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Electrochemical Preparation of Poly(arginine)-Modified Carbon Nanotube Paste Electrode and its Application for the Determination of Pyridoxine in the Presence of Riboflavin: An Electroanalytical Approach

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Journal of Analysis and Testing 2019年第4期3卷 331-340页

作者： Girish Tigari J.G.Manjunatha Department of Chemistry FMKMC CollegeMangalore University Constituent CollegeMadikeriKarnatakaIndia

A simple poly(arginine)film-modified carbon nanotube paste electrode(PAMCNTPE)was prepared using cyclic voltam-metry(CV).The devised sensor was subjected to field-emission scanning electron microscope(FESEM)and CV charac-terization.The sensing of 0.1 mM pyridoxine(PY)was upgraded at PAMCNTPE as compared to the bare carbon nanotube paste electrode(BCNTPE).The PAMCNTPE detects the 0.1 mM PY at a specific potential 0.727 V with a current response of 10.68μA.In the case of BCNTPE,the PY appeared at 0.798 V with a current 2.90μA.The proposed analytical method was optimized by prime parameters such as the impact scan rate,pH and PY concentration.Under optimal conditions,the concentration of PY is directly proportional to oxidation current(I_(pa))in linear range 2-10μM,and 10-80μM with a detection limit(LOD)of 9.6×10^(−7) M and limit of quantification(LOQ)of 3.21×10^(−6) M.The simultaneous determination,concen-tration variation analysis of PY is performed with Riboflavin(RF)and interference analysis in detecting PY also examined.The proposed sensor was effectively applied for the determination of PY in natural food supplement with excellent recovery.

关键词： Poly(arginine) Carbon nanotube Pyridoxine Riboflavin Cyclic voltammetry

SDS-PAGE study on photooxidation damage of lysozyme induced by Riboflavin

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Science China Chemistry 2007年第1期50卷 84-90页

作者： ZHANG ZhaoXia ZHAO HongWei ZHU HongPing GE Min WANG WenFeng YAO SiDe LI WenXin Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China Graduate University of Chinese Academy of Sciences Beijing 100049China

The photooxidation damage of lysozyme under 315-375 nm irradiation in the presence of Riboflavin was studied by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE).Indica- tions showed that the mechanisms and products of oxidative damage were relative to the concentra- tion of Riboflavin,the time of irradiation and the ambience.The type I process was examined in a nitrogen saturated solution,whereas both type I and type II were observed in an aerobic atmosphere and type II was the dominant process.The study also suggested that antioxidants,such as melatonin, can reduce the damage of lysozyme effectively.

关键词： lysozyme Riboflavin photooxidation SDS-PAGE antioxidant

Evaluation of a Modified Scleral Contact Lens as a Riboflavin Delivery Device for Corneal Collagen Crosslinking

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Open Journal of Ophthalmology 2017年第4期7卷 273-280页

作者： Ricardo Torres Soares Neil F.Novo Willy Marcus Franca Faculty of Medical and Health Science Catholic University of Sao PauloSao PauloBrazil

Introduction: Keratoconus is a complex corneal disease that reduces visual acuity by progressively modifying the corneal shape and thickness, usually producing myopia and irregular astigmatism. Corneal collagen crosslinking with Riboflavin + ultraviolet-A radiation (CXL) has become a widely accepted treatment for progressive keratoconus. During CXL, Riboflavin administration is performed by repeated manual instillation of solution drops on the cornea for 30 minutes, a procedure that is often uncomfortable for many patients and that consumes surgical facilities and staff resources. In this study, especially modified scleral contact lenses (MSCL) were employed for delivering Riboflavin to the cornea during CXL. Objective: The study aimed at evaluating the safety and efficacy of MSCL as a drug delivery system, verifying if anterior chamber flare confirms Riboflavin penetration and describes the impact on patient comfort and optimization of surgical staff and facility resources. Material and Method: This study included 8 eyes of 6 patients aged 16 - 25 years old with history of progressive keratoconus. After mechanical removal of corneal epithelium, the concave surface of the modified scleral contact lens was filled with Riboflavin solution and the lens was placed on the patient’s eye during 30 minutes. The lens design allows the formation of a Riboflavin layer between the lens and the exposed corneal stroma to facilitate Riboflavin penetration. Patients with lens were allowed to stand up and wait for the second UVA phase outside the surgical room. Riboflavin diffusion was confirmed by biomicroscopic examination of the corneal stroma and anterior chamber with the lens in place. Patients returned and the lens was removed before UV-A irradiation at 3 mW/cm2 for 30 minutes. Statistical analysis was performed by comparing the following parameters of each patient pre- and post-CXL: Spherical equivalent (Sph.Eq.), Mean simulated keratometry (SimK-m) and corrected distance visual acuity (CDVA) using the Wilcoxon method for

