Effects of Intra- and Intermolecular Hydrogen Bonding on O–H Bond Photodissociation Pathways of a Catechol Derivative

Grieco, Christopher; Hanes, A.; Blancafort, Lluı́s; Kohler, Bern

doi:10.1021/acs.jpca.9b04573

Cited by 17 publications

(13 citation statements)

References 30 publications

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“…The dark spots marked by red circles in the TEM images are supposed to be the hydrophobic cores of the assembled NP 2 nanoparticles, while the catechol-functionalized hydrophilic PEG shell acts as a flexible polymer matrix that connects the hydrophobic cores to form the stable NPA 2 coacervate dense phase. It is noted that the free hydroxyl (-OH) groups generally exhibit narrow and intense absorption bands, while -OH groups involved in hydrogen bonding show a broader absorption band in FTIR 39 , 40 . The FTIR result of freeze-dried NPA 2 coacervate showed an obvious broad -OH band, indicating the existence of hydrogen bonding interactions derived from catechol groups (Supplementary Fig.…”

Section: Resultsmentioning

confidence: 99%

Nanoparticle-assembled bioadhesive coacervate coating with prolonged gastrointestinal retention for inflammatory bowel disease therapy

Zhao

Xia

et al. 2021

Nat Commun

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A key challenge for the effective treatment of gastrointestinal diseases including inflammatory bowel disease is to develop an orally administered drug delivery system capable of prolonged retention in the gastrointestinal tract. Herein we report a bioadhesive liquid coacervate based on hydrogen bonding-driven nanoparticle assembly. Free from electrostatic interactions, our fluid nanoparticle-assembled coacervate demonstrates significant pH- and salt-independent structural stability and forms a physically adhesive coating on a large surface area of intestinal tract with an extended residence time of more than 2 days to mediate the sustained release of preloaded water-soluble small molecule drugs in vivo. The orally administered drug-laden nanoparticle-assembled coacervate significantly mitigates the symptoms of inflammatory bowel disease, restores the diversity of gut microbiota, reduces systemic drug exposure, and improves the therapeutic efficacy in a rat acute colitis model compared with the oral administration of the same amount of drug in solution form. We suggest that the nanoparticle-assembled coacervate provides a promising drug delivery platform for management and treatment of numerous gastrointestinal diseases where controlled drug release with extended residence time is desired.

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Section: Resultsmentioning

confidence: 99%

Nanoparticle-assembled bioadhesive coacervate coating with prolonged gastrointestinal retention for inflammatory bowel disease therapy

Zhao

Xia

et al. 2021

Nat Commun

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“…Additional shifting of the corresponding vibrations to lower frequencies (1404 cm −1 and, probably, 1380 cm −1 ) can be caused by the formation of intramolecular hydrogen bonds between oxygen radicals and hydroxyl groups (Figure 7IVc,VIc). This is an essential consideration since the importance of intramolecular H-bonds for the photoconductivity of melanin-like systems was recently raised in the work of Grieco et al [82]. Correspondingly, we suggest that a wide 2890 cm −1 band contains O-H stretching vibrations of semiquinones with intramolecular hydrogen bonds.…”

Section: Discussionmentioning

confidence: 51%

Water-Activated Semiquinone Formation and Carboxylic Acid Dissociation in Melanin Revealed by Infrared Spectroscopy

et al. 2021

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Eumelanin is a widespread biomacromolecule pigment in the biosphere and has been widely investigated for numerous bioelectronics and energetic applications. Many of these applications depend on eumelanin’s ability to conduct proton current at various levels of hydration. The origin of this behavior is connected to a comproportionation reaction between oxidized and reduced monomer moieties and water. A hydration-dependent FTIR spectroscopic study on eumelanin is presented herein, which allows for the first time tracking the comproportionation reaction via the gradual increase of the overall aromaticity of melanin monomers in the course of hydration. We identified spectral features associated with the presence of specific “one and a half” C𝌁O bonds, typical for o-semiquinones. Signatures of semiquinone monomers with internal hydrogen bonds and that carboxylic groups, in contrast to semiquinones, begin to dissociate at the very beginning of melanin hydration were indicated. As such, we suggest a modification to the common hydration-dependent conductivity mechanism and propose that the conductivity at low hydration is dominated by carboxylic acid protons, whereas higher hydration levels manifest semiquinone protons.

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“…The intramolecular hydrogen bond in a phenolic group in lignin is observed at around 3562–3577 cm −1. 56 In cellulose, an intramolecular hydrogen bond vibration appears at around 3432 cm −1 . Another intramolecular hydrogen bond in cellulose normally occurs at 3342 cm −1.…”

Section: Resultsmentioning

confidence: 99%

A sustainable approach to enhance fruit shelf‐life: Edible coating from pineapple fruit waste biomass

Bhattacharjee

Haldar

Manna

et al. 2020

J of Applied Polymer Sci

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The quality and commercial value of fruits largely depend on color, texture, appearance, nutritional value, and other factors that cease the growth of the microbes causing food spoilage. Coating with suitable edible material would keep fruits fresh for a considerable time after their harvest till it reaches to the demanding consumers. The nonedible portions (peel, crown) of pineapple are identified as an inexpensive source for the production of such edible coating material. The present work is focused on the extraction and physicochemical analysis of cellulose prepared from waste bio‐mass of pineapple fruit. Physicochemical characterization of the cellulose is performed using X‐ray diffraction, Fourier‐transform infrared spectroscopy and scanning electron microscopy. The extracted cellulose is converted to carboxymethyl cellulose and formulated as a coating film in conjugation with other suitable substances. The formulated coating is applied on banana fruit to check the performance of protection against the natural degradation of the fruit. FTIR analysis of the extracted cellulose has confirmed the removal of lignin and hemicelluloses molecules from the waste biomass of pineapple. X‐ray diffraction analysis has shown the crystal size of extracted cellulose was 3.23 nm with 35.62% crystallinity. Degree of substitution (DS) is estimated 0.523 for carboxymethyl cellulose prepared from the extracted cellulose. Application of coating has shown the increment in shelf‐life period of banana in comparison with control up to 8 days of storage at ambient condition. This study has demonstrated a sustainable process to transform waste biomass into carboxymethyl cellulose based coating for improving storage capacity of banana fruit.

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Effects of Intra- and Intermolecular Hydrogen Bonding on O–H Bond Photodissociation Pathways of a Catechol Derivative

Cited by 17 publications

References 30 publications

Nanoparticle-assembled bioadhesive coacervate coating with prolonged gastrointestinal retention for inflammatory bowel disease therapy

Nanoparticle-assembled bioadhesive coacervate coating with prolonged gastrointestinal retention for inflammatory bowel disease therapy

Water-Activated Semiquinone Formation and Carboxylic Acid Dissociation in Melanin Revealed by Infrared Spectroscopy

A sustainable approach to enhance fruit shelf‐life: Edible coating from pineapple fruit waste biomass

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