongly inhibited transcriptional silencing mediated by EZH2 dependent on PRC2 and transcriptional activation mediated by EZH2 independent of PRC2, showing significant antiproliferative activities against cancer cell lines dependent on the enzymatic and nonenzymatic activities of EZH2.

Substituted adamantylphthalimides: Synthesis, antiviral and antiproliferative activity.

In this study, three groups of adamantylphthalimides, bearing different substituents at the phthalimide moiety, N-(4'-R2 )phthalimidoadamantanes (1-7), 3-[N-(4'-R2 )phthalimido]-1-adamantanols (8-10), and 3-[N-(4'-R2 )phthalimido]adamantane-1-carboxylic acids (11-15), were synthesized and screened against tumor cells and viruses. The most potent compounds are not substituted at the adamantane and bear an OH or NH2 substituent at the phthalimide (compounds 3 and 5). The antiproliferative activities of compounds 3 and 5 are in the micromolar range, much higher than the one of thalidomide. A minor antiviral activity against cytomegalovirus and varicella-zoster virus was found for compounds 3 and 5, but these compounds lacked selectivity. The results presented are important for the rational design of the next-generation compounds with anticancer and antiviral activities.

Advances in Synthesis and Medicinal Applications of Compounds Derived from Phthalimide.

Phthalimide derivatives have been presenting several promising biological activities in the literature, such as anti-inflammatory, analgesic, antitumor, antimicrobial and anticonvulsant. The most well-known and studied phthalimide derivative (isoindoline-1,3-dione) is thalidomide: this compound initially presented important sedative effects, but it is now known that thalidomide has effectiveness against a wide variety of diseases, including inflammation and cancer. This review approaches some of the recent and efficient chemical synthesis pathways to obtain phthalimide analogues and also presents a summary of the main biological activities of these derivatives found in the literature. Therefore, this review describes the chemical and therapeutic aspects of phthalimide derivatives.

Design, Synthesis, and Herbicidal Activity of Novel Diphenyl Ether Derivatives Containing Fast Degrading Tetrahydrophthalimide.

To seek new protoporphyrinogen oxidase (PPO) inhibitors with better biological activity, a series of novel diphenyl ether derivatives containing tetrahydrophthalimide were designed based on the principle of substructure splicing and bioisomerization. PPO inhibition experiments exhibited that 6c is the most potential compound, with the half-maximal inhibitory concentration (IC50) value of 0.00667 mg/L, showing 7 times higher activity than Oxyfluorfen (IC50 = 0.0426 mg/L) against maize PPO and similar herbicidal activities to Oxyfluorfen in weeding experiments in greenhouses and field weeding experiments. In view of the inspected bioactivities, the structure-activity relationship (SAR) of this series of compounds was also discussed. Crop selection experiments demonstrate that compound 6c is safe for soybeans, maize, rice, peanuts, and cotton at a dose of 300 g ai/ha. Accumulation analysis experiments showed that the accumulation of 6c in some crops (soybeans, peanuts, and cotton) was significantly lower than Oxyfluorfen. Current work suggests that compound 6c may be developed as a new herbicide candidate in fields.

Benzo[4,5]thieno[2,3-d]pyrimidine phthalimide derivative, one of the rare noncompetitive inhibitors of dipeptidyl peptidase-4.

A small library of benzo[4,5]thieno[2,3-d]pyrimidine phthalimide and amine derivatives was evaluated for inhibitory activity against dipeptidyl peptidase-4 (DPP-4). The phthalimide derivatives exhibited better activity than the amine precursors, with 2-(2-(3-chlorobenzyl)-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4-yl)isoindoline-1,3-dione (compound 14) as the most effective inhibitor (IC50 = 34.17 ± 5.11 µM). The five most potent selected inhibitors did not show cytotoxicity to a greater extent on Caco-2 cells, even at a concentration of 250 µM. Compound 14 is considered as a novel representative of the rare noncompetitive DPP-4 inhibitors. Molecular docking and dynamics simulation indicated the importance of the Tyr547, Lys554, and Trp629 residues of DPP-4 in the formation of the enzyme-inhibitor complex. These observations could be potentially utilized for the rational design and optimization of novel (structurally similar, with phthalimide moiety, or different) noncompetitive DPP-4 inhibitors, which are anyway rare, but favorable in terms of the saturation of substrate competition.

