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Hydrolysed tannins (HTs) are polyphenols, which are related to the astringency, flavour, colour, stability, medicinal value and other characteristics of many fruits and vegetables. The biosynthetic mechanism of the majority of HTs remains unknown, and many biosynthetic pathways of HTs are speculative conclusions that have not been confirmed. The fruit of Canarium album L. (Chinese olive), which is notable for its pharmacological and edible properties, is rich in HTs. The fruit has a distinctive bitter and astringent taste when initially consumed, which mellows to a sweet sensation upon chewing. HTs serve as the primary material basis for the formation of the Chinese olive fruit's astringent quality and pharmacological effects. In this study, the fruit of C. album Changying was utilised as the research material. The objective of this study was to provide a theoretical basis for the quality control of Chinese olive fruit and the application and development of its medicinal value. In addition, the study aimed to identify and screen related MYB transcription factors involved in the synthesis of HTs in the fruit and to clarify the mechanism of MYBs in the process of synthesis and regulation of HTs in Chinese olive fruit. The principal findings were as follows. A total of 83 differentially expressed Chinese olive MYB transcription factors (CaMYBs) were identified, including 54 1R-MYBs (MYB-related), 25 2R-MYBs (R2R3-MYBs), 3 3R-MYBs, and 1 4R-MYB. Through trend analysis and correlation analysis, it was found that CaMYBR04 (Isoform0032534) exhibited a significantly higher expression (FPKM) than the other CaMYBs. The full-length cDNA sequence of CaMYBR04 was cloned and transformed into strawberry. The results demonstrated that CaMYBR04 significantly enhanced the fruit's hydrolysable tannin content. Consequently, this study elucidated the function of CaMYBR04, a regulator of the Chinese olive fruit hydrolysable tannin synthesis pathway, and established a theoretical foundation for the synthesis and regulation of fruit HTs. [ABSTRACT FROM AUTHOR]

This paper explores the emerging subject of extracting tannins from various plant sources using deep eutectic solvents (DESs). Tannins are widely used in the food and feed industries as they have outstanding antioxidant qualities and greatly enhance the flavor and nutritional content of a wide range of food products. Organic solvents are frequently used in traditional extraction techniques, which raises questions about their safety for human health and the environment. DESs present a prospective substitute because of their low toxicity, adaptability, and environmental friendliness. The fundamental ideas supporting the application of DESs in the extraction of tannins from a range of plant-based materials frequently used in daily life are all well covered in this paper. Furthermore, this paper covers the impact of extraction parameters on the yield of extracted tannins, as well as possible obstacles and directions for future research in this emerging subject. This includes challenges such as high viscosity, intricated recovery of compounds, thermal degradation, and the occurrence of esterification. An extensive summary of the diversity, structure, biosynthesis, distribution, and roles of tannins in plants is given in this paper. Additionally, this paper thoroughly examines various bioactivities of tannins and their metabolites. [ABSTRACT FROM AUTHOR]

Persian gum (PG) is a novel natural exudate gum and the main challenge regarding PG is tannin content of gum which limits its application in food and pharmaceutical industries. In fact, tannins are known as anti-nutrient compounds because they limit bioavailability of proteins and minerals. Hence, in this study, the effect of microwave radiation (180, 450, 600 W for 5 min), autoclaving (121 °C for 20 min), boiling (5, 10 and 15 min) and soaking either in water or saline solutions (mono- and divalent salts) was evaluated to remove tannins from Persian gum. Moreover, the effect of tannin removal on the physicochemical properties was investigated by evaluation of rheological properties (flow behavior and viscoelastic tests), zeta potential and Fourier transform infrared spectroscopy (FTIR) data. Our outcomes demonstrated that the highest tannin removal efficiency found to be 75.67 ± 0.25, 74.32 ± 0.54 and 67.08 ± 0.19 % which belonged to soaking in water (180 min), soaking in CaCl2 solution (1% w/v, 90 min) and boiling (15 min) treatments of brownish PG granules, respectively (p < 0.05). Interestingly, removal of tannin increased apparent viscosity of PG dispersion. Based on oscillatory tests, boiling treatment caused exhibition of solid-like behavior, in contrast to control sample. Tannin removal reduced zeta potential and the lowest reduction belonged to the gums soaked in water (from -32.3 to -28.7 mV); however, formation of ion-bridging in the presence of CaCl2 caused a remarkable decrease. FTIR analysis declared that in the boiled sample, a decrease was detected in vibration intensity within the range of 3200–3500 cm−1 (-OH groups) which can be due to heat degradation. Findings of the present research confirmed that soaking in water is a low-cost and practical method for tannin removal of PG, which almost had no negative effect on physiochemical properties of gum.

