A COX2-targeting cancer-specific fluorescent probe for hydrogen sulfide detection in living cells, Caenorhabditis elegans, and zebrafish.

A novel cyclooxygenase-2 (COX-2) targeted H2S-activated cancer-specific fluorescent probe, namely, COX2-H2S, was designed and synthesized, with naphthalimide as the fluorophore and indomethacin as the targeting group. This H2S-sensing probe was developed to differentiate tumor cells from normal cells and was tested in living cells, Caenorhabditis elegans (C. elegans), and zebrafish. The probe could successfully be used for imaging endogenous and exogenous H2S in living cells, demonstrating high sensitivity and specificity and strong anti-interference. COX2-H2S had the ability to not only discern cancer cells from normal cells but also specifically recognize 9L/lacZ cells from other glioblastoma cells (U87-MG and LN229). It could also be successfully applied for the fluorescent live imaging of H2S in both C. elegans and zebrafish.

Palladium/Norbornene Cooperative-Catalyzed Cascade Decarboxylative Cyclization of 4-Iodoisoquinolin-1(2H)-ones with o-Bromobenzoic Acids: Access to Diverse Fused Phenanthridinones and Hepta[1,2-c]isoquinolinones.

A novel three-component Pd/norbornene cooperative catalysis cascade decarboxylative [2+2+2]/[2+2+3]cyclization of 4-iodoisoquinolin-1(2H)-ones and o-bromobenzoic acids or 8-bromo-1-naphthoic acid has been developed. The method affords a range of fused phenanthridinones and hepta[1,2-c]isoquinolinones and displays unique regioselectivity and broad substrate scope. Palladium/norbornene (Pd/NBE)-catalyzed C-H activation and subsequent decarboxylative coupling reactions were involved, and NBE acts as a building block for the construction of rigid nonplanar molecular architectures.

The terpene synthase gene family in Gossypium hirsutum harbors a linalool synthase GhTPS12 implicated in direct defence responses against herbivores.

Herbivore-induced terpenes have been reported to function as ecological signals in plant-insect interactions. Here, we showed that insect-induced cotton volatile blends contained 16 terpenoid compounds with a relatively high level of linalool. The high diversity of terpene production is derived from a large terpene synthase (TPS) gene family. The TPS gene family of Gossypium hirsutum and Gossypium raimondii consist of 46 and 41 members, respectively. Twelve TPS genes (GhTPS4-15) could be isolated, and protein expression in Escherichia coli revealed catalytic activity for eight GhTPS. The upregulation of the majority of these eight genes additionally supports the function of these genes in herbivore-induced volatile biosynthesis. Furthermore, transgenic Nicotiana tabacum plants overexpressing GhTPS12 were generated, which produced relatively large amounts of (3S)-linalool. In choice tests, female adults of Helicoverpa armigera laid fewer eggs on transgenic plants compared with non-transformed controls. Meanwhile, Myzus persicae preferred feeding on wild-type leaves over leaves of transgenic plants. Our findings demonstrate that transcript accumulation of multiple TPS genes is mainly responsible for the production and diversity of herbivore-induced volatile terpenes in cotton. Also, these genes might play roles in plant defence, in particular, direct defence responses against herbivores.

Complexes of nickel(II) and copper(II) with 1,2,4-triazole-3-carboxylic acid and of cobalt(III) with 3-amino-1,2,4-triazole-5-carboxylic acid.

