betadex and 1-1-diphenyl-2-picrylhydrazyl

Topics: Anti-Bacterial Agents; Antioxidants; beta-Cyclodextrins; Biphenyl Compounds; Capsules; Escherichia coli; Models, Molecular; Molecular Conformation; Oils, Volatile; Picrates; Solubility; Sonication; Staphylococcus aureus; Water

The use of synthetic packaging films causes serious environmental problems due to difficulty in recycling and poor biodegradability. Therefore, the present study aimed to develop natural biopolymer-based packaging films. As natural materials, chitosan (CS)-based films containing various concentrations (0.05 %, 0.1 %, and 0.15 %) of the hexahydro-β-acid/2-O-methyl-β-cyclodextrin (HBA/M-β-CD) inclusion complex were prepared and evaluated for structural, physicochemical, antioxidant, and antimicrobial properties. Results of morphological analysis and Fourier transform infrared spectroscopy (FT-IR) demonstrated good compatibility between CS and the HBA/M-β-CD complex and indicated that intermolecular hydrogen bonds were probably formed. Moisture content of the films decreased, whereas water solubility, swelling ratio, and water vapor permeability increased after the addition of HBA/M-β-CD. Optical test showed that addition of the inclusion complex improved the UV light barrier property. The mechanical properties of the film were considerably increased after the incorporation of 0.1 % HBA/M-β-CD. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity of HBA/M-β-CD-CS films was ten times higher than that of the control CS film. Furthermore, the incorporation of HBA/M-β-CD conferred the films with good antimicrobial activity against various foodborne pathogens. In summary, our results indicated that encapsulation with M-β-CD was an effective way of introducing HBA into CS film. This film can be used as an active packaging material for food preservation.

Topics: Anti-Bacterial Agents; Antifungal Agents; Antioxidants; beta-Cyclodextrins; Biphenyl Compounds; Candida albicans; Chemistry, Physical; Chitosan; Gram-Negative Bacteria; Gram-Positive Bacteria; Microbial Sensitivity Tests; Particle Size; Picrates; Surface Properties

Cyclodextrins have a wide range of applications in different areas of drug delivery and pharmaceutical industry due to their complexation ability and other versatile characteristics. Here we have studied the binding interactions of a small biologically important phenolic molecule, Thymol (Th), with both α and β cyclodextrins (CDs), which are well known drug delivery vehicles. Extent of encapsulation has been determined using several spectroscopic techniques. In fluorescence experiments, significant increase in fluorescence intensities have been discerned for both the CDs but there had been a much early saturation for αCD. Anisotropy experiments have been performed too and very surprisingly no appreciable increase in anisotropy value was observed in either case. Isothermal titration calorimetry (ITC) data, however, show signature of binding of Th with the βCD. These intriguing results were explained with the help of molecular docking and dynamics simulation studies. The docking calculations have shown that Th goes inside both α and βCD. In keeping with the final NMR data and molecular dynamics we have ultimately concluded that solvated Th molecules are the main participants in the interaction with CDs which is responsible for these intriguing behaviors. Finally we have also performed an antioxidant assay to reveal the practical application of such encapsulation. It has been found that on encapsulation there is an enhancement of the antioxidant behavior of Th. Then we have also performed an antibacterial assay to show the unchanged antibacterial properties of Th on encapsulation. Hence it can be deduced that Th can be safely delivered through CDs in living system without hampering its beneficial properties.

Topics: Anisotropy; Anti-Infective Agents; Bacillus subtilis; beta-Cyclodextrins; Biphenyl Compounds; Calorimetry; Free Radical Scavengers; Hydrogen Bonding; Microbial Sensitivity Tests; Models, Theoretical; Molecular Docking Simulation; Molecular Dynamics Simulation; Picrates; Proton Magnetic Resonance Spectroscopy; Spectrometry, Fluorescence; Spectrum Analysis; Thymol

