Synthesis, characterization and multiple targeting with selectivity: Anticancer property of ternary metal phenanthroline-maltol complexes.

The cobalt(II), copper(II) and zinc(II) complexes of 1,10-phenanthroline (phen) and maltol (mal) (complexes 1, 2, 3 respectively) were prepared from their respective metal(II) chlorides and were characterized by FT-IR, elemental analysis, UV spectroscopy, molar conductivity, p-nitrosodimethylaniline assay and mass spectrometry. The X-ray structure of a single crystal of the zinc(II) analogue reveals a square pyramidal structure with distinctly shorter apical chloride bond. All complexes were evaluated for their anticancer property on breast cancer cell lines MCF-7 and MDA-MB-231, and normal cell line MCF-10A, using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and morphological studies. Complex 2 was most potent for 24, 48 and 72 h treatment of cancer cells but it was not selective towards cancer over normal cells. The mechanistic studies of the cobalt(II) complex 1 involved apoptosis assay, cell cycle analysis, dichloro-dihydro-fluorescein diacetate assay, intracellular reactive oxygen species assay and proteasome inhibition assay. Complex 1 induced low apoptosis, generated low level of ROS and did not inhibit proteasome in normal cells. The study of the DNA binding and nucleolytic properties of complexes 1-3 in the absence or presence of H2O2 or sodium ascorbate revealed that only complex 1 was not nucleolytic.

A Novel Electrophoretic Deposited Coordination Supramolecular Network Film for Detecting Phosphate and Biophosphate.

A series of new lanthanide coordination supramolecular networks (CSNs) based on nalidixic acid (HNA) ligand were designed and synthesized. Their crystal structures were determined by single-crystal XRD techniques. Thin films of these compounds were first successfully deposited on indium tin oxide (ITO) glass through one-step electrophoretic deposition under mild conditions. The europium CSN film exhibits intense red emission and can act as a highly sensitive luminescent sensor for H2 PO4- anions and adenosine triphosphate (ATP) in aqueous solution. The limits of detection of H2 PO4- and ATP can achieve 0.68 and 1.9 µm respectively. The sensing mechanism was further explored through fluorescence and UV techniques. The fabricated sensor also showed excellent selectivity towards these phosphates in the presence of other coexisting ions (F- , Cl- , Br- , I- , SO4- , CO32- , NO3- , and AcO- ) without interference. Moreover, we demonstrated the feasibility of using this sensor to detect ATP in bovine serum samples, suggesting the potential value of application in real biosystems.

Thiosemicarbazone Derivative Induces in vitro Apoptosis in Metastatic PC-3 Cells via Activation of Mitochondrial Pathway.

BACKGROUND: Thiosemicarbazone (TSC) is a Schiff base that has been receiving considerable attention owing to its promising biological implication and remarkable pharmacological properties. The most promising drug candidate of this class would be Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone) which has entered phase II clinical trials as a potent anti-cancer chemotherapeutic agent. OBJECTIVE: The current research aimed to synthesize several Schiff base ligands from (3-formyl-4-hydroxyphenyl) methyltriphenylphosphonium (T). Additionally, the current research aimed to study the growth inhibitory effect of triphenylphosphonium containing thiosemicarbazone derivatives on PC-3 cells by deciphering the mechanisms involved in cell death. METHOD: The compounds were characterized by various spectroscopic methods (infrared spectra, 1H NMR, 13C NMR, HRESIMS and X-ray crystallography) and the results were in conformity with the structure of the targeted compounds. Growth inhibitory effect of the compounds were performed against six human cell lines. RESULTS: DM(tsc)T displayed most potent activity against PC-3 cells with IC50 value of 2.64 ± 0.33 µM, surpassing that of the positive control cisplatin (5.47 ± 0.06 µM). There were marked morphological changes observed in DM(tsc)T treated cells stained with acridine orange and ethidium bromide which were indicative of cell apoptosis. Treatment with DM(tsc)T showed that the cell cycle is arrested in the G0/G1 phase after 72 hours. Mitochondrial membrane potential loss was observed in cells treated with DM(tsc)T, indicating the apoptosis could be due to mitochondria mediated pathway. CONCLUSION: This study indicates that DM(tsc)T would serve as a lead scaffold for rational anticancer agent development.

