Riboflavin Tetrabutyrate Research Articles

Interaction between soy protein isolate and surfactant at the interface of antibacterial nanoemulsions loaded with riboflavin tetra butyrate

SummaryRiboflavin tetra butyrate (RTB) is an effective antimicrobial photosensitiser that poses a challenge for long‐term preservation and application due to its hydrophobicity and instability. To overcome this problem, a series of nanoemulsions loaded with photosensitiser RTB was prepared in this study by using soy protein isolate (SPI) as an emulsifier and small molecule surfactant (X) as co‐emulsifier. The interaction mechanism of SPI+X co‐emulsifier and its influence on the stability of emulsion and photosensitiser were explored, and the photodynamic bactericidal effect of the prepared RTB emulsion on S. aureus was studied. SPI and four types of surfactants were present in the form of synergistic (Tween 80, T80) or competition (Span 80, S80 and lecithin, LEC) adsorption or formation of Pickering emulsion (Sodium dodecyl sulphate, SDS) at the oil–water interface. The experimental results revealed that the stable encapsulation ability of RTB emulsions for photosensitisers and their preservation ability can be drastically improved. This work verified that all RTB emulsions could inactive S. aureus under blue light, with an antibacterial ratio of more than 70%. Therefore, the emulsion‐based delivery system effectively improved the water dispersibility and chemical stability of RTB. These results demonstrate that RTB emulsion has the potential to be used as a food‐grade antibacterial emulsion.

A Simple and Efficient Model to Determine the Photonic Parameters of a Photopolymerizable Resin Usable in 3D Printing

AbstractThis study provides insight into the relationship between the photochemical reactivity and the photonic parameters of an acrylate formulation usable in digital light processing (DLP) 3D printing. First the photoreactivity of riboflavin tetrabutyrate (RFT) used as a non‐toxic photoinitiator is assessed by laser flash photolysis in the absence and in the presence of an amine as co‐initiator. RFT alone is able to photopolymerize the acrylate formulation at a rate which is drastically increased when the co‐initiator is added. Then, the depth of light penetration (Dp) and the critical energy (Ec) to form a polymer film were measured and compared to those determined from the Bouguer‐Lambert‐Beer law for Dp and from the Stockmayer equation and photopolymerization experiments for Ec. A new proposed model is able to predict the in‐depth acrylate conversion within a printed part with a relatively low input of experimental parameters. Confocal Raman microscopy is used to discuss the effect of the photobleaching of RFT in the absence of co‐initiator on the photopolymerized films. Finally, it is shown that this formulation performs quite well for 3D printing with a resolution close to the best performance of the DLP printer.

Photoinduced flavin-tryptophan electron transfer across vesicle membranes generates magnetic field sensitive radical pairs

ABSTRACTDue to the photobiology of the flavoproteins DNA photolyase and cryptochrome, electron transfer reactions between flavins and tryptophan are of significant biological relevance. In addition, electron transfer across vesicle membranes has also seen much attention. In this work, we study the electron transfer reaction between flavins and tryptophan across lipid bilayer membranes in 1,2-dipalmitoyl-sn-glycero-3-phosphocholine small unilamellar vesicles using time-resolved optical absorption microspectroscopy and magnetically affected reaction yield spectroscopy. We demonstrate that riboflavin tetrabutyrate is embedded in the vesicle bilayer and can undergo electron transfer with tryptophan molecules in either the inner water pool or the bulk solution. Remarkably, flavin mononucleotide encapsulated in the inner water pool can undergo electron transfer across the vesicle bilayer to generate a magnetically sensitive radical pair with tryptophan molecules located in the bulk solution. The observed kinetics suggest that back electron transfer occurs between radical pairs generated by diffusive reencounter, either in the vesicle surface water or via electron hopping through degenerate electron exchange.