Tertiary butylhydroquinone (TBHQ) is a water-insoluble antioxidant. In this study, three cyclodextrin inclusion complexes were prepared to improve the water solubility of TBHQ and expand its range of application. Analysis of phase solubility indicated that TBHQ can form 1:1 inclusion complex with hydroxypropyl-beta-cyclodextrin (HP-β-CD) and dimethyl-beta-cyclodextrin (DM-β-CD) and 1:2 inclusion complex with beta-cyclodextrin (β-CD). The possible inclusion configuration between TBHQ and CDs was determined through FT-IR, PXRD, DSC, NMR, and SEM analyses. Results were validated by theoretical study of AutoDock molecular docking. The scavenging effects of the inclusion complexes were not effective on DPPH radical but higher on hydroxyl, superoxide and ABTS+ radicals than that of TBHQ monomer. Moreover, the water solubility of TBHQ increased after complexation with HP-β-CD and DM-β-CD. The stability of TBHQ is related to the type of storage materials used, and the stability can be improved by complexation with CDs.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Antioxidants; beta-Cyclodextrins; Biphenyl Compounds; Cell Line; Humans; Hydroquinones; Magnetic Resonance Spectroscopy; Microscopy, Electron, Scanning; Molecular Docking Simulation; Picrates; Solubility; Solutions; Spectroscopy, Fourier Transform Infrared; Water; X-Ray Diffraction

Polyphenolic catechins prevalent in tea are powerful antioxidants for therapeutics of various free radical-related diseases. The non-epicatechins are thermally obtained from the naturally abundant epicatechins. In our study series on the structure-antioxidant property relationship of the CD inclusion complexes with tea catechins, this closing chapter presents the β-CD encapsulation of three non-epicatechins, i.e., (-)-gallocatechin (GC) 1, (-)-catechin gallate (GC) 2, and (-)-gallocatechin gallate (GCG) 3 investigated by means of single-crystal X-ray diffraction, DFT calculation and DPPH radical scavenging activity assay. Detailed structural comparisons of the β-CD inclusion complexes with both non-epi and epi type catechins reveal that a common host-guest hydrogen bonding scheme and the shielding of catechin OH groups inside the host circular wall play a prime role in flourishing antioxidant capacities in the order of 3 > 2 > 1. This is consistent with the relative thermodynamic stabilities derived from DFT energy minimization.

Topics: Antioxidants; beta-Cyclodextrins; Biphenyl Compounds; Molecular Structure; Picrates; Quantum Theory; Tea; X-Rays

Dihydroquercetin is a kind of dihydroflavonol compounds with antioxidant, antitumor, antivirus and radioresistance activities. This study attempted to produce the dihydroquercetin complexes with lecithin and β-cyclodextrin, and research their characteristics and bioactivities via ultraviolet spectrum (UV), infrared spectroscopy (IR), scanning electron microscope (SEM), differential scanning calorimetry (DSC), X-ray diffraction spectrum (XRD), and MTT assay. Results showed that the complexes with lecithin and β-cyclodextrin could improve the solubility and dissolution rate, and remove the characteristic endothermic peak of dihydroquercetin. IR spectra proved their interaction, and results of SEM and XRD showed the amorphous characteristics of the dihydroquercetin compounds. These results indicated that dihydroquercetin was combined by lecithin or β-cyclodextrin with better physical and chemical properties, which would effectively improve the application value in the food and drug industries.

Topics: Antineoplastic Agents; Antioxidants; Benzothiazoles; beta-Cyclodextrins; Biphenyl Compounds; Cell Survival; Hep G2 Cells; Humans; Lecithins; Picrates; Quercetin; Solubility; Structure-Activity Relationship; Sulfonic Acids