Topoisomerase I inhibition and DNA cleavage by zinc, copper, and nickel derivatives of 2-[2-bromoethyliminomethyl]-4-[ethoxymethyl]phenol complexes exhibiting anti-proliferation and anti-metastasis activity.

Three transition metal derivatives (Zn, Cu, and Ni) of 2-[2-bromoethyliminomethyl]-4-[ethoxymethyl]phenol (L) were synthesized by the reaction of the metal salts with the Schiff base ligand in one pot. In the crystal structure of [Zn(L)Br], the Schiff base ligand binds to the metal center through its phenolate oxygen and imine nitrogen, and adopts a distorted tetrahedral geometry. These compounds were found to inhibit topoisomerase I (topo I) activity, induce DNA cleavage and show DNA binding activity. Moreover, these compounds were found to be cytotoxic towards several cancer cell lines (A2780, MCF-7, HT29, HepG2, A549, PC3, LNCaP) and prevent metastasis of PC3. Collectively, Cu(II) complex 2 shows superior activity relative to its Zn(II) and Ni(II) analogs.

Dinuclear Gold(I) Pyrrolidinedithiocarbamato Complex: Cytotoxic and Antimigratory Activities on Cancer Cells and the Use of Metal-Organic Framework.

A dinuclear gold(I) pyrrolidinedithiocarbamato complex (1) with a bidentate carbene ligand has been constructed and shows potent in vitro cytotoxic activities towards cisplatin-resistant ovarian cancer cells A2780cis. Its rigid scaffold enables a zinc(II)-based metal-organic framework (Zn-MOF) to be used as a carrier in facilitating the uptake and release of 1 in solutions. Instead of using a conventional dialysis approach for the drug-release testing, in this study, a set of transwell assay-based experiments have been designed and employed to examine the cytotoxic and antimigratory activities of 1@Zn-MOF towards A2780cis.

Synthesis of a DNA-targeting nickel (II) complex with testosterone thiosemicarbazone which exhibits selective cytotoxicity towards human prostate cancer cells (LNCaP).

Testosterone thiosemicarbazone, L and its nickel (II) complex 1 were synthesized and characterized by using FTIR, CHN, (1)H NMR, and X-ray crystallography. X-ray diffraction study confirmed the formation of L from condensation of testosterone and thiosemicarbazide. Mononuclear complex 1 is coordinated to two Schiff base ligands via two imine nitrogens and two tautomeric thiol sulfurs. The cytotoxicity of both compounds was investigated via MTT assay with cisplatin as positive reference standard. L is more potent towards androgen-dependent LNCaP (prostate) and HCT 116 (colon). On the other hand, complex 1, which is in a distorted square planar environment with L acting as a bidentate NS-donor ligand, is capable of inhibiting the growth of all the cancer cell lines tested, including PC-3 (prostate). It is noteworthy that both compounds are less toxic towards human colon cell CCD-18Co. The intrinsic DNA binding constant (Kb) of both compounds were evaluated via UV-Vis spectrophotometry. Both compounds showed Kb values which are comparable to the reported Kb value of typical classical intercalator such as ethidium bromide. The binding constant of the complex is almost double compared with ligand L. Both compounds were unable to inhibit the action topoisomerase I, which is the common target in cancer treatment (especially colon cancer). This suggest a topoisomerase I independent-cell death mechanism.

Two isoreticular metal-organic frameworks with CdSO4-like topology: selective gas sorption and drug delivery.

