Host-Guest Inclusion Systems of Morin Hydrate and Quercetin with Two Bis(β-cyclodextrin)s: Preparation, Characterization, and Antioxidant Activity

2019 ◽  
Vol 72 (6) ◽  
pp. 440 ◽  
Author(s):  
Li-Juan Zhao ◽  
Song-Lin Yang ◽  
Wen Jin ◽  
Hui-Wen Yang ◽  
Fei-Yang Li ◽  
...  

The inclusion complexation behaviour of morin hydrate (MH) and quercetin (QCT) with the two amide-bridged bis(β-cyclodextrin (β-CD))s, 1 and 2, was investigated in both solution and the solid state. The inclusion complexations were characterised by proton nuclear magnetic resonance, 2D rotating-frame Overhauser effect spectroscopy, X-ray powder diffraction, infrared spectroscopy and scanning electron microscopy. Ultraviolet titration analysis indicated that 1 and 2 form 1:1 molar stoichiometry inclusion complexes with MH and QCT, and the data obtained showed that 2 with two guests has a higher complex stability constant (KS) when compared with that of 1. Moreover, 1 and 2 were able to solubilize MH and QCT to high levels, up to ~200-fold. Furthermore, the antioxidant activity of MH, QCT and their inclusion compounds were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. Together, these results showed that the inclusion complexes exhibited a more effective antioxidant activity when compared with free MH. The satisfactory antioxidant activity and high water solubility of the bis(β-CD)s/flavonoid complexes may have potential use as healthcare products and herbal medicine.

2019 ◽  
Vol 20 (4) ◽  
pp. 975 ◽  
Author(s):  
Sui-Ping Deng ◽  
Yi-Li Yang ◽  
Xing-Xing Cheng ◽  
Wen-Rong Li ◽  
Ji-Ye Cai

Kaempferol (Kae) is a natural flavonoid with potent antioxidant activity, but its therapeutic use is limited by its low aqueous solubility. Here, a series of Kae derivatives were synthesized to improve Kae dissolution property in water and antioxidant activity. These compounds included sulfonated Kae (Kae-SO3), gallium (Ga) complexes with Kae (Kae-Ga) and Kae-SO3 (Kae-SO3-Ga). The compound structures were characterized by high-resolution mass spectrometry (HRMS), nuclear magnetic resonance (NMR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and thermal methods (TG/DSC). The results showed that a sulfonic group (-SO3) was successfully tethered on the C3’ of Kae to form Kae-SO3. And in the metal complexation, 4-CO and 3-OH of the ligand participated in the coordination with Ga(III). The metal-to-ligand ratio 1:2 was suggested for both complexes. Interestingly, Kae-SO3-Ga was obviously superior to other compounds in terms of overcoming the poor water-solubility of free Kae, and the solubility of Kae-SO3-Ga was about 300-fold higher than that of Kae-Ga. Furthermore, the evaluation of antioxidant activities in vitro was carried out for Kae derivatives by using α,α-diphenyl-β-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS) free radical scavenging. The results showed that Kae-SO3-Ga was also optimal for scavenging free radicals in a dose-dependent manner. These data demonstrate that sulfonate kaempferol-gallium complex has a promising future as a potential antioxidant and as a potential therapeutic agent for further biomedical studies.


Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6214
Author(s):  
Garland Kgosi More ◽  
Stephen Meddows-Taylor ◽  
Gerhard Prinsloo