关键词： Keratoconus Riboflavin UVA Rigid Contact Lens Cross-Linking

Anti-aging effect Riboflavin via endogenous antioxidant in fruit fly drosophila melanogaster

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Anti-aging effect riboflavin via endogenous antioxidant in f...

Riboflavin-UVA collagen cross-linking for the treatment of acanthamoeba keratitis

首届东方药理论坛暨2018年全国心脑血管药理学术会议、上海市药理学会第十九届学术年会

作者： Y.-X ZOU M.-H RUAN J.LUAN X.FENG S.CHEN Zhi-Yong Chu Naval Medical Research Institute Jiangxi University of Traditional Chinese Medicine

Objectives:This study investigated the effect of Riboflavin on aging in Drosophila melanogaster（fruit fly）.Design:Experimental study.Setting:Naval Medical Research Institute.Participants:Fruit fly Drosophila melanogaster.Intervention:After lifelong supplement of Riboflavin,the lifespan and the reproduction of fruit flies were observed.Hydrogen peroxide（H2 O2） was used to mimic oxidative stress damage to fruit flies and the survival time was recorded.Measurements:The activity of copper-zinc-containing superoxide dismutase（SOD1）,manganese containing SOD（SOD2） and catalase（CAT） and lipofuscin（LF） content were determined.Results:Riboflavin significantly prolonged the lifespan（Log rankχ2=16.677,PRiboflavin supplement.Conclusion:Riboflavin prolonged the lifespan and increased the reproduction of fruit flies through anti-oxidative stress pathway involving enhancing the activity of SOD 1 and CAT and inhibiting LF accumulation.Riboflavin deserves more attention for slowing human aging.

关键词： Riboflavin aging lifespan reproduction oxidativestress

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Annals of Eye Science 2019年第1期4卷 23-28页

作者： Choul Yong Park Roy S.Chuck Department of Ophthalmology Dongguk UniversityIlsan HospitalGoyangSouth Korea Department of Ophthalmology and Visual Sciences Montefiore Medical CenterAlbert Einstein College of MedicineBronxNYUSA

In this review,recent studies regarding Riboflavin-ultraviolet A(UVA)collagen cross-linking for the treatment of acanthamoeba keratitis(AK)were reviewed.English written studies about acanthamoeba,keratitis,Riboflavin and collagen cross-linking were retrieved from PubMed search engine(www.***.nlm.***.gov/pubmed).Although there were significant numbers of cases reporting the effectiveness of Riboflavin-UVA collagen cross-linking in AK,experimental studies(in vivo and in vitro)failed to verify amoebicidal or cysticidal effect of Riboflavin-UVA collagen cross-linking.In conclusion,the efficacy of Riboflavin-UVA collagen cross-linking for the treatment of AK is still debatable.It is necessary to conduct a prospective case-control study for clear guidance for clinicians.

关键词： Acanthamoeba keratitis collagen ultraviolet A(UVA) Riboflavin cross-linking

Selective Tumor Cell Death induced by Irradiated Riboflavin through Recognizing DNA G-T Mismatch

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Selective Tumor Cell Death induced by Irradiated Riboflavin ...

