A novel class of Cd(II), Hg(II) turn-on and Cu(II), Zn(II) turn-off Schiff base fluorescent probes.

N,N'-((5,5'-(quinoxaline-2,3-diyl)bis(1H-pyrrole-5,2-diyl))bis(methanylylidene))bis(4-methoxyaniline) 4 and N,N'-((5,5'-(quinoxaline-2,3-diyl)-bis(1H-pyrrole-5,2-diyl))bis(methanylylidene))dianiline 5 have been prepared and structurally characterized. The X-ray crystal structures of compounds 4 and 4a have been determined. These compounds displayed good sensitivity toward transition metal ions with Cd(II), Zn(II) turn-on and Cu(II), Hg(II) turn-off in fluorescence. It is an elegant example of on/off behavior like a lamp. When Cd(II) or Zn(II) is added into compounds 4 or 5, the lamp will switch on, and then when Cu(II) or Hg(II) is added into the mixture, the lamp will switch off. The binding properties of 4 and 5 for cations were examined by fluorescence spectroscopy. The fluorescence data and crystal structure indicate that a 1:1 stoichiometry complex is formed between compound 4 (or 5) and metal ions, and the binding affinity is very high. The recognition mechanism between compound 4 (or 5) and metal ion was discussed based on the their chemical constructions and the CHEF/CHEQ effect when they interacted with each other.

Synthesis and in vitro and in vivo evaluation of manganese(III) porphyrin-dextran as a novel MRI contrast agent.

5-(4-Aminophenyl)-10,15,20-tris(4-sulfonatophenyl) manganese(III) porphyrin conjugated with dextran was synthesized. Its potential of being used as a tumor-targeting magnetic resonance imaging contrast agent was evaluated in vitro and in vivo. The results demonstrated that the compound has a longitudinal relaxivity (R(1)) higher than Gd-DTPA, low cytotoxicity and binding specificity to tumor cell membrane.

Synthesis of dendritic stationary phases with surface-bonded L-phenylalanine derivate as chiral selector and their evaluation in HPLC resolution of racemic compounds.

Four dendrimers were synthesized on aminopropyl-modified silica gel using methyl acrylate and ethylene diamine as building blocks by divergent method. Four generations of chiral stationary phases (CSPs) were prepared by coupling of L-2-(p-toluenesulfonamido)-3-phenylpropionyl chloride to corresponding dendrimers. The derivatives prepared on silica gel were characterized by FT-IR, (1)H NMR, and elemental analysis. The selector loadings of these four generations of CSPs generally showed a decrease tendency with the increase of generation numbers of dendrimers. The enantioseparation properties of these CSPs were preliminarily investigated by high-performance liquid chromatography. The CSP derived from the three-generation dendrimer exhibited the best enantioseparation capability. Effects of the mobile phase composition and molecular structures of racemic mixtures on enantioseparation were further studied.

Synthesis, and DNA-binding and DNA-photocleavage properties of multiply charged porphyrins.

Four new cationic porphyrins, compounds 1-4, with five to seven positive charges, were synthesized, characterized, and investigated for their binding properties towards calf-thymus DNA (CT-DNA). UV/VIS and fluorescence-titration data indicated strong binding, the apparent binding constants (K(app); (1.3-10)x10(-6) M) increasing with increasing number of charges, as determined by competitive fluorescence titration using ethidium bromide (EB) as molecular probe. These results were qualitatively confirmed by the observed photocleavage efficiency of the porphyrins towards plasmid pBR322 DNA.

Binding and photocleavage of cationic porphyrin-phenylpiperazine hybrids to DNA.

The binding properties of cationic porphyrin-phenylpiperazine hybrids to calf thymus (CT) DNA were investigated by using absorption, fluorescence and circular dichroism (CD) spectra, and the apparent affinity binding constants (K(app)) of the porphyrins for CT DNA were determined by using a competition method with ethidium bromide (EB). Intercalation of porphyrin into CT DNA occurred when two phenylpiperazines were introduced at cis position onto the periphery of cationic porphyrin. The photocleavages of pBR322 plasmid DNA by the porphyrins were consistent with the values of K(app). With [porphyrin]/[DNA base pairs] ratio increased, the binding mode tended to be outside binding, and the cleavage abilities of the porphyrins varied. In the presence of sodium azide, a quencher of 1O2, the cleavage of DNA by the porphyrin of intercalation was less inhibited.

Dipyrrolylquinoxaline-bridged Schiff bases: a new class of fluorescent sensors for mercury(II).

Novel 2,3-bis(1H-pyrrol-2-yl)quinoxaline-functionalized Schiff bases were prepared and characterized as new fluorescent sensors for mercury(II) ion. The X-ray crystal structures of compounds 4, 5, 4a and 5a were determined. The binding properties of 4 and 5 for cations were examined by UV-vis and fluorescence spectroscopy. The UV-vis and fluorescence data indicate that a 1 : 1 stoichiometric complex is formed between compound 4 (or 5) and mercury(II) ion, and the association constant is (3.81 +/- 0.7) x 10(5) M(-1) for 4 and (3.43 +/- 0.53) x 10(5) M(-1) for 5. The recognition mechanism between compound 4 (or 5) and metal ion was discussed based on their chemical construction and the fluorescence quenching effect when they interact with each other. Competition experiments revealed that compound 4 (or 5) has a highly selective response to mercury(II) ion in aqueous solution.

[Effect of photodynamic therapy with metalloporphyrin compound on human prostate cancer PC-3 cells in vitro].