The genus Vachellia, previously known as Acacia, belongs to the family Fabaceae, subfamily Leguminosae, which are flowering plants, commonly known as thorn trees. They are traditionally used medicinally in various countries including South Africa for the treatment of ailments such as fever, sore throat, Tuberculosis, convulsions and as sedatives. The aim of this study was to determine biochemical variations in five Vachellia species and correlate their metabolite profiles to antioxidant activity using a chemometric approach. The antioxidant activity of five Vachellia aqueous-methanolic extracts were analyzed using three methods: 2,2-di-phenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+) analysis and the ferric reducing antioxidant power (FRAP) assay by means of serial dilution and bioautography with the thin-layer chromatography (TLC) method. Amongst the Vachellia extracts tested, V. karroo, V. kosiensis and V. xanthophloea demonstrated the highest DPPH, ABTS+ and FRAP inhibitory activity. The antioxidant activities of DPPH were higher than those obtained by ABTS+, although these values varied among the Vachellia species. Proton nuclear magnetic resonance (1H NMR), coupled with multivariate statistical modeling tools such as principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA), were performed to profile metabolites responsible for the observed activity. The OPLS-DA categorized the five Vachellia species, separating them into two groups, with V. karroo, V. kosiensis and V. xanthophloea demonstrating significantly higher radical scavenging activity than V. tortilis and V. sieberiana, which clustered together to form another group with lower radical scavenging activity. Annotation of metabolites was carried out using the ultra-high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UHPLC-qTOF-MS), and it tentatively identified 23 metabolites of significance, including epigallocatechin (m/z = 305.0659), methyl gallate (m/z = 183.0294) and quercetin (m/z = 301.0358), amongst others. These results elucidated the metabolites that separated the Vachellia species from each other and demonstrated their possible free radical scavenging activities.


2016 ◽  
Vol 94 (6) ◽  
pp. 575-582 ◽  
Author(s):  
Yafei Guo ◽  
Jiuling Li ◽  
Yuqi Liu ◽  
Yongping Ma ◽  
Huilin Cheng ◽  
...  

This article describes the preparation of a series of inclusion complexes of anhydrolycorine with three cyclodextrins (CDs), namely β-CD, γ-CD, and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), and their successful characterization through UV, TG, DSC, XRD, SEM, 1H NMR, and 2D NMR spectroscopies. The results demonstrated that the water solubility of anhydrolycorine increased notably by about 23–42 times after the inclusion complexation with these CDs. Furthermore, preliminary in vitro cytotoxicity experiments on human colon cancer cell lines HT-29, SW480, HCT116, and DLD-1 were also performed, and the complexes showed remarkable anticancer activity against HT-29, SW480, and HCT116. These results suggested that the inclusion complexes would be potentially useful for applications for human colon cancer chemotherapy.


Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1708 ◽  
Author(s):  
Lin Zhao ◽  
Yingmin Wang ◽  
Yan Li

Antioxidants can reduce or inhibit damage such as oxidative decay caused by elevated levels of free radicals. Therefore, pursuing antioxidants with excellent properties has attracted more and more attention. Graphene quantum dots (GQDs) are considered a promising material because of their good free radical scavenging activity, low toxicity, and excellent water solubility. However, their scavenging efficiency, antioxidant mechanism, and effective control methods need to be improved. Herein, in order to further reveal the antioxidant mechanism of GQDs, the role of electrolytes in improving the antioxidant activity of GQDs is explored. In addition, 1,1-diphenyl-2-picrazine (DPPH∙), hydroxyl (∙OH), and superoxide (∙O2−) free radicals are used to evaluate the antioxidant activity of the as-prepared GQDs. Combined with transmission electron microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, and cyclic volt–ampere characteristic curves, the effects of an electrolytic environment on the surface functional groups, charge transfer capability, and defect states of GQDs are obtained. The antioxidant mechanism of GQDs and how to improve their antioxidant activity are further elucidated.


Biomolecules ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 883 ◽  
Author(s):  
Juliana Villasante ◽  
Esther Pérez-Carrillo ◽  
Erick Heredia-Olea ◽  
Isidoro Metón ◽  
María Pilar Almajano

The pecan (Carya illinoinensis) nut shell is an important byproduct of the food processing industry that has not been previously explored as an antioxidant compound. This work aims to study the effect of the extrusion temperature and screw speed on the moisture content, water and oil absorption index, water solubility index, color, phenolic compounds, condensed tannin compounds, and antioxidant activity of pecan nut shell extrudates. Extrusion variables were adjusted using a response surface methodology. Extrusion, performed at 70 °C and 150 rpm, almost doubled the concentration of polyphenols in the non-extruded shell and significantly increased radical scavenging activity. Compounds in extrudates, performed at 70 °C and 150 rpm, were quantified by high-performance liquid chromatography (HPLC) with a diode-array detector (DAD) and identified by liquid chromatography coupled with time-of-flight mass spectrometry (LC-MSD-TOF). Extrusion significantly increased most phenolic acid compounds, including gallic acid, ellagic acid pentose, ellagic acid, dimethyl ellagic acid rhamnoside, and dimethyl ellagic acid. The soluble fiber in extrudates was more than three-fold higher than in the control. Therefore, extrusion at 70 °C and 150 rpm increased the concentration of phenolic compounds, antioxidant activity, and total dietary and soluble fiber. Our findings support the notion that extruded pecan nut shell can be used in clean-label products and improve their nutraceutical value.


