ABSTRACT
The sonodynamic damage to protein in the presence of methylene blue (MB) and the various influencing factors including ultrasonic irradiation time and MB concentration on the damage of protein were studied by fluorescence and absorption spectra. In addition, the mechanisms of the synergistic effects of ultrasound and MB were studied by oxidation-extraction photometry with several reactive oxygen species (ROS) scavengers. The results indicated that the damage of protein induced by the synergistic effects of ultrasound and MB were more serious than those that ultrasound or MB alone was applied. The damage of protein could be mainly due to the generation of ROS. The damage degree of protein increased with the increase of ultrasonic irradiation time and MB concentration because of the increased quantities of ROS generation. Both (1)O2 and ·OH were the important mediators of the ultrasound-inducing protein damage in the presence of MB.
Subject(s)
Methylene Blue/adverse effects , Reactive Oxygen Species/chemistry , Serum Albumin, Bovine/chemistry , Sonication/adverse effects , Animals , Cattle , Spectrometry, Fluorescence , UltrasonicsABSTRACT
Three new rimantadine Schiff bases (RSBs) were prepared, and then the interaction of RSBs with bovine serum albumin (BSA) was investigated using fluorescence, synchronous fluorescence, UV-vis absorption spectroscopy under physiological conditions. The results showed that the three RSBs effectively quenched the intrinsic fluorescence of BSA via static quenching. Binding constant (K a), number of binding sites (n), and the binding distance (r) between three RSBs and BSA were calculated by Stern-Volmer equation and Förster's theory in this study. According to the results of displacement experiments of site probes, it was considered that the binding sites were located in hydrophobic cavities in sub-domains IIA of BSA. What is more, synchronous fluorescence studies indicated that the hydrophobicity around tryptophan residues was increased with the addition of rimantadine-o-vanillin (ROV) and rimantadine-4-methoxy-salicylaldehyde (RMS), while there was no apparent change with the addition of rimantadine-salicylaldehyde (RS).
ABSTRACT
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.
Subject(s)
Cerium/chemistry , Ferric Compounds/chemistry , Reactive Oxygen Species/analysis , Titanium/chemistry , Catalysis , Diphenylcarbazide/chemistry , Light , Oxidation-Reduction , Photometry/methods , SoundABSTRACT
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.
Subject(s)
Durapatite/chemistry , Serum Albumin, Bovine/chemistry , Serum Albumin, Bovine/radiation effects , Ultrasonics/methods , Zinc Oxide/chemistry , Animals , Catalysis/radiation effects , Cattle , Hot Temperature , Powders , Sodium Chloride/chemistry , Solutions , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet , Time Factors , X-Ray DiffractionABSTRACT
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.
Subject(s)
Riboflavin/metabolism , Serum Albumin, Bovine/metabolism , Animals , Cattle , Protein Binding , Reactive Oxygen Species/metabolism , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet , UltrasonicsABSTRACT
In recent years, sonodynamic activities of many drugs have attracted more and more attention of researchers. The correlative study will promote the development of sonodynamic therapy (SDT) in anti-tumor treatment. In this work, bovine serum albumin (BSA) was used as a protein model to investigate the intensifying effects of ciprofloxacin (CPFX) ultrasonically induced protein damage by UV-vis and fluorescence spectra. Meanwhile, the conformation of BSA is changed upon the addition of CPFX and metal ions under ultrasound (US) so that the damaging site of BSA is considered. Various influencing factors, such as US irradiation time, metal ions, solution temperature and ionic strength, on the ultrasonically induced BSA damage are discussed. It was showed that CPFX could enhance ultrasonically induced BSA damage. The damage degree of BSA was aggravated with the increasing of US irradiation time, solution temperature, ionic strength as well as the addition of metal ions. Furthermore, the reactive oxygen species (ROS) in reaction system were detected by oxidation-extraction photometry (OEP). Experimental results also showed that US could activate CPFX to produce ROS, which were mainly determined as superoxide radical anion (.O2-) and hydroxyl radical (.OH).
