Macroporous Resin Research Articles

Extraction, purification and anticancer activity studies on triterpenes from pomegranate peel.

Pomegranate peel is the by-product of pomegranate processing, which contains a lot of triterpene compounds. In this study, the total triterpenes of pomegranate peel (TPP) were extracted using an ultrasonic-assisted ethanol extraction method under optimal conditions, purified using D-101 macroporous resin to obtain a purity of 75.28%. The triterpenes in TPP were mainly pentacyclic triterpenes determined by LC-MS/MS. Network pharmacological analysis predicted that the anticancer targets were closely related to the MAPK pathway. The in vitro results showed that TPP could inhibit cell proliferation, promote apoptosis, reduce mitochondrial membrane potential and increase ROS levels. The western blot results indicated that the expression levels of the apoptotic proteins Bax, Bcl-2, cytochrome C, cleaved caspase-3 and cleaved caspase-9 were increased. In addition, the protein expression of the MAPK pathway predicted by network pharmacology also changed significantly. These results provided that TPP has potential for adjuvant therapy of tumors.

Bioactivity-guided isolation of potential antidiarrheal constituents from Euphorbia hirta L. and molecular docking evaluation.

Euphorbia hirta L., a member of the Euphorbiaceae family, is extensively used as a folk medicine across various regions. In China, its decoction is traditionally consumed to alleviate diarrhea. This study aimed to evaluate the antidiarrheal activities of Euphorbia hirta and to identify its bioactive constituents through a bioactivity-guided isolation technique. Oral administration of E. hirta extract to mice was conducted to assess its effects on diarrhea. The anti-diarrheal effects were investigated in an aqueous extract and in three fractions of varying polarities derived from the aqueous extract, as well as in different eluates from D-101 macroporous resin, and in the compounds quercitrin and isoquercitrin, using mouse models with castor oil-induced diarrhea. The aqueous extract demonstrated significant anti-diarrheal activities in a dose-dependent manner in the castor oil-induced diarrheal model. Notably, the ethyl acetate (EtOAc) fraction showed prominent effects. Through bioactivity-guided isolation, two major compounds, isoquercitrin and quercitrin from the active fraction were found to possess antidiarrheal effects. Molecular docking studies revealed that the affinity energy of isoquercitrin and quercitrin were -8.5 and -8.2 kcal mol-1, respectively, which were comparable to the reference drug loperamide, with an affinity energy of -9.1 kcal mol-1. This research provides evidence supporting the development of E. hirta as a therapeutic agent for diarrhea, with isoquercitrin and quercitrin emerging as two key constituents that are likely responsible for its antidiarrheal activity. These findings validate the traditional use of E. hirta and highlight its potential as a natural treatment for diarrhea.

Isolation, characterization, and LC MS/MS determination of anti-obesity components from pine needles of Cedrus deodara (Roxb.) G. Don.

This study aimed to isolate and analyze the components in cedar pine needles (needle leaves of Cedrus deodara (Roxb.) G. Don) that exhibit anti-obesity effects, as determined through animal experiments. The extract of cedar pine needles was separated into four fractions of different polarities using a macroporous resin column. The fraction that retained anti-obesity activity was evaluated based on the results of animal experiments. Monomeric compounds were structurally characterized and isolated from the active fraction using a preparative liquid chromatography system. Combined with subsequent glucose gel chromatographic separation. The content of the separated components was determined using ultrahigh performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-QQQ-MS/MS). The water-washed fraction retained anti-obesity activity of the cedar pine needles more effectively. A total of 16 compounds were separated from this fraction, and the contents of 14 of these compounds were determined to be present in cedar pine needles. Nine components, namely p-hydroxy benzyl alcohol, chlorogenic acid, vanillic acid, syringic acid, P-coumaric acid, sinapic acid, benzoic acid, phenylacetic acid, salicylic acid, were characterized and determined for the first time in cedar pine needles. The components with anti-obesity activity in the pine needles of Cedrus are mainly derived from phenolic acids.