Because of their versatile coordination modes and strong coordination ability for metals, triazole ligands can provide a wide range of possibilities for the construction of metal-organic frameworks. Three transition-metal complexes, namely bis(µ-1,2,4-triazol-4-ide-3-carboxylato)-κ3N2,O:N1;κ3N1:N2,O-bis[triamminenickel(II)] tetrahydrate, [Ni2(C3HN3O2)2(NH3)6]·4H2O, (I), catena-poly[[[diamminediaquacopper(II)]-µ-1,2,4-triazol-4-ide-3-carboxylato-κ3N1:N4,O-[diamminecopper(II)]-µ-1,2,4-triazol-4-ide-3-carboxylato-κ3N4,O:N1] dihydrate], {[Cu2(C3HN3O2)2(NH3)4(H2O)2]·2H2O}n, (II), (µ-5-amino-1,2,4-triazol-1-ide-3-carboxylato-κ2N1:N2)di-µ-hydroxido-κ4O:O-bis[triamminecobalt(III)] nitrate hydroxide trihydrate, [Co2(C3H2N4O2)(OH)2(NH3)6](NO3)(OH)·3H2O, (III), with different structural forms have been prepared by the reaction of transition metal salts, i.e. NiCl2, CuCl2 and Co(NO3)2, with 1,2,4-triazole-3-carboxylic acid or 3-amino-1,2,4-triazole-5-carboxylic acid hemihydrate in aqueous ammonia at room temperature. Compound (I) is a dinuclear complex. Extensive O-H...O, O-H...N and N-H...O hydrogen bonds and π-π stacking interactions between the centroids of the triazole rings contribute to the formation of the three-dimensional supramolecular structure. Compound (II) exhibits a one-dimensional chain structure, with O-H...O hydrogen bonds and weak O-H...N, N-H...O and C-H...O hydrogen bonds linking anions and lattice water molecules into the three-dimensional supramolecular structure. Compared with compound (I), compound (III) is a structurally different dinuclear complex. Extensive N-H...O, N-H...N, O-H...N and O-H...O hydrogen bonding occurs in the structure, leading to the formation of the three-dimensional supramolecular structure.

Synthesis, crystal structures and luminescence properties of seven mononuclear zinc(II), cadmium(II), cobalt(II) and nickel(II) complexes with 5-(4-methylphenyl)-3-(pyridin-2-yl)-1H-1,2,4-triazole.

Due to their versatile coordination modes and metal-binding conformations, triazolyl ligands can provide a wide range of possibilities for the construction of supramolecular structures. Seven mononuclear transition metal complexes with different structural forms, namely aquabis[3-(4-methylphenyl)-5-(pyridin-2-yl)-1H-1,2,4-triazolato-κ2N1,N5]zinc(II), [Zn(C14H11N4)2(H2O)], (I), bis[5-(4-methylphenyl)-3-(pyridin-2-yl)-1H-1,2,4-triazole-κ2N3,N4]bis(nitrato-κO)zinc(II), [Zn(NO3)2(C14H12N4)2], (II), bis(methanol-κO)bis[3-(4-methylphenyl)-5-(pyridin-2-yl)-1H-1,2,4-triazolato-κ2N1,N5]zinc(II), [Zn(C14H11N4)2(CH4O)2], (III), diiodidobis[5-(4-methylphenyl)-3-(pyridin-2-yl)-1H-1,2,4-triazole-κ2N3,N4]cadmium(II), [CdI2(C14H12N4)2], (IV), bis[5-(4-methylphenyl)-3-(pyridin-2-yl)-1H-1,2,4-triazole-κ2N3,N4]bis(nitrato-κO)cadmium(II), [Cd(NO3)2(C14H12N4)2], (V), aquabis[3-(4-methylphenyl)-5-(pyridin-2-yl)-1H-1,2,4-triazolato-κ2N1,N5]cobalt(II), [Co(C14H11N4)2(H2O)], (VI), and diaquabis[3-(4-methylphenyl)-5-(pyridin-2-yl)-1H-1,2,4-triazolato-κ2N1,N5]nickel(II), [Ni(C14H11N4)2(H2O)2], (VII), have been prepared by the reaction of transition metal salts (ZnII, CdII, CoII and NiII) with 3-(4-methylphenyl)-5-(pyridin-2-yl)-1H-1,2,4-triazole (pymphtzH) under either ambient or hydrothermal conditions. These compounds have been characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. All the complexes form three-dimensional supramolecular structures through hydrogen bonds or through π-π stacking interactions between the centroids of the pyridyl or arene rings. The pymphtzH and pymphtz- entities act as bidentate coordinating ligands in each structure. Moreover, all the pyridyl N atoms are coordinated to metal atoms (Zn, Cd, Co or Ni). The N atom in the 4-position of the triazole group is coordinated to the Zn and Cd atoms in the crystal structures of (II), (IV) and (V), while the N atom in the 1-position of the triazolate group is coordinated to the Zn, Co and Ni atoms in (I), (III), (VI) and (VII).

