The Impact of Inorganic Systems and Photoactive Metal Compounds on Cytochrome P450 Enzymes and Metabolism: From Induction to Inhibition.

While cytochrome P450 (CYP; P450) enzymes are commonly associated with the metabolism of organic xenobiotics and drugs or the biosynthesis of organic signaling molecules, they are also impacted by a variety of species. Metallic nanoparticles, clusters, ions, and complexes can alter CYP expression, modify enzyme interactions with reductase partners, and serve as direct inhibitors. This commonly overlooked topic is reviewed here, with an emphasis on understanding the structural and physiochemical basis for these interactions.

A monoadduct generating Ru(ii) complex induces ribosome biogenesis stress and is a molecular mimic of phenanthriplatin.

Ruthenium complexes are often investigated as potential replacements for platinum-based chemotherapeutics in hopes of identifying systems with improved tolerability and reduced susceptibility to cellular resistance mechanisms. Inspired by phenanthriplatin, a non-traditional platinum agent that contains only one labile ligand, monofunctional ruthenium polypyridyl agents have been developed, but until now, few demonstrated promising anticancer activity. Here we introduce a potent new scaffold, based on [Ru(tpy)(dip)Cl]Cl (tpy = 2,2':6',2''-terpyridine and dip = 4,7-diphenyl-1,10-phenanthroline) in pursuit of effective Ru(ii)-based monofunctional agents.

Ru(II) photocages enable precise control over enzyme activity with red light.

The cytochrome P450 family of enzymes (CYPs) are important targets for medicinal chemistry. Recently, CYP1B1 has emerged as a key player in chemotherapy resistance in the treatment of cancer. This enzyme is overexpressed in a variety of tumors, and is correlated with poor treatment outcomes; thus, it is desirable to develop CYP1B1 inhibitors to restore chemotherapy efficacy.

Biological Investigations of Ru(II) Complexes With Diverse β-diketone Ligands.

The β-diketone scaffold is a commonly used synthetic intermediate, and is a functional group found in natural products such as curcuminoids. This core structure can also act as a chelating ligand for a variety of metals. In order to assess the potential of this scaffold for medicinal inorganic chemistry, seven different κ-O,O'-chelating ligands were used to construct Ru(II) complexes with polypyridyl co-ligands, and their biological activity was evaluated.

Biological activities of polypyridyl-type ligands: implications for bioinorganic chemistry and light-activated metal complexes.

Polypyridyl coordinating ligands are common in metal complexes used in medicinal inorganic chemistry. These ligands possess intrinsic cytotoxicity, but detailed data on this phenomenon are sparse, and cytotoxicity values vary widely and are often irreproducible. To provide new insights into the biological effects of bipyridyl-type ligands and structurally related metal-binding systems, reports of free ligand cytotoxicity were reviewed.

Fine-Feature Modifications to Strained Ruthenium Complexes Radically Alter Their Hypoxic Anticancer Activity.

In an earlier study of π-expansive ruthenium complexes for photodynamic and photochemo-therapies, it was shown that a pair of structural isomers differing only in the connection point of a naphthalene residue exhibited vastly different biological activity. These isomers are further explored in this paper through the activity of their functionalized derivatives. In normoxia, the inactive 2-NIP isomer (5) can be made as photocytotoxic as the active 1-NIP isomer (1) by functionalizing with methyl or methoxy groups, while methoxy variants of the 1-NIP isomer became inactive.

Avobenzone incorporation in a diverse range of Ru(II) scaffolds produces potent potential antineoplastic agents.

Four structurally distinct classes of polypyridyl ruthenium complexes containing avobenzone exhibited low micromolar and submicromolar potencies in cancer cells, and were up to 273-fold more active than the parent ligand. Visible light irradiation enhanced the cytotoxicity of some complexes, making them promising candidates for combined chemo-photodynamic therapy.

Photochemical and Photobiological Properties of Pyridyl-pyrazol(in)e-Based Ruthenium(II) Complexes with Sub-micromolar Cytotoxicity for Phototherapy.

The discovery of new light-triggered prodrugs based on ruthenium (II) complexes is a promising approach for photoactivated chemotherapy (PACT). The light-mediated activation of "strained" Ru(II) polypyridyl complexes resulted in ligand release and produced a ligand-deficient metal center capable of forming covalent adducts with biomolecules such as DNA. Based on the strategy of exploiting structural distortion to activate photochemistry, biologically active small molecules were coordinated to a Ru(II) scaffold to create light-triggered dual-action agents.