Core-shell nanofibers were designed via electrospinning using inclusion complex (IC) of model hydrophobic drug (curcumin, CUR) with cyclodextrin (CD) in the core and polymer (polylactic acid, PLA) in the shell (cCUR/HPβCD-IC-sPLA-NF). CD-IC of CUR and HPβCD was formed at 1:2 molar ratio. The successful formation of core-shell nanofibers was revealed by TEM and CLSM images. cCUR/HPβCD-IC-sPLA-NF released CUR slowly but much more in total than PLA-CUR-NF at pH 1 and pH 7.4 due to the restriction of CUR in the core of nanofibers and solubility improvement shown in phase solubility diagram, respectively. Improved antioxidant activity of cCUR/HPβCD-IC-sPLA-NF in methanol:water (1:1) is related with the solubility enhancement achieved in water based system. The slow reaction of cCUR/HPβCD-IC-sPLA-NF in methanol is associated with the shell inhibiting the quick release of CUR. On the other hand, cCUR/HPβCD-IC-sPLA-NF exhibited slightly higher rate of antioxidant activity than PLA-CUR-NF in methanol:water (1:1) owing to the enhanced solubility. To conclude, slow release of CUR was achieved by core-shell nanofiber structure and inclusion complexation of CUR with HPβCD provides high solubility. Briefly, electrospinning of core-shell nanofibers with CD-IC core could offer slow release of drugs as well as solubility enhancement for hydrophobic drugs.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Antioxidants; beta-Cyclodextrins; Biphenyl Compounds; Curcumin; Drug Carriers; Drug Liberation; Nanofibers; Picrates; Polyesters; Solubility; Water

Quercetin (Qu), a polyphenolic flavonoid, is one of the most effective plant originated antioxidants. Despite the potential use of Qu in clinical trials, low water solubility, stability problems and the scarcity of cellular bioavailability limit its applications. The purpose of this study was to enhance aqueous solubility, dissolution rate and antioxidant activity of Qu by complexation with Methyl-β- cyclodextrin (M-β-CD). Analyses results showed that the aqueous solubility, dissolution rate and antioxidant activity of the complex were increased 254-fold, ~3-fold and 10% respectively compared to the pure Qu. Complexes were prepared by freeze-drying and evaporation method. The characteristics of the complexes were evaluated by DSC, XRD, (1)H-NMR, FT-IR, SEM, encapsulation efficacy, in-vitro dissolution rate analyses. Antioxidant activity studies on complexes carried out with DPPH tests. Analyses results showed that the formation of the complexes resulted in enhanced solubility with increased its antioxidant activity of Qu.

Topics: Antioxidants; beta-Cyclodextrins; Biphenyl Compounds; Calorimetry, Differential Scanning; Magnetic Resonance Spectroscopy; Picrates; Quercetin; Solubility; Spectroscopy, Fourier Transform Infrared; X-Ray Diffraction

Electrospinning of polyacrylic acid (PAA) nanofibres (NF) incorporating β-cyclodextrin inclusion complex (β-CD-IC) of quercetin (QU) was performed. Here, β-CD was used as not only the crosslinking agent for PAA nanofibres but also as a host molecule for inclusion of QU. The phase solubility test showed enhanced solubility of QU due to the inclusion complexation; in addition, the stoichiometry of QU/β-CD-IC was determined to be 1:1. Computational modelling studies confirmed that 1:1 and 1:2 complex formation are desirable; 1:1 complex formation was chosen to have higher weight loading of QU. SEM images showed that PAA/QU/β-CD-IC-NF were bead-free and uniform. XRD indicated that PAA/QU/β-CD-IC-NF were amorphous in nature without the crystalline peaks of QU. Comparative results revealed that the release profile of QU from PAA/QU/β-CD-IC-NF was much slower but greater in total than from PAA/QU/β-CD-IC-film. Moreover, high antioxidant activity and photostability of QU was achieved in PAA/QU/β-CD-IC-NF.

Topics: Antioxidants; beta-Cyclodextrins; Biphenyl Compounds; Drug Carriers; Drug Compounding; Drug Liberation; Drug Stability; Microscopy, Electron, Scanning; Models, Molecular; Nanofibers; Particle Size; Picrates; Quercetin; Solubility; Surface Properties; X-Ray Diffraction

Green tea catechins are potent antioxidant for prevention of various free radical-related diseases. Their antioxidant properties can be improved by encapsulation in cyclodextrins (CDs). Four inclusion complexes of β-CD with (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG) and (-)-epigallocatechin gallate (EGCG) have been investigated using single-crystal X-ray diffraction analysis combined with full geometry optimization by DFT/B3LYP calculation and the DPPH assay, aiming to deepen the understanding on their structure-antioxidant activity relationship. Scrutinizing the inclusion structures and conformational changes of the four encapsulated epicatechins reveals the common host-guest stabilization scheme and the epicatechin conformational flexibility facilitating the enhancement of activity. Thermodynamic stability order derived from DFT calculation in vacuum fairly agrees with the order of improved antioxidant capacity deduced from the DPPH assay, β-CD-EGCG>β-CD-ECG>β-CD-EGC≈β-CD-EC.