Synthesis and crystal structures of two coordination polymers and a binuclear cadmium(II) complex containing 3- and 4-aminobenzoate ligands.

Due to their wide range of coordination modes and versatile conformations when binding to metal atoms, multicarboxylate ligands are of interest in the design of metal-organic frameworks (MOFs). Three Cd(II) complexes, namely catena-poly[diammonium [[chloridocadmium(II)]-di-µ-chlorido-[chloridocadmium(II)]-bis(µ-3-aminobenzoato)-κ(3)N:O,O';κ(3)O,O':N]], {(NH4)[CdCl2(C7H6NO2)]}n, (I), catena-poly[[[aquacadmium(II)]-bis(µ-4-aminobenzoato)-κ(3)N:O,O';κ(3)O,O':N] monohydrate], {[Cd(C7H6NO2)2(H2O)]·H2O}n, (II), and di-µ-acetato-κ(4)O:O'-bis[(4-aminobenzoato-κ(2)O,O')(2,2'-bipyridine-κ(2)N,N')cadmium(II)], [Cd2(CH3COO)2(C7H6NO2)2(C10H8N2)2], (III), with different stuctural forms are reported. Complex (I) has a one-dimensional ladder structure, with strong N-H···O and weak N-H···Cl hydrogen bonds linking the cations and anions in the three-dimensional supramolecular structure. Complex (II) has a one-dimensional chain structure. Extensive O-H···O and N-H···O hydrogen bonds between the anionic ligands and the solvent water molecules and π-π stacking interactions between the centroids of the benzene rings lead to the three-dimensional supramolecular structure. Complex (III) is a binuclear molecule which is extended into a three-dimensional supramolecular structure via strong N-H···O and weak C-H···O hydrogen bonds.

Highly selective in vivo imaging of endogenous/exogenous phosphate ion over ATP and PPi.

A chemodosimeter was designed to function as a highly selective phosphate ion (Pi ) sensor, showing a 91-fold ratiometric fluorescence enhancement. The probe successfully visualized exogenous and endogenous apyrase-catalyzed Pi generation and was the first probe able to trace the generation and enrichment of Pi through hemichannel closure in Sf9 cells.

Crystal structure of tetraaquabis(8-chloro-9,10-dioxo-9,10-dihydroanthracene-1-carboxyl-ato-κO (1))cobalt(II) dihydrate.

In the title complex, [Co(C15H6ClO4)2(H2O)4]·2H2O, the Co(II) ion is bound by two carboxylate O atoms of two 5-chloro-9,10-anthra-quinone-1-carboxyl-ate anions and four water O atoms in a trans conformation, forming an irregular octa-hedral coordination geometry. This arrangement is stabilized by intra-molecular O-H⋯O hydrogen bonds between water and carboxyl-ate. Further O-H⋯O hydrogen bonds between coordinating and non-coordinating water and carboxyl-ate produce layers of mol-ecules that extend parallel to (001). The organic ligands project above and below the plane. Those ligands of adjacent planes are inter-digitated and there are π-π inter-actions between them with centroid-centroid distances of 3.552 (2) and 3.767 (2) Šthat generate a three-dimensional supra-molecular structure.

Crystal structure of 4-acetamido-benzoic acid monohydrate.

In the title compound, C9H9NO3·H2O, the plane of the acetamide group is oriented at 20.52 (8)° with respect to the benzene ring, whereas the plane of the carb-oxy-lic acid group is essentially coplanar with the benzene ring [maximum deviation = 0.033 (1) Å]. In the crystal, classical O-H⋯O and N-H⋯O hydrogen bonds and weak C-H⋯O hydrogen bonds link the organic mol-ecules and water mol-ecules of crystallization into a three-dimensional supra-molecular architecture.

