Sephadex LH-20 fractionation and bioactivities of phenolic compounds from extracts of Finnish berry plants

Investigation of the phytochemical profiling and antioxidant, anti-diabetic, anti-inflammatory, and MDA-MB-231 cell line antiproliferative potentials of extracts from Ephedra alata Decne

Ephedra is one of the many medicinal herbs that have been used as folk/traditional medicine in Jordan and other countries to cure various illnesses. Plants of this genus are well known for their antioxidant and antibacterial properties. In this study, three different solvents were used to obtain Ephedra extracts. When evaluated, the Ephedra alata Decne ethanolic extract reportedly had the greatest levels of total phenolic compounds (TPC) and total flavonoid compounds (TFC). The aqueous extracts displayed the highest antioxidant activity in the DPPH and ABTS assays, demonstrating their considerable capacity to neutralize free radicals. However, when evaluated using the FRAP method, the acetone extracts showed the strongest antioxidant activity, indicating their high reducing power. LC-MS/MS, a potent method of analysis that combines the liquid chromatographic separation properties with mass spectrometry detection and identification capabilities, was used in this study to detect and measure phytochemical content of a total of 24 phenolic compounds and 16 terpene compounds present in the extracts of Ephedra alata Decne. Various concentrations of these chemicals were found in these extracts. The extracts' inhibitory effects on albumin denaturation and alpha-amylase activity were also assessed; the findings demonstrated the potentials of these extracts as anti-inflammatory and anti-diabetic medicines, with the acetone extract having the lowest IC50 values in the concomitant tests (306.45 µg/ml and 851.23 µg/ml, respectively). Furthermore, the lowest IC50 value (of 364.59 ± 0.45 µg/ml) for the 80% ethanol extract demonstrated that it has the strongest antiproliferative impact regarding the MDA-MB-231 breast cancer cell line. This finding indicates that this particular extract can be potentially used to treat cancer.

Research Progress on the Extraction and Purification of Anthocyanins and Their Interactions with Proteins

Anthocyanins, as the most critical water-soluble pigments in nature, are widely present in roots, stems, leaves, flowers, fruits, and fruit peels. Many studies have indicated that anthocyanins exhibit various biological activities including antioxidant, anti-inflammatory, anti-tumor, hypoglycemic, vision protection, and anti-aging. Hence, anthocyanins are widely used in food, medicine, and cosmetics. The green and efficient extraction and purification of anthocyanins are an important prerequisite for their further development and utilization. However, the poor stability and low bioavailability of anthocyanins limit their application. Protein, one of the three essential nutrients for the human body, has good biocompatibility and biodegradability. Proteins are commonly used in food processing, but their functional properties need to be improved. Notably, anthocyanins can interact with proteins through covalent and non-covalent means during food processing, which can effectively improve the stability of anthocyanins and enhance their bioavailability. Moreover, the interactions between proteins and anthocyanins can also improve the functional characteristics and enhance the nutritional quality of proteins. Hence, this article systematically reviews the extraction and purification methods for anthocyanins. Moreover, this review also systematically summarizes the effect of the interactions between anthocyanins and proteins on the bioavailability of anthocyanins and their impact on protein properties. Furthermore, we also introduce the application of the interaction between anthocyanins and proteins. The findings can provide a theoretical reference for the application of anthocyanins and proteins in food deep processing.

Influence of Major Polyphenols on the Anti-Candida Activity of Eugenia uniflora Leaves: Isolation, LC-ESI-HRMS/MS Characterization and In Vitro Evaluation

The content of chemical constituents in Eugenia uniflora leaf extracts correlates positively with biological activities. The experimental objective was to carry out the phytochemical screening and purification of the major polyphenols from the leaves of E. uniflora. In addition, the anti-Candida activity of the hydroalcoholic extract, fraction, subfractions and polyphenols purified were evaluated. After partitioning of the extract with ethyl acetate, the fractions were chromatographed on Sephadex® LH-20 gel followed by RP-flash chromatography and monitored by TLC and RP-HPLC. The samples were characterized by mass spectrometry (LC-ESI-QTOF-MS2) and subjected to the microdilution method in 96-well plates against strains of C. albicans, C. auris, and C. glabrata. Myricitrin (93.89%; w/w; m/z 463.0876), gallic acid (99.9%; w/w; m/z 169.0142), and ellagic acid (94.2%; w/w; m/z 300.9988) were recovered. The polyphenolic fraction (62.67% (w/w) myricitrin) and the ellagic fraction (67.86% (w/w) ellagic acid) showed the best antifungal performance (MIC between 62.50 and 500 μg/mL), suggesting an association between the majority constituents and the antifungal response of E. uniflora derivatives. However, there is a clear dependence on the presence of the complex chemical mixture. In conclusion, chromatographic strategies were effectively employed to recover the major polyphenols from the leaves of the species.