Design and Synthesis of N-phenyl Phthalimides as Potent Protoporphyrinogen Oxidase Inhibitors.

Protoporphyrinogen oxidase (PPO) has been identified as one of the most promising targets for herbicide discovery. A series of novel phthalimide derivatives were designed by molecular docking studies targeting the crystal structure of mitochondrial PPO from tobacco (mtPPO, PDB: 1SEZ) by using Flumioxazin as a lead, after which the derivatives were synthesized and characterized, and their herbicidal activities were subsequently evaluated. The herbicidal bioassay results showed that compounds such as 3a (2-(4-bromo-2,6-difluorophenyl) isoindoline-1,3-dione), 3d (methyl 2-(4-chloro-1,3-dioxoisoindolin-2-yl)-5-fluorobenzoate), 3g (4-chloro-2-(5-methylisoxazol-3-yl) isoindoline-1,3-dione), 3j (4-chloro-2-(thiophen-2-ylmethyl) isoindoline-1,3-dione) and 3r (2-(4-bromo-2,6-difluorophenyl)-4-fluoroisoindoline-1,3-dione) had good herbicidal activities; among them, 3a showed excellent herbicidal efficacy against A. retroflexus and B. campestris via the small cup method and via pre-emergence and post-emergence spray treatments. The efficacy was comparable to that of the commercial herbicides Flumioxazin, Atrazine, and Chlortoluron. Further, the enzyme activity assay results suggest that the mode of action of compound 3a involves the inhibition of the PPO enzyme, and 3a showed better inhibitory activity against PPO than did Flumioxazin. These results indicate that our molecular design strategy contributes to the development of novel promising PPO inhibitors.

Aminonaphthalimide hybrids of mitoxantrone and amonafide as anticancer and fluorescent cellular imaging agents.

Novel water-soluble 4-aminonaphthalimides were synthesised and their cellular fluorescent imaging, cytotoxicity and ability to induced apoptosis evaluated. The lead compound 1 was designed from the cross-fertilisation of the basic hydrophilic amino pharmacophore of mitoxantrone, and an aminonaphthalimide scaffold of the drug candidate, amonafide. The compounds are also fluorescent pH probes based on photoinduced electron transfer (PET) and internal charge transfer (ICT). The compounds are sensitive to solvent polarity with large Stoke shifts (>90 nm) and provide emissive-coloured solutions (blue to yellow). Excited state pKas of 9.0-9.3 and fluorescence quantum yields of 0.47-0.58 were determined in water. The cytotoxicity and cellular fluorescent imaging properties of the compounds were tested on human cancer cell lines K562 and MCF-7 by the MTT assay, phase contrast and fluorescence microscopy. Compounds 1 and 3 with flexible aminoalkyl chains exhibited GI50 comparable to amonafide, while 2 and 4 with a rigid piperazine moiety and butyl chain are less cytotoxic. Fluorescence microscopy with 1 allowed for the visualization of the intracellular microenvironment exemplifying the potential utility of such hybrid molecules as anticancer and fluorescent cellular imaging agents.

Novel phthalimide based analogues: design, synthesis, biological evaluation, and molecular docking studies.

Pyrazolylphthalimide derivative 4 was synthesized and reacted with different reagents to afford the target compounds imidazopyrazoles 5-7, pyrazolopyrimidines 9, 12, 14 and pyrazolotriazines 16, 17 containing phthalimide moiety. The prepared compounds were established by different spectral data and elemental analyses. Additionally, all synthesized derivatives were screened for their antibacterial activity against four types of Gram + ve and Gram-ve strains, and for antifungal activity against two fungi micro-organisms by well diffusion method. Moreover, the antiproliferative activity was tested for all compounds against human liver (HepG-2) cell line in comparison with the reference vinblastine. Moreover, drug-likeness and toxicity risk parameters of the newly synthesized compounds were calculated using in silico studies. The data from structure-actvity relationship (SAR) analysis suggested that phthalimide derivative bearing 3-aminopyrazolone moiety, 4 illustrated the best antimicrobial and antitumor activities and might be considered as a lead for further optimization. To investigate the mechanism of the antimicrobial and anticancer activities, enzymatic assay and molecular docking studies were carried out on E. coli topoisomerase II DNA gyrase B and VEGFR-2 enzymes.

