Novel pyrrolo[2,1-f][1,2,4]triazin-4-amines: Dual inhibitors of EGFR and HER2 protein tyrosine kinases

A novel series of 5-((4-aminopiperidin-1-yl)methyl)-pyrrolo[2,1-f][1,2,4]triazin-4-amines with small aniline substituents at the C4 position were optimized for dual EGFR and HER2 protein tyrosine kinase inhibition. Compound 8l exhibited promising oral efficacy in both EGFR and HER2-driven human tumor xenograft models.     

Synthesis of carbon-11-labeled 4-(phenylamino)-pyrrolo[2,1-f][1,2,4]triazine derivatives as new potential PET tracers for imaging of p38α mitogen-activated protein kinase

The reference standards methyl 4-(2-methyl-5-(methoxycarbamoyl)phenylamino)-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylate (10a), methyl 4-(2-methyl-5-(ethoxycarbamoyl)phenylamino)-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylate (10b) and corresponding precursors 4-(2-methyl-5-(methoxycarbamoyl)phenylamino)-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylic acid (11a), methyl 4-(2-methyl-5-(ethoxycarbamoyl)phenylamino)-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylic acid (11b) were synthesized from methyl crotonate and 3-amino-4-methylbenzoic acid in multiple steps with moderate to excellent yields. The target tracer [¹¹C]methyl 4-(2-methyl-5-(methoxycarbamoyl)phenylamino)-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylate ([¹¹C]10a) and [¹¹C]methyl 4-(2-methyl-5-(ethoxycarbamoyl)phenylamino)-5-methylpyrrolo[2,1-f][1,2,4]triazine-6-carboxylate ([¹¹C]10b) were prepared from their corresponding precursors with [¹¹C]CH₃OTf under basic condition through O-[¹¹C]methylation and isolated by a simplified solid-phase extraction (SPE) method in 50–60% radiochemical yields at end of bombardment (EOB) with 185–555 GBq/μmol specific activity at end of synthesis (EOS).     

Synthesis,structure elucidation and in vitro anticancer activities of novel derivatives of diethyl (2E)-2-[(2E)-(1-arylimidazolidin-2-ylidene)hydrazono]succinate and ethyl (4-oxo-8-aryl-4,6,7,8-tetrahydroimidazo[2,1-c][1,2,4]triazin-3-yl)acetate

The worked out and optimized synthesis routes and remarkable antitumour activities in vitro of novel polynitrogenated derivatives of diethyl (2E)-2-[(2E)-(1-arylimidazolidin-2-ylidene)hydrazono]succinate (7–10) and ethyl (4-oxo-8-aryl-4,6,7,8-tetrahydroimidazo[2,1-c][1,2,4]triazin-3-yl)acetate (11–16) are presented. Small molecules based on the privileged 7,8-dihydroimidazo[2,1-c][1,2,4]triazin-4(6H)-one scaffold (11–16) were obtained with fairly modest to good overall yields by very facile addition reactions of the nucleophilic centred 1-aryl-2-hydrazonoimidazolidine hydroiodides to diethyl acetylenedicarboxylate (DEAD) in the presence of triethylamine (TEA) and a subsequent cyclocondensation of the putative intermediate chain hydrazones. Heterobicyclic products 12 and 14–16 could also be prepared in high overall yields by an effective intramolecular cyclocondensation of the isolated stable and antiproliferative active heterocyclic hydrazones, namely, diethyl (2E)-2-[(2E)-(1-arylimidazolidin-2-ylidene)hydrazono]succinates (7–10), performed in refluxing DMF. These intermediates are the first products to be formed in the result of an addition of the nucleophilic reactants, namely, 1-aryl-2-hydrazonoimidazolidines of the 1–6 type, bearing the basic nitrogen atom of the hydrazono moiety (N–NH₂), to the carbon–carbon triple bond of the highly electrophilic alkyne, that is, DEAD. Molecular structures of the synthesized compounds (7–16) in the DMSO-d₆ solutions were verified by ¹H NMR and ¹³C NMR spectral data. These were finally confirmed based on the advanced 2D HMBC and HMQC NMR experiments, which were performed for the two representatives (8 and 11) of the two synthesized sets of the bioactive substances. Among the majority of antiproliferative active molecules, the disclosed herein ethyl [4-oxo-8-(3-chlorophenyl)-4,6,7,8-tetrahydroimidazo[2,1-c][1,2,4]triazin-3-yl]acetate (14) is proposed as a promising lead structure for the design of novel highly selective antitumour agents because of the distinctly marked lower cytotoxicity towards the primary cell line of normal HSF cells and several-fold higher against cancer cells used. A double fluorochrome mix-staining was performed in order to find out about the possible mode of action by which this novel small heterobicycle reveals remarkable antiproliferative effects in vitro. Taking into account the obtained double staining results, this small molecule was identified as capable of inducing significantly higher levels of necrotic cells in human cancer cell lines (T47D and HeLa) than in normal HSF cells. Furthermore, its cytotoxicity against cells was found to be connected to the predominant induction of necrosis over apoptosis.     