Exploring separation patterns and mechanisms of proanthocyanidins in grape seeds and pomace with diverse molecular weights, compositions, and structures

The function of proanthocyanidins (PAs) relies on their structure and requires high-purity PAs. Though Sephadex LH-20 gel permeation chromatography (GPC) is expected to separate PAs based on structure, its usage rules and mechanisms remain unclear. This study delves into the PAs separation patterns on Sephadex LH-20, first confirming the purification mechanisms of PAs with various mean degrees of polymerization (DP) using the adsorption kinetic model. The study found that an increase in the molecular weight or mean DP of PAs results in decreased polarity, reduced hydrogen bonding actions, and intensified hydrophobic effect, causing delayed extraction of PAs on Sephadex LH-20, with galloylated PA as an exception, which was extracted first despite its high DP. Additionally, the principles for separating specific composition, such as monomers, dimers, etc., were evaluated. The study sheds light on enhancing the purification efficiency of PAs, thus advancing the precise separation technology of diverse proanthocyanidins.

Litsea glaucescens Kuth possesses bactericidal activity against Listeria monocytogenes

Background

Litsea glaucencens Kuth is an aromatic plant used for food seasoning food and in Mexican traditional medicine. Among, L. glaucencens leaves properties, it has proven antibacterial activity which can be used against opportunistic pathogens like Listeria monocytogenes, a foodborne bacteria that is the causal agent of listeriosis, a disease that can be fatal in susceptible individuals. The aim of this work was to investigate the antibacterial activity of L. glaucescens Kuth leaf extracts against L. monocytogenes and to identify its bioactive components.

Material and Methods

L. glaucences leaves were macerated with four solvents of different polarity (n-hexane, dichloromethane, ethyl acetate, and methanol). To determine the capacity to inhibit bacterial proliferation in vitro, agar diffusion and microdilution methods were used. Next, we determined the minimal bactericidal concentration (MBC). Finally, we determined the ratio of MBC/MIC. Metabolites present in the active methanolic extract from L. glaucescens Kuth (LgMeOH) were purified by normal-phase open column chromatography. The structure of the antibacterial metabolite was determined using nuclear magnetic resonance (1H, 13C, COSY, HSQC) and by comparison with known compounds.

Results

The LgMeOH extract was used to purify the compound responsible for the observed antimicrobial activity. This compound was identified as 5,7-dihydroxyflavanone (pinocembrin) by analysis of its spectroscopic data and comparison with those described. The MIC and MBC values obtained for pinocembrin were 0.68 mg/mL, and the ratio MBC/MIC for both LgMeOH and pinocembrin was one, which indicates bactericidal activity.

Conclusion

L. glaucences Kuth leaves and its metabolite pinocembrin can be used to treat listeriosis due the bactericidal activity against L. monocytogenes.

Willow (Salix spp.) bark hot water extracts inhibit both enveloped and non-enveloped viruses: study on its anti-coronavirus and anti-enterovirus activities

Introduction

Recurring viral outbreaks have a significant negative impact on society. This creates a need to develop novel strategies to complement the existing antiviral approaches. There is a need for safe and sustainable antiviral solutions derived from nature.

Objective

This study aimed to investigate the antiviral potential of willow (Salix spp.) bark hot water extracts against coronaviruses and enteroviruses. Willow bark has long been recognized for its medicinal properties and has been used in traditional medicines. However, its potential as a broad-spectrum antiviral agent remains relatively unexplored.

Methods

Cytopathic effect inhibition assay and virucidal and qPCR-based assays were used to evaluate the antiviral potential of the bark extracts. The mechanism of action was investigated using time-of-addition assay, confocal microscopy, TEM, thermal, and binding assays. Extracts were fractionated and screened for their chemical composition using high-resolution LC-MS.

Results

The native Salix samples demonstrated their excellent antiviral potential against the non-enveloped enteroviruses even at room temperature and after 45 s. They were equally effective against the seasonal and pandemic coronaviruses. Confocal microscopy verified the loss of infection capacity by negligible staining of the newly synthesized capsid or spike proteins. Time-of-addition studies demonstrated that Salix bark extract had a direct effect on the virus particles but not through cellular targets. Negative stain TEM and thermal assay showed that antiviral action on enteroviruses was based on the added stability of the virions. In contrast, Salix bark extract caused visible changes in the coronavirus structure, which was demonstrated by the negative stain TEM. However, the binding to the cells was not affected, as verified by the qPCR study. Furthermore, coronavirus accumulated in the cellular endosomes and did not proceed after this stage, based on the confocal studies. None of the tested commercial reference samples, such as salicin, salicylic acid, picein, and triandrin, had any antiviral activity. Fractionation of the extract and subsequent MS analysis revealed that most of the separated fractions were very effective against enteroviruses and contained several different chemical groups such as hydroxycinnamic acid derivatives, flavonoids, and procyanidins.

Conclusion

Salix spp. bark extracts contain several virucidal agents that are likely to act synergistically and directly on the viruses.

Separation of Antioxidant-Rich Alternanthera Sessilis Red Extracts by Sephadex LH-20 and Identification of Polyphenols Using HPLC-QToF-MS/MS

This study aimed to fractionate Alternanthera sessilis Red (ASR) crude extracts and determine their antioxidant activities as well as the related active components in the whole plant. ASR was extracted with water and ethanol, and further separated using a Sephadex LH-20 column. Following the assessments of the polyphenolic contents and antioxidant activities of crude extracts (H2 OASR and EtOHASR ) and fractions, a HPLC-QToF analysis was performed on the crude extracts and selected fractions (H2 OASR FII and EtOHASR FII). Three water fractions (H2 OASR FI, FII and FIII) and four ethanolic fractions (EtOHASR FI, FII, FIII and FIV) were derived from their crude extracts, respectively. EtOHASR FII exhibited the greatest total phenolic content (120.41 mg GAE/g fraction), total flavonoid content (223.07 mg RE/g fraction), and antioxidant activities (DPPH IC50 =159.43 μg/mL; FRAP=1.93 mmol Fe2+ /g fraction; TEAC=0.90 mmol TE/g fraction). Correlation analysis showed significant (p<0.01) positive correlations between both TPC (r=0.748-0.970) and TFC (r=0.686-0.949) with antioxidant activities in the crude extracts and fractions. Flavonoids were the major compounds in the four selected samples tentatively identified using HPLC-QToF-MS/MS, with the highest number of 30 polyphenol compounds detected in the most active fraction, EtOHASR FII.

Isolation and purification of 12 flavonoid glycosides from Ginkgo biloba extract using sephadex LH-20 and preparative high-performance liquid chromatography

An efficient and rapid preparative method for the separation and purification of flavonoid glycosides from the Ginkgo biloba extract (GBE) was developed by sephadex LH-20 and preparative high-performance liquid chromatography (HPLC). 40 g GBE of 24% flavonoids were loaded onto the sephadex LH-20 column and five fractions (1.15, 2.57, 1.32, 4.45, and 3.31 g) at flavonoid content of 72.3, 54.2, 63.5, 51.2, and 59.2% were produced. Ultimately, 12 flavonoid glycosides that are at least purities of 97.7% were obtained from 100 mg of each fraction by preparative HPLC. The fraction A, B, and D each contained two flavonoids, yielded 35, 30, 23, 20, 25, and 25 mg, respectively. The fraction C and E each contained three flavonoids, produced 20, 13, 15, 18, 15, and 20 mg, respectively. The chemical structures of the purified compounds were identified by nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI/MS).

Anthocyanins in Different Food Matrices: Recent Updates on Extraction, Purification and Analysis Techniques

Anthocyanins (ANCs), a kind of natural pigments, are widely present in food substrates. Evidence has shown that ANCs can promote health in terms of anti-oxidation, anti-tumor, and anti-inflammation. However, the oxidative stability of ANCs limits accurate quantitation and analysis. Therefore, faster, more accurate, and highly sensitive extraction and determination methods are necessary for understanding the role of ANCs in medicine and food. This review presents an updated overview of pretreatment and detection techniques for ANCs in various food substrates since 2015. Liquid-liquid extraction and various green solvent extraction methods, such as accelerated solvents extraction, deep eutectic solvents extraction, ionic liquids extraction, and supercritical fluid extraction, are commonly used pretreatment methods for extraction and purification of ANCs. Liquid chromatography coupled with different detectors (tandem mass spectrometry and UV detectors) and spectrophotometry methods are some of the determination methods for ANC. This study has updated, compared, and discussed different pretreatment and analysis methods. Moreover, the advanced methods and development prospects in this field are comprehensively summarized, which can provide references for further utilization of ANCs.

