Zhiqiu Wang

Detection of reactive oxygen species (ROS) generated by TiO2(R), TiO2(R/A) and TiO2(A) under ultrasonic and solar light irradiation and application in degradation of organic dyes

In the present work, the rutile, anatase and mixed (rutile and anatase) crystal phase TiO(2) powders were irradiated by ultrasound and solar light, respectively, and the generation of reactive oxygen species (ROS) were detected through the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). The DPCO can be extracted by the mixed solvent of benzene and carbon tetrachloride and the extract liquors display an obvious absorption peak around 563nm. In addition, the influences of (ultrasonic or solar light) irradiation time, TiO(2) addition amount and DPCI concentration on the quantities of generated ROS were also reviewed. The kinds of generated ROS were determined by using several radical scavengers. At last, the researches on the sonocatalytic and photocatalytic degradation of several organic dyes were also performed. It is wished that this paper might offer some important subjects for broadening the applications of sonocatalytic and photocatalytic technologies.

Spectroscopic analyses on interaction of o-Vanillin-d-Phenylalanine, o-Vanillin-l-Tyrosine and o-Vanillin-l-Levodopa Schiff Bases with bovine serum albumin (BSA)

In this work, three o-Vanillin Schiff Bases (o-VSB: o-Vanillin-D-Phenylalanine (o-VDP), o-Vanillin-L-Tyrosine (o-VLT) and o-Vanillin-L-Levodopa (o-VLL)) with alanine constituent were synthesized by direct reflux method in ethanol solution, and then were used to study the interaction to bovine serum albumin (BSA) molecules by fluorescence spectroscopy. Based on the fluorescence quenching calculation, the bimolecular quenching constant (K(q)), apparent quenching constant (K(sv)), effective binding constant (K(A)) and corresponding dissociation constant (K(D)) as well as binding site number (n) were obtained. In addition, the binding distance (r) was also calculated according to Fosters non-radioactive energy transfer theory. The results show that these three o-VSB can efficiently bind to BSA molecules, but the binding array order is o-VDP-BSA>o-VLT-BSA>o-VLL-BSA. Synchronous fluorescence spectroscopy indicates that the o-VDP is more accessibility to tryptophan (Trp) residues of BSA molecules than to tyrosine (Tyr) residues. Nevertheless, the o-VLT and o-VLL are more accessibility to Tyr residues than to Trp residues.

Detection and comparison of reactive oxygen species (ROS) generated by chlorophyllin metal (Fe, Mg and Cu) complexes under ultrasonic and visible-light irradiation

In this paper, in order to examine the mechanisms of sonodynamic and photodynamic reactions, the chlorophyllin metal (Chl-M (M=Fe, Mg and Cu)) complexes were irradiated by ultrasound (US) and visible-light (VL), respectively, and the generation of reactive oxygen species (ROS) were detected by the method of Oxidation-Extraction Spectrometry (OES). That is, the 1,5-diphenyl carbazide (DPCI) is oxidized by the generated ROS into 1,5-diphenyl carbazone (DPCO), which can display a various visible absorption around 563 nm wavelength. Besides, some influence parameters on the generation of ROS were also reviewed. The results demonstrated an apparent synergistic effect of Chl-M and ultrasonic or visible-light irradiation for the generation of ROS. Moreover, the quantities of generated ROS increase with the increase of (ultrasonic or visible-light) irradiation time and Chl-M (M=Fe, Mg and Cu) concentration. Finally, several quenchers were used to determine the kind of the generated ROS. It is wished that this paper might offer some valuable references for the study on the sonodynamic therapy (SDT) and photodynamic therapy (PDT) mechanisms and the application of Chl-M in tumor treatment.

Spectroscopic analyses on ROS generation catalyzed by TiO2, CeO2/TiO2 and Fe2O3/TiO2 under ultrasonic and visible-light irradiation.