Toward Optimal Ru(II) Photocages: Balancing Photochemistry, Stability, and Biocompatibility Through Fine Tuning of Steric, Electronic, and Physiochemical Features.

Ru(II) complex photocages are used in a variety of biological applications, but the thermal stability, photosubstitution quantum yield, and biological compatibility of the most commonly used Ru(II) systems remain unoptimized. Here, multiple compounds used in photocaging applications were analyzed and found to have several unsatisfactory characteristics. To address these deficiencies, three new scaffolds were designed to improve key properties through modulation of a combination of electronic, steric, and physiochemical features.

Ru(ii) complexes with diazine ligands: electronic modulation of the coordinating group is key to the design of "dual action" photoactivated agents.

Coordination complexes can be used to photocage biologically active ligands, providing control over the location, time, and dose of a delivered drug. Dual action agents can be created if both the ligand released and the ligand-deficient metal center effect biological processes. Ruthenium(ii) complexes coordinated to pyridyl ligands generally are only capable of releasing one ligand in H2O, wasting equivalents of drug molecules, and producing a Ru(ii) center that is not cytotoxic.

Structure-activity relationships of anticancer ruthenium(II) complexes with substituted hydroxyquinolines.

8-Hydroxyquinolines (HQ), including clioquinol, possess cytotoxic properties and are widely used as ligands for metal-based anticancer drug research. The number and identity of substituents on the HQ can have a profound effect on activity for a variety of inorganic compounds. Ruthenium complexes of HQ exhibit radically improved potencies, and operate by a new, currently unknown, mechanism of action.

Photochemical Properties and Structure-Activity Relationships of Ru Complexes with Pyridylbenzazole Ligands as Promising Anticancer Agents.

Ruthenium complexes capable of light-triggered cytotoxicity are appealing potential prodrugs for photodynamic therapy (PDT) and photoactivated chemotherapy (PACT). Two groups of Ru(II) polypyridyl complexes with 2-(2-pyridyl)-benzazole ligands were synthesized and investigated for their photochemical properties and anticancer activity to compare strained and unstrained systems that are likely to have different biological mechanisms of action. The structure-activity relationship was focused on the benzazole core bioisosterism and replacement of coligands in Ru(II) complexes.

5-Ene-4-thiazolidinones induce apoptosis in mammalian leukemia cells.

The article presents the synthesis of 5-ene-4-thiazolidinone derivatives with pyrazole core linked by enamine group. The structure and purity of compounds were confirmed by analytical and spectral data including X-ray analysis. Target compounds were screened for their anticancer activity and selective antileukemic action was confirmed.

Synthetic approaches, structure activity relationship and biological applications for pharmacologically attractive pyrazole/pyrazoline-thiazolidine-based hybrids.

The features of the chemistry of 4-thiazolidinone and pyrazole/pyrazolines as pharmacologically attractive scaffolds were described in a number of reviews in which the main approaches to the synthesis of mentioned heterocycles and their biological activity were analyzed. However, the pyrazole/pyrazoline-thiazolidine-based hybrids as biologically active compounds is poorly discussed in the context of pharmacophore hybrid approach. Therefore, the purpose of this review is to summarize the data about the synthesis and modification of heterocyclic systems with thiazolidine and pyrazoline or pyrazole fragments in molecules as promising objects of modern bioorganic and medicinal chemistry.

3D-MoRSE descriptors explained.

3D-MoRSE is a very flexible 3D structure encoding framework for chemoinformatics and QSAR purposes due to the range of scattering parameter values and variety of weighting schemes used. While arising in many QSAR studies, up to this time they were considered as hardly interpreted and were treated like a "black box". This study is intended to lift the veil of mystery, providing a comprehensible way to the interpretation of 3D-MoRSE descriptors in QSAR/QSPR studies.

Synthesis of pyrazoline-thiazolidinone hybrids with trypanocidal activity.

A series of novel 4-thiazolidinone-pyrazoline conjugates have been synthesized and tested for anti-Trypanosoma brucei activity. Screening data allowed us to identify five thiazolidinone-pyrazoline hybrids, which possess promising trypanocidal activity, with IC50 ≤ 1.2 μM.

Bradykinin antagonists and thiazolidinone derivatives as new potential anti-cancer compounds.

Glioblastoma (GB), the most aggressive brain tumour, and mantle cell lymphoma (MCL), a rare but very aggressive type of lymphoma, are highly resistant to chemotherapy. GB and MCL chemotherapy gives very modest results, the vast majority of patients experience recurrent disease. To find out the new treatment modality for drug-resistant GB and MCL cells, combining of bradykinin (BK) antagonists with conventional temozolomide (TMZ) treatment, and screening of thiazolidinones derivatives were the main objectives of this work.

