13C‐CPMAS and 1H‐NMR Study of the Inclusion Complexes of β‐Cyclodextrin with Carvacrol, Thymol, and Eugenol Prepared in Supercritical Carbon Dioxide

Locci, Emanuela; Lai, Simona; Piras, Alessandra; Marongiu, Bruno; Laı̈, Adolfo

doi:10.1002/cbdv.200490098

Cited by 63 publications

(44 citation statements)

References 23 publications

(15 reference statements)

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“…The assignments of EPC and phenols hydrogen signals are indicated in Figure 2, where capital letters refer to the phospholipid, and lower-case letters identify the nonequivalent resonance peaks of each phenol compound These assignments were in good agreement with those reported in the literature for EPC [15][16][17] and carvacrol, thymol and eugenol [18,19].…”

Section: Effects Of Gabaergic Phenols On Phospholipid Bilayers As Evasupporting

confidence: 83%

Effects of Gabaergic Phenols on Phospholipid Bilayers as Evaluated by 1H-NMR

Reiner¹,

Fraceto²,

Paula³

et al. 2013

JBNB

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The phenols propofol and thymol, and lately carvacrol, eugenol and chlorothymol, have been shown to act as positive allosteric modulators on GABA A receptor, which is the main inhibitory receptor of the central nervous system. GABA A receptor is an intrinsic membrane protein which activity may be affected by surface-active compounds and by physical changes in the membrane. Recently, we demonstrated that these phenols interacted with the lipid membrane phase, suggesting their anesthetic activity could be the combined result of their specific (with receptor proteins) as well as nonspecific (with surrounding lipid molecules) interaction modulating the supramolecular organization of the receptor environment. In the current study, by using 1 H-NMR spectroscopy, we have investigated the effects of the insertion and the possible preferential location of the five phenol derivatives with GABAergic activity on EPC membranes. The results indicate that all compounds are able to insert in EPC phospholipid vesicles and to locate in the region between the polar group (choline molecule), the glycerol and the first atoms of the acyl chains, being the more lipophilic compounds (propofol and chlorothymol) that seem to prefer a deeper bilayer insertion. The location of the phenol molecules would reduce the repulsive forces among phospholipids head groups allowing closer molecular packing and finally diminishing the mobility of the hydrocarbon chains, as revealed by 1 H spin relaxation times.

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Section: Effects Of Gabaergic Phenols On Phospholipid Bilayers As Evasupporting

confidence: 83%

Effects of Gabaergic Phenols on Phospholipid Bilayers as Evaluated by 1H-NMR

Reiner¹,

Fraceto²,

Paula³

et al. 2013

JBNB

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“…If prepared as b-CyD inclusion complexes they are stabilized as CyDs and greatly reduce volatility, oxidation and heat-decomposition. [88] The colour preservation of fruit juice during processing and storage was proved by Lopez-Nicolas et al [25] CyDs have been successfully used as anti-browning agents in different fruit juices including the prevention of enzymatic browning in peach juice, as browning inhibitors.…”

Section: Applications Of Cyclodextrin-assisted Molecular Encapsulatiomentioning

confidence: 99%

“…[47] Also a marked increase in solubility occurs in the guest molecules in water, when inclusion complexes of b-CyD and the essential oils carvacrol, thymol and eugenol were prepared by the SC-CO2 technique. [88] Smart food packaging. Szente and Szejtli [60] reported special applications of CyDs in foods and CyD-containing food packaging materials.…”

Section: Applications Of Cyclodextrin-assisted Molecular Encapsulatiomentioning

confidence: 99%

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A review on cyclodextrin encapsulation of essential oils and volatiles

Cabral-Marques

2010

Flavour & Fragrance J

557

360

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Cyclodextrins (CyDs) are cyclic carbohydrates derived from starch. The parent CyDs contain six, seven and eight glucopyranose units and are referred as a-, b-and g-CyD, respectively. The most important property of the CyDs is the ability to establish specific interactions -molecular encapsulation -with various types of molecules through the formation of noncovalently bonded entities, either in the solid phase or in aqueous solution. These nano-encapsulating agents may form inclusion complexes with essential oils and volatiles, or their components, in order to improve their characteristics, such as transformation of liquid compounds into crystalline form; masking unpleasant smells and tastes of some compounds; improving the physical and/or chemical stability; and stabilizing volatile compounds by reducing or eliminating any losses through evaporation. Complexation has been used to avoid the destruction of certain flavours by processing or, on storage, allowing the use of minor amounts of flavours. The guest molecule is released in the warm moisture of the mouth. Examples are spices, essential oils of vegetable origin and plant flavours, chamomile oil and extract, eucalyptus oil, fennel oil, lemon oil, onion and garlic oil, camphor, menthol, thymol, etc. There are several methods for the preparation of inclusion complexes; kneading, co-precipitation, freeze-drying and spray-drying the most commonly used. Evidence for a guest inclusion into the apolar CyD cavity may be proved by various analytical techniques, including NMR spectroscopy, UV-visible absorption spectroscopy, optical rotatory dispersion and circular dichroism, fluorescence, infrared/FT-IR spectroscopy, thermo-analysis, TLC, mass spectromety, and powder X-ray diffractometry.