Subject(s)
Ciprofloxacin/pharmacology , Serum Albumin, Bovine/drug effects , Serum Albumin, Bovine/radiation effects , Ultrasonics/methods , Absorption/drug effects , Absorption/radiation effects , Animals , Cattle , Ciprofloxacin/chemistry , Metals , Osmolar Concentration , Protein Conformation/drug effects , Protein Conformation/radiation effects , Reactive Oxygen Species/chemistry , Serum Albumin, Bovine/chemistry , Solutions , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet , Temperature , Time Factors , Ultrasonics/instrumentation , Xanthenes/chemistryABSTRACT
Recently, the sonocatalytic technology using various semiconductors combined with ultrasonic irradiation has been received much attention to solve the environmental problems. In this paper, nano-sized titanium dioxide (TiO(2)) powder as a sonocatalyst was irradiated by ultrasound and the generation of reactive oxygen species (ROS) during sonocatalytic reaction process has been estimated by the method of Oxidation-Extraction Photometry (OEP). That is, the 1,5-diphenylcarbohydrazide (DPCI) can be oxidized by ROS into diphenylcarbonzone (DPCO), which can be extracted by the mixed solution of benzene and carbon tetrachloride and show the great absorbance at 563 nm wavelength. The synergistic effect of TiO(2) and ultrasonic irradiation was estimated and some influencing factors, such as ultrasonic irradiation time and TiO(2) addition amount on the generation of ROS were reviewed. The results indicate that the quantities of generated ROS increase with the increase of ultrasonic irradiation time and TiO(2) addition amount. Moreover, the relationship between quantities of generated ROS and DPCI concentration was also studied. And then, several quenchers were used to determine the kind of the generated ROS. At last, the researches on the sonocatalytic degradation of organic dyes and the corresponding reaction kinetics have also been performed, which is found to follow the pseudo first-order kinetics approximately. This paper may offer some important subjects for broadening the applications of sonocatalytic technology.
Subject(s)
Coloring Agents/chemistry , Nanoparticles/chemistry , Reactive Oxygen Species/metabolism , Titanium/chemistry , Ultrasonics , Catalysis , Particle SizeABSTRACT
Taking bovine serum albumin (BSA) as typical molecules, the sonodynamic damage of protein in the presence of Levofloxacin (LVFX) and its mechanism were studied by fluorescence and UV-vis spectra. Various influencing factors such as ultrasonic irradiation time, pH value, ionic strength and solution temperature on the damage of BSA were also discussed. The results showed that ultrasound can enhance the damage of LVFX on BSA. The damage degree of BSA was aggravated with the increase of ultrasonic irradiation time, solution temperature and ionic strength, whereas decreased with the increase of solution pH value. Furthermore, the reactive oxygen species (ROS) in reaction system were studied by oxidation and extraction photometry. Experimental results showed that the amounts of superoxide anion radical (·O(2)(-)) and hydroxyl radical (·OH) were significantly more than that of singlet oxygen ((1)O(2)) in the presence of LVFX under ultrasonic irradiation.
Subject(s)
Levofloxacin , Ofloxacin/chemistry , Serum Albumin, Bovine/chemistry , Spectrum Analysis/methods , Animals , Cattle , Fluorescence , Hydrogen-Ion Concentration , Hydroxyl Radical , Osmolar Concentration , Oxidation-Reduction , Reactive Oxygen Species/analysis , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet , Superoxides , Temperature , UltrasonicsABSTRACT
Microtubes of alpha-K4SiW12O40 with the length around 1 cm and inner diameter and wall thickness in the ranges of 7-55 mum and 3-15 mum, respectively, were copiously fabricated by a one-step, template-free aqueous synthesis. The formation mechanism is discussed. The discovered tubular structure of the polyoxometalate is believed to be promising for use in templates, as a precursor of tungsten oxide ceramic microtubes, and for other uses associated with tubular structures.