Ultrasound-assisted macroporous resin treatment improves the color and functional properties of sunflower meal protein

Sunflower meal protein (SMP) has been considered as a high-quality source of plant protein. However, because the chlorogenic acid (CA) contained in sunflower seed meal was prone to oxidation reactions under traditional alkali extraction conditions, the extracted protein has a dark color and some poor functional properties. To this end, this study used ultrasound-assisted macroporous resin treatment to extract SMP. The improvement effects and potential mechanisms of ultrasonic-assisted macroporous resin treatment with different powers (100, 300, and 500 W) on the color and functional properties of SMP were studied. The results showed that compared with untreated sunflower meal protein (USMP), the lightness value (L*), solubility, emulsification, and gel elasticity were significantly enhanced when treated with 100 W and 300 W ultrasonic-assisted macroporous resin. However, when the ultrasonic power was increased to 500 W, the L* value, solubility, emulsification, and gel elasticity decreased instead, indicating that lower power (100 W and 300 W) ultrasonic-assisted macroporous resin treatment significantly improved the color and functional properties of SMP. Further research found that ultrasound-assisted macroporous resin treatment changed the secondary and tertiary structures of SMP, transformed β-sheet into α-helix and β-turn through rearrangement, and significantly improved surface hydrophobicity. It shows that ultrasonic-assisted macroporous resin treatment expands the SMP structure and exposes hydrophobic groups, thereby improving the color and functional properties of SMP. This study provides a potential strategy for extracting SMP with light color and good functional properties. It also provides a theoretical basis for the wide application of SMP in food processing.

Extraction and Purification of Aucubin from Eucommia ulmoides Seed Draff in Natural Deep Eutectic Solvents Using Macroporous Resins.

Aucubin (AU) is an active ingredient that exerts strong antioxidant and anti-inflammatory effects in the treatment of several diseases. In order to improve the efficiency of resource utilization of traditional biomass waste, Eucommia ulmoides seed-draff (EUSD) waste biomass was used as the raw material, and a series of deep eutectic solvents were selected to evaluate the extraction efficiency of aucubin from EUSD. A response surface experiment was designed based on a single-factor experiment to optimize the extract conditions. The results showed that the best conditions for aucubin extraction were an HBD-HBA ratio of 2.18, a liquid-solid ratio of 46.92 mL/g, a water percentage of 37.95%, a temperature of 321.03 K, and an extraction time of 59.55 min. The maximum amount of aucubin was 156.4 mg/g, which was consistent with the theoretical value (156.8 mg/g). Then, the performance of 12 resins for adsorption and desorption was contrasted. The results revealed that HPD950 resin exhibited the best performance, with an adsorption capacity of 95.2% and a desorption capacity of 94.3%. Additionally, the pseudo-second-order model provided the best match to the kinetics data, the Langmuir model provided the best fit to the isotherm data, and adsorption was a beneficial, spontaneous, exothermic, and physical process. In the recyclability test, the HPD950 resin had great potential and excellent sustainability in aucubin recovery. In the antioxidant activity study, the aucubin extract exerted a strong antioxidant ability with scavenging capabilities for four free radicals. Furthermore, the antifungal activity study found that the aucubin extract exhibited a good antifungal effect against 5 tested pathogens. The research results can provide a theoretical basis for the extraction of high-value components from waste biomass by deep eutectic solvent and a certain application value for the development and utilization of natural aucubin products.

A green process for extracting and purifying coconut mesocarp polyphenols

Coconut, as one of the main tropical economic crops, has high yield and high demand. Coconut mesocarp (CM) is the main waste in coconut production, causing resource waste and bulk pollution issues. In this study, a green process for extracting and purifying CM polyphenols was developed, which was beneficial for turning waste into treasure and saving resources. The process included a series of steam explosion (SE) assisted alkali extraction methods for the total phenolic content (TPC) of total phenols (CTP) and insoluble phenols (CIP) in CM and purification process of macroporous resin. These results showed after SE treatment at 123 °C for 5 min, the TPC of CTP and CIP increased to 558.57 mg GAE/g dw and 280.67 mg GAE/g dw, which was higher 9% and 17.8% than the untreated sample, respectively. After purification with LX-83, the TPC of purified CTP (P-CTP) and CIP (P-CIP) increased to 773.16 mg GAE/g dw and 542.83 mg GAE/g dw. Both Langmuir and Freundlich adsorption models could be used to describe the adsorption behaviors of CTP and CIP. They were influenced by multiple factors and belonged to a pseudo second-order kinetic model. Subsequently, the main compounds in P-CTP and P-CIP were the abundant catechin, epicatechin, caffeic acid, p-coumaric acid and 4-hydroxybenzoic acid by HPLC-MS analysis. These results provided a basis for the green extraction and purification process of CM polyphenols.