Two isoreticular metal-organic frameworks with chemical formulae [Cu(L)(4,4'-bipy)(H2O)]n 1.5nCH3CN (1) and [Cu(L)(4,4'-bipy)(H2O)]n·4nH2O (2) (H2L = diphenylmethane-4,4'-dicarboxylic acid) were synthesized and structurally characterized. They show the CdSO4 (6(5) 8) net and have an obvious 1D channel that is spread along the crystallographic c axis. More importantly, 1 shows high selectivity for H2 over N2 and CO2 at low pressure, which could be confirmed via computational calculations using the Connolly algorithm to reveal the size and shape of accessible voids. The incorporation of the drug 5-fluorouracil (5-FU) into the desolvated 1 was around 27.5 wt% per gram of the dehydrated 1. 5-FU is released in a highly controlled and progressive fashion with 61% of the drug released after 95 hours. In addition, we have applied molecular docking calculations to investigate the preferred conformation of 5-FU molecules upon binding to MOF 1. These calculations provide a structural basis to explain the 5-FU release from MOF 1.

Diaporine, a novel endophyte-derived regulator of macrophage differentiation.

Diaporine (1), an unprecedented symmetric polyketide, was characterized from the endophytic fungus. The structure was determined by extensive spectroscopic analyses. Diaporine can inhibit significantly the differentiation of macrophages and has potential to induce conversion from the M2 to the M1 phenotype, in addition to regulation of the TLR4-MAPK signal pathway and PPARγ activity.

Bis{µ-N-[(E)-4-benz-yloxy-2-oxidobenzyl-idene]-4-nitro-benzene-carbo-hydrazidato}bis-[di-aqua-nickel(II)] di-methyl-formamide tetra-solvate.

The molecule of the title complex, [Ni2(C21H15N3O5)2(H2O)4]·4C3H7NO, is located on an inversion centre. This results in a dimeric Ni(II) complex, with the two Ni(II) atoms bridged by phenolate O atoms. The tridentate ligand is chelated to each Ni(II) atom via one N and two O atoms of the imino-late form of the hydrazide moiety, which has the same conformation as the free ligand. The coordination geometry around each Ni(II) ion is slightly distorted octa-hedral. A supra-molecular three-dimensional architecture is created by dominant inter-molecular O-H⋯N, O-H⋯O and C-H⋯O hydrogen-bonding inter-actions. These are augmented by two C-H⋯π inter-actions and a π-π inter-action with a centroid-centroid distance of 3.681 (2) Å.

Zinc (II) complex with a cationic Schiff base ligand: synthesis, characterization, and biological studies.

A cationic Schiff base ligand, TSB (L) and its Zn (II) complex (1) were synthesized and characterized by using CHN, (1)H-NMR, FT-IR, UV, LC-MS, and X-ray methods. Their ability to inhibit topoisomerase I, DNA cleavage activities, and cytotoxicity were studied. X-ray diffraction study shows that the mononuclear complex 1 is four coordinated with distorted tetrahedral geometry. The singly deprotonated Schiff base ligand L acts as a bidentate ON-donor ligand. Complexation of L increases the inhibitory strength on topoisomerase I activity. Complex 1 could fully inhibit topoisomerase I activity at 250 µM, while L did not show any inhibitory effect on topoisomerase I activity. In addition, L and complex 1 could cleave pBR322 DNA in a concentration and time dependent profile. Surprisingly, L has better DNA cleavage activity than complex 1. The cleavage of DNA by complex 1 is altered in the presence of hydrogen peroxide. Furthermore, L and complex 1 are mildly cytotoxic towards human ovarian cancer A2780 and hepatocellular carcinoma HepG2.

Multiple anion...π interactions in tris(1,10-phenanthroline-κ(2)N,N')iron(II) bis[1,1,3,3-tetracyano-2-(2-hydroxyethyl)propenide] monohydrate.

