High Antiproliferative Activity Research Articles

Novel Copper(II) Complexes with N4,S-Diallylisothiosemicarbazones as Potential Antibacterial/Anticancer Drugs

The six new copper(II) coordination compounds [Cu(HL1)Cl2] (1), [Cu(HL1)Br2] (2), [Cu(H2O)(L1)(CH3COO)]·1.75H2O (3), [Cu(HL2)Cl2] (4), [Cu(HL2)Br2] (5), [Cu(H2O)(L2)(CH3COO)] (6) were synthesized with 2-formyl- and 2-acetylpyridine N4,S-diallylisothiosemicarbazones (HL1 and HL2). The new isothiosemicarbazones were characterized by NMR, FTIR spectroscopy, and X-ray crystallography ([H2L2]I). All copper(II) coordination compounds were characterized by elemental analysis, FTIR spectroscopy, and molar conductivity of their 1mM methanol solutions. Furthermore, the crystal structure of complex 3 was determined using single-crystal X-ray diffraction analysis. The studied complexes manifest antibacterial and antifungal activities, that in many cases are close to the activity of medical drugs used in this area, and in some cases even exceed them. The complexes 4 and 5 showed the highest indexes of selectivity (280 and 154) and high antiproliferative activity against BxPC-3 cell lines that surpass the activity of Doxorubicin. The complexes 1–3 also manifest antioxidant activities against cation radicals ABTS•+ that are close to that of trolox, the antioxidant agent used in medicine.

Synthesis and biological evaluation of atropisomeric tetrahydroisoquinolines overcoming docetaxel resistance in triple-negative human breast cancer cells

Herein, atropisomeric 8-aryltetrahydroisoquinolines have been synthesized and biologically evaluated. Based on our structure–activity relationship study, a highly bioactive racemic compound has been produced, and it exhibited high antiproliferative activities against various cancer cell lines, including docetaxel-resistant breast cancer cell lines. Each enantiomer can be synthesized in an enantioselective manner by employing the chiral phosphoric acid-catalyzed atroposelective Pictet–Spengler cyclization. An axially (R)-configured enantiomer showed a higher biological activity compared with the axially (S)-configured enantiomer. Further biological studies suggested that the (R)-enantiomer overcomes docetaxel resistance via the downregulation of signal transducer and activator of transcription 3 activation and consequently induces cellular apoptosis in docetaxel-resistant triple-negative breast cancer cell lines.

Novel substituted 1,8-naphthyridines: Design, synthesis, radiolabeling, and evaluation of apoptosis and topoisomerase II inhibition.

A series of seventeen 1,8-naphthyridine derivatives (5a-5q) conjugated at N1 to various substituted phenyl rings were designed and synthesized as potential topoisomerase II (Topo II) inhibitors. The antiproliferative activity of the target compounds against three cancer cell lines showed that compounds 5g and 5p had the highest antiproliferative activity. In addition, 5p and 5g displayed a high selectivity index (SI) for cancer cells when tested on WI38 normal cells, whereby compound 5p showed the highest SI. Furthermore, 5g and 5p induced cell cycle arrest at the S and G1/S phases, respectively, triggering apoptosis in HepG-2 cells. The in vitro Topo II inhibitory effect (plasmid-based) of both compounds revealed that 5p had better inhibition of Topo II. In addition, 5p displayed potent topoisomerase IIβ inhibitory effect when compared to known topoisomerase inhibitors (doxorubicin and topotecan). Molecular docking proposed a unique binding pattern of 5p in the etoposide binding pocket of topoisomerase IIβ, endorsing its potential role as a Topo II poison. Accordingly, 5p was chosen for radioiodination to study the degree of tumor localization following administration in solid tumor-bearing mice. The radioiodinated 5p showed a selective localization at the tumor site, which further confirmed the value of 5p as a lead 1,8-naphthyridine anticancer agent.

Evaluation of the Anticancer Activity and Mechanism Studies of Glycyrrhetic Acid Derivatives toward HeLa Cells.

In this paper, a series of glycyrrhetic acid derivatives 3a-3f were synthesized via the esterification reaction. The cytotoxicity of these compounds against five tumor cells (SGC-7901, BEL-7402, A549, HeLa and B16) and normal LO2 cells was investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The results showed that compound 3a exhibited high antiproliferative activity against HeLa cells (IC50 = 11.4 ± 0.2 μM). The anticancer activity was studied through apoptosis, cloning, and scratching; the levels of the intracellular ROS, GSH, and Ca2+; and the change in the mitochondrial membrane potential, cell cycle arrest and RNA sequencing. Furthermore, the effects of compound 3a on gene expression levels and metabolic pathways in HeLa cells were investigated via transcriptomics. The experimental results showed that this compound can block the cell cycle in the S phase and inhibit cell migration by downregulating Focal adhesion kinase (FAK) expression. Moreover, the compound can reduce the intracellular glutathione (GSH) content, increase the Ca2+ level and the intracellular ROS content, and induce a decrease in the mitochondrial membrane potential, further leading to cell death. In addition, it was also found that the mechanism of compounds inducing apoptosis was related to the regulation of the expression of mitochondria-related proteins B-cell lymphoma-2 (Bcl-2), Bcl-2-Associated X (Bax), and the activation of the caspase proteins. Taken together, this work provides a help for the development of glycyrrhetinic acid compounds as potential anticancer molecules.

Synthesis and in vitro study of pyrimidine-phthalimide hybrids as VEGFR2 inhibitors with antiproliferative activity.

Aim: Thalidomide, a once notorious sedative, is now clinically used as an antitumor agent. We aimed to use it as a lead compound for designing pyrimidine-phthalimide hybrids. Materials & methods: Nucleophilic substitution reaction of thalidomide analog 4 with primary and/or secondary aliphatic amines afforded pyrimidine-phthalimide hybrids 5a-g, 6 and 7a-d. Results & conclusion: Compound 7c showed high antiproliferative activity against four cell lines: HepG-2 (IC50: 7.86±0.5μM), MCF-7 (IC50: 2.77±0.1μM), HCT-116 (IC50: 5.73±0.4μM) and PC-3 (IC50: 8.32±0.5μM), with selective cytotoxicity for WI-38 (IC50: 43.2±2.56μM). 7c arrested MCF-7 cells at S phase of the cell cycle and increased the total apoptotic cells by 50-fold. 7c inhibited VEGFR2 in vitro (IC50: 0.130±0.02μM). 7c was capable of binding at the VEGFR2 binding site, forming hydrogen bond interactions with Asp1046 and Glu885 in a similar way to sorafenib.

Docking experiments suggest that gloriosine has microtubule-targeting properties similar to colchicine

Gloriosine, the predominant metabolite of Gloriosa superba L., shares chemical properties with colchicine. We analyze the microtubule-binding affinity of gloriosine at the colchicine binding site (CBS) using an in silico-in vivo approach. The In silico docking of gloriosine showed a binding score of (−) 7.5 kcal/Mol towards β-tubulin at CBS and was validated by overlapping the coupling pose of the docked ligand with co-crystallized colchicine. 2D plots (Ligplot +) showed > 85% overlap between gloriosine and colchicine. The ADMET profile of gloriosine was in accordance with Lipinski’s rule of five. Gloriosine belongs to class II toxicity with anLD50 value of 6 mg/kg. In vivo and transmission electron microscopy studies revealed that gloriosine induces abnormalities in cell division such as condensed chromosomes in C-metaphase and enlarged nucleus with increased nuclear material. Gloriosine treated cells exhibited mitotic index of about 14% compared to control of 24% and high anti-proliferative activity i.e. 63.94% cell viability at a low concentration (0.0004 mg/ml). We conclude that gloriosine has a strong affinity for β-tubulin at CBS and thus can be used as a colchicine alternative in cytology and other clinical conditions.

Platinum(IV)-Loaded Degraded Glycol Chitosan as Efficient Platinum(IV) Drug Delivery Platform.