Polyphenols play a crucial role in fruit flavor. To elucidate the mechanism of fruit polyphenol metabolism, we constructed a transcriptome atlas through PacBio single-molecule real-time (SMRT) sequencing and Illumina next-generation sequencing (NGS) using Canarium album (Lour.) Raeusch., which is a fantastic fruit rich in polyphenolic compounds. In this work, PacBio full-length transcriptome assembly generated 135,439 isoforms with an average length of all isoforms of 2687.94 bp and an N50 length of 3224 bp. To gain deeper insights into the molecular mechanisms of polyphenol biosynthesis in C. album, we constructed twelve RNA-Seq libraries from four developmental stages of the fruits. We identified a total of 28,658 differentially expressed genes (DEGs). We found that many DEGs were involved in metabolic pathways, biosynthesis of secondary metabolites, biosynthesis of antibiotics, starch and sucrose metabolism, and plant hormone signal transduction. Here, we report the expression profiles of 215 DEGs encoding 27 enzymes involved in the polyphenol biosynthesis pathway in C. album. In addition, 285 differentially expressed transcription factors (TFs) continuously down-regulated in four developmental periods of C. album fruit, which may indicate their potential role in the response to polyphenol metabolism and phenylpropanoid biosynthesis pathways. This report will help us understand polyphenol biosynthesis's functions and metabolic mechanism in C. album. The transcriptome data provide a valuable resource for genetic and genomics research. They will facilitate future work exploiting C. album and other fruits used as medicine and food. [ABSTRACT FROM AUTHOR]

We aimed to study the obtention of valuable phenolic compounds from tissue by-products of agro-industrial processing of apple (GS) and strawberry (RF) using green solvents and Soxhlet extraction methodology. The effects of solvent type [water (W); 80% ethanol, (EtOH)] and extraction ratio (1:10, 1:20, 1:30, and 1:40 p/v) were determined on total phenolic content (TPC), antioxidant capacity (DPPH), and the profile of phenolic compounds of the GS and RF extracts. The solvent type and the extraction ratio significantly affected TPC and DPPH of GS and RF extracts. Extraction with EtOH and 1:40 ratio produced the highest yields, obtaining an RF extract with 15.8 g GAE/Kg (TPC) and 19 mmol TE/Kg (DPPH). The tetra-galloyl glucose isomer and agrimoniin (0.8-0.4 g/Kg) were the main RF phenolic compounds of the eight identified. GS extract, obtained with EtOH and 1:40 ratio, had 11.9 g GAE/Kg (TPC) and 20.5 mmol TE/Kg (DPPH), having quercetin -3-o-glucuronide (0.43 g/Kg) the highest concentration among the eight phenolic compounds identified. The results highlight the potential of green solvents to obtain valuable compounds from low-cost raw materials, like the high-antioxidant capacity phenolic compound extracts obtained herein. Highlights: • Valuable bioactive compounds can be extracted from strawberry and apple agro-industrial waste. • Extraction parameters affected phenolic compound profile and antioxidant capacity. • Apple and strawberry by-products are low-cost sources of hydrolysable tannins and flavonols. • Green solvents used for biowaste valorisation can help in circular economy transformation.

The leaves of Eucalyptus are abundant in natural resources as a novel potential antioxidant and have broad market prospect. Four of characteristic hydrolysable tannins from Eucalyptus leaves have been demonstrated great application potential as natural antioxidants in our previous research. In this study, the bioactive activities of another hydrolysable tannin isolated and identified as oenothein B (OEB) were evaluated. Content of bioactive compound (hydrolysable tannin) from different Eucalyptus species and regions in southern China were investigated. The results showed that OEB not only exerted anti-proliferative activity against HepG2 cell, but also showed higher cellular antioxidant activity than some common antioxidants. Generally, content of characteristic hydrolysable tannins decreased in the order of OEB > tellimagrandin Ⅰ (T1) > pedunculagin > gemin D > pentagalloyl glucose (PGG). E. grandis × E. urophylla GL9 and E. urophylla × E. grandis could be recommended as new natural sources to exploit hydrolysable tannins because of high content, widely plantation and strong adaptability. This study supplied first insight on introduction of high cellular antioxidant activity of OEB and selecting the species and region to exploit natural antioxidants. It will promote the increasing of economic value of Eucalyptus.

In our search for bioactive components, various chromatographic separations of the organic fractions from Filipendula glaberrima leaves led to the isolation of a new ellagitannin and a triterpenoid, along with 26 known compounds. The structures of the isolates were determined based on their spectroscopic properties and chemical evidence, which were then evaluated for their antioxidant activities, inhibitory activities on 3-hydroxy-3-methylglutaryl-coenzyme A reductase, and foam cell formation in THP-1 cells to prevent atherosclerosis. Rugosin B methyl ester (1) showed the best HMG-CoA reductase inhibition and significantly reduced ox-low-density lipoprotein-induced THP-1 macrophage-derived foam cell formation at 25 µM. In addition, no cytotoxicity was observed in THP-1 cells at 50 μg/mL of all extracts in the macrophage foam cell formation assay. Therefore, F. glaberrima extract containing 1 is promising in the development of dietary supplements due to its potential behavior as a novel source of nutrients for preventing and treating atherosclerosis. [ABSTRACT FROM AUTHOR]