In this work, the TiO2, CeO2/TiO2 and Fe2O3/TiO2 powders were irradiated, respectively, by ultrasound and visible-light, and the generation of reactive oxygen species (ROS) were estimated by the method of Oxidation-Extraction Photometry (OEP). That is, the 1,5-diphenyl carbazide (DPCI) can be oxidized by generated ROS into 1,5-diphenyl carbazone (DPCO), which can be extracted by mixed solvent of benzene and carbon tetrachloride. The DPCO extract liquor displays an obvious absorbance at 563 nm wavelength. In addition, some influencing factors, such as (ultrasonic or visible-light) irradiation time, catalyst addition amount and DPCI concentration, on the generation of ROS were also reviewed. The results indicated that the quantities of generated ROS increase with the increase of (ultrasonic or visible-light) irradiation time and catalyst addition amount. Moreover, the displayed quantities of ROS are also related with DPCI concentration. And then, several radical scavengers were used to determine the kinds of the generated ROS. At last, the researches on the sonocatalytic and photocatalytic degradation of several organic dyes have also been performed. It is wished that this paper might offer some important subjects for broadening the applications of sonocatalytic and photocatalytic technologies in future environment treatment.

Spectroscopic studies on interaction and sonodynamic damage of metallochlorophyllin (Chl-M (M = Fe, Zn and Cu)) to protein under ultrasonic irradiation

In this paper, the chlorophyll derivatives, metallochlorophyllin (Chl-M) (M=Fe, Zn and Cu) including chlorophyllin iron (Chl-Fe), chlorophyllin zinc (Chl-Zn) and chlorophyllin copper (Chl-Cu), were adopted as sonosensitizers to combine with ultrasonic irradiation, and the sonodynamic damage of bovine serum albumin (BSA) was investigated. At first, the interaction of Chl-M with BSA was studied by fluorescence spectroscopy. The results show that the quenching mechanism belongs to a static process and among them the affinity of Chl-Fe to BSA is the most obvious. Then, some influence factors on the sonodynamic damage of BSA molecules in the presence of Chl-M under ultrasonic irradiation were also studied. Synchronous fluorescence spectra show that the binding and damage sites of Chl-M to BSA molecule are mainly on the tryptophan (Trp) residues. The generation of ROS in Chl-M sonodynamic process is estimated by the method of Oxidation-Extraction Spectrometry (OEP). This paper may offer some valuable references for the study of the sonodynamic activity of Chl-M and the effect of the central metals. Synchronously, it contributes to the application of Chl-M in SDT for tumor treatment.

Oxidation-extraction spectrometry of reactive oxygen species (ROS) generated by chlorophyllin magnesium (Chl-Mg) under ultrasonic irradiation.

In order to examine the mechanism and process of sonodynamic reaction, the chlorophyllin magnesium (Chl-Mg) acting as a sonosensitizer was irradiated by ultrasound, and the generation of reactive oxygen species (ROS) were detected by the method of oxidation-extraction spectrometry (OES). That is, under ultrasonic irradiation in the presence of Chl-Mg, the 1,5-diphenyl carbazide (DPCI) is oxidized by generated ROS into 1,5-diphenyl carbazone (DPCO), which can be extracted by mixed organic solvent and display a obvious visible absorption at 563 nm wavelength. Besides, the generation conditions of ROS were also reviewed. The results demonstrated that the quantities of generated ROS increased with the increase of ultrasonic irradiation time, Chl-Mg concentration and DPCI concentration. Finally, several radical scavengers (l-Histidine (His), 2,6-Di-tert-butyl-methylphenol (BHT) and Vitamin C (VC)) were used to determine the kind of the generated ROS. It was found that at least the hydroxyl radical (OH) and singlet oxygen (1O2) were generated in the presence of Chl-Mg under ultrasonic irradiation. It is wish that this paper might offer some valuable references for the study on the mechanism of SDT and the application of Chl-Mg in tumor treatment.

Spectrometry researches on interaction and sonodynamic damage of riboflavin (RF) to bovine serum albumin (BSA).

In this paper, the riboflavin (RF) was used to study the interaction and sonodynamic damage to bovine serum albumin (BSA) by fluorescence and UV-vis spectroscopy. The results showed that the RF could efficiently bind to BSA in aqueous solution. Under ultrasonic irradiation, the RF could obviously damage the BSA. In addition, synchronous fluorescence spectroscopy revealed that the RF showed more accessible to tryptophan (Trp) residues than to tyrosine (Tyr) residues. Also, it damaged Trp residues more seriously than Tyr residues under ultrasonic irradiation. At last, the generation of reactive oxygen species (ROS) in sonodynamic process was estimated by the method of Oxidation-Extraction Spectrometry (OES). And then, several radical scavengers were used to determine the kind of ROS. It was found that at least the singlet oxygen ((1)O(2)) and hydroxyl radicals (*OH) were generated.