Solution-Processed Bio-OLEDs with a Vitamin-Derived Riboflavin Tetrabutyrate Emission Layer

Solution processed biomaterials are required for the active component to develop printed biodegradable and biocompatible optoelectronic devices. Ideal film formation is crucial for the fabrication of multilayer thin film sandwich devices. We report on the characterization of thin films of the riboflavin-derived biomaterial riboflavin tetrabutyrate and its utilization in an organic light-emitting diode. We show that the nonsolution processable precursor can form homogeneous and smooth films with the addition of tailored side groups that change its solubility. We demonstrate by grazing incidence wide-angle X-ray scattering that this chemical derivative reduces the crystallinity and enhances emission, likely by suppressing π–π stacking interactions. Organic light-emitting diodes with a poly(9-vinylcarbazole)–emissive riboflavin tetrabutyrate bilayer structure yield a maximum luminance of 10 cd/m2 and external quantum efficiency of 0.02% with a 640 nm peak orange exciplex emission. External quantum efficiency...

Highly versatile nanohydrogel platform based on riboflavin-polysaccharide derivatives useful in the development of intrinsically fluorescent and cytocompatible drug carriers

In this work we describe a new nanohydrogel platform, based on polysaccharides modified with the hydrophobic and fluorescent molecule riboflavin tetrabutyrate, which leads to innovative structures useful for drug delivery applications. Hyaluronic acid and pullulan were chosen as representative of anionic and neutral polysaccharides, respectively, and the bromohexyl derivative of riboflavin tetrabutyrate was chemically linked to these polymer chains. Because of such derivatization, polymer chains were able to self-assemble in aqueous environment thus forming nanohydrogels, with mean diameters of about 312 and 210nm, for hyaluronan and pullulan, respectively. These new nanohydrogels showed low polydispersity index, and negative ζ-potential. Moreover, the nanohydrogels, which can be easily loaded with model drugs, showed long-term stability in water and physiological conditions and excellent cytocompatibility. All these properties allow to consider these intrinsically fluorescent nanohydrogels suitable for the formulation of innovative drug dosage forms.

Different cell death mechanisms are induced by a hydrophobic flavin in human tumor cells after visible light irradiation

Riboflavin (RF) is an endogenous cell component and an efficient photosensitizer that can act by both types I and II photochemical mechanisms. Human tumor cells lines cultured in vitro, were used as model to study the effect of a photosensitizer synthesized from riboflavin, the 2′,3′,4′,5′-riboflavin-tetrabutyrate (RTB), to increase the flavin concentration in the human promyelocytic leukemia cell line HL-60 and the human epithelial cervical cancer cell line HeLa. We demonstrate that this compound, alone or with Trp, has a toxic dose-response effect evidenced by abnormal cell morphology and a decrease in the cell proliferation rate. The mechanism of cell death was investigated and the experimental evidence indicates that it proceeds primarily via apoptosis; however, autophagy cannot be discarded. Nuclear fluorescent staining with Hoechst 33258 and transmission electron microscopy of the cells showed condensed chromatin margination at the nuclear periphery and the formation of apoptotic bodies. Furthermore, Caspase-3 activity was demonstrated in both cell lines. In addition, the characteristic apoptotic DNA ladder was observed in HL-60 cells. On the other hand, a high cytoplasmic vacuolization was observed by electron transmission and confocal microscopy. LysoTraker-red localization in the vacuoles was observed by fluorescence microscopy, and a significant decrease in the number of vacuoles and in the cell proliferation rate diminution was observed when irradiation was performed in the presence of the autophagy inhibitor 3-methyladenine. Considering that both cell death mechanisms have a dual role in the killing of tumor cells in vivo, a harmful effect that does not cause inflammation leading to tumor prophylaxis, we conclude that RTB could have potential clinical applications.

Urinary and serum flavin levels after a single dose of riboflavin or riboflavin tetrabutyrate in man.

Urinary and Serum Flavin Levels after a Single Dose of Riboflavin Or Riboflavin Tetrabutyrate in Man Nutrition Reviews, Volume 36, Issue 7, July 1978, Pages 210–211, https://doi.org/10.1111/j.1753-4887.1978.tb07361.x Published: 01 July 1978

Inhibitory Effect of Riboflavin Tetrabutyrate on the Lipid Peroxidation by Pentachlorophenol.