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“…The exothermic peaks around 300°C for the β-cyclodextrin sample due to melting and thermal decomposition of the β-cyclodextrin itself [5]. Besides UV-vis spectra, Phase solubility study and Differential Scanning Calorimetry (DSC), there are other several techniques to characterize inclusion complex formation of cyclodextrin which are Infrared Spectroscopy [3], Vacuum Methods [33], X-ray Diffraction [36], Chromatography [37], Mass Spectrometry [3], Nuclear Magnetic Resonance Spectroscopy [38], Fluorescence Spectroscopy [39] and Optical Methods [40].…”

Section: Differential Scanning Calorimetry (Dsc)mentioning

confidence: 99%

Inclusion complex formation of cyclodextrin with its guest and their applications

Cheirsilp¹,

Rakmai²

2017

Biol Eng Med

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Cyclodextrin (CD) are cyclic oligosaccharides consisting of glucopyranosyl units linked by α-(1,4) bonds. The widely used natural cyclodextrins are α-, β-and γ-cyclodextrin consisting of 6, 7 and 8 glucopyranose units, respectively. The cyclodextrin molecules have a unique structure with a hydrophobic cavity and a hydrophilic surface which can form inclusion complex with a wide variety of guests. The use of cyclodextrins and their derivatives for the encapsulation of bioactive compounds can protect the compounds from environmental conditions and improve the aqueous solubility for increasing their capacity to functionalize the products. In some cases, there is a need to enhance water solubility of β-cyclodextrin by adding the hydroxyalkyl groups on the β-cyclodextrin surface. This review aimed to summarize the method for inclusion complex formation of cyclodextrin with its guests and its applications. Table 1. The cyclodextrin molecules have a unique structure with a hydrophobic cavity and a hydrophilic surface in which a guest molecule can be entrapped. Cyclodextrin can form inclusion complex with a wide variety of solid, liquid and gaseous compounds. Complex formation is a dimensional, geometrically limited fit, between cyclodextrin cavity and the guest molecule [2].Generally, hydrophobic molecules have greater affinity for the cyclodextrin cavity when they are in water solution. Moreover, the encapsulation changes the physical and chemical properties of the guests, such as solubility and stability. Therefore, cyclodextrins are suitable for application in food and flavors, pharmaceutical products, cosmetic, agriculture and chemical industries. Cyclodextrins can link specifically to other cyclodextrins (covalent or noncovalent). Because of this property, cyclodextrins can be used as building blocks for the construction of supramolecular complexes. Building blocks which cannot be prepared by common methods can be applied, such as separation of complex mixtures of molecules and enantiomers [3]. Cyclodextrins are produced by reacting gelatinized starch with the enzyme cyclodextrin glucosyltransferase (CGTase) as a result of intramolecular transglycosylation reaction from degradation of starch. Inclusion complex formationCyclodextrins have an internal non-polar hole and hydroxyl groups placed on the surface, the inclusion of hydrophobic compounds takes place mainly by hydrophobic interactions between guest molecules and the walls of cyclodextrin cavity [5]. However, other forces, such as van der Walls and dipole-dipole interactions, may be involved in the binding of the guest. Despite the number of factors and different forces involved in the complexation with cyclodextrins, the production of complexes is a rather simple process. There are several methods to obtain cyclodextrin-guest complexes depending on the properties of the guest and the nature of the chosen cyclodextrin. Kneading methodKneading technique is suitable for poorly water-soluble guests, because the guest is dissolved slowly during the forma...

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¹³C‐CPMAS and ¹H‐NMR Study of the Inclusion Complexes of β‐Cyclodextrin with Carvacrol, Thymol, and Eugenol Prepared in Supercritical Carbon Dioxide

Cited by 63 publications

References 23 publications

Effects of Gabaergic Phenols on Phospholipid Bilayers as Evaluated by <sup>1</sup>H-NMR

Effects of Gabaergic Phenols on Phospholipid Bilayers as Evaluated by <sup>1</sup>H-NMR

A review on cyclodextrin encapsulation of essential oils and volatiles

Inclusion complex formation of cyclodextrin with its guest and their applications

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13C‐CPMAS and 1H‐NMR Study of the Inclusion Complexes of β‐Cyclodextrin with Carvacrol, Thymol, and Eugenol Prepared in Supercritical Carbon Dioxide

Cited by 63 publications

References 23 publications

Effects of Gabaergic Phenols on Phospholipid Bilayers as Evaluated by &lt;sup&gt;1&lt;/sup&gt;H-NMR

Effects of Gabaergic Phenols on Phospholipid Bilayers as Evaluated by &lt;sup&gt;1&lt;/sup&gt;H-NMR

A review on cyclodextrin encapsulation of essential oils and volatiles

Inclusion complex formation of cyclodextrin with its guest and their applications

Contact Info

Product

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¹³C‐CPMAS and ¹H‐NMR Study of the Inclusion Complexes of β‐Cyclodextrin with Carvacrol, Thymol, and Eugenol Prepared in Supercritical Carbon Dioxide

Effects of Gabaergic Phenols on Phospholipid Bilayers as Evaluated by <sup>1</sup>H-NMR

Effects of Gabaergic Phenols on Phospholipid Bilayers as Evaluated by <sup>1</sup>H-NMR