We aimed to study the obtention of valuable phenolic compounds from tissue by-products of agro-industrial processing of apple (GS) and strawberry (RF) using green solvents and Soxhlet extraction methodology. The effects of solvent type [water (W); 80% ethanol, (EtOH)] and extraction ratio (1:10, 1:20, 1:30, and 1:40 p/v) were determined on total phenolic content (TPC), antioxidant capacity (DPPH), and the profile of phenolic compounds of the GS and RF extracts. The solvent type and the extraction ratio significantly affected TPC and DPPH of GS and RF extracts. Extraction with EtOH and 1:40 ratio produced the highest yields, obtaining an RF extract with 15.8 g GAE/Kg (TPC) and 19 mmol TE/Kg (DPPH). The tetra-galloyl glucose isomer and agrimoniin (0.8-0.4 g/Kg) were the main RF phenolic compounds of the eight identified. GS extract, obtained with EtOH and 1:40 ratio, had 11.9 g GAE/Kg (TPC) and 20.5 mmol TE/Kg (DPPH), having quercetin -3-o-glucuronide (0.43 g/Kg) the highest concentration among the eight phenolic compounds identified. The results highlight the potential of green solvents to obtain valuable compounds from low-cost raw materials, like the high-antioxidant capacity phenolic compound extracts obtained herein. [ABSTRACT FROM AUTHOR]

The escalation of many coronavirus variants accompanied by the lack of an effective cure has motivated the hunt for effective antiviral medicines. In this regard, 18 Saudi Arabian medicinal plants were evaluated for SARS CoV-2 main protease (Mpro) inhibition activity. Among them, Terminalia brownii and Acacia asak alcoholic extracts exhibited significant Mpro inhibition, with inhibition rates of 95.3 % and 95.2 %, respectively, at a concentration of 100 µg/mL. Bioassay-guided phytochemical study for the most active n-butanol fraction of T. brownii led to identification of eleven compounds, including two phenolic acids (1, and 2), seven hydrolysable tannins (3–10), and one flavonoid (11) as well as four flavonoids from A. asak (12–15). The structures of the isolated compounds were established using various spectroscopic techniques and comparison with known compounds. To investigate the chemical interactions between the identified compounds and the target Mpro protein, molecular docking was performed using AutoDock 4.2. The findings identified compounds 4, 5, 10, and 14 as the most potential inhibitors of Mpro with binding energies of −9.3, −8.5, −8.1, and −7.8 kcal mol−1, respectively. In order to assess the stability of the protein–ligand complexes, molecular dynamics simulations were conducted for a duration of 100 ns, and various parameters such as RMSD, RMSF, Rg, and SASA were evaluated. All selected compounds 4, 5, 10, and 14 showed considerable Mpro inhibiting activity in vitro, with compound 4 being the most powerful with an IC50 value of 1.2 µg/mL. MM-GBSA free energy calculations also revealed compound 4 as the most powerful Mpro inhibitor. None of the compounds (4, 5, 10, and 14) display any significant cytotoxic activity against A549 and HUVEC cell lines.

UV‑C treatment is a non-thermal technology that could be used for the microbiological stabilisation of must and wine. However, light - in this case UV‑C light - has an impact on wine. UV‑C is a high-energy light source and can promote photo-induced oxidation reactions. The formation of reactive oxygen species during the UV-C treatment of wine can be prevented via supplementation with antioxidants. These have the ability to neutralise reactive oxygen species or directly interact with the products of photo-induced oxidation reactions. This study investigates the impact of different UV‑C doses on the chemical and sensory characteristics of Chardonnay wine and examines the protective effect of two antioxidants: sulphur dioxide (SO2) and hydrolysable tannins. A sensory evaluation revealed that UV‑C doses higher than 1 kJ/l increased the colour intensity and the oxidised and burnt odour attributes of the wine. The peach odour attribute decreased with UV‑C treatment. On a chemical level, increasing UV‑C doses promoted the formation of compounds such as acetaldehyde and 2‑aminoacetophenone (2‑AAP), while causing the degradation of C13‑norisoprenoids, higher alcohols, monoterpenes and esters. Contrary to expectations, SO2 did not act as an antioxidant when wine was treated with UV-C. It intensified the burnt odour attribute and did not mitigate the intensity of the oxidised odour attribute, which can be explained by the formation of acetaldehyde. However, hydrolysable tannins acted as antioxidants when combined with UV‑C treatment, effectively mitigating the formation of 2‑AAP and acetaldehyde, while preventing the wine from becoming oxidised.