Topics: Antioxidants; beta-Cyclodextrins; Biphenyl Compounds; Catechols; Crystallography, X-Ray; Models, Molecular; Molecular Conformation; Picrates; Quantum Theory; Structure-Activity Relationship; Tea; Thermodynamics

Stable hydrophilic C60(OH)10 nanoparticles were prepared from 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and applied to the treatment of an acetaminophen overdose induced liver Injury. C60(OH)10 nanoparticles were produced by cogrinding α-CD, β-CD, γ-CD and HP-β-CD and characterized in terms of solubility, mean particle diameter, ζ-potential and long term dispersibility in water. Hydrophilic C60(OH)10 nanoparticles with particle sizes less than 50 nm were effectively produced by cogrinding HP-β-CD with C60(OH)10 at a molar ratio of 1:3 (C60(OH)10:CD). The resulting C60(OH)10/HP-β-CD nanoparticles were stable in water and showed no aggregation over a 1 month period. The C60(OH)10/CDs nanoparticles scavenged not only free radicals (DPPH and ABTS radicals) but also reactive oxygen species (O2(•-) and •OH). When C60(OH)10/HP-β-CD nanoparticles were intraperitoneally administered to mice with a liver injury induced by an overdose of acetaminophen (APAP), the ALT and AST levels were markedly reduced to almost the same level as that for normal mice. Furthermore, the administration of the nanoparticles prolonged the survival rate of liver injured mice, while all of the mice that were treated with APAP died within 40 h. To reveal the mechanism responsible for liver protection by C60(OH)10 nanoparticles, GSH level, CYP2E1 expression and peroxynitrite formation in the liver were assessed. C60(OH)10/HP-β-CD nanoparticles had no effect on CYP2E1 expression and GSH depletion, but suppressed the generation of peroxynitrite in the liver. The findings indicate that the protective effect of C60(OH)10/HP-β-CD nanoparticles was due to the suppression of oxidative stress in mitochondria, as the result of scavenging ROS such as O2(•-), NO and peroxynitrite, which act as critical mediators in the liver injuries.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Acetaminophen; Animals; Antioxidants; Benzothiazoles; beta-Cyclodextrins; Biphenyl Compounds; Chemical and Drug Induced Liver Injury; Cytochrome P-450 CYP2E1; Drug Overdose; Electron Spin Resonance Spectroscopy; Free Radical Scavengers; Fullerenes; Glutathione; Hydrophobic and Hydrophilic Interactions; Hydroxylation; Liver; Male; Mice, Inbred C57BL; Nanoparticles; Nitric Oxide; Oxidative Stress; Particle Size; Peroxynitrous Acid; Picrates; Protective Agents; Solubility; Static Electricity; Sulfonic Acids; Tyrosine

A 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙) was successfully solubilised in water by β-cyclodextrin (β-CD). DPPH˙/β-CD thus obtained was demonstrated to be a powerful tool to evaluate the antioxidative activity of water-soluble antioxidants, such as ascorbate and Trolox, in aqueous buffer solutions.

Topics: Ascorbic Acid; beta-Cyclodextrins; Biphenyl Compounds; Chromans; Free Radical Scavengers; Free Radicals; Picrates; Solubility; Water

The complexes formed by two polyphenols, trans-Ferulic acid (FA) and Gallic acid (GA) with 2-hydroxypropyl-b-cyclodextrin (HPβCD), by the spray-drying method, were studied. Encapsulation-efficiencies (EE) of the complexes prepared were evaluated by HPLC. In the case of co-encapsulation, the EE of GA was lowered, whereas that of FA was almost stable, indicating a possible antagonistic relationship between the two phenols for the HPβCD cavity. The physicochemical characterization of the complexes was carried out by Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM). SEM observations revealed that the coencapsulated phenolic complex resulted in a more rounded shape outer surfaces of HPβCD than when encapsulated separately. FT-IR and DSC data indicated that the two polyphenols exhibit a possible interaction in the coencapsulated complex. The complexes showed no loss of their ability to scavenge DPPH radical relatively to the single agent at the concentrations used.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; beta-Cyclodextrins; Biphenyl Compounds; Calorimetry, Differential Scanning; Chemical Phenomena; Coumaric Acids; Drug Compounding; Gallic Acid; Microscopy, Electron, Scanning; Picrates; Spectroscopy, Fourier Transform Infrared