Bioassay-guided discovery and identification of new potent α-glucosidase inhibitors from Morus alba L. and the interaction mechanism

Ethnopharmacological relevanceMorus alba L. (mulberry) is a well-known medicinal species that has been used by herbalist doctors for the treatment of diabetes for a long history, and modern ethnopharmacological studies have demonstrated the ameliorating effects of different mulberry extracts toward diabetes-related symptoms and identified a number of α-glucosidase inhibitors as hypoglycemic ingredients. Aim of the studyThe present study aims to explore new potent α-glucosidase inhibitors from the root bark of M. alba (known as Sang-Bai-Pi in traditional medicine) based on an in vivo antidiabetic evaluation of its extract fractions and further characterize the preliminary mechanism of the new active constituents. Materials and methodsα-Glucosidase inhibitory assay and diabetic mice model were used to locate and evaluate the active fractions from the extract. Diverse separation techniques (e.g. Sephadex LH-20 column chromatograph (CC) and HPLC) and spectroscopic methods (e.g. MS, NMR and ECD) were employed to isolate and structurally characterize the obtained constituents, respectively. Fluorescence quenching, kinetics and molecular docking experiments were conducted to investigate the enzyme inhibitory mechanism of the active compounds. ResultsThe 80% ethanol eluate from the macroporous resin CC exerted good antidiabetic effects in the tested mice. Fifty-two flavonoids including 22 new ones were then separated and identified, and most of them showed strong inhibition against α-glucosidase with their structure-activity relationship being also discussed. The four new most active ingredients were further characterized to be mixed type of α-glucosidase inhibitors, and their binding modes with the enzyme were also explored. ConclusionsOur current work has demonstrated that the root bark of M. alba is an extremely rich source of flavonoids as potent α-glucosidase inhibitors and potential antidiabetic agents, which makes it a promising candidate species to develop new natural remedies for the prevention and treatment of diabetes.

Heavy metal on stage: Making ion-exchange resin selective by peptide tetrazine-norbornene ligation

The challenge of recycling metal salt-contaminated wastewater is more relevant than ever, and cost-effective materials for specific ion-binding are required. A generic route to functionalize a macroporous polystyrene ion-exchange resin (LR-NH2) via chemoselective inverse electron-demand Diels-Alder (IEDDA) ligation is demonstrated. The resin is modified using accessible endo-/exo-5-norbornene-2-carboxylic acid (Nb-COOH) and a set of tetrazine-functionalized 5mer peptides based on sequence variations of the literature known Cu2+ binding domain HGGGW is employed for the IEDDA ligation. The resulting peptide-functionalized resins (LR-Pz-Peptides) are studied for Cu2+ binding to correlate ion-binding capacity with sequence properties by single bead analysis of metal amounts via inductively-coupled plasma mass spectrometry (ICP-MS). The complexation preferences are demonstrated and utilized for specific binding of Cu2+versus Ni2+ from 1:1 salt mixture as a model system. Enrichment factors of up to 305 could be realized, which might open the potential for applications in metal recycling or waste water purification.

Research Progress on Extraction, Separation, and Purification Methods of Plant Essential Oils

Essential oils (EOs), also called liquid gold, are known for their wide range of applications and biological activities. The modern use of EOs has received increasing attention for more than 60 years. The precious EOs have been refined from plant raw materials using a variety of methods. Since the extraction, separation, and purification methods determine the type, quantity, and stereochemical structure of EO molecules as well as the final yield and quality of EOs, the selection of an appropriate method is crucial. The traditional and emerging extraction methods (hydrodistillation, steam distillation, organic solvent extraction, etc.), as well as separation and purification methods (chromatography, macroporous resin, chemical reaction, etc.), of plant EOs and their main volatile compounds were shown. Our review focused on the principles, processes, characteristics, and applications of these methods, so as to better understand the preparation of pure plant EOs and further guide their large-scale use.