Introduction. Acca sellowiana, or feijoa belongs to the Myrtaceae family and it is an evergreen shrub or small tree 4–6 meters high. The phytochemical composition has been most thoroughly studied in the fruits of A. sellowiana. It has been shown that feijoa is rich in phenolic acids, hydrolysable and condensed tannins, steroidal saponins, and flavonoids. Hydrolysable tannins are known to have high biological activity.Aim. To study the composition and content of hydrolysable tannins in the leaves of A. sellowiana.Materials and methods. Ultra-high performance liquid chromatography coupled with diode array detection and mass spectrometry.Results and discussion. The results obtained showed the presence of 22 phenolic compounds in the extract of the A. sellowiana leaves. They have been classified as flavan-3-ols, flavonoids and hydrolysable tannins. Two compounds could not be identified. The total content of hydrolysable tannins was 44,28 mg/g (90 % of the total phenolic content). At the same time, ellagitannins were the main phenolic compounds of the extract (40,47 mg/g), while the amount of galloyl-glucose was only 3,81 mg/g.Conclusions. Composition and content of hydrolysable tannins in the leaves of A. sellowiana introduced in the greenhouse of VILAR have been studied. The leaves accumulate mainly monomeric ellagitannins represented 92 % of the total content of hydrolysable tannins. The data obtained indicate that the leaves of A. sellowiana can be used as a raw material for obtaining extracts with a high content of ellagitannins and developing drugs based on them.

Hydrolysed tannins (HTs) are polyphenols, which are related to the astringency, flavour, colour, stability, medicinal value and other characteristics of many fruits and vegetables. The biosynthetic mechanism of the majority of HTs remains unknown, and many biosynthetic pathways of HTs are speculative conclusions that have not been confirmed. The fruit of Canarium album L. (Chinese olive), which is notable for its pharmacological and edible properties, is rich in HTs. The fruit has a distinctive bitter and astringent taste when initially consumed, which mellows to a sweet sensation upon chewing. HTs serve as the primary material basis for the formation of the Chinese olive fruit’s astringent quality and pharmacological effects. In this study, the fruit of C. album Changying was utilised as the research material. The objective of this study was to provide a theoretical basis for the quality control of Chinese olive fruit and the application and development of its medicinal value. In addition, the study aimed to identify and screen related MYB transcription factors involved in the synthesis of HTs in the fruit and to clarify the mechanism of MYBs in the process of synthesis and regulation of HTs in Chinese olive fruit. The principal findings were as follows. A total of 83 differentially expressed Chinese olive MYB transcription factors (CaMYBs) were identified, including 54 1R-MYBs (MYB-related), 25 2R-MYBs (R2R3-MYBs), 3 3R-MYBs, and 1 4R-MYB. Through trend analysis and correlation analysis, it was found that CaMYBR04 (Isoform0032534) exhibited a significantly higher expression (FPKM) than the other CaMYBs. The full-length cDNA sequence of CaMYBR04 was cloned and transformed into strawberry. The results demonstrated that CaMYBR04 significantly enhanced the fruit’s hydrolysable tannin content. Consequently, this study elucidated the function of CaMYBR04, a regulator of the Chinese olive fruit hydrolysable tannin synthesis pathway, and established a theoretical foundation for the synthesis and regulation of fruit HTs.

In this study, we present data on the effects of condensed tannins (CTs) and hydrolysable tannins (HTs), polyphenols extracted from plants, at different concentrations on zebrafish development to identify the range of concentrations with toxic effects. Zebrafish embryos were exposed to CTs and HTs at two different concentration ranges (5.0–20.0 μgL−1 and 5.0–20.0 mgL−1) for 72 h. The toxicity parameters were observed up to 72 h of treatment. The uptake of CTs and HTs by the zebrafish larvae was assessed via HPLC analysis. A qRT-PCR analysis was performed to evaluate the expressions of genes cd63, zhe1, and klf4, involved in the hatching process of zebrafish. CTs and HTs at 5.0, 10.0, and 20.0 μgL−1 were not toxic. On the contrary, at 5.0, 10.0, and 20.0 mgL−1, HTs induced a delay in hatching starting from 48 h of treatment, while CTs showed a delay in hatching mainly at 48 h. The analysis of gene expression showed a downregulation in the group exposed to HTs, confirming the hatching data. We believe that this study is important for defining the optimal doses of CTs and HTs to be employed in different application fields such as the chemical industry, the animal feed industry, and medical science.

This paper explores the emerging subject of extracting tannins from various plant sources using deep eutectic solvents (DESs). Tannins are widely used in the food and feed industries as they have outstanding antioxidant qualities and greatly enhance the flavor and nutritional content of a wide range of food products. Organic solvents are frequently used in traditional extraction techniques, which raises questions about their safety for human health and the environment. DESs present a prospective substitute because of their low toxicity, adaptability, and environmental friendliness. The fundamental ideas supporting the application of DESs in the extraction of tannins from a range of plant-based materials frequently used in daily life are all well covered in this paper. Furthermore, this paper covers the impact of extraction parameters on the yield of extracted tannins, as well as possible obstacles and directions for future research in this emerging subject. This includes challenges such as high viscosity, intricated recovery of compounds, thermal degradation, and the occurrence of esterification. An extensive summary of the diversity, structure, biosynthesis, distribution, and roles of tannins in plants is given in this paper. Additionally, this paper thoroughly examines various bioactivities of tannins and their metabolites.