Myricetin, a bioactive plant flavonol, readily forms inclusion complex with the drug delivery vehicle beta-cyclodextrin (β-CD). Appearance of typical "dual emission", consisting of normal (470 nm) and ESIPT tautomer (530 nm) bands, with concomitant rise in fluorescence intensity and dramatically blue shifted normal fluorescence of myricetin with increasing β-CD concentration, indicates facile entry of myricetin into the cavity of β-CD. The stoichiometry of the inclusion complex has been established to be equimolar (1:1), with an equilibrium constant of 439 ± 18 M(-1) at 25 °C. The driving force of inclusion is attributed to strong van der Waals interaction and formation of hydrogen bond between host (β-CD) and guest (myricetin). Both experimental and theoretical studies indicate that myricetin possibly incorporates within β-CD through its benzoyl moiety. Inclusion in β-CD increases the antioxidant potency of myricetin which has been attributed to the less delocalised HOMO and reduced HOMO-LUMO energy gap in the confined state.

Topics: beta-Cyclodextrins; Biphenyl Compounds; Circular Dichroism; Drug Carriers; Flavonoids; Hydrogen Bonding; Kinetics; Models, Molecular; Molecular Docking Simulation; Molecular Structure; Picrates; Quantum Theory; Solubility; Spectrometry, Fluorescence; Thermodynamics

Myricetin shows low oral bioavailability (<10%) in rats due to poor aqueous solubility, though it has various pharmacological activities. Complexation with cyclodextrins (CDs) is a potent pharmaceutical method to enhance the bioavailability of poorly soluble compounds. The myricetin/HP-β-CD inclusion complex was prepared and confirmed by DSC, PXRD, and SEM. Here, the inclusion mode is described in detail with regard to structural and energetic aspects using a phase solubility diagram and 1H NMR, NOESY, and FT-IR spectra. The water solubility and dissolution rate of myricetin were greatly enhanced by forming the myricetin/HP-β-CD inclusion complex. Consequently, the oral bioavailability of the myricetin/HP-β-CD inclusion complex in rats was effectively increased 9.4-fold over free myricetin, and its antioxidant activity was also improved. The present study provides useful information for the potential application of complexation with myricetin, a naturally occurring hydrophobic phenolic compound in herbal medicine.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Administration, Oral; Animals; Antioxidants; beta-Cyclodextrins; Biological Availability; Biphenyl Compounds; Drug Carriers; Flavonoids; Male; Picrates; Rats; Rats, Sprague-Dawley; Solubility

A sensitive on-line DPPH-CE-DAD method was developed and validated for both screening and determining the concentration of seven antioxidants of Reduning injection. The pH and concentrations of buffer solution, SDS, β-CD and organic modifier were studied for the detection of DPPH and seven antioxidants. By on-line mixing DPPH and sample solution, a DPPH-CE method for testing the antioxidant activity of the complex matrix was successfully established and used to screen the antioxidant components of Reduning injection. Then, antioxidant components including caffeic acid, isochlorogenic acid A, isochlorogenic acid B, isochlorogenic acid C, chlorogenic acid, neochlorogenic acid and cryptochlorogenic acid were quantified by the newly established CE-DAD method. Finally, the total antioxidant activity and the multiple active components were selected as markers to evaluate the quality of Reduning injection. The results demonstrated that the on-line DPPH-CE-DAD method was reagent-saving, rapid and feasible for on-line simultaneous determination of total pharmacological activity and contents of multi-components samples. It was also a powerful method for evaluating the quality control and mechanism of action of TCM injection.