In the ionic structure of the title compound, [Fe(C12H8N2)3](C9H5N4O2)2·H2O, the octahedral tris-chelate [Fe(phen)3](2+) dications [Fe-N = 1.9647 (14)-1.9769 (14) Å; phen is 1,10-phenathroline] afford one-dimensional chains by a series of slipped π-π stacking interactions [centroid-to-centroid distances = 3.792 (3) and 3.939 (3) Å]. The 1,1,3,3-tetracyano-2-(2-hydroxyethyl)propenide anions, denoted tcnoetOH(-), reveal an appreciable delocalization of π-electron density, involving the central propenide [C-C = 1.383 (3)-1.401 (2) Å] fragment and four nitrile groups, and this is also supported by density functional theory (DFT) calculations at the B97D/6-311+G(2d,2p) level. Primary noncovalent inter-moiety interactions comprise conventional O-H...O(N) and weak C-H...O(N) hydrogen bonding [O...O(N) = 2.833 (2)-3.289 (5) Šand C...O(N) = 3.132 (2)-3.439 (2) Å]. The double anion...π interaction involving a nitrile group of tcnoetOH(-) and two cis-positioned pyridine rings (`π-pocket') of [Fe(phen)3](2+) [N...centroid = 3.212 (2) and 3.418 (2) Å] suggest the relevance of anion...π stackings for charge-diffuse polycyanoanions and common M-chelate species.

Phosphanegold(I) dithiocarbamates, R3PAu[SC(=S)N((i)Pr)CH2CH2OH] for R = Ph, Cy and Et: role of phosphane-bound R substituents upon in vitro cytotoxicity against MCF-7R breast cancer cells and cell death pathways.

The synthesis and characterisation of R3PAu[S2CN((i)Pr)CH2CH2OH], for R = Ph (1), Cy (2) and Et (3)4, is reported. Compounds 1-3 are cytotoxic against the doxorubicin-resistant breast cancer cell line, MCF-7R, with 1 exhibiting greater potency and cytotoxicity than either of doxorubicin and cisplatin. Based on human apoptosis PCR-array analysis, caspase activities, DNA fragmentation, cell apoptotic assays, intracellular reactive oxygen species (ROS) measurements and human topoisomerase I inhibition, induction of apoptosis by 1, and necrosis by 2 and 3, are demonstrated, by both extrinsic and intrinsic pathways. Compound 1 activates the p53 gene, 2 activates only the p73 gene, whereas 3 activates both the p53 and p73 genes. Compounds 1 and 3 activate NF-κB, and each inhibits topoisomerase I.

The influence of R substituents in triphenylphosphinegold(I) carbonimidothioates, Ph3PAu[SC(OR)=NPh] (R=Me, Et and iPr), upon in vitro cytotoxicity against the HT-29 colon cancer cell line and upon apoptotic pathways.

The Ph3PAu[SC(OR)=NPh], R=Me (1), Et (2) and iPr (3), compounds are significantly cytotoxic to the HT-29 cancer cell line with 1 being the most active. Based on human apoptosis PCR-array analysis, caspase activities, DNA fragmentation, cell apoptotic assays, intracellular reactive oxygen species (ROS) measurements and human topoisomerase I inhibition, induction of apoptosis is demonstrated and both the extrinsic and intrinsic pathways of apoptosis have been shown to occur. Compound 1 activates the p73 gene, whereas each of 2 and 3 activates the p53 gene. An additional apoptotic mechanism is exhibited by 2, that is, via the JNK/MAP pathway.

Tris(1,10-phenanthroline-κ(2) N,N')iron(II) bis-(1,1,3,3-tetra-cyano-2-eth-oxy-propenide) hemihydrate.

In the title hydrated mol-ecular salt, [Fe(C12H8N2)3](C9H5N4O)2·0.5H2O, the water mol-ecule site is half-occupied. The Fe-N bond lengths within the octa-hedral tris-chelate [Fe(phen)3](2+) ion (phen is 1,10-phenantroline) are indicative of a low-spin d(6) electronic configuration for the metal ion. The C-N, C-C and C-O bond lengths in the polynitrile anions indicate extensive electronic delocalization. In the crystal, the components are linked through O-H⋯N hydrogen bonds, forming [100] chains, as well as through Coulombic inter-actions.