Abstract This study aimed to identify and classify the type of plants used for tanning historical leathers using cost-effective Fourier transform infrared (FTIR) spectroscopy. The investigation was carried out on five plants (oak bark, sumac, valonia, tara, and gallnut) and four historical leather samples from book bindings dating back to the Qajar period. Tannin extraction from both plants and leathers was performed using acetone–water solvent, and the samples were then subjected to FTIR spectroscopy. Pre-processing of the spectra included baseline correction, smoothing, and normalization. Principal component analysis (PCA) was used to identify the source of tannins based on FTIR results. FTIR was found to provide a good separation of condensed tannins from hydrolysable ones. However, PCA analysis allowed for the separation and identification of the type of plant used for tannin extraction. The examination of historical leather samples revealed that the primary classification based on the type of tannin is possible, but accurate identification faces challenges due to structural changes and degradation over time. Graphical abstract

Cascalote pods are an important source of phenolic compounds, mainly recovered using solvent extraction methods. To find a sustainable alternative to these methods, this study aimed to evaluate solid-state fermentation (SSF) in order to enhance the extractability of total phenolic compounds (TPC) with antioxidant activity (AA) from cascalote pods. Aspergillus niger GH1 was selected based on the amount of TPC released and AA measured (ABTS, DPPH, FRAP) in a short period of time. Moreover, moisture, temperature, inoculum size, and mineral composition were evaluated. The largest amount of TPC released was 124.17 mg/gdw (g of dry weight) after 12 h of culture, which significantly correlated with the AA (Pearson's R = 0.94). Moisture and KH2PO4 concentration were the main influencing factors of TPC release. Treatment 6 (1 × 107 spores/gdw, 30 °C, 60% moisture, mineral composition (g/L): KH2PO4, 1.52; NaNO3, 7.65; and MgSO4, 1.52) was selected due to the highest values of both TPC and AA. SSF-assisted extraction allowed for an increase of 118% and 93% in TPC and AA values, respectively. Corilagin, lagerstannin, geraniin, and ellagic acid were the main phenolic compounds identified by RP-HPLC-ESI-MS in the cascalote extracts. The results obtained demonstrate the feasibility of SSF-assisted extraction as a biotechnological alternative for the recovery of important bioactive molecules from this underutilized material. [ABSTRACT FROM AUTHOR]

Polyphenols play a crucial role in fruit flavor. To elucidate the mechanism of fruit polyphenol metabolism, we constructed a transcriptome atlas through PacBio single-molecule real-time (SMRT) sequencing and Illumina next-generation sequencing (NGS) using Canarium album (Lour.) Raeusch., which is a fantastic fruit rich in polyphenolic compounds. In this work, PacBio full-length transcriptome assembly generated 135,439 isoforms with an average length of all isoforms of 2687.94 bp and an N50 length of 3224 bp. To gain deeper insights into the molecular mechanisms of polyphenol biosynthesis in C. album, we constructed twelve RNA-Seq libraries from four developmental stages of the fruits. We identified a total of 28,658 differentially expressed genes (DEGs). We found that many DEGs were involved in metabolic pathways, biosynthesis of secondary metabolites, biosynthesis of antibiotics, starch and sucrose metabolism, and plant hormone signal transduction. Here, we report the expression profiles of 215 DEGs encoding 27 enzymes involved in the polyphenol biosynthesis pathway in C. album. In addition, 285 differentially expressed transcription factors (TFs) continuously down-regulated in four developmental periods of C. album fruit, which may indicate their potential role in the response to polyphenol metabolism and phenylpropanoid biosynthesis pathways. This report will help us understand polyphenol biosynthesis’s functions and metabolic mechanism in C. album. The transcriptome data provide a valuable resource for genetic and genomics research. They will facilitate future work exploiting C. album and other fruits used as medicine and food.