Synthesis and in vitro evaluation of [18F]BMS-754807: A potential PET ligand for IGF-1R

Radiosynthesis and in vitro evaluation of [¹⁸F](S)-1-(4-((5-cyclopropyl-1H-pyrazol-3-yl)amino)pyrrolo[2,1-f][1,2,4]triazin-2-yl)-N-(6-fluoropyridin-3-yl)-2-methylpyrrolidine-2-carboxamide ([¹⁸F]BMS-754807 or [¹⁸F]1) a specific IGF-1R inhibitor was performed. [¹⁸F]1 demonstrated specific binding in vitro to human cancer tissues. Synthesis of reference standard 1 and corresponding bromo derivative (1a), the precursor for radiolabeling were achieved from 2,4-dichloropyrrolo[2,1-f][1,2,4]triazine (4) in three steps with 50% overall yield. The radioproduct was obtained in 8% yield by reacting 1a with [¹⁸F]TBAF in DMSO at 170 °C at high radiochemical purity and specific activity (1–2 Ci/μmol, N = 10). The proof of concept of IGF-IR imaging with [¹⁸F]1 was demonstrated by in vitro autoradiography studies using pathologically identified surgically removed grade IV glioblastoma, breast cancer and pancreatic tumor tissues. These studies indicate that [¹⁸F]1 can be a potential PET tracer for monitoring IGF-1R.     

Crystal structure,antitumour and antimetastatic activities of disubstituted fused 1,2,4-triazinones

Molecular structure of 3,8-disubstituted 7,8-dihydroimidazo[2,1-c][1,2,4]triazin-4(6H)-ones (8–14) was confirmed by X-ray crystallography of 14. All the compounds were evaluated for their antitumour and antimetastatic activities in vitro. Furthermore, their cytotoxicities towards human normal cell line—HSF cells were established, allowing us to point out some structure–activity relationships. Among them, imidazotriazinone 12, revealing remarkable dose-dependent viability decreases in human myeloma RPMI 8226 cells, was found to be completely non-toxic towards normal HSF cells. In addition, heterobicycles 8–12 were proved to exhibit significant antimetastatic potentials in the motility assay.     

Imidazo[1,5-a][1,2,4]-triazolo[1,5-d][1,4]benzodiazepines as potent and highly selective GABAA α5 inverse agonists with potential for the treatment of cognitive dysfunction

In a search for GABA_A α5 ligands that combine high subtype binding selectivity with a marked inverse agonism imidazo[1,5-a][1,2,4]-triazolo[1,5-d][1,4]benzodiazepines were identified as a promising class. A short tandem reaction allowed rapid access to this chemical series, thereby facilitating rapid SAR generation which guided the optimization process. Two compounds (10e and 11f) were found to be active in an in vivo paradigm for cognitive improvement.     

Novel [1,2,4]triazolo[1,5-a]pyrimidine derivatives as potent antitubulin agents: Design,multicomponent synthesis and antiproliferative activities

