Non-inclusion complexes between riboflavin and cyclodextrins

Jesus, Marcelo Bispo de; Fraceto, Leonardo Fernandes; Martini, M. Florencia; Pickholz, Mónica; Ferreira, Carmen Verı́ssima; Paula, Eneida de

doi:10.1111/j.2042-7158.2012.01492.x

Cited by 39 publications

(30 citation statements)

References 51 publications

(104 reference statements)

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“…The formation of noninclusion complexes among chemical compounds and cyclodextrins was already reported for other systems, such as for erythromycin 29 and riboflavin. 41 …”

Section: Results and Discussionmentioning

confidence: 99%

Stimulatory Effects of Methyl-β-cyclodextrin on Spiramycin Production and Physical–Chemical Characterization of Nonhost@Guest Complexes

Calcagnile¹,

Bettini²,

Damiano³

et al. 2018

ACS Omega

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Spiramycin is a macrolide antibiotic and antiparasitic that is used to treat toxoplasmosis and various other infections of soft tissues. In the current study, we evaluated the effects of α-cyclodextrin, β-cyclodextrin, or methyl-β-cyclodextrin supplementation to a synthetic culture medium on biomass and spiramycin production by Streptomyces ambofaciens ATCC 23877. We found a high stimulatory effect on spiramycin production when the culture medium was supplemented with 0.5% (w/v) methyl-β-cyclodextrin, whereas α-cyclodextrin or β-cyclodextrin weakly enhanced antibiotic yields. As the stimulation of antibiotic production could be because of spiramycin complexation with cyclodextrins with effects on antibiotic stability and/or efflux, we analyzed the possible formation of complexes by physical–chemical methods. The results of Job plot experiment highlighted the formation of a nonhost@guest complex methyl-β-cyclodextrin@spiramycin I in the stoichiometric ratio of 3:1 while they excluded the formation of complex between spiramycin I and α- or β-cyclodextrin. Fourier-transform infrared spectroscopy measurements were then carried out to characterize the methyl-β-cyclodextrin@spiramycin I complex and individuate the chemical groups involved in the binding mechanism. These findings may help to improve the spiramycin fermentation process, providing at the same time a new device for better delivery of the antibiotic at the site of infection by methyl-β-cyclodextrin complexation, as it has been well-documented for other bioactive molecules.

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“…The formation of noninclusion complexes among chemical compounds and cyclodextrins was already reported for other systems, such as for erythromycin 29 and riboflavin. 41 …”

Section: Results and Discussionmentioning

confidence: 99%

Stimulatory Effects of Methyl-β-cyclodextrin on Spiramycin Production and Physical–Chemical Characterization of Nonhost@Guest Complexes

Calcagnile¹,

Bettini²,

Damiano³

et al. 2018

ACS Omega

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“…Different types of cyclodextrins have been studied for complexation with RF to achieve its stabilization [111–117]. In a comparative study of complexation between α- and β-cyclodextrins with RF, β-cyclodextrin was found to form more stable inclusion complexes with RF [116].…”

Section: Reviewmentioning

confidence: 99%

“…Such β-cyclodextrin complexes are suitable for fluorescent compounds for which the fluorescence intensity is influenced by the presence of cyclodextrins [113]. A non-inclusion complexation between RF and β-cyclodextrin or hydroxypropyl-β-cyclodextrin at low concentrations occurred through hydrogen bonding and resulted in a better solubility of RF along with an enhanced antitumor activity [117]. On the contrary, the formation of inclusion complexes between RF and hydroxypropylated α-, β-, and γ-cyclodextrins showed no stabilization effect towards RF.…”

Section: Reviewmentioning

confidence: 99%

Photo, thermal and chemical degradation of riboflavin

Sheraz¹,

Kazi²,

Ahmed³

et al. 2014

Beilstein J. Org. Chem.

207

156

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SummaryRiboflavin (RF), also known as vitamin B2, belongs to the class of water-soluble vitamins and is widely present in a variety of food products. It is sensitive to light and high temperature, and therefore, needs a consideration of these factors for its stability in food products and pharmaceutical preparations. A number of other factors have also been identified that affect the stability of RF. These factors include radiation source, its intensity and wavelength, pH, presence of oxygen, buffer concentration and ionic strength, solvent polarity and viscosity, and use of stabilizers and complexing agents. A detailed review of the literature in this field has been made and all those factors that affect the photo, thermal and chemical degradation of RF have been discussed. RF undergoes degradation through several mechanisms and an understanding of the mode of photo- and thermal degradation of RF may help in the stabilization of the vitamin. A general scheme for the photodegradation of RF is presented.

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“…In the UVX corneas, the anterior stroma at both timepoints and intermediate stroma in the first month did not produce a significantly bigger average SHG than the control stroma and even less in the first month UVX. A likely reason for the lower signal in UVX is the non-zero one-photon absorption value of riboflavin at 400 nm, 50 which attenuates the total SHG signal. The calculated attenuation immediately after riboflavin installation, based on an average concentration of 3.79 mM and average path length of 175 µm, is approximately 44%.…”

Section: Discussionmentioning

confidence: 99%

Corneal Collagen Ordering After In Vivo Rose Bengal and Riboflavin Cross-Linking

Germann

Martinez-Enriquez

Martínez‐García

et al. 2020

Invest. Ophthalmol. Vis. Sci.

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Photoactivated cornea collagen cross-linking (CXL) increases corneal stiffness by initiating formation of covalent bonds between stromal proteins. Because CXL depends on diffusion to distribute the photoinitiator, a gradient of CXL efficiency with depth is expected that may affect the degree of stromal collagen organization. We used second harmonic generation (SHG) microscopy to investigate the differences in stromal collagen organization in rabbit eyes after corneal CXL in vivo as a function of depth and time after surgery. METHODS. Rabbit corneas were treated in vivo with either riboflavin/UV radiation (UVX) or Rose Bengal/green light (RGX) and evaluated 1 and 2 months after CXL. Collagen fibers were imaged with a custom-built SHG scanning microscope through the central cornea (350 μm depth, 225 × 225 μm en face images). The order coefficient (OC), a metric for collagen organization, and total SHG signal were computed for each depth and compared between treatments. RESULTS. OC values of CXL-treated corneas were larger than untreated corneas by 27% and 20% after 1 month and 38% and 33% after 2 months for the RGX and UVX, respectively. RGX OC values were larger than UVX OC values by 3% and 5% at 1 and 2 months. The SHG signal was higher in CXL corneas than untreated corneas, both at 1 and 2 months after surgery, by 18% and 26% and 1% and 10% for RGX and UVX, respectively. CONCLUSIONS. Increased OC corresponded with increased collagen fiber organization in CXL corneas. Changes in collagen organization parallel reported temporal changes in cornea stiffness after CXL and also, surprisingly, are detected deeper in the stroma than the regions stiffened by collagen cross-links.

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Non-inclusion complexes between riboflavin and cyclodextrins

Cited by 39 publications

References 51 publications

Stimulatory Effects of Methyl-β-cyclodextrin on Spiramycin Production and Physical–Chemical Characterization of Nonhost@Guest Complexes

Stimulatory Effects of Methyl-β-cyclodextrin on Spiramycin Production and Physical–Chemical Characterization of Nonhost@Guest Complexes

Photo, thermal and chemical degradation of riboflavin

Corneal Collagen Ordering After In Vivo Rose Bengal and Riboflavin Cross-Linking

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