Design, synthesis and biological evaluation of novel isoindolinone derivatives as potent histone deacetylase inhibitors.

Histone deacetylases (HDACs) as appealing targets for the treatment of many diseases has been studied extensively and its use in cancer care is the most important. Here, we developed a series of novel derivatives containing isoindolinone skeleton. Twelve compounds demonstrated nanomolar IC50 values against HDAC1, and the best compounds were 5a (65.6 nM), 5b (65.1 nM) and 13a (57.9 nM). In vitro, 5a and 5b also showed potent antiproliferative activities against several cancer cell lines, in particular 5b, which behaved better than approved drug chidamide. Morever, enzyme inhibition and western blot assay established 5b to be a selective inhibitor for HDAC1-3. Molecular docking was performed to rationalize the high potency of isoindolinones. Additionally, 5b had more appropriate drug metabolism in human liver microsome (HLM) compared with chidamide and moderate pharmacokinetics properties. These results indicated that 5b was worthy of further biological studies.

3-Hydroxyisoindolin-1-one derivates: Synthesis by palladium-catalyzed CH activation as BRD4 inhibitors against human acute myeloid leukemia (AML) cells.

Bromodomain protein 4 (BRD4) is a member of the bromodomain and extra-terminal domain (BET) protein family, which plays a key role in transcriptional regulation. Recent biological and pharmacological studies have enabled linking of the BET bromodomains with diseases, including inflammation and cancer, suggesting that bromodomains are druggable targets. In this study, we made further structural modifications of our previously reported BRD4 inhibitors, to develop new chemical scaffold 3-Hydroxyisoindolin-1-One. Then a series of compounds (10a-q) were synthesized via palladium-catalyzed CH activation and BRD4-inhibitory activities and anti-proliferative effects of these compounds were evaluated. Compound 10e exhibited excellent BRD4-inhibitory activity with IC50 value of 80 nM and anti-proliferation potency with IC50 value of 365 nM in HL-60 (humanpromyelocytic leukemia) cancer cell lines. We have demonstrated compound 10e modulated the intrinsic apoptotic pathway. In conclusion, these results suggested that compound 10e could be utilized as a BRD4 inhibitor for further leukemia treatment.

Synthesis, Structural Characterization, and Antiangiogenic Activity of Polyfluorinated Benzamides.

The introduction of fluorine into bioactive molecules is a matter of importance in medicinal chemistry. In this study, representatives of various chemical entities of fluoroaromatic compounds were synthesized. Depending on the reaction conditions, either tetrafluorophthalimides or ammonium tetrafluorophthalamates are accessible from tetrafluorophthalic anhydride and primary amines. Tetrafluorophthalamic acids undergo thermal decarboxylation to yield tetrafluorobenzamides. These could be successfully converted upon treatment with primary amines, in the course of an aromatic nucleophilic substitution, to 2,3,5-trifluorobenzamides with respective amino substituents at the 4-position. The five structure types were characterized by means of spectroscopic and crystallographic methods. The synthesized compounds were evaluated as inhibitors of angiogenesis by measuring microvessel outgrowth in a rat aortic ring assay. The biological activity was maintained throughout these different polyfluorinated chemotypes.

Design, synthesis, biological evaluations, molecular docking, and in vivo studies of novel phthalimide analogs.

A series of novel phthalimide analogs containing an indole or brominated indole moiety were synthesized and their antimicrobial activity was evaluated. Compound 8 showed a broad spectrum activity, revealing 53-67% of erythromycin activity on the tested bacteria and 60-70% of miconazole activity on the tested fungi. Anticancer activity was evaluated on the cell lines HepG2, MCF-7, A549, H1299, and Caco2. The results revealed that the new phthalimide analog 8 has broad-spectrum anticancer activity toward all the tested cancer cell lines, followed by compound 11, which showed good activity toward all the tested cell lines except for MCF-7. The ability of the promising analogs 5, 8, and 11 to bind to topoisomerase II DNA gyrase was investigated. Caspase-3 activation and Bcl-2 assay of the best active derivatives 8, 11 in addition to compound 5 were evaluated. The antifibrotic activity was studied in an in vivo model and the histopathological studies revealed that treatment with the new compound 8 improved the fibrotic liver tissues to normality.