A new class of anticancer prodrugs was designed by combining the cytotoxicity of platinum(IV) complexes and the drug carrier properties of glycol chitosan polymers: Unsymmetrically carboxylated platinum(IV) analogues of cisplatin, carboplatin and oxaliplatin, namely (OC-6-44)-acetatodiammine(3-carboxypropanoato)dichloridoplatinum(IV), (OC-6-44)-acetaodiammine(3-carboxypropanoato)(cyclobutane-1,1-dicarboxylato)platinum(IV) and (OC-6-44)-acetato(3-carboxypropanoato)(1R,2R-cyclohexane-1,2-diamine)oxalatoplatinum(IV) were synthesised and conjugated via amide bonding to degraded glycol chitosan (dGC) polymers with different chain lengths (5, 10, 18 kDa). The 15 conjugates were investigated with 1H and 195Pt NMR spectroscopy, and average amounts of platinum(IV) units per dGC polymer molecule with ICP-MS, revealing a range of 1.3-22.8 platinum(IV) units per dGC molecule. Cytotoxicity was tested with MTT assays in the cancer cell lines A549, CH1/PA-1, SW480 (human) and 4T1 (murine). IC50 values in the low micromolar to nanomolar range were obtained, and higher antiproliferative activity (up to 72 times) was detected with dGC-platinum(IV) conjugates in comparison to platinum(IV) counterparts. The highest cytotoxicity (IC50 of 0.036 ± 0.005 µM) was determined in CH1/PA-1 ovarian teratocarcinoma cells with a cisplatin(IV)-dGC conjugate, which is hence 33 times more potent than the corresponding platinum(IV) complex and twice more potent than cisplatin. Biodistribution studies of an oxaliplatin(IV)-dGC conjugate in non-tumour-bearing Balb/C mice showed an increased accumulation in the lung compared to the unloaded oxaliplatin(IV) analogue, arguing for further activity studies.

The Potent G-Quadruplex-Binding Compound QN-302 Downregulates S100P Gene Expression in Cells and in an In Vivo Model of Pancreatic Cancer

The naphthalene diimide compound QN-302, designed to bind to G-quadruplex DNA sequences within the promoter regions of cancer-related genes, has high anti-proliferative activity in pancreatic cancer cell lines and anti-tumor activity in several experimental models for the disease. We show here that QN-302 also causes downregulation of the expression of the S100P gene and the S100P protein in cells and in vivo. This protein is well established as being involved in key proliferation and motility pathways in several human cancers and has been identified as a potential biomarker in pancreatic cancer. The S100P gene contains 60 putative quadruplex-forming sequences, one of which is in the promoter region, 48 nucleotides upstream from the transcription start site. We report biophysical and molecular modeling studies showing that this sequence forms a highly stable G-quadruplex in vitro, which is further stabilized by QN-302. We also report transcriptome analyses showing that S100P expression is highly upregulated in tissues from human pancreatic cancer tumors, compared to normal pancreas material. The extent of upregulation is dependent on the degree of differentiation of tumor cells, with the most poorly differentiated, from more advanced disease, having the highest level of S100P expression. The experimental drug QN-302 is currently in pre-IND development (as of Q1 2023), and its ability to downregulate S100P protein expression supports a role for this protein as a marker of therapeutic response in pancreatic cancer. These results are also consistent with the hypothesis that the S100P promoter G-quadruplex is a potential therapeutic target in pancreatic cancer at the transcriptional level for QN-302.

Design, Synthesis, and Anti-Cancer Evaluation of Novel Cyclic Phosphate Prodrug of Gemcitabine.

ProTide and cyclic phosphate ester are two successful prodrug technologies to overcome the limitations of nucleoside drugs, among which the cyclic phosphate ester strategy has not been widely used in the optimization of gemcitabine. Herein, we designed a series of novel ProTide and cyclic phosphate ester prodrugs of gemcitabine. Cyclic phosphate ester derivative 18c exhibits much higher anti-proliferative activity than positive control NUC-1031 with IC50s of 3.6-19.2 nM on multiple cancer cells. The metabolic pathway of 18c demonstrates that 18c's bioactive metabolites prolong its anti-tumor activity. More importantly, we separated the two P chiral diastereomers of gemcitabine cyclic phosphate ester prodrugs for the first time, revealing their similar cytotoxic potency and metabolic profile. 18c displays significant in vivo anti-tumor activity in both 22Rv1 and BxPC-3 xenograft tumor models. These results suggest that compound 18c is a promising anti-tumor candidate for treating human castration-resistant prostate and pancreatic cancer.