Topics: Acetonitriles; Antioxidants; beta-Cyclodextrins; Biphenyl Compounds; Calibration; Drugs, Chinese Herbal; Electricity; Electronics; Electrophoresis, Capillary; Hydrogen-Ion Concentration; Inhibitory Concentration 50; Injections; Limit of Detection; Online Systems; Picrates; Reference Standards; Temperature; Time Factors

Storage stability of astaxanthin/hydroxypropyl-β-cyclodextrin (HPCD) inclusion complex was evaluated and which was compared with native astaxanthin. The storage stability of astaxanthin was enhanced after included in HPCD under 4 °C and 25 °C storage conditions. Antioxidant activity of astaxanthin/HPCD inclusion complex was also assayed using ascorbic acid as a control sample. The reducing power and DPPH radical scavenging activity of native astaxanthin were lower than ascorbic acid, while which of the complex were higher at low concentration for the good water solubility. The hydroxyl radical scavenging activities of astaxanthin and astaxanthin/HPCD complex far outclassed that of ascorbic acid, and the activity of the complex was a little lower than that of the native astaxanthin.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; beta-Cyclodextrins; Biphenyl Compounds; Drug Stability; Drug Storage; Free Radical Scavengers; Hydroxyl Radical; Oxidation-Reduction; Picrates; Xanthophylls

The inclusion complexation behavior of chlorogenic acid (CGA) with the hydroxypropyl-β-cyclodextrin (HP-β-CD) was investigated in both solution and the solid state by UV-vis and fluorescence spectroscopy, infrared spectroscopy (IR), NMR spectroscopy as well as differential scanning calorimetry (DSC). The experimental results indicate that CGA is able to form an inclusion complex with HP-β-CD. The inclusion complex has a stoichiometry of 1:1 and the formation constant was calculated to be 155.7 M(-1). The antioxidant activity of CGA on complexation with HP-β-CD increased as compared to uncomplexed CGA. NMR spectroscopic studies show that the aromatic ring and the vinyl group of CGA are deeply included inside the CD cavity.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Antioxidants; beta-Cyclodextrins; Biphenyl Compounds; Calorimetry, Differential Scanning; Chlorogenic Acid; Free Radical Scavengers; Indicators and Reagents; Magnetic Resonance Spectroscopy; Models, Chemical; Picrates; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Temperature

The formation of the complexes of Wogonin with β-cyclodextrin (β-CD) and hydroxypropyl-cyclodextrin (HP-β-CD) was studied by fluorescence spectra and nuclear magnetic resonance spectroscopy (NMR). The formation constants (Ks) of complexes were determined by fluorescence method. The results suggested that HP-β-CD was easier to form inclusion with Wogonin than β-CD in solution. In different pH solutions, CDs have different inclusive capacity to Wo. β-CD was most suitable for inclusion of neutral form and HP-β-CD was suitable for acidic form. In addition, the experimental resulted confirmed the existence of 1:1 inclusion complex of Wogonin with CDs. Besides, kinetic studies of DPPH with Wogonin and CDs complexes were done. The results obtained indicated that the complex was the most reactive form. Special configuration of complex has been proposed on NMR technique.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Antioxidants; beta-Cyclodextrins; Biphenyl Compounds; Drugs, Chinese Herbal; Flavanones; Free Radicals; Magnetic Resonance Spectroscopy; Picrates; Scutellaria; Spectrometry, Fluorescence

The formation of the complexes of BG with beta-CD and HP-beta-CD was studied by UV-vis absorption spectroscopy, fluorescence spectra, Phase-solubility measurements and nuclear magnetic resonance spectroscopy (NMR) in solution. The formation constants (K) of complexes were determined by fluorescence method and Phase-solubility measurements. The results showed that the inclusion ability of beta-CD and its derivatives was the order: HP-beta-CD>beta-CD. In addition, the experimental resulted confirmed the existence of 1:1 inclusion complex of BG with CDs. The antioxidant ability studies of BG and CDs complexes were done. The results obtained indicated that the BG/HP-beta-CD complex was the most reactive form, and then was the BG/beta-CD complex; the last was BG. Special configuration of complex has been proposed on NMR technique.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Antioxidants; beta-Cyclodextrins; Biphenyl Compounds; Excipients; Flavonoids; Free Radicals; Magnetic Resonance Spectroscopy; Molecular Structure; Picrates; Scutellaria baicalensis; Solubility; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet