Synthesis and biological evaluation of arylpiperazine derivatives as potential anti-prostate cancer agents

Comprehensive Review on Recent Strategies for Management of Prostate Cancer: Therapeutic Targets and SAR

Prostate cancer is a disease that is affecting a large population worldwide. Androgen deprivation therapy (ADT) has become a foundation for the treatment of advanced prostate cancer, as used in most clinical settings from neo-adjuvant to metastatic stage. In spite of the success of ADT in managing the disease in the majority of men, hormonal manipulation fails eventually. New molecules are developed for patients with various hormone-refractory diseases. Advancements in molecular oncology have increased understanding of numerous cellular mechanisms which control cell death in the prostate and these insights can lead to the development of more efficacious and tolerable therapies for carcinoma of the prostate. This review is focused on numerous therapies that might be a boon for prostate therapy like signaling inhibitors, vaccines, and inhibitors of androgen receptors. Along with these, various bioactive molecules and their derivatives are highlighted, which act as potential antiprostate cancer agents. This article also emphasized the recent advances in the field of medicinal chemistry of prostate cancer agents.

Synthesis, biological evaluation, and molecular docking of novel hydroxyzine derivatives as potential AR antagonists

Prostate cancer (PCa) is a malignant tumor with a higher mortality rate in the male reproductive system. In this study, the hydroxyazine derivatives were synthesized with different structure from traditional anti-prostate cancer drugs. In the evaluation of in vitro cytotoxicity and antagonistic activity of PC-3, LNCaP, DU145 and androgen receptor, it was found that the mono-substituted derivatives on the phenyl group (4, 6, 7, and 9) displayed strong cytotoxic activities, and compounds 11–16 showed relatively strong antagonistic potency against AR (Inhibition% >55). Docking analysis showed that compounds 11 and 12 mainly bind to AR receptor through hydrogen bonds and hydrophobic bonds, and the structure-activity relationship was discussed based on activity data. These results suggested that these compounds may have instructive implications for drug structural modification in prostate cancer.

Synthesis, bioactivity, and molecular docking of novel arylpiperazine derivatives as potential AR antagonists

Prostate cancer is one of the malignant tumors and the second most common malignant tumor in men. Clinically used androgen receptor (AR)–targeted drugs can antagonize androgen and inhibit tumor growth, but these drugs can cause serious resistance problems. To develop novel AR antagonists, 22 kinds of arylpiperazine derivatives were designed and synthesized, and the derivatives 5, 8, 12, 19, 21, 22, 25, and 26 not only showed strong antagonistic potency (>55% inhibition) and binding affinities (IC50 <3 μM) to AR, but also showed stronger inhibitory activity to LNCaP cells versus PC-3 cells. Among them, derivative 21 exhibited the highest binding affinity for AR (IC50 = 0.65 μM) and the highest antagonistic potency (76.2% inhibition). Docking studies suggested that the derivative 21 is primarily bound to the AR-LBP site by the hydrophobic interactions. Overall, those results provided experimental methods for developing novel arylpiperazine derivatives as potent AR antagonists.

Design, synthesis, and biological evaluation of N-arylpiperazine derivatives as interferon inducers

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We designed and synthesized a series of arylpiperazine derivatives as interferon inducers.

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We tested different linker system and carbonyl moiety resulted in increase of potency.

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5i exhibited the activity of interferon inducer with EC₅₀ of 13.1 μM and no cytotoxicity.

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5i initiated immune responses by mediating type I IFN signaling.

Type I Interferon (IFN) signaling plays an important role in the immune defense system against virus infection and in the innate immune response, thus IFNs are widely used as anti-viral agents and treatment for immune disorder or cancer. However, there is a growing demand for novel small-molecule IFN inducer due to tolerance, toxicity, or short duration of action following direct administration of IFNs. In this study, we assessed arylpiperazine (ARP) as a new core skeleton of IFN inducer. To investigate structure–activity relationship, we designed and synthesized a series of ARP analogues and evaluated the ability to stimulate IFN response in THP-1 human monocyte cells. Compound 5i was identified as a potent type I IFN inducer as it significantly increased cytokine secretion and increased expression of various IFN-stimulating genes which are representative biomarkers of type I IFN pathway. Our results suggested a beneficial therapeutic potential of 5i as an anti-viral agent.

QSAR, QSTR, and molecular docking studies of the anti-proliferative activity of phenylpiperazine derivatives against DU145 prostate cancer cell lines

Background

Prostate cancer is the most common non-cutaneous cancer in males and accounts for about 4% of all cancer-related deaths in males annually. In silico methods provide faster, economical, and environmentally friendly alternatives to the traditional trial and error method of lead identification and optimization. This study, therefore, was aimed at building a robust QSAR and QSTR model to predict the anti-proliferate activity and toxicity of some phenylpiperazine compounds against the DU145 prostate cancer cell lines and normal prostate epithelial cells as well as carry out molecular docking studies between the compounds and the androgen receptor.

Results

Genetic Function Algorithm–Multilinear Regression approach was employed in building the QSAR and QSTR model. The QSAR model built had statistical parameters R2 = 0.7792, R2adj. = 0.7240, Q2cv = 0.6607, and R2ext = 0.6049 and revealed the anti-proliferate activity to be strongly dependent on the molecular descriptors: VR3_Dzp, VE3_Dzi, Kier3, RHSA, and RDF55v. The QSTR model, on the other hand, had statistical parameters R2 = 0.8652, R2adj. = 0.8315, Q2cv = 0.7788, and R2ext = 0.6344. The toxicity of the compounds was observed to be dependent on the descriptors MATS8c, MATS3s, ETA_EtaP_F, and RDF95m. The molecular descriptors in both models were poorly correlated (R < 0.4) and had variance inflation factors < 3. Molecular docking studies between the androgen receptor and compounds 25 and 32 revealed the compounds primarily formed hydrogen, halogen, and hydrophobic interactions with the receptor.

Conclusion

Findings from this study can be employed in in silico design of novel phenylpiperazine compounds. It can also be employed in predicting the toxicity and anti-proliferate activity of other phenylpiperazine compounds against DU145 prostate cancer cell lines.

Crystal structure of 1-(3-chlorophenyl)-4-(4-(((2,3-dihydro-1H-inden-5-yl)oxy)methyl)phenethyl)piperazine, C28H31ClN2O

C28H31ClN2O, monoclinic, P1̄ (no. 2), a = 21.9309(11) Å, b = 9.9648(5) Å, c = 11.0049(7) Å, β = 93.403(6)°, V = 2400.7(2) Å3, Z = 4, R gt(F) = 0.0566, wR ref(F 2) = 0.1355, T = 293 K.

In silico studies of piperazine derivatives as potent anti-proliferative agents against PC-3 prostate cancer cell lines

Quantitative Structure Activity Relationship studies were carried out on arylpiperazine derivatives to investigate their anti-proliferate activity against prostate PC-3 cancer cell lines. The built model with statistical parameters; R2 = 0.8483, R2 adj = 0.8078, Q2 cv = 0.7122 and external validation (R2 test) 0.6682 revealed that the anti-proliferate activities were strongly dependent on the descriptors: MATS7c, MATS3e, maxwHBa and WPSA-3. The Variance Inflation Factor of the descriptors were all greater than one but less than two and all descriptors were poorly correlated (r < 0.4). A graph of the experimental activities and predicted activities showed a high correlation and a William's plot showed the presence of only one outlier compound. These results are similar to those reported for stable and robust models with high predicting power. Molecular docking studies of compounds 5 (1-phenyl-4-(4-(2-(p-tolyloxy)ethyl)benzyl)piperazine) and 17 (4-(4-((4-phenylpiperazin-1-yl)methyl)phenethoxy)benzonitrile) with the androgen receptor gave binding affinities of -7.5 and -7.1 kcal/mol respectively. Compound 5 formed a more stable complex having hydrogen, electrostatic and hydrophobic bond interactions while compound 17 had hydrogen and hydrophobic bond interactions only. This study provides a roadmap to the design of more potent anti-prostate cancer compounds.

Crystal structure of 2-(3-(2-(4-phenylpiperazin-1-yl)ethyl)benzyl)isoindoline-1,3-dione, C27H27N3O2

C27H27N3O2, triclinic, P1̄ (no. 2), a = 6.9263(4) Å, b = 10.0832(7) Å, c = 17.3531(10) Å, α = 75.708(5)°, β = 87.142(5)°, γ = 74.935(6)°, V = 1133.92(13) Å3, Z = 2, Rgt(F) = 0.0605, wRref(F2) = 0.1661, T = 290(1) K.

Synthesis, biological evaluation and molecular docking of 4-Amino-2H-benzo[h]chromen-2-one (ABO) analogs containing the piperazine moiety

Prostate cancer (PCa) is a major cause of cancer-related male death in worldwide. To develop of potential anti-prostate cancer agents, 22 kinds of 4-Amino-2H-benzo[h]chromen-2-one analogs were designed and synthesized as potent androgen receptor (AR) antagonist through rational drug modification leading to the discovery of a series of novel antiproliferative compounds. Analogs (3, 4, 5, 7, 8, 10, 11, 12, 16, 18, 21, 23, and 24) exhibited potent antagonistic potency against AR (inhibition >50%), and exhibited potent AR binding affinities as well as displayed the higher activities than finasteride toward LNCaP cells (AR-rich) versus PC-3 cells (AR-deficient). Moreover, the docking study suggested that the most potent antagonist 23 mainly bind to AR ligand binding pocket (LBP) site through Van der Waals' force interactions. The structure-activity relationship (SAR) of these designed 4-Amino-2H-benzo[h]chromen-2-one analogs was rationally explored and discussed. Collectively, this work provides a potential lead compound for anticancer agent development related to prostate cancer therapy, and took a step forward towards the development of novel and improved AR antagonists.