Effects of Riboflavin and desferrioxamine B on Fe(Ⅱ)oxidation by 0_(2)

第十届全国化学生物学学术会议

作者： Yi Yuan Zhuo Tang Natural Products Research Center Chengdu Institute of Biology

Riboflavin（vitamin B2） has been thought to be a promising antitumoral agent in photodynamic therapy, though the further application of the method was limited by the unclear molecular mechanism. G-T mismatch was the most abundant mismatches that were generated by replication errors and endogenous damages.Our work reveals that Riboflavin was able to recognize G-T mismatch specifically and induce single-strand breaks in duplex DNA targets efficiently under irradiation. Riboflavin was proved selectively interacting with G-T bases. Certain cancer cells were certified deficient in mismatch repair system, generating high level of G-T mismatches. In the presence of Riboflavin, the photo-irradiation could induce the death of tumor cells that are defective in mismatch repair system selectively, highlighting the G – T mismatch as potential drug target for tumor cells. Moreover, Riboflavin is a promising leading compound for further drug design due to its inherent specific recognition of the G–T mismatch.

关键词： cell death Riboflavin photocleavage tumor cells DNA mismatch

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Fundamental Research 2022年第2期2卷 208-217页

作者： Peng Zhang Philippe Van Cappellen Kunfu Pi Songhu Yuan State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences68 Jincheng StreetEast Lake High-Tech Development ZoneWuhanHubei 430078China Ecohydrology Research Group Water Institute and Department of Earth and Environmental SciencesUniversity of WaterlooWaterlooOntario N2L 3G1Canada Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science School of Environmental StudiesChina University of Geosciences68 Jincheng StreetEast Lake High-Tech Development ZoneWuhanHubei 430078China

Flavins and siderophores secreted by various plants,fungi and bacteria under iron(Fe)deficient conditions play important roles in the biogeochemical cycling of Fe in the environment.Although the mechanisms of flavin and siderophore mediated Fe(Ⅱ)reduction and dissolution under anoxic conditions have been widely studied,the influence of these compounds on Fe(ID)oxidation under oxic conditions is still unclear.In this study,we investi-gated the kinetics of aqueous Fe(Ⅱ)(17.8μM)oxidation by O_(2)at pH 5-7 in the presence of Riboflavin(oxidized(RBF)and reduced(RBFH_(2)))and desferrioxamine B(DFOB)as representative flavins and siderophores,respec-tively.Results showed that the addition of RBF/RBFH_(2)or DFOB markedly accelerates the oxidation of aqueous Fe(Ⅱ)by O_(2).For instance,at pH 6,the rate of Fe(Ⅱ)oxidation was enhanced 20-70 times when 10μM RBFH_(2)was added.The mechanisms responsible for the accelerated Fe(Ⅰ)oxidation are related to the redox reactivity and complexation ability of RBFH_(2),RBF and DFOB.While RBFH_(2)does not readily complex Fe(Ⅰ)/Fe(Ⅱ),it can activate O_(2)and generate reactive oxygen species,which then rapidly oxidize Fe(Ⅱ).In contrast,both RBF and DFOB do not reduce O_(2)but react with Fe(Ⅱ)to form RBF/DFOB-complexed Fe(Ⅱ),which in turn accelerates Fe(Ⅰ)oxidation.Furthermore,the lower standard reduction potential of the Fe(Ⅰ)-DFOB complex,compared to the Fe(Ⅰ)-RBF complex,correlates with a higher oxidation rate constant for the Fe(Ⅰ)-DFOB complex.Our study reveals an overlooked catalytic role of flavins and siderophores that may contribute to Fe(Ⅱ)/Fe(Ⅱ)cycling at oxic-anoxic interfaces.

关键词： Riboflavin Desferrioxamine B Ferrous iron Abiotic oxidation Oxygen

Riboflavin-induced Priming for Pathogen Defense in Arabidopsis thaliana

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Riboflavin-induced Priming for Pathogen Defense in Arabidops...