As restricted CA-4 analogues, a novel series of [1,2,4]triazolo[1,5-a]pyrimidines possessing 3,4,5-trimethoxylphenyl groups has been achieved successfully via an efficient one-pot three-component reaction of 3-(3,4,5-trimethoxyphenyl)-1H-1,2,4-triazol-5-amine, 1,3-dicarbonyl compounds and aldehydes. Initial biological evaluation demonstrated some of target compounds displayed potent antitumor activity in vitro against three cancer cell lines. Among them, the most highly active analogue 26 inhibited the growth of HeLa, and A549 cell lines with IC₅₀ values at 0.75, and 1.02 μM, respectively, indicating excellent selectivity over non-tumoural cell line HEK-293 (IC₅₀ = 29.94 μM) which suggested that the target compounds might possess a high safety index. Moreover, cell cycle analysis illustrated that the analogue 26 significantly induced HeLa cells arrest in G2/M phase, meanwhile the compound could dramatically affect cell morphology and microtubule networks. In addition, compound 28 exhibited potent anti-tubulin activity with IC₅₀ values of 9.90 μM, and molecular docking studies revealed the analogue occupied the colchicine-binding site of tubulin. These observations suggest that [1,2,4]triazolo[1,5-a]pyrimidines represent a new class of tubulin polymerization inhibitors and well worth further investigation aiming to generate potential anticancer agents.     

Synthesis and anti-tumor activity of [1,4] dioxino [2,3-f] quinazoline derivatives as dual inhibitors of c-Met and VEGFR-2

Both c-Met and VEGFR-2 were important targets for cancer therapies. In order to develop reversible and non-covalent c-Met and VEGFR-2 dual inhibitors, a series of [1,4]dioxino[2,3-f]quinazoline derivatives were designed and synthesized. The enzyme assay demonstrated that most target compounds had inhibition potency on both c-Met and VEGFR-2 with IC₅₀ values in nanomolar range especially compounds 7m and 7k. Based on further cell proliferation assay in vitro, compound 7k showed significantly anti-tumor activity in vivo on a hepatocellular carcinoma (MHCC97H cells) xenograft mouse model. We docked the compound 7m with c-Met and VEGFR-2 kinases, and interpreted the SAR of these analogues. All results indicated that the target compounds were dual inhibitors of c-Met and VEGFR-2 kinases that held promising potential in cancer therapy.     

Synthesis,cytotoxicity, antimicrobial and anti-biofilm activities of novel pyrazolo[3,4-b]pyridine and pyrimidine functionalized 1,2,3-triazole derivatives

A series of novel pyrazolo[3,4-b]pyridine and pyrimidine functionalized 1,2,3-triazole derivatives 8a–g and 9a–g were prepared starting from 6-trifluoromethylpyridine-2(1H)one 2 via selective O-alkylation, followed by cyclisation using hydrazine hydrate to obtain 6-(trifluoromethyl)-1H-pyrazolo[3,4-b]pyridin-3-amine 4. Compound 4 was diazotized followed by reaction with sodium azide, resulted in 3-azido-6-(trifluoromethyl)-1H-pyrazolo[3,4-b]pyridine 5. Compound 5 was further cyclized with N-/O-propargylated pyrimidine derivatives under Sharpless conditions and obtained compounds 6 and 7, respectively. Each set of compounds 6 and 7 were alkylated with different alkyl halides and obtained respective products 8 and 9. All the products were screened for cytotoxicity against four human cancer cell lines such as A549-Lung (CCL-185), MCF7-Breast (HTB-22), DU145-Prostate (HTB-81) and HeLa-Cervical (CCL-2), compounds 9d, 9e and 9f which showed promising activity have been identified. The products were also screened for antimicrobial, anti bio-film and MBC activities. Promising compounds in each case have been identified.     

Synthesis,anti-thymidine phosphorylase activity and molecular docking of 5-thioxo-[1,2,4]triazolo[1,5-a][1,3,5]triazin-7-ones

In our lead finding program, a series of 5-thioxo-[1,2,4]triazolo[1,5-a][1,3,5]triazin-7-ones and their 5-thio-alkyl derivatives were designed and synthesized which contained different substituents at ortho-position of 2-phenyl ring attached to the fused ring structure. The preliminary pharmacological evaluation demonstrated that the synthesized compounds exhibited a varying degree of inhibitory activity towards thymidine phosphorylase (TP), comparable to reference compound, 7-Deazaxanthine (7-DX, 2) (IC₅₀ value = 42.63 μM). The study also inferred that the ortho-substituted group at the phenyl ring and 5-thio-alkyl moiety imparted steric hindrance effects in the binding site of the enzyme, leading to a reduced inhibitory response. In addition, compound 3a was identified as a mixed-type inhibitor of TP. Moreover, computational docking study was performed to illustrate the important structural information on the plausible ligand-enzyme binding interactions.     