Increasing minor ginsenosides contents and enhancing neuroprotective effects of total ginsenosides fermented by Lactiplantibacillus plantarum

Minor ginsenosides have been proven to have higher pharmacological activity than the major ginsenosides. The transformation of major ginsenosides to minor ginsenosides by lactic acid bacteria was considered to be a promising method. Therefore, this study focuses on utilizing glycosidase-producing Lactiplantibacillus plantarum GLP40 to transform total ginsenosides (TG) and increase the content of minor ginsenosides, as well as investigate the neuroprotective effects of fermented total ginsenosides (FTG). After 21d fermentation, the transformation products were purified using D101 macroporous resin column chromatography, and identified by HPLC and LC-MS analyses. The neuroprotective effect of FTG was evaluated using MPTP-induced neural injury mice model. Lact. plantarum GLP40 fermentation increased the contents of minor ginsenosides in TG, such as Rg3, Rh2, CK, and Rk3. FTG showed stronger alleviation of 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine Hydrochloride (MPTP) induced memory loss and dyskinesia in mice, and inhibited tyrosine hydroxylase (TH) depletion and ionized calcium binding adapter molecule 1 (Iba-1) production than TG. Further, FTG significantly increased serum IL-10 levels and inhibited the expression of pro-inflammatory cytokines compared to TG. Moreover, FTG treatment activated the anti-apoptotic PI3K/AKT/mTOR signaling pathway and inhibited the expression of the inflammatory NF-κB/COX-2/iNOS pathway. In conclusion, Lact. plantarum GLP40 fermentation enhances the neuroprotective effects of total ginsenosides by increasing minor ginsenosides. FTG protected MPTP induced neural injury in mice by regulating inflammation and cell apoptosis signaling pathways.

Corydalis tomentella Franch. Exerts anti-inflammatory and analgesic effects by regulating the calcium signaling pathway

Ethnopharmacological relevanceCorydalis tomentella Franch. is a perennial cespitose plant commonly used to treat stomachaches as a folk medicine. The C. tomentella total alkaloids have good protective effects against acute liver injury and potential anti-hepatoma and anti-Alzheimer's disease activities. Aim of the studyTo establish an effective purification process for total alkaloids from C. tomentella and investigate the mechanism of their anti-inflammatory effects. Materials and methodsCorydalis tomentella were purified using macroporous resin. Then the crude and purified C. tomentella extracts (cCTE and pCTE) were qualitatively analyzed using UPLC-Triple-TOF-MS/MS. The cCTE and pCTE were used to investigate and compare their anti-inflammatory effects on lipopolysaccharide (LPS)-induced RAW264.7 cells. Doses at 100, 200 and 400 mg/kg/d of pCTE were used to study their anti-inflammatory and analgesic activities in mice with xylene-induced ear swelling and acetic acid-induced writhing tests. Content of nitric oxide (NO), interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) were determined both in RAW264.7 cells and mice. Network pharmacology was used to predict the anti-inflammatory mechanism of C. tomentella, and the key enzymes were validated using qPCR and Western Blot analysis. Concentration of intracellular Ca2+ was detected using flow cytometric analysis. ResultsThe C. tomentella total alkaloid purity increased from 6.29% to 47.34% under optimal purification conditions. A total of 54 alkaloids were identified from CTE. Both cCTE and pCTE could suppress the LPS-induced production of NO, IL-6, IL-1β, and TNF-α in RAW264.7 cells. The pCTE exhibited a more potent anti-inflammatory effect; it also inhibited pain induced by xylene and acetic acid in mice. The calcium signaling pathway is associated with the anti-inflammatory and analgesic activities of C. tomentella. The mRNA expression of nitric oxide synthase (NOS) 2, NOS3 and calmodulin1 (CALM1) was regulated by C. tomentella through the reduction of inflammation-induced Ca2+ influx, and it also exhibited a more pronounced effect than the positive control (L-NG-nitro arginine methyl ester). ConclusionsPurified C. tomentella extract shows anti-inflammatory effect both in vitro and in vivo. It exerts anti-inflammatory and analgesic effects through the calcium signaling pathway by down-regulating NOS2 and CALM1 expression and up-regulating NOS3 expression in LPS-induced RAW264.7 cells, and decreasing intracellular Ca2+ concentration.