Computational Search for Possible Mechanisms of 4-Thiazolidinones Anticancer Activity: The Power of Visualization.

Public databases of NCI-60 tumor cell line screen results and measurements of molecular targets in the NCI-60 panel give the opportunity to assign possible anticancer mechanism to compounds with positive outcome from antitumor assay. Here, the novel protocol of NCI databases mining where inferences are based on the visualization is presented and utilized with the aim to identify putative biological routes of 4-thiazolidinones anticancer effect. As a result, highly potent 4-thiazolidinone-pyrazoline-isatin conjugates show the similarity of activity patterns with puromycin and CBU-028 and their pattern is also highly correlated with fraction of methylated CpG sites in CD34, AF5q31 and SYK.

Synthesis and biological activity evaluation of 5-pyrazoline substituted 4-thiazolidinones.

A series of novel 5-pyrazoline substituted 4-thiazolidinones have been synthesized. Target compounds were evaluated for their anticancer activity in vitro within DTP NCI protocol. Among the tested compounds, the derivatives 4d and 4f were found to be the most active, which demonstrated certain sensitivity profile toward the leukemia subpanel cell lines with GI₅₀ value ranges of 2.

Synthesis of new 4-thiazolidinone-, pyrazoline-, and isatin-based conjugates with promising antitumor activity.

The synthesis and antitumor activity screening of novel 3-[2-(3,5-diaryl-4,5-dihydropyrazol-1-yl)-4-oxo-4,5-dihydro-1,3-thiazol-5-ylidene]-2,3-dihydro-1H-indol-2-ones 1-23 and 3-(3,5-diarylpyrazol-1-yl)-2,3-dihydro-1H-indol-2-ones 24-39 are performed. In vitro anticancer activity of the synthesized compounds was tested by the National Cancer Institute. Most of them displayed anticancer activity on leukemia, melanoma, lung, colon, CNS, ovarian, renal, prostate, and breast cancers cell lines.

Synthesis and anticancer activity of isatin-based pyrazolines and thiazolidines conjugates.

The synthesis and antitumor activity screening of novel isatin based conjugates with thiazolidine and pyrazoline moieties were performed. Reaction of 3,5-diaryl-4,5-dihydropyrazoles with chloroacetyl chloride yielded starting 2-chloro-1-(3,5-diaryl-4,5-dihydropyrazol-1-yl)-ethanones which were utilized in alkylation of isatin and 5-bromoisatin. Thus, corresponding 1-[2-(3,5-diaryl-4,5-dihydropyrazol-1-yl)-2-oxoethyl]-1H-indole-2,3-diones (1a-1d) have been obtained.

Synthesis and anticancer activity evaluation of 4-thiazolidinones containing benzothiazole moiety.

Antitumor screening of several novel 4-thiazolidinones with benzothiazole moiety has been performed. Reactions of (benzothiazole-2-yl)hydrazine with trithiocarbonyl diglycolic acid or 6-methyl-2-aminobenzothiazole with 2-carbethoxymethylthio-2-thiazoline-4-one have yielded starting 3- (1) or 2-substituted (11) 4-thiazolidinones which have been subsequently utilized in a Knoevenagel condensation for obtaining a series of 5-arylidene derivatives 2-10, 12-16. Compound 11 has been obtained alternatively by a counter synthesis method based on the reaction of 2-chloro-N-(6-methylbenzothiazol-2-yl)-acetamide and ammonium thiocyanate.

Synthesis of novel thiazolone-based compounds containing pyrazoline moiety and evaluation of their anticancer activity.

To examine the anticancer activity several novel thiazolone-based compounds containing 5-aryl-3-phenyl-4,5-dihydro-1H-pyrazol-1-yl framework were obtained. Reaction of 5-aryl-3-phenyl-4,5-dihydropyrazole with 4-thioxo-2-thiazolidinone or 2-carbethoxymethylthio-2-thiazoline-4-one yielded starting 4- (1 and 2) or 2-substituted (11 and 12) thiazolones which were utilized in Knoevenagel condensation for obtaining a series of 5-arylidene derivatives 3-10, 13-18. Alternatively 11, 12 and their 5-arylidene derivatives were synthesized by means of 3-phenyl-5-aryl-1-thiocarbamoyl-2-pyrazoline as S,N-binucleophile via [2+3]-cyclocondensation approach.