Docosahexaenoic Acid Potentiates the Anticancer Effect of the Menadione/Ascorbate Redox Couple by Increasing Mitochondrial Superoxide and Accelerating ATP Depletion.

Mitochondria-targeted anticancer drugs ("mitocans") of natural origin are attractive candidates as adjuvants in cancer therapy. The redox couple menadione/ascorbate (M/A), which belongs to the "mitocans" family, induces selective oxidative stress in cancerous mitochondria and cells, respectively. DHA has also been found to regulate the mevalonate pathway, which is closely related to the prenylation of the cytotoxic menadione to the non-cytotoxic menaquinone. The aim of this study was to elucidate the ability of docosahexaenoic acid (DHA) to potentiate the anticancer effect of M/A by increasing ROS production, as well as affecting steady-state ATP levels in cancer cells. The experiments were performed on leukemic lymphocyte Jurkat. Cells were treated with DHA, M/A, and their combination (M/A/DHA) and four parameters were examined using the following assays: cell viability and proliferation, steady-state ATP, mitochondrial superoxide, intracellular hydroperoxides. Three independent experiments with two or six parallel measurements were performed for each parameter. The triple combination M/A/DHA was characterized by much higher antiproliferative activity and cytotoxicity than M/A and DHA administered alone. DHA significantly accelerated M/A-induced ATP depletion in cells, which was accompanied by an additional increase in mitochondrial superoxide compared to cells treated with M/A or DHA alone. DHA significantly enhanced M/A-induced cytotoxicity in leukemic lymphocytes by inducing severe mitochondrial oxidative stress and accelerated ATP depletion. Selective DHA-mediated suppression of cholesterol synthesis in cancer cells (involved in the prenylation of cytotoxic menadione to the less cytotoxic phylloquinone), as well as DHA-mediated inhibition of superoxide dismutase are suggested to underlie the potentiation of the anticancer effect of M/A.

Effect of Extraction Solvent and Harvest Time on Recovery of Bioactive Com-pounds, Antioxidant and Cancer Cell Growth Inhibition Activities of Korean Ca-mellia mistletoe

This study aimed to determine the phytochemical profiles,in vitroantioxidant and antiproliferative properties of KoreanCamellia mistletoe(Korthalsella japon-ica(Thunb.) Engl.) depending on the harvest time (August and November) and sol-vent (100% methanol, 70% ethanol, and hot water). TheCamellia japonicaL. mistle-toe extracts were analyzed for total phenol, flavonoid, carotenoid, and L-ascorbic acid contents and antioxidant properties such as scavenging capacities (1,1-diphenyl-2-pic-rylhydrazyl (DPPH) and NO•),ferrous ion chelating and reducing power. Concur-rently, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) as-say was used to assess the antiproliferative properties against human cancer cell lines; MCF (human breast cancer cells), HeLa (human cervical cancer cells), A375 (human malignant melanoma cells), HCT116 (human colon cancer cells), HepG2 (human liver cancer cells) and A549 (human non-small cell lung adenocarcinoma cells). The results showed that extraction solvent and harvest time had significant impacts on antioxidant and anticancer activities and selectivity for free phenolic compounds inCamellia ja-ponicaL. mistletoe. Among all the tested extracts, the highest amounts of total phe-nolic and total flavonoids content were found in ethanol extracts ofCamellia japon-icaL. mistletoe harvested in November, while the methanol extracts ofCamellia ja-ponicaL. mistletoe collected in August showed the highest contents of total carote-noids and L-ascorbic acidscompared to the other tested extracts. Additionally, the highest NO•radical scavenging activity was found in ethanol extracts, whereas the strongest DPPH radical scavenging activity was found in methanol extracts ofCamel-lia japonicaL. mistletoe harvested in November. Furthermore, methanol extracts showed much higher antiproliferative activity against all human cancer cells than eth-anol extracts ofCamellia japonicaL. mistletoe harvested in November. In conclusion, the antioxidant and anticancer properties ofCamellia japonicaL. mistletoe showed significant dependence on the extraction solvent type and harvest time. With optimum harvest time and extraction solvent, they boast a wide range of promising medical, pharmaceutical, and food applications