One-step enrichment of phenolics from Chaenomeles speciosa (Sweet) Nakai fruit using macroporous resin: Adsorption/desorption characteristics, process optimization and UPLC-QqQ-MS/MS-based quantification

Chaenomeles speciosa (Sweet) Nakai fruit is a good source of phenolics with many health benefits. In this work, the enrichment of C. speciosa fruit total phenolics (CSFTP) using macroporous resins was studied. NKA-Ⅱ resin was selected for enriching CSFTP due to its highest adsorption/desorption quantity. Adsorption characteristics of CSFTP on NKA-Ⅱ resin exhibited a good fit with the Langmuir isotherm model and pseudo-second order kinetics model. This adsorption was spontaneous, exothermic, and entropy-decreasing through a physisorption mechanism. The breakthrough-elution curves were studied to optimize CSFTP enrichment conditions. One-step enrichment increased CSFTP content in the extracts from 26.51 % to 78.63 %, with a recovery of 81.03 %. A UPLC-QqQ-MS/MS method in multiple reaction monitoring (MRM) mode was established and validated for the simultaneous quantification of seven phenolic compounds. This study demonstrates the feasibility of industrial enrichment of CSFTP using NKA-Ⅱ resin and proposes a reliable method for quality control of CSFTP-rich products.

Phytochemical study: Fragmentation patterns of flavonoid‐C‐glycosides in the enriched flavonoids from corn silk using high‐efficiency ultra‐high‐performance liquid chromatography combined with quadrupole time‐of‐flight mass spectrometry

AbstractFlavonoid‐C‐glycosides with various pharmacological actions were abundant in corn silk, and fragmentation in mass spectra of flavonoid‐C‐glycosides compounds was particularly important. This paper aimed to supervise the fragmentation patterns of flavonoid‐C‐glycosides in the enriched flavonoids from corn silk by high‐efficiency ultra‐high‐performance liquid chromatography combined with a quadrupole time‐of‐flight mass spectrometry approach. Therefore, the flavonoids were extracted by heating reflux and then purified based on D101 macroporous resin. Thirty‐five flavonoids were triumphantly identified in the purified product. Among them, 14 were flavonoid‐C‐glycosides, seven of them owned luteolin mother nuclei (luteolin‐C‐glycosides) and seven of them owned apigenin mother nuclei (apigenin‐C‐glycosides). Importantly, the diagnostic product ions of luteolin‐C‐glycosides including m/z (431, 413, 395, 369, 367, 313, and 299) and m/z (429, 411, 393, 367, 365, 311, and 297), and the characteristic product ions of apigenin‐C‐glycosides covered m/z (353, 339, and 299) and m/z (339, 327, and 309). In addition, diagnostic H2O neutral loss and glycosyl craking were familiar, and the difference values among product ions mainly contained 40, 60, 70, 80, 90, 100, and 120 Da. Thus, the fragmentations of luteolin‐C‐glycosides and apigenin‐C‐glycosides identified in corn silk were with proper regularity. The obtained fragmentation patterns provided rapid recognition and meaningful guidance for the purification study of flavonoid‐C‐glycosides.

Mass transfer study on noncovalent adsorption and desorption of soluble phenolics by plant cell wall materials for green purification

This study originated from the observation that plant cell walls can bind soluble phenolics through noncovalent interactions. Celery and blueberry cell wall materials obtained from waste sources were selected as effective adsorbents for purifying phenolics. First, the impact of environmental ionic strength on the adsorption of phenolics by plant cell walls was investigated, indicating that ionic interactions play a more important role in adsorption than hydrophobic interactions. Second, numerical simulation results found that the increments of diffusivities of phenolics both within the liquids in the pores of plant cell wall materials and the skeleton of cell wall adsorbents accelerated the adsorption. The abundance of adsorption sites within plant cell wall adsorbents determined their adsorption capacity, and the penetration of phenolics across the adsorbent/liquid interface was unrelated to the adsorption behavior. Third, due to the porous structure of celery cell wall adsorbents, the pore volume diffusion of phenolics impacted intraparticle diffusion within celery cell wall materials more than blueberry cell wall materials. Fourth, after plant cell wall adsorption and desorption, the obtained phenolics achieved a purity of 60%, comparable to the purification achieved by macroporous resin adsorption/desorption. Moreover, purification using plant cell wall adsorption/desorption was more efficient. These findings contribute to the theoretical understanding of interactions between plant cell walls and polyphenols and provide valuable insights for designing natural plant cell wall adsorbents and developing environmentally friendly polyphenol purification techniques.