Isolation, characterization of bamboo leaf flavonoids by size exclusion chromatography and their antioxidant properties

The utilization of bamboo industry exhibits varied but still needs to be improved. Bamboo leaf flavonoid (BLF) is an important resource of bamboo which has become a research focus. However, the isolation and purification techniques of four flavonoid carbon glycosides (orientin, isoorientin, vitexin, and isovitexin) from BLF were still confronted with difficulties due to their complex and similar structures, which obstructed the development of bamboo utilization. In this paper, a purification technology of four flavonoid carbon glycosides from BLF by Sephadex LH-20 was improved. The results were evaluated by HPLC and pharmacological activity. Specifically, the eluent, flow rate, and loading amount were investigated respectively. According to the results, the eluent would dominate the isolation effect among three factors. High concentration of isoorientin and four flavonoid carbon glycosides would be obtained under the optimized condition (The eluent was 70% methanol, the loading amount was 1.5 g, and the flow rate was 0.5 mL·min-1). Meanwhile, the link between flavonoid carbon glycosides content and their antioxidant activity in vitro was also revealed. Overall, the results suggested that BLF may serve as potential functional food additives and medicine.

Antioxidant Activity and Inhibitory Effects of Black Rice Leaf on the Proliferation of Human Carcinoma Cells

The leaves of black rice, well-known as postharvest agricultural waste, contain a rich source of antioxidants with multiple benefits for human health. In the present study, the ethyl acetate fraction obtained from black rice leaf was separated into five subfractions using Sephadex LH-20 column chromatography, and their antioxidant and anticancer activities were investigated. The results revealed that among all the subfractions, subfraction 5 (Sub5) showed the highest total phenolic and flavonoid values. The antioxidant activity was also superior in Sub5 (the IC₅₀ values are 3.23, 31.95, and 72.74 μg/mL, in the DPPH, ABTS, and reducing power assays, respectively) compared to the other subfractions. All subfractions, in a time-dependent manner, inhibited the proliferation of hepatoma (HepG2), breast (MCF-7), and colorectal (Caco-2) cancer cells, especially the Sub5. Thus, Sub5 was employed to conduct the cell cycle and cell apoptosis by flow cytometry. Sub5 significantly increased the accumulation of cells at the Sub-G1 phase in HepG2 cells (44.5%, at 48 h). Furthermore, it could trigger annexin V-detected apoptosis through mitochondrial and death receptor pathways accompanied by the suppression of PI3K/Akt and Erk signaling pathways. In addition, HPLC-DAD-MS/MS was conducted to characterize the bioactive constituents in the most potent antioxidant, cytotoxic, and apoptosis-inducing subfraction. Conclusively, Sub5 may have high potential as functional dietary supplements to inhibit the development of HepG2 liver cancer.

Research Progress of Quercetin Delivery Systems

Quercetin is the main dietary flavonoid with a wide range of pharmacological activities. However, the poor gastrointestinal absorption and low bioavailability of quercetin curtails its clinical applications.. Enhancement the bioavailability of quercetin focuses on the application of delivery systems technologies such as microparticle delivery systems, solid dispersions, encapsulation, phospholipid complexes, and hydrogels , which have been systematically reviewed .And theirapplications in vitro and in vivo animal experiments also been described, promoting the development and optimization of drug delivery system for clinical applications.

An efficient method based on an inhibitor-enzyme complex to screen an active compound against lipase from Toona sinensis

As a popular vegetable, Toona sinensis has a wide range of bioactivities including lipase inhibitory activity. In the present study, an efficient and rapid method using a ligand-enzyme complex was established for screening of an active compound against lipase from Toona sinensis. The ethyl acetate extract of Toona sinensis showed good lipase inhibitory activity. After incubation with lipase, one of the compounds in the extract decreased significantly while comparing the HPLC chromatograms before and after incubation, which indicated that it may be the active compound bound to lipase. Then, the compound was isolated using a Sephadex LH-20 column and identified as 1,2,3,4,6-penta-O-galloyl-β-D-glucose. The in vitro activity test showed that the compound had good inhibitory activity against lipase, and its IC₅₀ value was 118.8 ± 1.53 μg mL^-1. The kinetic experiments indicated that 1,2,3,4,6-penta-O-galloyl-β-D-glucose inhibited lipase through mixed competitive and non-competitive inhibitions. Further docking results showed that the target compound could bind to the active site of lipase stably through seven hydrogen bonds, resulting in a docking energy of -8.31 kcal mol^-1. The proposed method can not only screen the lipase inhibitors from Toona sinensis quickly and effectively, but also provide an effective way for the rapid screening of active substances in natural food and plants.