Thioalbamide inhibits FoF1-ATPase in breast cancer cells and reduces tumor proliferation and invasiveness in breast cancer in vivo models

ObjectiveThioalbamide is a ribosomally synthesized and post-translationally modified peptide (RiPP) belonging to the family of thioamitides, a rare class of microbial specialized metabolites with unusual post-translational modifications and promising biological activities. Recent studies have demonstrated the ability of thioalbamide to exert highly selective cytotoxic effects on tumor cells by affecting their energy metabolism, thus causing abnormal ROS production and triggering apoptosis. This study is aimed to investigate the molecular mechanisms underlying the antitumor activity of thioalbamide in order to identify its exact molecular target. MethodsWild type MCF-7 and MDA-MB-231 breast cancer cell lines as well as cancer cells deprived of mitochondrial DNA (ρ0 cells) were employed in order to assess thioalbamide effects on tumor bioenergetics. In this regard, metabolic profile was evaluated by a Seahorse XFe96 analyzer, and the activity of the enzyme complexes involved in oxidative phosphorylation was quantified by spectrophotometric assays. Thioalbamide effects on tumor invasiveness were assessed by gelatin zymography experiments and invasion assays. In vivo experiments were carried out on breast cancer xenograft and “experimental metastasis” mouse models. ResultsExperiments carried out on ρ0 breast cancer cells, together with Seahorse analysis and the application of spectrophotometric enzymatic assays, highlighted the ability of thioalbamide to affect the mitochondrial respiration process, and allowed to propose the FoF1-ATPase complex as its main molecular target in breast cancer cells. Additionally, thioalbamide-mediated OXPHOS inhibition was shown, for the first time, to reduce tumor invasiveness by inhibiting metalloproteinase-9 secretion. Furthermore, this study has confirmed the antitumor potential of thioalbamide in two different in vivo models. In particular, experiments on MCF-7 and MDA-MB-231 xenograft mouse models have confirmed in vivo its high anti-proliferative and pro-apoptotic activity, while experiments on MDA-MB-231 ″experimental metastasis” mouse models have highlighted its ability to inhibit breast cancer cell invasiveness. ConclusionsOverall, our results shed more light on the molecular mechanisms underlying the pharmacological potential of thioamidated peptides, thus reducing the gap that separates this rare class of microbial metabolites from clinical studies, which could validate them as effective tools for cancer treatment.

New Nitric Oxide-Releasing Compounds as Promising Anti-Bladder Cancer Drugs.

Bladder cancer is a worldwide problem and improved therapies are urgently needed. In the search for newer strong antitumor compounds, herein, we present the study of three nitric oxide-releasing compounds and evaluate them as possible therapies for this malignancy. Bladder cancer cell lines T24 and 253J were used to evaluate the antiproliferative, antimigratory, and genotoxic effects of compounds. Moreover, we determined the NF-κB pathway inhibition, and finally, the survivin downregulation exerted by our molecules. The results revealed that compounds 1 and 3 exerted a high antiproliferative activity against bladder cancer cells through DNA damage and survivin downregulation. In addition, compound 3 reduced bladder cancer cell migration. We found that nitric oxide donors are promising molecules for the development of a new therapeutic targeting the underlying mechanisms of tumorigenesis and progression of bladder cancer.

Platinum(terpyridine) complexes with N-heterocyclic carbene co-ligands: high antiproliferative activity and low toxicity in vivo.

Pt(terpyridine) complexes are well-known DNA intercalators. The introduction of an NHC co-ligand rendered such a complex highly antiproliferative in cancer cells compared to its chlorido derivative. Despite the high potency, zebrafish embryos tolerated the compound well, especially compared to cisplatin. DNA interaction studies support a mode of action related to intercalation.

In silico evaluation of binding interaction and ADME study of new 1,3-diazetidin-2-one derivatives with high antiproliferative activity.