Application of the selected macroporous resin for the separation and identification of flavonoids from Chinese Radix Pueraria Lobata by HPLC-Q-TOF-MS

A systematic investigation was conducted on the adsorption and desorption properties of macroporous resins including D101, ADS7, HPD600, XAD2 and HPD100 for flavonoids of Radix Pueraria Lobata. Based on the results of the adsorption capacity, desorption ratio, and physical properties of the investigated resins, ADS7 was selected for the purification of flavonoids in this study. On the basis of the correlation coefficients, the experimental results fitted the pseudo-second-order model compared to the pseudo-first model. The separation parameters of the RPL flavonoids were optimised through dynamic adsorption/desorption experiments with a column packed with ADS7. The breakthrough point was found at 30 mL of RPL flavonoids solution, while at 105 mL of 60 % ethanol, the flavonoids were completely desorbed. Furthermore, the total flavonoid content was 3.16 mg/g. HPLC-Q-TOF-MS analysis helped identify five isoflavones, including puerarin, 3′-methoxy puerarin, daidzin, 3′-hydroxy puerarin and daidzein from radix pueraria Lobata.

Preparation of functional polytertiary amine macroporous resin and its adsorption and separation properties for tungsten and molybdenum

Separation of tungsten (W) and molybdenum (Mo) is a key challenge for the efficient and high-value-added utilization and recycling of W and Mo resources. The clean and recyclable separation technology has been the research focus in this field. To improve the effectiveness of W-Mo adsorption and separation and avoid sulfurization in the ion exchange method, a functional polytertiary amine macroporous resin (TA12-MR) was designed and prepared first time. Optimal synthesis conditions were determined by optimizing preparation time, temperature, and modifier addition, FTIR, XRD, SEM and BET characterizations revealed that TA12-MR exhibited enriched amine groups, dense structure and abundant pores. After optimizing the adsorption conditions, QWMax reached 743.6 mg·g−1, βMoW reached 20.1 at pH = 7.4, T = 25 °C, t = 4 h, n(CTAB)/n(Mo) = 0.5). The adsorption isotherms and kinetics fitting results indicated that the adsorption of W and Mo was a monolayer spontaneous chemically adsorption. The mechanism was found to be a combination of electrostatic adsorption and chemisorption. Firstly, W migrated near N which on TA12-MR, followed by HWO4− replaced Cl− for ion exchange and coordinated with N. The adsorption property remained high with QW = 849 mg·g−1, QMo = 85 mg·g−1, after ten adsorption–desorption cycles. It is an environmentally friendly and high recyclable method without sulfurization and H2S generation. TA12-MR is expected to be a clean, efficient, reusable, and green material, which can be applied to the efficient separation and comprehensive recovery of W and Mo secondary resources, to provide support for solving the problem of W-Mo separation.

Pinobanksin from peony seed husk: A flavonoid with the potential to inhibit the proliferation of SH-SY5Y.

Pinobanksin, as one of the flavonoids, has powerful biological activities but has been under-recognized. In this study, we optimized the extraction method of phragmites from peony seed shells by using organic solvent extraction. The yield of PSMS was 10.54 ± 0.13% under the conditions of ethanol volume fraction 70%, extraction temperature 70°C, material-liquid ratio 1:25 g/mL, and extraction time 60 min; the optimized PSMS could be effectively separated in S-8 macroporous resin coupled with C18. The relative content of PSMS was increased from 0.42% in PSMS to 92.53% after C18 purification; the antioxidant activity test revealed that pinobanksin could exert antioxidant ability by binding catalase (CAT) enzyme. Second, it was found that pinobanksin could effectively inhibit the proliferation of SH-SY5Y cells, mainly by binding to BCL2-associated X (BAX), B-cell lymphoma-2 (BCL-2), and cyclin-dependent Kinase 4/6 (CDK4/6) to produce more hydrogen bonds to inhibit their activities. This study confirms the medicinal potential of pinobanksin and provides the basis for the proper understanding of pinobanksin and the development of related products.