It is suspected that pentachlorophenol (PCP), used as an organochlorine herbicide, has toxicity related with the lipid peroxidation. The lipid peroxidation by the in vitro metabolism of PCP in a microsomal system was inhibited by riboflavin tetrabutyrate (B2-But), a fat-soluble riboflavin, but not inhibited by water-soluble flavins. The lipid peroxidation in the liver of mice exposed to 35 μmol/kg of PCP was suppressed by the simultaneous administration of B2-But, but scarcely suppressed by other flavins. Moreover, the changes of mitochondrial ADP/O ratio and flavin contents in the liver of mice were also suppressed by B2-But. It was considered that the suppressive effect of B2-But on the liver injury by PCP due to the inhibition of the lipid peroxidation and the flavin supply by B2-But in the liver.

Spectral properties of riboflavin tetrabutyrate in the presence of hydrogen-bonding agents

The electronic spectra of riboflavin tetrabutyrate in solvents of different polarity change in the presence of trifluoroacetic acid and hexafluoroisopropanol as hydrogen-bonding agents. The characteristic red shift of the near-UV maximum, which indicates hydrogen bonding with trifluoroacetic acid, is larger in the absorption than in the excitation spectra suggesting the formation of non-fluorescent species. In the presence of 0.8 M trifluoroacetic acid, weakly fluorescent cationic forms of riboflavin tetrabutyrate are formed in 1,2-dichloroethane and acetonitrile. In the emission spectra a rapid decrease in intensity is observed. In the presence of 0.8 M hexafluoroisopropanol, the changes in the absorption, excitation and emission spectra reach the values observed in aqueous solution, thus indicating its usefulness as a hydrogen-bonding agent in media of low polarity. Plots of the shifts in the absorption and emission intensities vs. the concentration of the hydrogen-bonding agents and Stern-Volmer plots are non-linear in all cases, indicating the complex interaction patterns in the ground and excited states.

溶液中におけるリボフラビン酪酸エステルの会合状態に関する研究

The association of riboflavin tetrabutyrate (RTB) in solution was studied by infrared, 1H-nuclear magnetic resonance and emission spectra. In CCl4, hydrogen bonds and stacking between isoalloxazine rings of RTB were observed, and in CHCl3 the solvation to RTB mainly took place. Both the solvation and stacking of RTB were observed in (CD3)2CO, CD3OD, and CH3OH over a wide range of the concentration of RTB. The maxima in emission spectra of RTB solution were respectively attributed to RTB monomer and associated molecules by stacking.

X-ray diffraction patterns and crystal structures of riboflavin tetrabutyrate.

The X-ray diffraction patterns of two polymorphic forms of riboflavin tetrabutyrate (RTB) powders were examined. The orange powder showed sharp peaks suggesting a well-crystallized material, while the yellow powder showed broad peaks suggesting a polymer-like material

リボフラビン酪酸エステルの固相における色調と化学構造に関する研究(第2報)

Riboflavin tetrabutyrate of yellow powder (RTB C) was prepared from a methanol-H2O (45 : 55) solvent and various spectra were compared with those of RTB A. The emission spectra around 500-600 nm explained the color of RTB C; a maximum of RTB C was about 40 nm shorter than RTB A. Powder X-ray diffraction pattern of RTB C showed an aggregate of fine crystallites. The differences in infrared spectra between RTB A and C at 3430, 1380, 880-865 and 465-445 cm-1, assigned as NH on isoalloxazine ring, suggested a weak hydrogen-bond formation of RTB C. RTB A, B (a charge transfer type) and C changed their phase each other by treating them with solvents or by heating.

シロップ剤の薬剤学的研究

Compatibility of riboflavin tetrabutyrate preparations (Modified syrup, Hibon syrup ®) with 45 medicines was investigated by sensory test, while residual potency of riboflavin tetrabutyrate was measured by absorptiometry. The data on change in compatibility with time were analyzed by time series analysis. A change of Modified syrup and Hibon syrup ® was showed in appearance, but wasn't observed in taste, odor, pH, residual potency and buffer capacity carve on every single syrup. In mixtures, a change was observed in appearance, taste, odor, but not in pH. Modified syrup, tested alone and in mixtures, was better than Hibon syrup in redispersion test. When we administer Hibon syrup ® mixture, we instruct patients to shake well before using.

Tissue lipid peroxidation and ultraweak chemiluminescence in rats dosed with methyl linoleate hydroperoxide.

This study was undertaken to elucidate the toxic nature of dietary hydroperoxides in rats by the measurement of tissue chemiluminescence (CL). By the oral administration of methyl linoleate hydroperoxide (HPO) for two days, the tissue CL intensities and thiobarbituric acid (TBA) reactants were significantly increased in the liver, kidney, heart and lung, and the increases of both indices were inhibited by the supplemental administration of antioxidants, i.e. d-α-tocopherol (TOC) and riboflavin-tetrabutyrate (RTB). TOC was especially effective on the liver and kidney and RTB was effective on the liver, lung and heart. Hepatic glutathione peroxidase activity was evidently elevated at the seventh day of HPO-feeding, and this activation resulted in the decay of CL intensities and TBA reactants in rat organs. The spectrum of CL from liver homogenates of rats dosed with HPO for two days revealed five emission bands in the visible region and was similar to that for a singlet oxygen.The results indicate that TOC ...

Antioxidative effects of .ALPHA.-tocopherol and riboflavin-butyrate in rats dosed with methyl linoleate hydroperoxide.

The antioxidative effects of dietary α-tocopherol (TOC) and riboflavin-tetrabutyrate (RTB) against tissue lipoperoxidation caused by the long-term administration of methyl linoleate hydroperoxide (HPO) to rats were investigated by measuring the spontaneous chemiluminescence (CL) intensities and thiobarbituric acid (TBA) reactants of the liver, lung and heart.TOC supplementation resulted in the effective decrease of CL intensities and TBA reactants in the three organs, while RTB supplementation led to the definitive decay of both indices of the lung and a significant decrease in the CL intensity of the heart, as compared with those of rats dosed with HPO and not given any supplemental antioxidant.Although the activities of glutathione peroxidase and glutathione reductase in the three organs obtained from rats dosed with HPO for 29 days were clearly lower than those of the control rats, both enzyme activities in rats dosed with antioxidants other than HPO were generally maintained at levels almost equal to ...

A Sandwich Photocell Using Chlorophyll Electrodes

Abstract A sandwich-type photocell was made by placing an electrolyte between two electrodes. A transparent electrode, a glass plate coated with In2O3, was used for one electrode. A mixture of chlorophyll and 2-(cis-10-heptadecenyl)-6-methoxy-p-benzoquinone was spread onto this transparent electrode. A Pt plate covered by chlorophyll or a mixture of chlorophyll and riboflavin tetrabutyrate was used as the other electrode. The electrolyte contained flavin mononucleotide in a phosphate buffer. The potential difference between the two electrodes was 314 mV and the maximum photovoltage under illumination was 176 mV. The photocell is compact and can produce a photocurrent for more than 90 h.

コイおよびニジマスにおけるリボフラビンの要求

The requirements and deficiency symptoms of riboflavin and the availability of riboflavin retrabutyrate were investigate wity the carp, Cyprinus carpio, and the rainbow trout, Salmo gairdneri. The intestinal homoginate of the rainbow trout was found to hydrolyze riboflavin tetrabutyrate and to liberate riboflavin from the ester. The feeding experiwents with these fish species also revealed that the riboflavin-ester was available like free ribofalvin. The fish fed diets containing riboflavin tetrabutyrate accumulated riboflavin in the liver or hepatopancreas. The anorexia, poor growth, and high mortality rate were observed in both fish species as the general deficiency symptoms of riboflavin. Together with these symptoms, hemorrhage of the skin and the fins in the carp and lesion of the fins and cataract in the rainbow trout were characteristic signs of the deficiercy. The dietary riboflavin levels required to provide the maximum storage of the vitamin in the hepatic tissue were 0.7 mg in the carp and 0.6mg in in the rainbow trout/100g dry tiet, respectively. The riboflavin requirements of these fish species were not influenced by the dietary lipid levels.