Di-µ-iodido-bis-(iodido-{methyl 4-[(pyridin-2-yl-methyl-idene)amino]-benzoate-κ(2) N,N'}cadmium).

The complete binuclear molecule of the title compound, [Cd2I4(C14H12N2O2)2], is generated by the application of a centre of inversion. The Cd-I bond lengths of the central core are close and uniformly longer than the exocyclic Cd-I bond. The coordination sphere of the Cd(II) atom is completed by two N atoms of a chelating methyl 4-[(pyridin-2-yl-methyl-idene)amino]-benzoate ligand, and is based on a square pyramid with the terminal I atom in the apical position. The three-dimensional crystal packing is stabilized by C-H⋯O and C-H⋯π inter-actions, each involving the pyridine ring.

Sesquiterpenoids from the mangrove-derived endophytic fungus Diaporthe sp.

A new sesquiterpenoid, diaporol A (1), possessing a unique tricyclic lactone framework, eight new drimane sesquiterpenoids, diaporols B-I (2-9), and the known compounds 10 and 11 were isolated from a culture of the mangrove-derived endophyte Diaporthe sp. The absolute configurations of 1-5 were determined by low-temperature (100 K) single-crystal X-ray diffraction with Cu Kα radiation. The compounds were evaluated for cytotoxic activity; however, no compound showed significant cytotoxicity against the tested cell lines at a concentration of 20 µM.

[2-(1-{2-[Aza-nid-yl(ethyl-sulfan-yl)methyl-idene-κN]hydrazin-1-yl-idene-κN¹}eth-yl)phenolato-κO](pyridine-κN)nickel(II).

The Ni(II) atom in the title complex, [Ni(C11H13N3OS)(C5H5N)], exists within a square-planar N3O donor set provided by N,N',O atoms of the dianionic tridentate ligand and a pyridine N atom. The maximum deviation from the ideal geometry is seen in the N-Ni-N five-membered chelate bite angle of 83.28 (12)°. The pyridine mol-ecule forms a dihedral angle of 44.43 (6)° with the N3O donor set. Supra-molecular stacks along the a axis mediated by alternating π-π inter-actions between the pyridine and five- [centroid-centroid distance = 3.4784 (16) Å] and six-membered [3.4633 (17) Å] chelate rings, feature in the crystal packing.

Bis(1-phenyl-3-{(Z)-[phen-yl(pyridin-2-yl)methyl-idene]amino-κ²N,N'}urea-κO)nickel(II) dinitrate.

The Ni(II) atom in the title salt, [Ni(C19H16N4O)2](NO3)2, is N,N',O-chelated by two neutral Schiff base ligands in a distorted octa-hedral geometry. One nitrate ion inter-acts with the metal atom indirectly, in an outer-sphere type of coordination, through N-H⋯O hydrogen bonds; the other nitrate ion does not engage in any inter-actions and is equally disordered over two positions in the crystal.

N-(3-Amino-bicyclo-[2.2.1]heptan-2-yl)-4-methyl-benzene-sulfonamide.

In the title compound, C(14)H(20)N(2)O(2)S, the sulfonamide O atoms lie to one side of the benzene ring and the amino-bicyclo-hepta-nyl to the other side [C(ar)-S-N-C torsion angle = -57.93 (11)°; ar = aromatic]. An intra-molecular N-H⋯N hydrogen bond is formed. In the crystal, a supra-molecular chain is formed along the b axis via N-H⋯O and N-H⋯N hydrogen bonds.

6-Amino-4-(3-iodo-anilino)-2-methyl-pyrimidin-1-ium chloride.

In the cation of the title salt, C(11)H(12)IN(4) (+)·Cl(-), the two aromatic rings are oriented to each other at 9.3 (2)°. In the crystal, the two independent Cl(-) anions lie on twofold rotation axes. N-H⋯Cl hydrogen bonds between the cations and anions generate a supra-molecular layer parallel to (010).