Study of the textural properties of non-ionic resins and their influence on polyphenol adsorption and desorption

Abstract Macroporous resins are employed for the purification of polyphenolic extracts. However, the relationship between the adsorption and desorption and the textural properties remains unexplored. Thus, we evaluated the textural properties of HP-20, XAD-16 and SP-825 resins and their impact on adsorption and desorption of specific polyphenols like gallic acid, epigallocatechin, and procyanidin B2. The HP-20 resin exhibited a type II isotherm with macroporous structure, while XAD-16 and SP-825 resins displayed type IV isotherms, typically associated with mesoporous materials. The HP-20 resin demonstrated superior adsorption capacity and rupture points for epigallocatechin (2.37 mg/g, 124 min) and procyanidin B2 (1.29 mg/g, 136 min) compared to SP-825 and XAD-16. Contrary, the SP-825 resin exhibited the highest adsorption capacity (5.34 mg/g) and rupture point (68 min) for gallic acid. However, the desorption was more efficient when HP-20 resin was used for all specific polyphenols. Therefore, for an efficient purification process is necessary to consider the chemical structure of the polyphenol and the textural properties.

Anthocyanin isolation from Hibiscus sabdariffa L. flowers by extraction, macroporous D101 resin purification, and biological evaluation

This study aimed to improve the purity of anthocyanins in the extract from Hibiscus sabdariffa L. (H. sabdariffa L.) by macroporous D101 resin. Thereby, we determined the main components, thermal stability properties, and some biological activities of anthocyanin mixture from Hibiscus flowers. The main anthocyanin identified in the anthocyanin sample was Cyanidin-3-O-sambubioside. In the purification stage with D101 resin, the anthocyanin fraction had the highest purity of 72.18 % compared with 12.07 % of that of the extract. Purified anthocyanins have very good color stability at low temperatures and in mildly alkaline media. The high antioxidant capacity of anthocyanins was recorded by methods of the free radical scavenging capacity of 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and Ferric-reducing antioxidant power (FRAP) with IC50 values of 93.14 ± 0.93 μg/mL, 75.51 ± 0.71 μg/mL and 73.26 ± 0.93 μg/mL, respectively. The total antioxidant activity (RP) of anthocyanin sample was dose-dependent, the absorbance increased from 0.149 (100 μg/mL) to 0.873 (500 μg/mL). Anthocyanin also can inhibit both Gram (+) and Gram (−) bacteria of Staphylococcus aureus and Escherichia coli, as well as the mold Aspergillus flavus. Research has also shown potential anti-inflammatory in vitro of anthocyanins. These findings provide evidence that the purified anthocyanin from H. sabdariffa L. is a potential source of natural antioxidants, anti-bacteria, and anti-inflammatory in functional food and medicine.

A new allo-aromadendrane sesquiterpene from Dendrobium nobile

To study the chemical constituents in the non-alkaloid part of stems of Dendrobium nobile. The macroporous adsorption resin, MCI, silica gel, RP-C_(18), and Sephadex LH-20 gel, preparative thin layer chromatography, and preparative high-performance liquid chromatography(HPLC) were used to isolate and purify the compounds. The structures of the compound were determined according to the spectra data, physicochemical properties, and relevant references. A total of 8 compounds were isolated from D. nobile, which were soltorvum F(1), p-hydroxyphenylpropionic acid(2), vanillic acid(3), p-hydroxybenzoic acid(4), N-trans-cinnamic acid acyl-p-hydroxybenzene ethylamine(5),(+)-(1R,2S,3R,4S,5R,6S,9R)-2,11,12-trihydroxypicrotoxane-3(15)-lactone(6), dendronobilin H(7), soltorvum E(8). Compound 1 was a novel compound, named as soltorvum F. Compound 8 was isolated from Dendrobium species for the first time.