Synthesis, Structural Characterization and Docking Studies of Sulfamoyl- Phenyl Acid Esters as Dipeptidyl Peptidase-IV Inhibitors.

BACKGROUND: Diabetes mellitus is a major worldwide health concern that has several serious complications including retinopathy, neuropathy, nephropathy and macrovascular diseases. OBJECTIVE: Dipeptidyl peptidase-IV (DPP-IV) inhibitors, gliptins, are a new class of antidiabetic agents that potentiate the action of incretins in decreasing the blood glucose levels. METHODS: In the present study, synthesis and characterization of a series of ten N4-sulfonamido-acrylic and phthalamic acid methyl esters (3a-e and 5a-e) were achieved. RESULTS: In vitro anti-DPP-IV activity of the synthesized compounds was evaluated, where compound 3b demonstrated the best activity with a % inhibition of 41.7 at 10 µM concentration and an IC50 of 23.9 µM. Moreover, Glide docking experiments revealed that our targeted compounds accommodate the binding site of DPP-IV and tend to form H-bonding with the backbones of R125, E206, S209, D545, K554, W629, Y631, and G632. CONCLUSION: Modeling findings recommend the attachment of bulky hydrophobic group on the ester side of the structure in addition to harboring extra aromatic rings that might be beneficial for better binding interaction and biological activity.

Design, synthesis and biological assessment of N-adamantyl, substituted adamantyl and noradamantyl phthalimidines for nitrite, TNF-α and angiogenesis inhibitory activities.

A library of 15 novel and heretofore uncharacterized adamantyl and noradamantyl phthalimidines was synthesized and evaluated for neuroprotective and anti-angiogenic properties. Phthalimidine treatment in LPS-challenged cells effected reductions in levels of secreted TNF-α and nitrite relative to basal amounts. The primary SAR suggests nitration of adamantyl phthalimidines has marginal effect on TNF-α activity but promotes anti-nitrite activity; thioamide congeners retain anti-nitrite activity but are less effective reducing TNF-α. Site-specific nitration and thioamidation provided phthalimidine 24, effecting an 88.5% drop in nitrite concurrent with only a 4% drop in TNF-α. Notable anti-angiogenesis activity was observed for 20, 21 and 22.

Proapoptotic modification of substituted isoindolinones as MDM2-p53 inhibitors.

A series of novel amino acid ester derivatives of 2,3-substituted isoindolinones was synthesized and evaluated for p53-mediated apoptotic activity. The rationale for augmentation of the target activity of 2,3-substituted isoindolinones was based on the introduction of new fragments in the structure of the inhibitor that would provide additional binding sites in the hydrophobic cavity of MDM2. To select for the anticipated modifications we employed molecular docking. Synthesized molecules were evaluated for their ability to induce apoptosis in two cancer cell lines and their derivatives with different status of p53 (colorectal HCT116 and osteosarcoma U2OS cells) by Annexin V staining. The target activity was estimated using high-content imaging system Operetta. Valine and phenylglycine ester derivatives were identified as potentially active MDM2-p53 inhibitors.

Design, synthesis and biological evaluation of phthalimide-alkylamine derivatives as balanced multifunctional cholinesterase and monoamine oxidase-B inhibitors for the treatment of Alzheimer's disease.

A series of novel phthalimide-alkylamine derivatives were synthesized and evaluated as multi-functions inhibitors for the treatment of Alzheimer's disease (AD). The results showed that compound TM-9 could be regarded as a balanced multi-targets active molecule. It exhibited potent and balanced inhibitory activities against ChE and MAO-B (huAChE, huBuChE, and huMAO-B with IC50 values of 1.2µM, 3.8µM and 2.6 µM, respectively) with low selectivity. Both kinetic analysis of AChE inhibition and molecular modeling study suggested that TM-9 binds simultaneously to the catalytic active site and peripheral anionic site of AChE. Interestingly, compound TM-9 abided by Lipinski's rule of five. Furthermore, our investigation proved that TM-9 indicated weak cytotoxicity, and it could cross the blood-brain barrier (BBB) in vitro. The results suggest that compound TM-9, an interesting multi-targeted active molecule, offers an attractive starting point for further lead optimization in the drug-discovery process against Alzheimer's disease.