A series of eight novels' 1,3-diazetidin-2-ones have been proposed to assess their potential activities. They are intended to examine antiproliferative effects through inhibition of epidermal growth factor receptor (EGFR) expression. These eight compounds strongly interact with the EGFR protein, responsible for the activity. As part of a present study, these compounds were docked to the crystal structure of the EGFR (Protein Data Bank code: 1 M17) to determine their binding affinity at the active site. Based on computer predictions, two compounds were demonstrated high scores of 80.80 and 85.89. After analyzing ADME properties, these compounds were found to have significant potential for binding. Consequently, the abilities of gefitinib, erlotinib, imatinib, and sorafenib were selected for comparison as controls. Computational methods were performed to predict the critical disposition of eight novels' 1,3-diazetidin-2-one derivatives to the EGFR. Moreover, a docking technique employing the Genetic Optimization for Ligand Docking program was conducted. Compounds 2 and 7 demonstrate a high docking peace-wise scoring function (PLP) fitness of 85.89 and 80.80, respectively. They fulfilled the Lipinski's rule, topological descriptors, and fingerprints of drug-like molecular structure keys. These compounds can be used as lead compounds to develop novel antiproliferative agents. The outcome of applying this study is novel series of 1,3-diazetidin-2-one compounds as new analogs were designed and evaluated for their antiproliferative activity with a higher potency profile and binding affinity within the active sites of EGFR.

Diorganotin(IV) complexes with hydroxamic acids derivatives of some histone deacetylases inhibitors

Organotin(IV) compounds show great potential as antitumor metallodrugs with lower toxicity and higher antiproliferative activity. Histone deacetylases (HDAC) inhibitors are characterised by high bioavailability and low toxicity. In this research, the two novel octahedral organotin(IV) complexes of physiologically active hydroxamate-based ligands, N-hydroxy-4-phenylbutanamide (HL1) and N-hydroxy-2-propylpentanamide (HL2), have been prepared and characterized using FTIR, 1H-, 13C- and 119Sn-NMR spectroscopy. Particular emphasis was put on the binding characteristics of ligands. The structures were additionally analysed by the density functional theory at B3LYP-D3BJ/6- -311++G(d,p)(H,C,N,O)/LanL2DZ(Sn) level. The theoretical IR and NMR spectra were compared to the spectroscopic data, and it was concluded that the predicted structures described well the experimental ones. The stability of different isomers of HL1 and HL2 was assessed by the natural bond orbital analysis, and the importance of intramolecular hydrogen bond was outlined. The interactions between donor atoms and Sn were investigated and correlated with the changes in chemical shift and the wavenumbers of characteristic vibrations.

Antiproliferative effects of 13α/β-steroids on triple-negative MDA-MB-231 breast cancer cells: unraveling intracellular signaling without ERα

This study aimed to investigate the activities of novel 20(R)-3,20-dihydroxy-19-norpregn-1,3,5(10)-trienes (kuz7 and kuz8b) of natural 13β- and epimeric 13α-series against triple-negative MDA-MB-231 breast cancer cells. High antiproliferative activity of synthesized compounds kuz8b and kuz7 against MDA-MB-231 triple-negative cancer cells was revealed. The steroid kuz7 of natural 13β-configuration was more active against MDA-MB-231 cells than the 13α-steroid kuz8b. Cell cycle analysis revealed common patterns for the action of both tested compounds. The number of cells in the subG1 phase increased in a dose-dependent manner, indicating induction of apoptosis, which was also verified by PARP cleavage. In contrast, the number of cells in the G0/G1 phase decreases with increasing compound concentration. Steroid kuz7 at micromolar concentrations reduced the expression of GLUT1, a glucose transporter. High efficacy of the combination of kuz7 with biguanide metformin was shown, and synergistic effects on MDA-MB-231 cell growth and expression of the anti-apoptotic protein Bcl-2 were revealed. According to the obtained results, including the high activity of kuz7 against triple-negative cancer cells, the detected induction of apoptosis, and the decrease in GLUT1 expression, 13β-steroid kuz7 is of interest for further preclinical studies both alone and in combination with the metabolic drug metformin.