This study aimed to identify and classify the type of plants used for tanning historical leathers using cost-effective Fourier transform infrared (FTIR) spectroscopy. The investigation was carried out on five plants (oak bark, sumac, valonia, tara, and gallnut) and four historical leather samples from book bindings dating back to the Qajar period. Tannin extraction from both plants and leathers was performed using acetone–water solvent, and the samples were then subjected to FTIR spectroscopy. Pre-processing of the spectra included baseline correction, smoothing, and normalization. Principal component analysis (PCA) was used to identify the source of tannins based on FTIR results. FTIR was found to provide a good separation of condensed tannins from hydrolysable ones. However, PCA analysis allowed for the separation and identification of the type of plant used for tannin extraction. The examination of historical leather samples revealed that the primary classification based on the type of tannin is possible, but accurate identification faces challenges due to structural changes and degradation over time. [ABSTRACT FROM AUTHOR]

BACKGROUND:The outer peels of pomegranate (Punica granatum L.) possess two groups of polyphenols that have health beneficial properties: anthocyanins (ATs, which also affect peel color); and hydrolysable tannins (HTs). Their biosynthesis intersects at 3-dehydroshikimate (3-DHS) in the shikimate pathway by the activity of shikimate dehydrogenase (SDH), which converts 3-DHS to shikimate (providing the precursor for AT biosynthesis) or to gallic acid (the precursor for HTs biosynthesis) using NADPH or NADP+ as a cofactor. The aim of this study is to gain more knowledge about the factors that regulate the levels of HTs and ATs, and the role of SDH. RESULTS:The results have shown that the levels of ATs and HTs are negatively correlated in the outer fruit peels of 33 pomegranate accessions, in the outer peels of two fruits exposed to sunlight, and in those covered by paper bags. When calli obtained from the outer fruit peel were subjected to light/dark treatment and osmotic stresses (imposed by different sucrose concentrations), it was shown that light with high sucrose promotes the synthesis of ATs, while dark at the same sucrose concentration promotes the synthesis of HTs. To verify the role of SDH, six PgSDHs (PgSDH1, PgSDH3-1,2, PgSDH3a-1,2 and PgSDH4) were identified in pomegranate. The expression of PgSDH1, which presumably contributes to shikimate biosynthesis, was relatively constant at different sucrose concentrations. However, the transcript levels of PgSDH3s and PgSDH4 increased with the accumulation of gallic acid and HTs under osmotic stress, which apparently accumulates to protect the cells from the stress. CONCLUSIONS:The results strongly suggest that the biosynthesis of HTs and ATs competes for the same substrate, 3-DHS, and that SDH activity is regulated not only by the NADPH/NADP+ ratio, but also by the expression of the PgSDHs. Since the outer peel affects the customer's decision regarding fruit consumption, such knowledge could be utilized for the development of new genetic markers for breeding pomegranates having higher levels of both ATs and HTs.

Simple Summary: The European pig industry needs to adapt to growing social interest regarding animal welfare. One of these concerns is the surgical castration of male piglets—a common practice primarily performed to avoid the risk of boar taint released from the meat of uncastrated males, especially during heat treatment. Several EU countries are trying to stop the surgical castration of pigs. The European Commission (EC) strongly supports these activities. One of the two currently feasible alternatives to the production of castrates is the fattening of entire male pigs. It is well known that skatole, one of two main compounds responsible for boar taint, can be eliminated or reduced by feeding additives. Recently, some promising results have been achieved using hydrolysable tannins in the diet of entire males. However, it should be mentioned that these studies focused on the influence of tannins on fattening, carcass value, meat quality and the deposition of androstenone and skatole in adipose tissue but not their influence on sensory characteristics. Therefore, the objective of this study was, in addition to determining the effects of tannins on skatole and androstenone accumulation in fatty tissue, to assess the sensory attributes of pork from entire males after supplementation of the diet with 1–4% tannins. The results showed that 2–4% supplementation of tannins in the feed reduced the accumulation of skatole in fatty tissue. The odour and flavour of pork were not influenced by tannin supplementation, but higher doses of tannins decreased the juiciness and tenderness of pork from entire males but only in men's evaluation. The effect of the sex of the panellists on both of these sensory traits was observed in both the control and tannin-supplemented groups. Boar taint is an unpleasant odour and flavour released during heat treatment of pork from uncastrated male pigs. The two main compounds responsible for boar taint are androstenone and skatole. Androstenone is a steroid hormone formed in the testis during sexual maturity. Skatole is a product of microbial degradation of the amino acid tryptophan in the hindgut of pigs. Both of these compounds are lipophilic, which means that they can be deposited in adipose tissue. Several studies have reported heritability estimates for their deposition from medium (skatole) to high magnitudes (androstenone). In addition to efforts to influence boar taint through genetic selection, much attention has also been paid to reducing its incidence using various feeding strategies. From this point of view, research has focused especially on the reduction in skatole content by supplementation of feed additives into the nutrition of entire male pigs. Promising results have been achieved using hydrolysable tannins in the diet. To date, most studies have investigated the effects of tannins on the production and accumulation of skatole in adipose tissue, intestinal microbiota, growth rate, carcasses and pork quality. Thus, the objective of this study was, in addition to determining the effects of tannins on androstenone and skatole accumulation, to assess the effects of tannins on the sensory traits of meat from entire males. The experiment was performed on 80 young boars—progeny of several hybrid sire lines. Animals were randomly assigned to one control and four experimental groups (each numbering 16). The control group (T0) received a standard diet without any tannin supplementation. Experimental groups were supplemented with 1% (T1), 2% (T2), 3% (T3) or 4% (T4) SCWE (sweet chestnut wood extract) rich in hydrolysable tannins (Farmatan). Pigs received this supplement for 40 days prior to slaughter. Subsequently, the pigs were slaughtered, and sensory analysis was applied to evaluate the odour, flavour, tenderness and juiciness of the pork. The results showed a significant effect of tannins on skatole accumulation in adipose tissue (p = 0.052–0.055). The odour and flavour of the pork were not affected by tannins. However, juiciness and tenderness were reduced by higher tannin supplementation (T3–T4) compared to the controls (p < 0.05), but these results were sex-dependent (in favour of men compared to women). Generally, women rated tenderness and juiciness worse than men regardless of the type of diet. [ABSTRACT FROM AUTHOR]