OBJECTIVE: To investigate the effect of the photodynamic therapy (PDT) with the new water-soluble metalloporphyrin compound on human prostate cancer PC-3 cells in vitro and the anticancer mechanism of PDT. METHODS: The new water-soluble manganese, 5,10,15, 20-tetra (N-methyl4-pyridyl) porphinato (2-) tetraiodide salt, was synthesized. The PC-3 cells were treated with the compound of serial concentrations(0, 0.1, 1, 1.0 micromol/L) followed by irradiation of different dosages of visible light. The techniques of MTT and Annexin-V/propidium iodide double-labeled flow cytometry (FCM) were applied to measuring the inhibitory effect of the compound on the growth activity and apoptosis of the cells. RESULTS: When the metalloporphyrin compound concentration was within 10 micromol/L and the irradiation time was within 30 min, the water-soluble metalloporphyrin compound had a significant inhibitory effect on the proliferation of PC-3 cells and induced PC-3 cell apoptosis, and the effects depended greatly on metalloporphyrin concentration and illumination dosages. Higher concentrations and dosages induced the death of the majority of PC-3 cells. CONCLUSION: The PDT of the water-soluble metalloporphyrin compound followed by light irradiation has a distinctive killing effect on PC-3 cells in vitro, and the rates of proliferation inhibition and cell apoptosis are correlated with metalloporphyrin concentration and the dosages of light irradiation. The results suggest that the mechanism of metalloporphyrin PDT may be involved with the induction of apoptosis in human prostate cancer cells.

[Synthesis and anti-active oxygen properties of water-soluble metal porphyrins].

AIM: To synthesize four water-soluble metal porphyrins [5, 10, 15, 20-tetra[4-(4'-pyridine-1) butyloxy phenyl] metalloporphyrins bromide, metal = Zn (I), Cu (II), Mn (III) and Co (IV)] as analogous enzyme having two anti-active oxygen functions. METHODS: The first function, scavenging O2-, has been proved by using riboflavine-methionine photoreduction methods. The second function, scavenging H2O2, has been demonstrated by using the oxidating Vit C. The third function, scavenging HO*, has been demonstrated by using Fenton reaction. The complexes were measured by the mice liver homogenate technique of mice. RESULTS: Four model compounds could scavenge O2- in the concentration range of 1.0 x 10(-5) - 1.0 x 10(-6) mol x L(-1), decompose H2O2 in the concentration of 1.5 x 10(-6) - 1.0 x 10(-6) mol x L(-1), scavenge HO* in the concentration of 2.0 x 10(-8) - 1.0 x 10(-8) mol x L(-1). All showed that they had obvious action of decreasing the lipid peroxidation in the concentration of 1.0 x 10(-7) mol x L(-1). CONCLUSION: All above-mentioned complexes were considered to be qualified analogous enzymes of anti-active oxygen.

Synthesis of Bis(aliphatic amine)osmium(II), Bis(arylamido)osmium(IV), and Bis(imido)- and Oxo(imido)osmium(VI) Porphyrins.

The syntheses, characterization, and reactivity of a series of osmium porphyrins, Os(II)(Por)(H(2)NR)(2) [Por = dianions of octaethylporphyrinato (OEP), tetraphenylporphyrinato (TPP), meso-tetrakis(p-tolyl)porphyrinato (TTP), meso-tetrakis(4-chlorophenyl)porphyrinato (4-Cl-TPP), meso-tetrakis(3,4,5-trimethoxyphenyl)porphyrinato (3,4,5-MeO-TPP), R = (t)Bu; Por = TPP, R = (i)Pr], Os(II)(Por)(HNEt(2))(2) (Por = TPP, 3,4,5-MeO-TPP), Os(IV)(Por)(NHAr)(2) (Por = OEP, TPP, 3,4,5-MeO-TPP; Ar = Ph, 4-F-Ph), Os(VI)(Por)(N(t)Bu)(2) (Por = TPP, TTP, 4-Cl-TPP, 3,4,5-MeO-TPP), Os(VI)O(Por)(N(t)Bu) (Por = TPP, TTP, 4-Cl-TPP, 3,4,5-MeO-TPP), and Os(VI)O(Por)(4-F-PhN) (Por = TPP, 3,4,5-MeO-TPP) are described. The complexes Os(Por)(HNAr)(2) are prepared from the reactions of Os(Por)(N(2))(THF) with arylamines in aerobic tetrahydrofuran. Air oxidations of Os(Por)(H(2)N(t)Bu)(2) in tetrahydrofuran and in the presence of H(2)N(t)Bu give OsO(Por)(N(t)Bu) and Os(Por)(N(t)Bu)(2). The X-ray crystal structures of OsO(TTP)(N(t)Bu).EtOH and Os(4-Cl-TPP)(N(t)Bu)(2) have been determined. Crystal data for OsO(TTP)(N(t)Bu).EtOH: monoclinic, space group P2(1)/c, a = 13.546(6) Å, b = 23.180(3) Å, c = 16.817(3) Å, beta = 90.84(2) degrees, V = 5279.7(1.0) Å(3), Z = 4. Os(4-Cl-TPP)(N(t)Bu)(2): monoclinic, space group P2(1)/c, a = 11.046(2) Å, b = 18.380(3) Å, c = 23.640(4) Å, beta = 97.22(1) degrees, V = 4759.8(1.0) Å(3), Z = 4. The Os=O and Os=N(t)Bu distances in OsO(TTP)(N(t)Bu).EtOH are 1.772(7) and 1.759(9) Å, respectively. The Os=N(t)Bu distances in Os(4-Cl-TPP)(N(t)Bu)(2) average 1.775 Å. The imido angles range from 165.8(8) to 170.6(9) degrees. For the infrared spectra of these complexes, a discussion on the "oxidation state marker" band in the vicinity of 1000 cm(-)(1) is presented. The differences in the electronic properties of osmium porphyrins at various oxidation states are also described.