Spectroscopic analyses on interaction of Amantadine-Salicylaldehyde, Amantadine-5-Chloro-Salicylaldehyde and Amantadine-o-Vanillin Schiff-Bases with bovine serum albumin (BSA)

In this work, three Tricyclo [3.3.1.1(3,7)] decane-1-amine (Amantadine) Schiff-Bases, Amantadine-Salicylaldehyde (AS), Amantadine-5-Chloro-Salicylaldehyde (AS-5-C) and Amantadine-o-Vanillin (AS-o-V), were synthesized by direct heating reflux method in ethanol solution and characterized by infrared spectrum and elementary analysis. Fluorescence quenching was used to study the interaction of these Amantadine Schiff-Bases (AS, AS-5-C and AS-o-V) with bovine serum albumin (BSA). According to fluorescence quenching calculations the bimolecular quenching constant (K(q)), apparent quenching constant (K(SV)), effective binding constant (K(A)) and corresponding dissociation constant (K(D)), binding site number (n) and binding distance (r) were obtained. The results show that these Amantadine Schiff-Bases can obviously bind to BSA molecules and the binding strength order is AS<AS-5-C=AS-o-V. Synchronous fluorescence spectroscopy reveals that these Amantadine Schiff-Bases adopt different way to bind with BSA molecules. That is, the AS and AS-5-C are accessibility to tryptophan (Trp) residues more than the tyrosine (Tyr) residues, while the AS-o-V is equally close to the Tyr and Trp residues.

Spectroscopic analyses on sonocatalytic damage to bovine serum albumin (BSA) induced by ZnO/hydroxylapatite (ZnO/HA) composite under ultrasonic irradiation.

ZnO/hydroxylapatite (ZnO/HA) composite with HA molar content of 6.0% was prepared by the method of precipitation and heat-treated at 500°C for 40min and was characterized by powder X-ray diffraction (XRD). The sonocatalytic activities of ZnO/HA composite was carried out through the damage of bovine serum albumin (BSA) in aqueous solution. Furthermore, the effects of several factors on the damage of BSA molecules were evaluated by means of UV-vis and fluorescence spectra. Experimental results indicated that the damage degree of BSA aggravated with the increase of ultrasonic irradiation time, irradiation power and ZnO/HA addition amount, but weakened with the increase of solution acidity and ionic strength. In addition, the damage site to BSA was also studied by synchronous fluorescence technology and the damage site was mainly at tryptophan (Trp) residue. This paper provides a valuable reference for driving sonocatalytic method to treat tumor in clinic application.

Investigation on Interaction and Sonodynamic Activity of Chlorophyll-Magnesium-Metronidazole (Chl-Mg-MTZ) with Bovine Serum Albumin (BSA) in Aqueous Solution

Sonodynamic therapy (SDT) is an innovative cancer treatment involving a tumor-localizing sonosensitizer. The synthesis, modification and activity of novel sonosensitizers have attracted more and more researchers’ attention. In the present study, chlorophyll-magnesium (Chl-Mg) and metronidazole (MTZ) were used as reactants and the chlorophyll-magnesium linked metronidazole complex (chlorophyll-magnesium-metronidazole, Chl-Mg-MTZ) was synthesized and characterized. Bovine serum albumin (BSA) was selected as the target protein; the biomolecule affinity and sonodynamic activity of Chl-Mg-MTZ were assessed by their UV–vis and fluorescence spectra. The results indicate that the interaction of Chl-Mg-MTZ to BSA is comparable with that of chlorophyll-magnesium (Chl-Mg). However, during damage of BSA, Chl-Mg-MTZ shows a higher sonodynamic activity than chlorophyll-magnesium (Chl-Mg). Moreover, synchronous fluorescence spectroscopy indicates that Chl-Mg-MTZ has similar binding ability with the tyrosine (Tyr) and tryptophan (Trp) residues of BSA molecules. However, the damage is mainly focused on the Trp residues. In addition, the production of reactive oxygen species (ROS) in the sonodynamic process was detected through the oxidation-extraction of 1,5-diphenylcarbazide (DPCI). The results promote the potential of Chl-Mg-MTZ as a new sonosensitive drug for use in SDT, encouraging further study on tumor treatment.