In our search for bioactive components, various chromatographic separations of the organic fractions from Filipendula glaberrima leaves led to the isolation of a new ellagitannin and a triterpenoid, along with 26 known compounds. The structures of the isolates were determined based on their spectroscopic properties and chemical evidence, which were then evaluated for their antioxidant activities, inhibitory activities on 3-hydroxy-3-methylglutaryl-coenzyme A reductase, and foam cell formation in THP-1 cells to prevent atherosclerosis. Rugosin B methyl ester (1) showed the best HMG-CoA reductase inhibition and significantly reduced ox-low-density lipoprotein-induced THP-1 macrophage-derived foam cell formation at 25 µM. In addition, no cytotoxicity was observed in THP-1 cells at 50 μg/mL of all extracts in the macrophage foam cell formation assay. Therefore, F. glaberrima extract containing 1 is promising in the development of dietary supplements due to its potential behavior as a novel source of nutrients for preventing and treating atherosclerosis.

Chinese seabass (Lateolabrax maculatus) is a popular carnivorous fish with delicious taste. Although the feed value of condensed tannins has been well documented for L. maculatus, information about the effects of hydrolyzable tannins (HTs) on the growth and health of L. maculatus is limited. This study was conducted to assess the effects of dietary HTs on growth performance, body composition, intestinal digestive enzyme activities, serum metabolites, antioxidant and immune response, and intestine and liver morphology of L. maculatus. A total of 640 fish were randomly divided into four groups with four replicates per group and 40 fish per replicate. Four diets were prepared to contain 0 (G0), 1 (G1), 2 (G2), and 4 (G4) g/kg of HTs. Fish were fed to apparent satiation twice a day during the 56-day feeding trial. Results showed that the final body weight, weight gain rate, specific growth rate, and feed intake were linearly decreased (p< 0.001) as dietary HTs increased. All fish had similar (p > 0.05) whole body compositions. Fish fed G2 and G4 had lower (p< 0.05) intestinal trypsin and lipase activities than those fed G0 and G1, whereas G4 had higher (p< 0.05) aspartate aminotransferase and alanine aminotransferase activities than G0. Serum total antioxidant capacity and lysozyme were linearly decreased (p< 0.01), but the malondialdehyde concentration was linearly increased (p< 0.01) as dietary HTs increased. Intestinal villi in G2 and G4 showed increased deformation, and the vacuolation of liver cells began to appear in G1 and was aggravated as dietary HTs increased. This study showed that HTs should be used with caution due to their growth-inhibiting effect, and the dietary HT level for L. maculatus is recommended to be less than 1 g/kg.

Both condensed and hydrolysable tannins (CTs and HTs, respectively) have the ability to reduce enteric CH4 production in ruminants. However, the precise mechanism of action is not fully understood. Among the proposed hypotheses are the reduction of ruminal digestibility, direct control action on protozoa, reduction of archaea, and a hydrogen sink mechanism. In this in vitro study, which simulated rumen fermentation, two additives, one containing CTs (70% based on DM) from quebracho and one with HTs (75% based on DM) from chestnut, at four levels of inclusion (2, 4, 6, 8% on an as-fed basis) were added to the fermentation substrate and tested against a negative control. Both types of tannins significantly reduced total gas (GP) and CH4 (ml/g DM) production during the 48 h of incubation. The lower GP and CH4 production levels were linked to the reduction in dry matter digestibility caused by CTs and HTs. Conversely, no significant differences were observed for the protozoan and archaeal populations, suggesting a low direct effect of tannins on these rumen microorganisms in vitro. However, both types of tannins had negative correlations for the families Bacteroidales_BS11 and F082 and positive correlations for the genera Prevotella and Succinivibrio. Regarding the fermentation parameters, no differences were observed for pH and total volatile fatty acid production, while both CTs and HTs linearly reduced the NH3 content. CTs from quebracho were more effective in reducing CH4 production than HTs from chestnut. However, for both types of tannins, the reduction in CH4 production was always associated with a lower digestibility without any changes in archaea or protozoa. Due to the high variability of tannins, further studies investigating the chemical structure of the compounds and their mechanisms of action are needed to understand the different results reported in the literature.

