Procyanidin A2 Research Articles

Health Status and Disinfection Prior to Grafting Affect the Phenolic Profile of Grapevine Hetero-Grafts and Grafting Yield

Grapevine trunk disease (GTD) is a major threat to grapevine propagation, severely affecting the growth and development of young vines. As one of the most destructive plant diseases in the world, GTD spreads easily through propagation material and threatens the sustainability of vineyards. While effective, biologically friendly treatments remain unavailable. This study investigated the graft yield, the growth potential of grapevine hetero-grafts, and phenolic responses focusing on (i) GTD scion health status (healthy—HLT; asymptomatic—ASYM; symptomatic—SYM) and (ii) disinfection methods. Grafting with HLT scions achieved the highest yield rates, particularly with Serenade® ASO (75%) and BioAction ES (79%), while infected scions showed lower yields. The growth potential of the scions was not affected by the disinfection method or the health status of the scions. Phenolic composition varied between scions, graft callus, rootstock canes, and roots, with scion health status strongly influencing most metabolites. Higher levels of flavanols were observed in HLT scions treated with BioAction ES and Serenade® ASO, with these treatments resulting in 1.6 and 1.5 times higher procyanidin dimer levels, respectively, compared to Beltanol. Flavanols and stilbenes were lower in the callus tissue of grafts with healthy scions compared to infected scions. Rootstock also showed higher levels of catechin and procyanidin dimers in grafts with HLT scions. These results indicate that the health status of scion GTD and the disinfection methods significantly influence the graft yield and phenolic composition, providing valuable insights for GTD management.

Lychee Peel Extract Ameliorates Hyperuricemia by Regulating Uric Acid Production and Excretion in Mice

Lychee peel generated during the industrial processing of lychee fruit are currently disposed of as agricultural waste. This study investigates the primary components of lychee peel extract (LPE) and the regulatory mechanisms of LPE on reducing uric acid (UA). Mice were injected with hypoxanthine and potassium oxonate to induce hyperuricemia and concurrently orally administered LPE. The analysis of the LPE composition reveals a predominance of polyphenolic compounds, including (-)-epicatechin, (-)-epigallocatechin, and procyanidin A2. In vitro tests have demonstrated that the LPE significantly inhibits the activity of xanthine oxidase (XOD). In vivo studies showed that LPE can reduce UA levels in hyperuricemia mice. Further mechanistic insights indicate that LPE inhibits hepatic XOD activity, thereby reducing UA synthesis within the organism. It also decreases the protein expression of urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9), which leads to diminished UA reabsorption and increased excretion of UA. Additionally, LPE enhances the activity of superoxide dismutase (SOD) while simultaneously reducing malondialdehyde (MDA) contents, thereby improving antioxidant capacity in mice. Our findings indicate that LPE not only inhibits the production of UA but also promotes its elimination, positioning it as a promising candidate for UA-lowering agents.

Comparative investigation of metabolite signatures and hypoadiposity effect between Dali tea and Yunkang tea

Dali tea (DLT) made by wild tea plant (Camellia taliensis) has been very popular in the market。However, the signature compounds and health benefits of DLT were not reported yet. To comprehensively understand metabolite signatures and potential health-function, the distinct metabolite signatures and hypoadiposity effect between DLT and Yunkang tea (YKT, made by Camellia sinensis var assamica cv. Yunkang 10) were comparative investigated. Our data found that catechins, and dimeric catechins were lower in DLT than YKT. In contrast, the levels of phenolic acid and amino acids were higher in DLT than YKT. An un-targeted metabolomics and a chemometric analysis indicated that flavonoid biosynthesis is a major pathway that distinguishes DLT from YKT. Additionally, chlorogenic acid, ellagic acid, arginine, tyrosine, and theanine were identified as characteristic metabolites of DLT. Furthermore, animal experiment showed that YKT performs better efficiency than DLT on alleviating hyperadiposity and renal damages in high-fat-diet induced obese mice.