Antioxidants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 153 ◽  
Author(s):  
Szabolcs Muráth ◽  
Adél Szerlauth ◽  
Dániel Sebők ◽  
István Szilágyi

Ellagic acid (EA), a polyphenolic antioxidant of poor water solubility, was intercalated into biocompatible layered double hydroxide (LDH) nanoparticles by the coprecipitation method. Structural investigation of the composite revealed that the lactone bonds split under the synthetic experimental conditions, and EA was transformed to 4,4′,5,5′,6,6′-hexahydroxydiphenic acid during intercalation. To improve the surface properties of the EA-LDH composite, the samples were treated with different organic solvents. The antioxidant activity of the LDH hybrids was assessed in test reactions. Most of the obtained hybrids showed antioxidant activity comparable to the one of the free EA indicating that the spontaneous structural transformation upon immobilization did not change the efficiency in radical scavenging. Treatments with organic solvents influenced the activities of the materials remarkably. The main advantage of the immobilization procedure is that the products can be applied in aqueous samples in high concentrations overcoming the problem related to the low solubility of EA in water. The developed composites of high antioxidant content can be applied as efficient reactive oxygen species scavenging materials during biomedical treatments or industrial manufacturing processes.


Author(s):  
Vijaya Jyothi M ◽  
Bhargav E ◽  
Pavan Kumar K ◽  
Praneeth Gowd K ◽  
Ram Pavan S

Nyctanthes arbour-tristis is a shrub belongs to the family Oleaceae. The flowers of this plant are fragrant since the presence of flavonol glycosides. It has also been reported for the presence of β-sitosterol, iridoid glycosides, tannins etc., and known to have immunostimulant, hepatoprotective, antiviral and antifungal activities. In the present study an attempt is made to identify antioxidant capacity and anthelminthic potential of methanolic flower extract of Nyctanthes arbour-tristis. Antioxidant activity was evaluated by total phenolic content assay, total flavonoids content assay, free radical scavenging activity and reducing ability methods. Anthelmintic activity was evaluated on Perithima posthuma using Piperazine citrate as standard drug. The results obtained for the above activities reveals that Nyctanthes arbour-tristis shows considerable antioxidant activity for all the methods and anthelminthic potential at 300 mg/ml. Keywords: arbour-tristis; antioxidant activity; anthelminthic activity; Perithima posthuma; Piperazine citrate.


2019 ◽  
Author(s):  
Chem Int

Verbena officinalis Linn is a traditionally known medicinal plant which is used against a number of diseases including inflammatory conditions. In this study its antioxidant activity (reducing powers, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities), ferric reduction activity potential (FRAP), total flavonoid concentration and antimicrobial activities of 80%, 90%, 100% methanol and chloroform extracts of V. officinalis Linn root and 90% and100% methanol leaf extracts were determined. Its antioxidant activity increases with increase in amount of extract (10% to 40%v/v). Total flavonoid content (TFC) varied from 73.32±0.002 mgQE/100g of dry weight (90% methanol) to 42.39±0.032 mgQE/100g dry weight (chloroform), 2,2-diphenyl-1-picrylhydrazyl (DPPH), radical scavenging activity (%) was varied between 87.39% (90% methanol) to 45.57% (chloroform) while Ferric reducing antioxidant power was observed between 372.93±0.04 mgAAE/100 g extract (90% methanol) to 129.41±0.026 mgAAE/100 g chloroform in the root extract. The methanolic extract of the leaf showed less antioxidant activity than the methanolic extract of the root. Crude extracts of V. officinalis root showed various degree of antimicrobial activity towards drug resistance microbial pathogens. Growth inhibition tests against bacterial pathogens demonstrated concentration dependence. Moreover, gram positive bacteria were more susceptible to V. officinalis root extract when compared to gram negative bacteria. In general V. officinalis root and leave extracts possess strong antioxidant and antimicrobial activities.


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