Design,synthesis, and evaluation of novel VEGFR2 kinase inhibitors: Discovery of [1,2,4]triazolo[1,5-a]pyridine derivatives with slow dissociation kinetics

For the purpose of discovering novel type-II inhibitors of vascular endothelial growth factor receptor 2 (VEGFR2) kinase, we designed and synthesized 5,6-fused heterocyclic compounds bearing a anilide group. A co-crystal structure analysis of imidazo[1,2-b]pyridazine derivative 2 with VEGFR2 revealed that the N1-nitrogen of imidazo[1,2-b]pyridazine core interacts with the backbone NH group of Cys919. To retain this essential interaction, we designed a series of imidazo[1,2-a]pyridine, [1,2,4]triazolo[1,5-a]pyridine, thiazolo[5,4-b]pyridine, and 1,3-benzothiazole derivatives maintaining a ring nitrogen as hydrogen bond acceptor (HBA) at the corresponding position. All compounds thus designed displayed strong inhibitory activity against VEGFR2 kinase, and the [1,2,4]triazolo[1,5-a]pyridine 13d displayed favorable physicochemical properties. Furthermore, 13d inhibited VEGFR2 kinase with slow dissociation kinetics and also inhibited platelet-derived growth factor receptor (PDGFR) kinases. Oral administration of 13d showed potent anti-tumor efficacy in DU145 and A549 xenograft models in nude mice.     

Synthesis and cytotoxic activity of new azepino[3′,4′:4,5]pyrrolo[2,1-a]isoquinolin-12-ones

A series of azepino[3′,4′:4,5]pyrrolo[2,1-a]isoquinolin-12-ones (3a–f), that were conformationally restricted analogs of lead compound 2, were designed as potential cytotoxic compounds and synthesized using a radical oxidative aromatic substitution reaction as the key step. Compounds 3a–f were tested on five tumor cell lines to determine the conformational requirements for biological activity of compound 2. The results show that conformational restrictions on compound 2, generating the derivatives 3a–f, do not appreciably reduce the cytotoxic activity of 2, although compound 3d (R = Br) showed good activity against U-251 cells. Preliminary structure–activity relationship studies with these compounds revealed the importance of halogens bonded to the isoquinoline moiety. Additionally, derivatives 3f (R = NO₂) and 3b (R = F) were cytotoxic to PC-3 and K-562 cells. However, none of the azepino[3′,4′:4,5]pyrrolo[2,1-a]isoquinolinones inhibited the enzymatic activity of CDK1/cyclin B, CDK5/p25, or GSK-3.     

Design,synthesis, and evaluation of pyrrolo[2,1-f][1,2,4]triazine derivatives as novel hedgehog signaling pathway inhibitors

A novel series of Hh signaling pathway inhibitors were designed by replacing the pyrimidine skeleton of our earlier reported lead compound 1 with pyrrolo[2,1-f][1,2,4]triazine scaffold. Starting from this new scaffold, SAR exploration was investigated based on structural modification on A-ring, C-ring and D-ring. And several much potent compounds were studies in vivo to profile their pharmacokinetic properties. Finally, optimization leads to the identification of compound 19a, a potent Hh signaling pathway inhibitor with superior potency in vitro and satisfactory pharmacokinetic properties in vivo.     

Efficient synthesis of antifungal active 9-substituted-3-aryl-5H,13aH-quinolino[3,2-f][1,2,4]triazolo[4,3-b][1,2,4]triazepines in ionic liquids

The title compounds, 9-substituted-3-aryl-5H,13aH-quinolino[3,2-f][1,2,4]triazolo[4,3-b][1,2,4]triazepines 8, are synthesized from 5-aryl-3,4-diamino-1,2,4-triazoles 5 and 2-chloro-3-formylquinolines 7 in ionic liquid as solvent under microwave heating as well as using oil-bath heating at 80 °C. The products are obtained in the good to moderate yields and in high purity. These compounds have been screened for antifungal activity. The screening data indicate that the compounds 8a, 8b, 8c and 8d show excellent activity against Aspergillus niger 1000 μg concentration and Pencillium notatum species at 500 μg as well as 1000 μg concentrations whereas, these compounds show good to moderate activity against Aspergillus flavus and Rhizopus species at both the concentrations. Moreover, ionic liquid is found to be recyclable for at least three consecutive runs what makes the process cost-effective and economic that lead to the area of Green Chemistry as recyclability is one of the most important feature of Green Chemistry.     

Design,synthesis, assessment,and molecular docking of novel pyrrolopyrimidine (7-deazapurine) derivatives as non-nucleoside hepatitis C virus NS5B polymerase inhibitors

Hepatitis C virus (HCV) infection is highly persistent and presents an unmet medical need requiring more effective treatment options. This has spurred intensive efforts to discover novel anti-HCV agents. The RNA-dependent RNA polymerase (RdRp), NS5B of HCV, constitutes a selective target for drug discovery due to its absence in human cells; also, it is the centerpiece for viral replication. Here, we synthesized novel pyrrole, pyrrolo[2,3-d]pyrimidine and pyrrolo[3,2-e][1,2,4]triazolo[4,3-c]pyrimidine derivatives. The non-toxic doses of these compounds on Huh 7.5 cell line were determined and their antiviral activity against HCVcc genotype 4a was examined. Compounds 7j, 7f, 5c, 12i and 12f showed significant anti HCV activity. The percent of reduction for the non-toxic doses of 7j, 7f, 5c, 12i and 12f were 90%, 76.7 ± 5.8%, 73.3 ± 5.8%, 70% and 63.3 ± 5.8%, respectively. The activity of these compounds was interpreted by molecular docking against HCV NS5B polymerase enzyme.     

Design and synthesis of pyrazolo[3,4-d]pyrimidinone derivatives: Discovery of selective phosphodiesterase-5 inhibitors

A novel series of 1,6-disubstituted pyrazolo[3,4-d]pyrimidin-7-one derivatives, 2a-h, 4a-d, 5 and 6, were successfully synthesized, which showed promising, and potent inhibition of phosphodiesterase 5 (PDE5). The inhibitory activities of 5, 4b, 2a, 2d, 2f, 4d and 4a against PDE5 were similar to that of sildenafil (100%). These compounds exhibited potent relaxant effects on isolated rat cavernosum tissue with pEC₅₀ values ranging from 8.31 to 5.16 µM. Pyrazolo[3,4-d]pyrimidin-7-one scaffolds have been rationally designed via consecutive molecular modelling studies prior to their synthesis and biological evaluation. In addition, the results of the pharmacophore-based virtual screening revealed that 1v0p_PVB might have promising activity as a PDE-5 inhibitor.     

1,3-Dialkyl-substituted tetrahydropyrimido[1,2-f]purine-2,4-diones as multiple target drugs for the potential treatment of neurodegenerative diseases

Adenosine receptors and monoamine oxidases are drug targets for neurodegenerative diseases such as Parkinson’s and Alzheimer’s disease. In the present study we prepared a library of 55 mostly novel tetrahydropyrimido[2,1-f]purinediones with various substituents in the 1- and 3-position (1,3-dimethyl, 1,3-diethyl, 1,3-dipropyl, 1-methyl-3-propargyl) and broad variation in the 9-position. A synthetic strategy to obtain 3-propargyl-substituted tetrahydropyrimido[2,1-f]purinedione derivatives was developed. The new compounds were evaluated for their interaction with all four adenosine receptor subtypes and for their ability to inhibit monoamine oxidases (MAO). Introduction of mono- or di-chloro-substituted phenyl, benzyl or phenethyl residues at N9 of the 1,3-dimethyl series led to the discovery of a novel class of potent MAO-B inhibitors, the most potent compound being 9-(3,4-dichlorobenzyl)-1,3-dimethyl-6,7,8,9-tetrahydropyrimido[1,2-f]purine-2,4(1H,3H)-dione (21g, IC₅₀ human MAO-B: 0.0629 μM), which displayed high selectivity versus the other investigated targets. Potent dually active A₁/A_2A adenosine receptor antagonists were identified, for example, 9-benzyl-1-methyl-3-propargyl-6,7,8,9-tetrahydropyrimido[1,2-f]purine-2,4(1H,3H)dione (19f, K_i, human receptors, A₁: 0.249 μM, A_2A: 0.253 μM). Several compounds showed triple-target inhibition, the best compound being 9-(2-methoxybenzyl)-1-methyl-3-(prop-2-ynyl)-6,7,8,9-tetrahydro pyrimido [1,2-f]purine-2,4(1H,3H)-dione (19g, K_i A₁: 0.605 μM, K_i A_2A: 0.417 μM, IC₅₀ MAO-B: 1.80 μM). Compounds inhibiting several different targets involved in neurodegeneration may exhibit additive or even synergistic effects in vivo.     

Discovery of 7-(3-(piperazin-1-yl)phenyl)pyrrolo[2,1-f][1,2,4]triazin-4-amine derivatives as highly potent and selective PI3Kδ inhibitors

As demonstrated in preclinical animal models, the disruption of PI3Kδ expression or its activity leads to a decrease in inflammatory and immune responses. Therefore, inhibition of PI3Kδ may provide an alternative treatment for autoimmune diseases, such as RA, SLE, and respiratory ailments. Herein, we disclose the identification of 7-(3-(piperazin-1-yl)phenyl)pyrrolo[2,1-f][1,2,4]triazin-4-amine derivatives as highly potent, selective and orally bioavailable PI3Kδ inhibitors. The lead compound demonstrated efficacy in an in vivo mouse KLH model.     

Synthesis and molecular docking study of new benzofuran and furo[3,2-g]chromone-based cytotoxic agents against breast cancer and p38α MAP kinase inhibitors

This study deals with synthesis of a new set of benzofuran and 5H-furo[3,2-g]chromone linked various heterocyclic functionalities using concise synthetic approaches aiming to gain new antiproliferative candidates against MCF-7 breast cancer cells of p38α MAP kinase inhibiting activity. The biological data proved the significant sensitivity of breast cancer cell lines MCF-7 towards most of the prepared compounds in comparison with doxorubicin. In addition, compounds IIa,b, Va,b, VIa,b, VIIa,b, VIIIa,b, XIc showed significant in vitro p38α MAPK inhibiting potency comparable to the reference standard SB203580. Cell cycle analysis and apoptosis detection data demonstrated that compound VIa induced G2/M phase arrest and apoptosis in MCF-7 cancer cells, in addition to its activation of the caspases-9 and -3. Gold molecular docking studies rationalized the highly acceptable correlation between the calculated docking scores of fitness and the biological data of p38α MAP kinase inhibition. The newly prepared benzofuran and 5H-furo[3,2-g]chromone derivatives might be considered as new promising nuclei in anti-breast cancer chemotherapeutics for further functionalization, optimization and in-depth biological studies.     

Novel multi-target directed ligands based on annelated xanthine scaffold with aromatic substituents acting on adenosine receptor and monoamine oxidase B. Synthesis,in vitro and in silico studies

N9-Benzyl-substituted imidazo-, pyrimido- and 1,3-diazepino[2,1-f]purinediones were designed as dual-target-directed ligands combining A_2A adenosine receptor (AR) antagonistic activity with blockade of monoamine oxidase B (MAO-B). A library of 37 novel compounds was synthesized and biologically evaluated in radioligand binding studies at AR subtypes and for their ability to inhibit MAO-B. A systematic modification of the tricyclic structures based on a xanthine core by enlargement of the third heterocyclic ring or attachment of various substituted benzyl moieties resulted in the development of 9-(2-chloro-6-fluorobenzyl)-1,3-dimethyl-6,7,8,9-tetrahydropyrimido[2,1-f]purine-2,4(1H,3H)-dione (9u; K_i human A_2AAR: 189?nM and IC₅₀ human MAO-B: 570?nM) as the most potent dual acting ligand of the series displaying high selectivity versus related targets. Moreover, some potent, selective MAO-B inhibitors were identified in the group of pyrimido- and 1,3-diazepino[2,1-f]purinediones. Compound 10d (10-(3,4-dichlorobenzyl)-1,3-dimethyl-7,8,9,10-tetrahydro-1H-[1,3]diazepino[2,1-f]purine-2,4(3H,6H)-dione) displayed an IC₅₀ value at human MAO-B of 83?nM. Analysis of structure–activity relationships was complemented by molecular docking studies based on previously published X-ray structures of the protein targets. An extended biological profile was determined for selected compounds including in vitro evaluation of potential hepatotoxicity calculated in silico and antioxidant properties as an additional desirable activity. The new molecules acting as dual target drugs may provide symptomatic relief as well as disease-modifying effects for neurodegenerative diseases, in particular Parkinson’s disease.