Phenolic compounds in Nordic berry species and their application as potential natural food preservatives

An increasing demand for natural food preservatives is raised by consumers. For Nordic berry species, abundance of phenolic compounds and potent activities of anti-oxidation and anti-bacteria enables a great potential as food preservatives. This review provides a systematic examination of current literature on phenolic profiles, anti-oxidative and anti-bacterial activities of various extracts of Nordic berry species, as well as the impact of various structure features of phenolics on the bioactivities. Special attention is placed on exploitation of leaves of berry species and pomaces after juice-pressing as side-streams of berry production and processing. The current progress and challenges in application of Nordic berry species as food preservatives are discussed. To fully explore the potential application of Nordic berry species in food industry and especially to valorize the side-streams of berry cultivation (leaves) and juice-pressing industry (pomaces), it is crucial to obtain extracts and fractions with targeted phenolic composition, which have high food preserving efficacy and minimal impact on sensory qualities of food products.

Phenolic Fractions from Vaccinium vitis-idaea L. and Their Antioxidant and Anticancer Activities Assessment

Lingonberry leaves and fruits are associated with a range of potential bioactivities related to their phenolic content and composition, but the identification of major biological activity markers remains limited. The present study aimed at the isolation of lingonberry phenolic fractions and biological activity evaluation of them. Crude dry extracts of lingonberry leaves and fruits were fractionated by chromatography using Sephadex LH-20 and analyzed by validated HPLC-PDA method. For each fraction, the anticancer activity against human clear cell renal cell carcinoma (CaKi-1), human colon adenocarcinoma (HT-29), and human malignant melanoma (IGR39) cell lines was determined using MTT assay, and the radical scavenging, reducing, and chelating activities were investigated using ABTS, FRAP, and FIC assays, respectively. Further, 28 phenolics were identified and quantified in the crude extract of lingonberry leaves and 37 in the extract of fruits. These compounds, during fractionation steps, were selectively eluted into active fractions, enriched with different groups of phenolics—monophenols, anthocyanins, phenolic acids, catechins, flavonols, or proanthocyanidins. Fractions of lingonberry leaves and fruits, obtained by the last fractionation step, proved to be the most active against tested cancer cell lines and possessed the greatest antioxidant activity. In this perspective, the predominant compounds of these fractions—polymeric and mainly A-type dimeric proanthocyanidins—also quercetin can be considered to be anticancer and antioxidant activity markers of lingonberries.

A novel online preparative high-performance liquid chromatography system with the multiple trap columns-valve switch technique for the rapid and efficient isolation of main flavonoids from Epimedium koreanum Nakai

In this work, a new online preparative high-performance liquid chromatography was developed for the fast and efficient separation of complex chemical mixtures from natural products. This system integrates two chromatographic systems into an online automatic separation system using the technique of multiple trap columns with valve switching. The sample was first separated into 18 subfractions in the online preparative high-performance liquid chromatography, and the sample eluents were then diluted and captured online on 18 trap columns by the multiple trap columns technique, respectively. Each subfraction retained on the trap column was transferred online to the separation column for the second separation. Finally, the target compounds were purified by appropriate separation conditions and multiple heart-cutting strategies. Importantly, the system was successfully used to separate 18 high-purity flavonoids from the crude extract of Epimedium koreanum Nakai online in one step. The entire separation time was approximately 20 h, and the structures were characterized by the high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry and nuclear magnetic resonance. This online preparative high-performance liquid chromatography system represents an efficient and rapid separation system that has the potential for a wide array of applications in the separation of complex chemical components from natural products.