Purple tea catechins exhibit high antiproliferative activity and synergism with cisplatin against the triple-negative breast cancer cell line 4T1

The objectives of this study were the selection of the best tea clones with high catechin content among the known tea clones in Rwanda and Kenya, the examination of their antiproliferative effects on the triple-negative breast cancer (TNBC) cell line (4T1), and an evaluation of their combination index with cisplatin. The quantification of catechin contents in 14 different tea clones and 5 different processed teas was performed by high-performance liquid chromatography (HPLC). A comparative study of antiproliferative activities of catechin extracts from purple, TRFK306, and BB35 tea clones on the TNBC cell line (4T1) was undertaken, and their combination index (CI) with cisplatin and the dose reduction index (DRI) were determined. The catechin extract from BB35 had the highest concentration of total catechins (817.81?24.2 mg/g DW). After 72 h, the catechin extracts from TRFK306 showed a high IC50 of 68.68?3.30 ?g/mL. The catechin extracts from TRFK306 showed the best synergism with cisplatin (CI=0.59), and they reduced the doses of cisplatin with the highest DRI=3.74493. Catechin extracts from purple tea showed higher antiproliferative activity and synergism with cisplatin against the TNBC cell line.

Exploiting click-chemistry: backbone post-functionalisation of homoleptic gold(I) 1,2,3-triazole-5-ylidene complexes.

The synthesis of a homoleptic azide-functionalised Au(I) bis-1,2,3-triazole-5-ylidene complex is reported, starting from a backbone-modified 1,2,3-triazolium salt ligand precursor. The incorporated azide handle allows for a straightforward modification of the complex according to click-chemistry protocols without impacting the steric shielding around the metal center, demonstrating the superiority of the presented triazole ligand framework over imidazole based systems. Employing the SPAAC and the CuAAC reactions, post-modification of the complex is facilitated with two model substrates, while retaining very high antiproliferative activity (nanomolar range IC50 values) in A2780 and MCF-7 human cancer cells.

Synthesis, biological evaluation of novel iridium(III) complexes targeting mitochondria toward melanoma B16 cells

A new ligand 2-(1E,3E,5E,7E)-2,6-dimethyl-8-(2,6,6-trimethylcyclohex-1-yl)octa-1,2,5,7-tetraen-1-yl)-1H-imidazo[4,5-f][1,10]phenanthroline (DTOIP) was synthesized and combined with [Ir(ppy)2Cl]2·2H2O (ppy = deprotonated Hppy: 2-phenylpyridine), [Ir(piq)2Cl]2·2H2O (piq = deprotonated Hpiq: 1-phenylisoquinoline) and [Ir(bzq)2Cl]2·2H2O (bzq = deprotonated Hbzq: benzo[h]quinolone) to form [Ir(ppy)2(DTOIP)](PF6) (Ir1), [Ir(piq)2(DTOIP)](PF6) (Ir2), and [Ir(bzq)2(DTOIP)](PF6) (Ir3), respectively. The complexes were characterized by elemental analysis, high-resolution mass spectrometry (HRMS), 1H NMR and 13C NMR. The antiproliferative activity of the complexes toward B16, BEL-7402, Eca-109 and normal LO2 cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Complexes Ir1, Ir2 and Ir3 showed high antiproliferative activity against B16 cells with a low IC50 values of 0.4 ± 0.1, 2.0 ± 0.1 and 1.4 ± 0.09 μM, respectively. Three-dimensional (3D) in vitro cell models also demonstrated that the iridium(III) complexes have a remarkable cytotoxicity to B16 cells. The experiments of cellular uptake, mitochondrial localization, and intracellular distribution of the drugs proved that the three iridium(III) complexes can enter the mitochondria, leading to the loss of mitochondrial membrane potential (MMP), decreased glutathione (GSH) levels, causing an increase of intracellular ROS content, and DNA damage, finally inducing apoptosis. RNA-sequence and bioinformatics analyses were used to analyze the differentially expressed genes and enriched biology processes. Antitumor in vivo demonstrated that complex Ir1 (5 mg/kg) exhibits a high efficacy to inhibit the tumor growth with an inhibitory rate of 71.67%. These results show that the complexes may be potent anticancer candidate drugs.