Engineering Shewanella carassii, a newly isolated exoelectrogen from activated sludge, to enhance methyl orange degradation and bioelectricity harvest

中国植物病理学会2008年学术年会

作者： Shujian Zhang Xue Yang Maowu Sun Feng Sun Sheng Deng Hansong Dong College of Plant Protection, Nanjing Agricultural University, Nanjing 210095

Riboflavin (vitamin B) participates in a variety of redox processes that affect plant defense responses. Previously we have shown that Riboflavin induces pathogen resistance in the absence of hypersensitive cell death (HCD) in plants. Herein, we report that Riboflavin induces priming of defense responses in Arabidopsis thaliana toward infection by virulent Pseudomonas syringae pv. tomato DC3000 (Pst). Induced resistance was mechanistically connected with the expression of defense response genes and cellular defense events, including H202 burst, HCD, and callose deposition in the plant. Riboflavin treatment and inoculation of plants with Pst were neither active but both synergized to induce defense responses. The priming process needed NPR1 (essential regulator of systemic acquired resistance) and maintenance of HO burst but was independent of salicylic acid, jasmonic acid, ethylene, and abscisic acid. Our results suggest that the role of Riboflavin in priming defenses is subject to signaling process distinct from the known pathways of hormone signal transduction.

关键词： Riboflavin priming defense responses hypersensitive cell death （HCD） hydrogen peroxide（H2O2） callose deposition

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Synthetic and Systems Biotechnology 2022年第3期7卷 918-927页

作者： Chi Yang Junqi Zhang Baocai Zhang Dingyuan Liu Jichao Jia Feng Li Hao Song Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering(Ministry of Education) Tianjin UniversityTianjin300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) School of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China Qingdao Institute Ocean Engineering of Tianjin University Tianjin UniversityQingdao266200China

Electroactive microorganisms(EAMs)play important roles in biogeochemical redox processes and have been of great interest in the fields of energy recovery,waste treatment,and environmental remediation.However,the currently identified EAMs are difficult to be widely used in complex and diverse environments,due to the existence of poor electron transfer capability,weak environmental adaptability,and difficulty with engineering modifications,etc.Therefore,rapid and efficient screening of high performance EAMs from environments is an effective strategy to facilitate applications of microbial fuel cells(MFCs).In this study,to achieve efficient degradation of methyl orange(MO)by MFC and electricity harvest,a more efficient exoelectrogen Shewanella carassii-D5 that belongs to Shewanella spp.was first isolated from activated sludge by WO_(3) nanocluster probe technique.Physiological properties experiments confirmed that S.carassii-D5 is a Gram-negative strain with rounded colonies and smooth,slightly reddish surface,which could survive in media containing lactate at 30℃.Moreover,we found that S.carassii-D5 exhibited remarkable MO degradation ability,which could degrade 66%of MO within 72 h,1.7 times higher than that of Shewanella oneidensis MR-1.Electrochemical measurements showed that MFCs inoculated with S.carassii-D5 could generate a maximum power density of 704.6 mW/m^(2),which was 5.6 times higher than that of S.oneidensis MR-1.Further investigation of the extracellular electron transfer(EET)mechanism found that S.carassii-D5 strain had high level of c-type cytochromes and strong biofilm formation ability compared with S.oneidensis MR-1,thus facilitating direct EET.Therefore,to enhance indirect electron transfer and MO degradation capacity,a synthetic gene cluster ribADEHC encoding Riboflavin synthesis pathway from Bacillus subtilis was heterologously expressed in S.carassii-D5,increasing Riboflavin yield from 1.9 to 9.0 mg/g DCW with 1286.3 mW/m^(2) power density output in lactate fed-MFCs.Furthermore,results showed

关键词： Microbial fuel cells WO_(3)nanocluster probe Shewanella carassii Riboflavin Methyl orange