Effect of Thermovinification Temperature on Phenolic Compounds and Colour of Syrah Wine

Background: Thermovinification is a non-conventional winemaking practice that replaces the traditional method of grape maceration. Methods: This study evaluated the influence of thermovinification temperature on the quality of Syrah wines. The treatments included traditional winemaking with 7 days of maceration during alcoholic fermentation at 23 °C (TW—control); and thermovinification for 2 h at 55 °C (TV55), 65 °C (TV65), and 75 °C (TV75). The red wines were made through microvinification (10-litre glass). Phenolic compounds (n = 26) were quantified by high-performance liquid chromatography and a colour analysis using the CIELab/CIEL*C*h systems and a sensory analysis was conducted to evaluate the acceptability of the thermovinified wine. Results: The results indicate that thermovinification increased the content of bioactive compounds and intensified the colour of the wine, reducing L* and a*. However, the content of phenolic acids decreased, except for trans-caftaric acid, which was approximately 50 times higher. A higher temperature of thermovinification (75 °C) promoted the degradation of all anthocyanins. Among flavonols, kaempferol-3-O-glucoside, quercetin-3-β-D-glucoside, and isorhamnetin-3-O-glucoside were higher in TV65 and TV75 wines. Greater amounts of stilbenes were quantified in TV65. Among the flavan-3-ols, TV75 stood out, especially for (+)-catechin, (−)-epicatechin, procyanidin A2, and procyanidin B1. Conclusions: The thermovinification at 65 °C is optimal for minimising anthocyanin degradation and improving Syrah wine quality.

Multiomics correlation analysis on the mechanism of flavor substance formation during the processing of "Huanong 53″ black tea

A comprehensive investigation was conducted using targeted metabolomics, transcriptomics, and GC-MS techniques to study the dynamic changes in volatile and non-volatile metabolites, as well as gene transcription levels, in five processing stages of 'Huanong 53′ black tea (Camellia sinensis). A total of 2062 metabolites were identified, with flavonoids (428) and amino acids and their derivatives (194) being the main categories. The types and contents of flavor characteristic components of black tea changed most significantly during the withering and fermentation stages. Key elements of tea aroma composition, including linalool, benzeneacetaldehyde, and geraniol were found to correspond significantly with specific transcripts annotated as linalool synthase, aromatic aminotransferase, and geraniol diphosphate synthase, respectively. Throughout processing, a decrease in catechins and concomitant increase in oxidized catechin dimers, such as theaflavin (TF), was positively correlated with down-regulated flavonoid pathway gene expression and up-regulated expression of putative TF biosynthetic genes, including laccases, polyphenol oxidase, and a wide range of peroxidases. This study provides a comprehensive perspective on the changes in metabolites during black tea processing, and contributes to the research on improving black tea quality and the suitability of tea varieties for processing.

Extraction and In Vitro and In Vivo Antioxidant Activity Evaluation of Polyphenols from Lychee Pericarp

Background Finding a new promising plant antioxidant to combat or prevent cardiovascular disease remains a major challenge for researchers. Lychee pericarp, which includes a variety of polyphenols, is a prospective source of botanical antioxidants. Purpose In response to this issue, we assessed the effect of lychee bark extract on oxygen radical scavenging capacity and separate vascular protective ability in vivo. Methods In the current study, the lychee pericarp enrichment product (RLP) was obtained by optimizing an extraction method and separated using modern separation methods. The structure of the isolated compounds was assessed using 1H-NMR, 13C-NMR, and electrospray ionization-mass spectrometry, and the content of polyphenols obtained from the extract was quantified using the area normalization method. In addition, the capacity of RLP to scavenge oxygen radicals in vitro was assessed using the DPPH (1,1-diphenyl-2-picrylhydrazyl) and T-AOC (total antioxidant capacity) techniques. Furthermore, an isoprenaline hydrochloride (ISO)-induced rat model of acute myocardial ischemia was established, and four biochemical indicators were used to assess the effect of lychee bark extract on oxygen radical scavenging capacity and cardiovascular protective ability in vivo. Results RLP extraction produced 11 chemicals, 6 of which were structurally assessed. Quantitative analysis revealed that epicatechin, PC-C(epicatechin-(4β↓8,2β↓O↓7)-epicatechin-(4β↓8)-epicatechin), type A proanthocyanidin trimer, proanthocyanidin A2, and type B proanthocyanidin dimer were the most abundant polyphenols. The in vitro DPPH and T-AOC findings revealed that RLP exhibited strong free radical scavenging activity, approximately 1.5-fold that of vitamin C. The four biochemical indicators confirmed the antioxidant activity and cardiovascular protective ability of RLP in vivo. Conclusion RLP has good in vivo and in vitro antioxidant activity, confirming lychee pericarp as a prospective source of botanical antioxidants.

Investigating the Phytochemistry and Underlying Glycemic Control Mechanisms of Litchi chinensis Sonn. (Litchi) Peel Ethyl Acetate Extract in a Fructose/Streptozotocin Diabetic Model of Rats.

The glycemic control potential and flavonoid profile of litchi have been documented for its hydroalcoholic extracts, while there is scarce information regarding its ethyl acetate extract. This study investigated the flavonoid profile, as well as the ameliorative potential and possible underlying mechanisms of litchi peel ethyl acetate extract on type 2 diabetes-related pathologies in a fructose/streptozotocin (STZ) model of diabetic rats. Sprague Dawley rats were induced with diabetes by administering 10% fructose for 2 weeks and a single i.p. injection of low-dose (40 mg/kg bw) STZ. Thereafter, the animals were orally administered with a low-dose (150 mg/kg bw) and high-dose (300 mg/kg bw) of the peel extract (LDPE and HDPE, respectively) and metformin (200 mg/kg bw). Compared to untreated diabetic rats (AUC = 1004 mg.h/dL), the HDPE significantly (p < 0.05) improved glucose tolerance (AUC = 847 mg.h/dL), which was statistically comparable (p ˃ 0.05) to the effect of metformin (AUC = 903 mg.h/dL). Serum insulin and pancreatic histology data showed that the STZ-induced pancreatic damage and insulin depletion was improved by the HDPE, which could be linked to the observed ameliorative effect of the extract on pancreatic lipid peroxidation and SOD and catalase activity. The extract further improved liver and muscle glycogen storage, as well as muscle hexokinase activity and Akt phosphorylation, suggesting that the extract exerts glycemic control by enhancing glycogen storage and modulating insulin-mediated signaling of glucose uptake and utilization. LC-MS data and documented reports suggest that flavonoids, such as epicatechin, cinnamtannin B2, procyanidin B5, and proanthocyanidin A2, are the possible influencing compounds. The ethyl acetate extract of litchi peel could be a source of bioactive flavonoids that can potentiate glycemic control in diabetes and mitigate oxidative stress-related pathologies.

Therapeutic potential of Zanha africana (Radlk.) Exell: antimycobacterial activity and safety evaluation

BackgroundZanha africana (Radlk.) Exell extracts are commonly utilized in Tanzania and other countries for treating conditions associated with HIV and AIDS, including tuberculosis (TB). In Tanzania, it is listed among the most frequently traded plant species for medicinal use in different marketplaces. However, limited literature exists regarding its antimycobacterial properties and safety profile. ObjectiveThis study aimed to evaluate Z. africana ethanolic extract for safety and antimycobacterial activity. MethodsThe antimycobacterial activity of the crude extracts was assessed using the broth microdilution method against various non-pathogenic mycobacteria strains including Mycobacterium aurum (MA), Mycobacterium madagascariense (MM), and Mycobacterium indicus pranii (MIP). Bioassay-guided fractionation was employed to isolate the active compounds. The safety profile of the crude extract was investigated through cytotoxicity assay on peripheral blood mononuclear cells (PBMCs) and the brine shrimp lethality test. ResultsThe 80% ethanolic extracts of Z. africana demonstrated activity against all tested non-pathogenic mycobacteria. The antimycobacterial activity of ethanolic extract of the stem bark was 625 µg/mL, 313 µg/mL and 125 µg/mL against MA, MM, and MIP, respectively. The most potent fraction was the ethyl acetate fraction, from which two active compounds were isolated: proanthocyanidin A2; Compound (1) and its monomer epicatechin, Compound (2). Compound (1) exhibited higher antimycobacterial activity compared to compound (2) with minimum inhibitory concentrations (MICs) of 19.50 µg/mL and 12.98 µg/mL against MM and MIP respectively. The ethanolic extract did not demonstrate toxicity on PBMCs and brine shrimps. ConclusionThis study demonstrates that Z. africana extracts and the isolated compounds possess antimycobacterial activity. This provides evidence supporting the traditional use of Z. africana extracts for TB management. Further research is recommended to comprehensively evaluate the efficacy and safety of the plant constituents using different models.

Exploring chemical markers and identifying phenolic markers using a metabolomics strategy and chemometrics to study the different origins of defatted Coix seed

Coix seed, a prevalent medicinal and food-homologous plant, is extensively consumed in Asia. It has various pharmacological properties, such as anti-inflammatory and anticancer effects. Coix seed oil, as its main component, is widely produced. However, during the industrial production process of Coix seed oil, substantial byproducts are produced, namely, defatted Coix seeds, which are also worth researching. Currently, it remains unclear whether there will be differences in defatted Coix seeds obtained from different geographical locations, with previous studies reporting that phenolic compounds in defatted Coix seeds have a significant utilization value. In this study, firstly, the TPC and TFC of samples collected in three temperature zones were detected. Subsequently, UPLC-Q-TOF/MS was used to analyze the samples, and a metabolomics data processing strategy and chemometric analysis method were established. We have confirmed the presence of flavonoids and phenolic compounds in 30 batches of Coix seed from different temperature zones in China, and concluded that the overall quality of Coix seed from different batches is relatively stable. With the established strategy, 12 characteristic chemical markers were identified, and 5 valuable phenolic chemical markers were selected for distinguishing the origin of Coix seed and evaluating the quality of defatted Coix seed. Among them, proanthocyanidin A2 has the highest content in defatted Coix seed in subtropical regions, while the content of caffeic acid, naringin, rutin, and chlorogenic acid decreases from north to south. The strategy proposed in this study may provide some basis for the quality control and rational use of defatted Coix seeds.

Selection and Mechanism Study of Q-Markers for Xanthocerais lignum Anti-Rheumatoid Arthritis Based on Serum Spectrum-Effect Correlation Analysis.

To elucidate the chemical profile of Xanthocerais lignum's extracts of different polarities and their impact on rheumatoid arthritis (RA), we identified anti-RA markers and predicted their action mechanisms. A collagen-induced arthritis rat model was established, and UPLC-Q-Exactive Orbitrap MS technology was employed to analyze and identify the chemical constituents within the alcohol extract of Xanthocerais lignum and its various extraction fractions, as well as their translocation into the bloodstream. Serum spectrum-effect correlation analysis was utilized to elucidate the pharmacodynamic material basis of Xanthocerais lignum against RA and to screen for Q-Markers. Finally, the potential anti-RA mechanisms of the Q-Markers were predicted through compound-target interaction data and validated using molecular docking techniques. We identified 71 compounds, with flavan-3-ols and flavanones as key components. Of these, 36 were detected in the bloodstream, including 17 original and 19 metabolized forms. Proanthocyanidin A2, dihydroquercetin, catechin, and epicatechin (plus glucuronides) showed potential anti-RA activity. These compounds, acting as Q-Markers, may modulate ERK, NF-κB, HIF-1α, and VEGF in the HIF-1 pathway. This research clarifies Xanthocerais lignum's pharmacodynamic material basis against RA, identifies 4 Q-Markers, and offers insights into their mechanisms, aiding quality assessment and lead compound development for RA treatment.

An insight into trichomes-deficiency and trichomes-rich black teas by comparative metabolomics: The impact of oxidized trichomes on metabolic profiles and infusion color

Tea trichomes were regarded as an essential evaluation index for reflecting tea flavor quality in terms of aroma and influence on infusion color. This study reveals the impact of golden oxidized trichomes on the color, volatile and non-volatile metabolites of black teas through comparative metabolomics combined quantitative analysis on hongbiluo (trichomes-deficiency black teas), hongjinluo (trichomes-rich black teas), and trichomes (from hongjinluo). Forty-six volatile components were detected using headspace solid-phase microextraction gas chromatography-mass spectrometry, while the results suggested that the contribution of trichomes to black teas is limited. A total of 60 marker non-volatile compounds were identified, including catechins, catechin oxidation products, flavonoid glycosides, organic acids, hydrolysable tannins and amino acids. Notably, p-coumaroyl-kaempferol glucosides, and catechin dimers demonstrated high levels in independent trichomes and showed a positive correlation with the brightness and yellow hue of black tea infusions, specifically kaempferol 3-O-di-(p-coumaroyl)-hexoside. Furthermore, results from fractional extraction analysis of separated trichomes provided that N-ethyl-2-pyrrolidinone-substituted epicatechin gallates, acylated kaempferol glycosides, and chromogenic catechins dimers, such as theaflavins, were primary color contributors in oxidized trichomes. Especially, we found that epicatechin gallate (ECG) and its derivates, 3′-O-methyl-ECG and N-ethyl-2-pyrrolidinone-substituted ECG, highly accumulated in trichomes, which may be associated with the varieties of hongbiluo and hongjinluo black teas. Eventually, addition tests were applied to verify the color contribution of trichome mixtures. Our findings employed comprehensive information revealing that golden oxidized trichomes contributed significantly to the brightness and yellow hue of black tea infusion, but their contribution to the aroma and metabolic profile is limited. These findings may contribute to the effective modulation of the infusion color during black tea production by regulating the proportion of tea trichomes or screening trichomes-rich or deficiency varieties.

Biotransformation of Cynomorium flavan-3-ols in dairy sheep and their effects on inflammation and liver growth retardation.

The stems of Cynomorium songaricum are used in traditional Chinese medicine as a tonic and also used locally as a food material and livestock feed. It is known that some of the falvan-3-ol monomers and dimers that entered the milk of dairy sheep fed with C. songaricum stems are biotransformation products of the original flavan-3-ol polymers in C. songaricum stems. This study was performed to investigate the biotransformation process of the flavan-3-ols in dairy sheep and to evaluate the bioactivities. The results showed that procyanidin A2 and epicatechin could be released from the polymeric flavan-3-ols of C. songaricum through rumen microbial metabolism. On traumatic and lipopolysaccharide (LPS)-induced inflammation models of Tg (mpx: EGFP) zebrafish larvae and LPS-induced liver injury models of Tg (fabp10a: DsRed) zebrafish larvae, the milk from sheep fed with C. songaricum stems showed stronger anti-inflammatory and hepatoprotective activities compared to blank milk. The absorbed chemical constituents of C. songaricum stems and the metabolites also exhibited anti-inflammatory and hepatoprotective activities, with the dimeric flavan-3-ols being more effective than the monomers. The milk, the absorbed chemical constituents of C. songaricum stems, and the metabolites alleviated the increased level of reactive oxygen species induced by LPS in zebrafish larvae. PRACTICAL APPLICATION: This study found that C. songaricum stems as livestock feed could produce milk that has a beneficial impact on consumer and livestock health in terms of anti-inflammation and hepatoprotection.

The Influence of Polyphenolic Compounds on Anaerobic Digestion of Pepper Processing Waste during Biogas and Biomethane Production

Pepper processing waste has the potential to be used as a substrate in the process of anaerobic digestion, but because of its high polyphenol content, certain limitations are expected. During the determination of the biodegradability of pepper samples, a biogas potential of 687 L/kg DM was observed, as well as a biomethane potential of 401 L/kg DM. While both the testing of biodegradability and the process in the pilot scale progressed, it was observed that total polyphenol content in both cases decreased. Also, as far as individual polyphenols during the process in the pilot scale are concerned, it can be observed that at the end of the process no procyanidin A2, epicatechin, myricetin, and quercetin were detected. The observed concentration of the ferulic acid on the last day of the process was 0.09 µg/g. Finally, it can be concluded that the presence of polyphenols did not significantly affect the biogas potential of pepper waste. Due to its relatively stable biogas production, as far as biogas production on the pilot scale is concerned, it can be concluded that pepper processing waste has the potential to be used as a substrate for biogas production.

Lychee peel extract obtained by ultrasound-assisted extraction: bioactive compounds and functional properties

The purpose of this study was to evaluate the impact of extracting solvent composition on the concentration of bioactive compounds and functional properties of lychee peel extracts obtained by ultrasound-assisted extraction. Five conditions were evaluated with different solvent proportions: 100% water, 25% ethanol and 75% water, 50% ethanol and 50% water, 75% ethanol and 25% water, and 100% ethanol. The use of an equitable mixture of water and ethanol (50% ethanol and 50% water) resulted in extracts with a higher content of total phenolic compounds (10964.3 mg EAG 100 g-1), antioxidant activity (27.40%), and inhibition of α-glucosidase (94.31%), α-amylase (33.49%) and angiotensin-converting enzyme (ACE, 51.82%). This extract showed a diversity of phenolic compounds (quercetin 3-glucoside, procyanidin A2, B1, and B2, epicatechin, catechin, kaempferol 3-glucoside, trans-resveratrol, myricetin, and gallic acid). Therefore, extracts of lychee peel with potential anti-diabetic and anti-hypertensive activity can be obtained by ultrasound-assisted extraction. 50% water and 50% ethanol may be suggested as the extracting solvent.

Bioaccessibility and Antioxidant Capacity of Grape Seed and Grape Skin Phenolic Compounds After Simulated In Vitro Gastrointestinal Digestion

Grapes present recognized beneficial effects on human health due to their polyphenolic composition. The grape overproduction together with the wine sales down and the world socioeconomic situation makes the wine grape valorization a promising strategy to give an added-value to this natural product. The objective of the present work was to study the influence of in vitro gastrointestinal digestion on antioxidant capacity and polyphenolic profile of skin and seed extracts of different grape varieties (Tempranillo, Graciano, Maturana tinta and Hondarrabi zuri). After in vitro gastrointestinal digestion, total phenolic content (TPC) of seed polyphenolic extracts decreased significantly for all the varieties. The highest decrease was for Tempranillo going from 108 ± 9 to 50 ± 3 mg / g dry matter (dm). This variety also showed the highest decrease of 90% in antioxidant capacity. However, for all the skin polyphenolic extracts there was an increase in TPC. The highest variation was also for Tempranillo. It varied from 10.1 ± 0.8 to 55.1 ± 0.9 mg / g dm. Among red varieties Tempranillo skin polyphenolic extract showed the lowest undigested anthocyanin content but the highest bioaccessibility index (BI) of 77%. For flavanols, flavonols and procyanidins the seed polyphenolic extracts showed a BI at the intestinal phase between 11% for (+)-epicatechin gallate to 130% procyanidin A2. The results of this study suggest that grape skin extracts and grape seed extracts are a reliable source of bioaccessible antioxidant polyphenols, to be used for the development of antioxidant supplements with specific functionalities depending on the grape variety.

FT-IR and HPLC analysis of silver fir (Abies alba Mill.) bark compounds from different geographical provenances

Fourier Transform Infrared Spectroscopy (FT-IR) and High-Performance Liquid Chromatography (HPLC) could be applied to study the provenance of wood, specifically the differentiation of wood resources, as well as the identification of chemical compounds that are connected to the changes that occur in wood as a result of drying treatments. To test this hypothesis, the bark of silver fir (Abies alba Mill.) from trees belonging to seven different geographical provenances was studied, using samples dried at three different temperatures (60, 80, and 100 °C). FT-IR spectroscopy revealed different band assignments in the mid-infrared region depending on fir provenances, whereas the vibrational bands of the biomass functional groups tended to shift to lower wavenumbers. Significant differences were identified between the chemical compounds in the bark depending on the provenances. The largest proportion of the total phenolics was represented by the epicatechin gallate, epicatechin, catechin, and procyanidin dimer B1. Exploratory data analysis was performed using principal component analysis (PCA), hierarchical clustering, and Pearson correlations. This allowed a comparative evaluation of the samples and interpret the findings according to the geographical provenances, respectively ecological conditions in the areas of origin, but also the influence of the drying temperatures of the samples on chemical compounds. The precipitation in the areas of origin decreased total phenolics in silver fir bark samples, and total phenolics differed not only due to the geographic provenance, but also due to drying temperature.

Intestinal Microbiome Metabolism of Cranberry (Vaccinium macrocarpon) Proanthocyanidin Dimers, but Not Trimers, Is Altered by Dysbiosis in Ulcerative Colitis Ex Vivo.

Cranberries contain proanthocyanidins with different interflavan bond types and degrees of polymerization. These chemical differences may impact the metabolism of proanthocyanidins by the intestinal microbiome. In our previous study, we found that healthy microbiomes produced higher concentrations of the phenolic acid metabolites 5-(3',4'-dihydroxyphenyl)-g-valerolactone and 3-hydroxyphenylacetic acid from the cranberry extract in comparison to ulcerative colitis (UC) microbiomes ex vivo. To understand this difference, LC-ESI-MS/MS was utilized to characterize the metabolism of the precursor proanthocyanidins. Healthy microbiomes metabolized procyanidin A2, procyanidin B2, and procyanidin dimeric intermediates but not A-type trimers, to a greater extent than UC microbiomes. The metabolism of procyanidin A2 and procyanidin B2 by fecal microorganisms was then compared to identify their derived phenolic acid metabolites. 5-(3',4'-Dihydroxyphenyl)-g-valerolactone and 3-hydroxyphenylacetic acid were identified as unique metabolites of procyanidin B2. Based on these results, the metabolism of procyanidin B2 contributed to the differential metabolism observed between healthy and UC microbiomes.

Synergistic ultrasound pulsed electric field extraction of litchi peel polyphenols and determination of their properties

The effects of pulsed electric field combined with ultrasound (PEF-US) on the recovery of polyphenols from litchi peels were investigated. In addition, the optimal purification parameters for polyphenol extracts and their biological activities were also explored in this study. Single-factor and orthogonal experiments were used to optimize the extraction conditions of polyphenols. After optimization, the total phenol content (TPC) of the sample extracted by PEF-US was 2.30 times higher than that of the sample extracted by traditional hot-water extraction. The mechanism of PEF-US enhancing polyphenol recovery was also revealed by morphological analysis of the powder surface. LX-7 was the best resin by comparing the purification effect of nine macroporous resins. The optimum conditions for purification of litchi peel polyphenols by LX-7 resin were also optimized through adsorption and desorption experiments. UHPLC-MS and HPLC results revealed that gentisic acid, catechin, procyanidin A2 and procyanidin B1 are four main substances in purified samples. The results of bioactivity experiments showed that the purified polyphenol samples had strong antioxidant and antibacterial activity. Overall, PEF-US is an efficient method for recovering polyphenols from litchi peels. Our study also provides a strategy for the comprehensive utilization of fruit processing waste.

Mathematical modeling of fluid dynamics in invitro gut fermentation systems: A new tool to improve the interpretation of microbial metabolism.

In vitro systems are widely employed to assess the impact of dietary compounds on the gut microbiota and their conversion into beneficial bacterial metabolites. However, the complex fluid dynamics and multi-segmented nature of these systems can complicate the comprehensive analysis of dietary compound fate, potentially confounding physical dilution or washout with microbial catabolism. In this study, we developed fluid dynamics models based on sets of ordinary differential equations to simulate the behavior of an inert compound within two commonly used invitro systems: the continuous two-stage PolyFermS system and the semi-continuous multi-segmented SHIME® system as well as into various declinations of those systems. The models were validated by investigating the fate of blue dextran, demonstrating excellent agreement between experimental and modeling data (with r2 values ranging from 0.996 to 0.86 for different approaches). As a proof of concept for the utility of fluid dynamics models in invitro system, we applied generated models to interpret metabolomic data of procyanidin A2 (ProA2) generated from the addition of proanthocyanidin (PAC)-rich cranberry extract to both the PolyFermS and SHIME® systems. The results suggested ProA2 degradation by the gut microbiota when compared to the modeling of an inert compound. Models of fluid dynamics developed in this study provide a foundation for comprehensive analysis of gut metabolic data in commonly utilized invitro PolyFermS and SHIME® bioreactor systems and can enable a more accurate understanding of the contribution of bacterial metabolism to the variability in the concentration of target metabolites.

Metabolomics investigation of the chemical variations in white teas with different producing areas and storage durations

In this study, we employed nontargeted metabolomics and quantitative analysis to explore the variations in metabolites among white teas from different production areas and with varying storage durations. A total of 83 compounds exhibited differential levels between Zhenghe and Fuding white tea, 89 between Zhenghe and Jinggu, and 75 between Fuding and Jinggu white tea. Concerning the storage of white tea, the concentrations of flavanols, dimeric catechins, and amino acids decreased over time, while N-ethyl-2-pyrrolidone-substituted flavanols (EPSFs), caffeine, adenosine monophosphate (AMP), and adenosine increased. Galloylated flavanols showed a higher propensity to form EPSFs with theanine compared to nongalloylated flavanols during storage. Theanine and epigallocatechin gallate were more inclined to generate S-configuration EPSFs during storage in Fuding and Jinggu white tea samples, while R-configuration EPSFs were more readily formed in Zhenghe white tea samples. This study offers a comprehensive understanding of the changes in metabolites during the storage of white tea.