Bimetallic ruthenium complexes bridged by divinylphenylene bearing oligo(ethylene glycol)methylether: synthesis, (spectro)electrochemistry and the lithium cation effect.

A series of 1,4-disubstituted ruthenium-vinyl complexes, (E,E)-[{(PMe3)3(CO)ClRu}2(µ-HC=CH-Ar-CH=CH)], in which the 1,4-diethenylphenylene bridge bears two oligo(ethylene glycol)methyl ether side chains at different positions (2,5- and 2,3-positions), were prepared. The respective products were characterized by elemental analyses and NMR spectroscopy. The structures of complexes 1b and 1e were established by X-ray crystallography. The electronic properties of the complexes were investigated by cyclic voltammetry, and IR and UV-vis/NIR spectroscopies. Electrochemical studies showed that the 2,5-substituents better stabilized the mixed-valence states; the electrochemical behavior was greatly affected by lithium cations, especially complex 1g with 2,3-substituents, which was further supported by IR and UV-vis/NIR spectra changes. Spectroelectrochemical studies showed that the redox chemistry was dominated by the non-innocent character of the bridging fragment.

A new natural naphtho[1,2-b]furan from the leaves of Cassia fistula.

A new naphtho[1,2-b]furan, 2,9-dihydroxy-7-methoxy-4-methylnaphtha[1,2-b]furan-3(2H)-one (1), along with 10 known compounds vanillic acid (2), naringenin (3), glyceryl-1-tetracosanoate (4), moracin J (5), 1,3,8-trihydroxyanthraquinone (6), esculetin (7), mauritianin (8), kaempferol 3-neohesperidoside (9), ß-sitosterol (10), and ß-daucosterol (11), was isolated from the leaves of Cassia fistula. The structure of the new compound was determined by NMR and X-ray analysis. Compounds 1, 3, 5-9 were isolated from this plant for the first time. The naphtha[1,2-b]furan was firstly isolated from the natural resources.

Ammonium 2-(3,4-di-methyl-benzo-yl)benzoate dihydrate.

In the anion of the title compound, NH4 (+)·C16H13O3 (-)·2H2O, the benzene rings are twisted with respect to each other by 73.56 (10)°. In the crystal, extensive N-H⋯O and O-H⋯O hydrogen bonds link the cations, anions and lattice water mol-ecules into a three dimensional supra-molecular structure.

N-(7-Dibromo-methyl-5-methyl-1,8-naphthyridin-2-yl)acetamide-pyrrolidine-2,5-dione (1/1).

In the title co-crystal, C(12)H(11)Br(2)N(3)O·C(4)H(5)NO(2), the naphthyridine derivative and the pyrrolidine-2,5-dione mol-ecules have crystallographic mirror-plane symmetry with all non-H atoms, except the Br atom, located on the mirror plane. In the crystal, N-H⋯N, N-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules into heterodimers. These dimers are further linked into a one-dimensional structure along [010] by weak C-Br⋯O inter-actions [Br⋯O = 3.028 (5) Šand C-Br⋯O = 158.52 (4)°].

(2,2'-Bi-pyridine-κ(2) N,N')bis-(nitrato-κ(2) O,O')copper(II).

In the title complex, [Cu(NO3)2(C10H8N2)], the Cu(II) cation is chelated by two nitrate anions and by one 2,2'-bi-pyridine ligand in a distorted N2O4 octa-hedral geometry. The dihedral angle between the pyridine rings is 1.92 (11)°. In the crystal, π-π stacking between parallel pyridine rings of adjacent complex mol-ecules is observed, the centroid-centroid distance being 3.6788 (19) Å. Weak C-H⋯O hydrogen bonds further link the mol-ecules into a three-dimensional supra-molecular architecture.

Synthesis, crystal structure, DNA interaction and anticancer activity of tridentate copper(II) complexes.

Three new tridentate copper(II) complexes [Cu(dthp)Cl(2)] (1) (dthp=2,6-di(thiazol-2-yl)pyridine), [Cu(dmtp)Cl(2)] (2) (dmtp=2,6-di(5-methyl-4H-1,2,4-triazol-3-yl)pyridine) and [Cu(dtp)Cl(2)] (3) (dtp=2,6-di(4H-1,2,4-triazol-3-yl)pyridine) have been synthesized and characterized. Crystal structure of complex 1 shows that the complex existed as distorted square pyramid with five co-ordination sites occupied by the tridentate ligand and the two chlorine anions. Ethidium bromide displacement assay, viscosity measurements, circular dichroism studies and cyclic voltammetric experiments suggested that these complexes bound to DNA via an intercalative mode. Three Cu(II) complexes were found to efficiently cleave DNA in the presence of sodium ascorbate, and singlet oxygen ((1)O(2)) and hydrogen peroxide were proved to contribute to the DNA cleavage process. They exhibited anticancer activity against HeLa, Hep-G2 and BEL-7402 cell lines. Nuclear chromatin cleavage has also been observed with AO/EB staining assay and the alkaline single-cell gel electrophoresis (comet assay). The results demonstrated that three Cu(II) complexes cause DNA damage that can induce the apoptosis of BEL-7402 cells.

Chiral ruthenium(II) anthraquinone complexes as dual inhibitors of topoisomerases I and II.

DNA topoisomerases (I and II) have been one of the excellent targets in anticancer drug development. Here two chiral ruthenium(II) anthraquinone complexes, Δ- and Λ-[Ru(bpy)(2)(ipad)](2+), where bpy is 2,2'-bipyridine and ipad is 2-(anthracene-9,10-dione-2-yl)imidazo[4,5-f][1,10]phenanthroline, were synthesized and characterized. As expected, both of the Ru(II) complexes intercalate into DNA base pairs and possess an obviously greater affinity with DNA. Topoisomerase inhibition and DNA strand passage assay confirmed that the two complexes are efficient dual inhibitors of topoisomerases I and II by interference with the DNA religation. In MTT cytotoxicity studies, two Ru(II) complexes exhibited antitumor activity against HeLa, MCF-7, HepG2 and BEL-7402 tumor cell lines. Flow cytometry analysis shows an increase in the percentage of cells with apoptotic morphological features in the sub-G1 phase for Ru(II) complexes. Nuclear chromatin cleavage has also been observed from AO/EB staining assay and alkaline single-cell gel electrophoresis (comet assay). The results demonstrated that Δ- and Λ-[Ru(bpy)(2)(ipad)](2+) act as dual inhibitors of topoisomerases I and II, and cause DNA damage that can lead to cell cycle arrest and/or cell death by apoptosis.

Synthesis, DNA-binding and topoisomerase inhibitory activity of ruthenium(II) polypyridyl complexes.

Two ruthenium(II) complexes [Ru(bpy)(2)(bfipH)](2+) (1) and [Ru(phen)(2)(bfipH)](2+) (2) have been synthesized and characterized. The DNA-binding behaviors of complexes were studied by using spectroscopic and viscosity measurements. Results suggested that the two complexes bind to DNA in an intercalative mode. Complexes 1 and 2 can efficiently photocleave pBR322 DNA in vitro under irradiation, singlet oxygen ((1)O(2)) was proved to contribute to the DNA photocleavage process. Topoisomerase inhibition and DNA strand passage assay confirmed that two Ru(II) complexes acted as efficient dual inhibitors of topoisomerases I and II. In MTT cytotoxicity studies, two Ru(II) complexes exhibited antitumor activity against BEL-7402, HeLa, MCF-7 tumor cells. The AO/EB staining assay indicated that Ru(II) complexes could induce the apoptosis of HeLa cells.

DNA condensation induced by ruthenium(II) polypyridyl complexes [Ru(bpy)(2)(PIPSH)](2+) and [Ru(bpy)(2)(PIPNH)](2+).

Two novel DNA-intercalating ruthenium(II) complexes, [Ru(bpy)(2)(PIPSH)](2+) and [Ru(bpy)(2)(PIPNH)](2+), have been synthesized and characterized. Gel retardation assay, atomic force microscopy, and dynamic light scattering studies show that both complexes can induce the condensation of originally circular plasmid pBR322 DNA to particulate structures under neutral conditions.