A Glimpse into the Extraction Methods of Active Compounds from Plants

Naturally active compounds are usually contained inside plants and materials thereof. Thus, the extraction of the active compounds from plants needs appropriate extraction methods. The commonly employed extraction methods are mostly based on solid-liquid extraction. Frequently used conventional extraction methods such as maceration, heat-assisted extraction, Soxhlet extraction, and hydrodistillation are often criticized for large solvent consumption and long extraction times. Therefore, many advanced extraction methods incorporating various technologies such as ultrasound, microwaves, high pressure, high voltage, enzyme hydrolysis, innovative solvent systems, adsorption, and mechanical forces have been studied. These advanced extraction methods are often better than conventional methods in terms of higher yields, higher selectivity, lower solvent consumption, shorter processing time, better energy efficiency, and potential to avoid organic solvents. They are usually designed to be greener, more sustainable, and environment friendly. In this review, we have critically described recently developed extraction methods pertaining to obtaining active compounds from plants and materials thereof. Main factors that affect the extraction performances are tuned, and extraction methods are chosen in line with the properties of targeted active compounds or the objectives of extraction. The review also highlights the advancements in extraction procedures by using combinations of extraction methods to obtain high overall yields or high purity extracts.

Amentoflavone, a novel cyanobacterial killing agent from Selaginella tamariscina

Harmful cyanobacterial bloom (HCB) by Microcystis aeruginosa is increasingly becoming a serious concern to the environment and human health alike. Currently, many physical, chemical, and biological controls are underway to eliminate HCB, but natural chemicals are rarely used. To find a control agent with low environmental toxicity and high potential for practical use, 60 plant extracts were screened. Only Selaginella tamariscina extract killed all four Microcystis aeruginosa strains, but not the other tested bacteria. Chloroform fraction of S. tamariscina extract (CSE) showed the highest killing activity. The effects of CSE on M. aeruginosa were monitored using differential interference contrast microscopy and flow-cytometry analysis, scanning electron microscopy, and transmission electron microscopy. The images showed that CSE-treated cells were abnormally altered, with damaged cell membranes, peptidoglycan layers, and cytoplasm. Quadrupole time-of-flight liquid chromatography-mass spectrometry was used to identify amentoflavone as a major active compound. Pure amentoflavone, even at low concentrations showed a powerful killing effect on M. aeruginosa, but not on other non-cyanobacteria. Overall, in this study, we have highlighted the potentials of S. tamariscina extracts and amentoflavone as selective HCB control agents.

Ultrasonic and microwave activation of raspberry extract: antioxidant and anti-carcinogenic properties

Safe and healthy nutrition has a beneficial effect on human well-being. Various foods, such as berries, are known to inhibit cancer-promoting pre-proliferative signals. Among European fruit and berry crops, raspberries demonstrate one with the widest ranges of biologically active substances. Extraction remains a reliable method of obtaining biologically active substances from plant materials. The research objective was to obtain a semi-finished raspberry product by using microwave and ultrasonic processing and to study its antioxidant, anti-carcinogenic, sensory, physico-chemical, and microbiological properties. The raspberry extracts were obtained by maceration, ultrasound treatment, and microwave processing. After that, the samples underwent a comparative analysis of their antioxidant properties. The ultrasonic method gave the best results. A set of experiments made it possible to define the optimal technological modes for the extraction process: ethanol = 50%, ultrasonic radiation = 35 kHz, temperature = 40 ± 5°C, time = 120 min, water ratio = 1:10. A set of experiments on cell cultures demonstrated that the raspberry extract was able to reduce the expression of the anti-inflammatory COX-2, iNOS, and IL-8 genes. Hense, we recommend further studies of the effect of the raspberry extract on the induced expression of COX-2, iNOS, and IL-8. In addition, its anticarcinogenic properties have to be studied in vivo.

Recovery of Oligomeric Proanthocyanidins and Other Phenolic Compounds with Established Bioactivity from Grape Seed By-Products

Grape seeds are a copious part of the grape pomace produced by wine and juice industry and they represent an interesting source of phenolic compounds. Proanthocyanidins (PAs) are the main class of grape seed phenols and are important dietary supplements for their well-known beneficial properties. In this study enriched extracts obtained from Chardonnay and Pignoletto grape seeds were characterized for their proanthocyanidins and other minor phenolic compounds content and composition. Seed PAs were fractionated using Sephadex LH-20, using different ethanol aqueous solutions as mobile phase and analysed by normal phase HPLC-FLD-ESI-MS. Monomers, oligomers up to dodecamers and polymers were recorded in all samples. For both cultivars, the extracts showed a high content in PAs. The determination of other phenolic compounds was carried out using a HPLC-QqQ-ESI-MS and Chardonnay samples reported a greater content compared to Pignoletto samples. Contrary to PAs fraction, extracts obtained with ethanol/water 50/50 (v/v) presented a significant higher phenolic content than the others.