FLAVIN PIGMENTS EMBEDDED IN LIPID MATRICES: A SPECTROSCOPIC AND PHOTOCHEMICAL INVESTIGATION

Abstract— –The spectroscopic properties of riboflavin tetrabutyrate have been studied in lecithin lipo‐somes and several detergent micellar systems. The results indicate that the flavin chromophore is located close to the liposome‐water interphase rather than in the hydrophobic region. By varying the number of flavins contained in each liposome and employing fluorescence spectroscopy and steady state photolysis techniques, the possible existence of two distinct environments for the flavin chromophore was demonstrated. Several basic photochemical properties of riboflavin tetrabutyrate in liposomes and micellar systems were investigated using laser flash and microsecond flash photolysis techniques.

抗脂血剤療法

The main antilipemic agents now in use and at the stage of clinical trial are hereunder enumerated by action. Most of the following drugs are in use selectively according to the type of hyperlipemia:1. Preventing the absorption of cholesterol β-Sitosterol, Nicomol (Cholexamin), Linoleamides, Cholestane-triol, Alisol A monoacetate etc.2. Preventing the absorption of bile acid Cholestyramine, Colestipol, Neomycin, Dimethylaminoethyl Sephadex etc.3. Inhibiting the biosynthesis of cholesterol Clofibrate (CPIB, Amotrol), Simfibrate (Cholesolvin), S-8527 (Lipoclin), Halofenate (MK-185), Tibric acid, Nicotinic acid etc. Anabolic Steroidsi. 2-Hydroxymethylene-17α-methyl-dihydrotestosterone (HMD, Anadrol)ii. 17β-Hydroxy-17α-methyl-5α-androstano [2, 3-C] furazan (Miotron)iii. 17β-Hydroxy-17α-methyl-2-oxa-androstan-3-one (Oxandrolone, Vasorome)iv. 17α-Ethyl-17β-hydroxy-estr-4-ene (Ethylnandrol, Orgabolin)4. Accelerating the catabolism of cholesterol Thyroid hormone (D-thyroxine), Acetiromate (TBF-43), Estrogen, Unsaturated fatty acids, EPL (Essential phospholipid), Cholagoga etc.5. Influencing the transport and/or distribution of lipids Heparin and heparinoids, Dextran sulfate, Elastase etc.6. Reducing the lipoperoxide in the serum Riboflavin tetrabutyrate, dl-α-Tocopheryl nicotinate etc.It is ascertained by epidemiological survey and experimental studies that there is a correlation between hyperlipemia and atherosclerosis. It is also certain that to reduce the serum lipids is an effective measure to prevent the onset or progress of atherosclerosis. Many antilipemic agents have been developed by these principles. The papers, reporting the effectiveness of antilipemic agents for primary or secondary prevention of coronary atherosclerosis, support these principles.However, as was recently reported by the Coronary Drug Project of the USA, such papers became occasionally seen as reporting that the treatment by these natilipemic agents is not always effective to prevent the progress of atherosclerosis. It must be said therefore that these reports gave an opportunity for severe reconsideration on the treatment of atherosclerosis with antilipemic agents.Although the relation of hyperlipemia and atherosclerosis is ascertained as mentioned previously, there are some problems to expect the therapeutic effect by the treatment only with antilipemic agents, since the atherosclerosis is considered to be a multifactorial disease.The treatment with antilipemic agents can hardly be considered at the present stage to be of no use as a therapy for atherosclerosis since the relation of hyperlipemia and atherosclerosis is already confirmed as mentioned and to reduce the serum lipids is currently authenticated as an effective measure to prevent the progress of atherosclerosis. It must be however pointed out that the development and the use of antilipemic agents require circumspection.

Effect of riboflavin tetrabutyrate on degradation of -lipoprotein by fatty acid peroxide.

Effect of riboflavin tetrabutyrate on degradation of -lipoprotein by fatty acid peroxide.