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Cascalote pods are an important source of phenolic compounds, mainly recovered using solvent extraction methods. To find a sustainable alternative to these methods, this study aimed to evaluate solid-state fermentation (SSF) in order to enhance the extractability of total phenolic compounds (TPC) with antioxidant activity (AA) from cascalote pods. Aspergillus niger GH1 was selected based on the amount of TPC released and AA measured (ABTS, DPPH, FRAP) in a short period of time. Moreover, moisture, temperature, inoculum size, and mineral composition were evaluated. The largest amount of TPC released was 124.17 mg/gdw (g of dry weight) after 12 h of culture, which significantly correlated with the AA (Pearson’s R = 0.94). Moisture and KH2PO4 concentration were the main influencing factors of TPC release. Treatment 6 (1 × 107 spores/gdw, 30 °C, 60% moisture, mineral composition (g/L): KH2PO4, 1.52; NaNO3, 7.65; and MgSO4, 1.52) was selected due to the highest values of both TPC and AA. SSF-assisted extraction allowed for an increase of 118% and 93% in TPC and AA values, respectively. Corilagin, lagerstannin, geraniin, and ellagic acid were the main phenolic compounds identified by RP-HPLC-ESI-MS in the cascalote extracts. The results obtained demonstrate the feasibility of SSF-assisted extraction as a biotechnological alternative for the recovery of important bioactive molecules from this underutilized material.

Abstract The use of flours or phenolic extracts obtained from non-traditional sources or agri-food industry by-products has been a strategy used to formulate new bakery products with characteristics of a functional food. However, phenolic compounds present great structural diversity, as well as the ability to interact in a complex way with the macromolecules that constitute the bread matrix. Therefore, the addition of these flours, extracts or pure compounds produces various effects on the microstructure of bread, and several of its sensory properties. This is mainly due to interactions between phenolic compounds and gluten proteins. The objective of this review is to analyze some of the most recent published works on the addition of phenolic compounds in wheat bread to identify the type of positive and negative effects that have been observed and how they can be related to the physicochemical interactions between phenolic compounds and the macromolecules that constitute the food matrix, mainly gluten. The effect of monomeric and polymeric phenolic compounds on the strength of these interactions and on the properties of dough and bread are discussed. Graphical Abstract

Abstract The post-harvest processing of strawberries generates considerable amounts of by-products that consist of the inedible parts of the fruit (sepal, calyx, stem, and non-marketable portion of the fruit), which is an environmental problem for local producers and industries. This study aimed to revalue these kinds of tissues through identifying and quantifying the genotype influence on the total phenolic content, phenolic profile, and the antioxidant activity of the by-products from three strawberry cultivars: ‘Festival’ (FE), ‘San Andreas ‘ (SA), and ‘Camino Real’ (CR). The total phenolic content was determined by the Folin–Ciocalteu method, in-vitro antioxidant activity by the DPPH* radical scavenging method and the phenolic profile by PAD–HPLC. The different genotypes showed significant differences (p /Kg of by-product ), followed by SA and CR cultivars. The antioxidant capacity of the SA and FE tissues were similar (p > 0.05) and higher (15.1–16.3 mmol Trolox equivalents /Kg R) than CR. Eight main phenolic compounds were identified and quantified on the three cultivars. Agrimoniin was the principal polyphenol (0.38–1.56 g/Kg R), and the cultivar FE had the highest concentration. This compound showed the highest correlation coefficient with the antioxidant capacity (R 2 0.87; p

Condensed tannins in plants are found free and attached to protein and fibre but it is not known whether these fractions influence rumen degradation and microbial colonisation. This study explored the rumen degradation of tropical tannin-rich plants and the relationship between the disappearance of free and bound condensed tannin fractions and microbial communities colonising plant particles using in situ and in vitro experiments. Leaves from Calliandra calothyrsus, Gliricidia sepium, and Leucaena leucocephala, pods from Acacia nilotica and the leaves of two agricultural by-products: Manihot esculenta and Musa spp. were incubated in situ in the rumen of three dairy cows to determine their degradability for up to 96 h. Tannin disappearance was determined at 24 h of incubation, and adherent microbial communities were examined at 3 and 12 h of incubation using a metataxonomic approach. An in vitro approach was also used to assess the effects of these plants on rumen fermentation parameters. All plants contained more than 100 g/kg of condensed tannins with a large proportion (32–61%) bound to proteins. Calliandra calothyrsus had the highest concentration of condensed tannins at 361 g/kg, whereas Acacia nilotica was particularly rich in hydrolysable tannins (350 g/kg). Free condensed tannins from all plants completely disappeared after 24-h incubation in the rumen. Disappearance of protein-bound condensed tannins was variable with values ranging from 93% for Gliricidia sepium to 21% for Acacia nilotica. In contrast, fibre-bound condensed tannin disappearance averaged ∼ 82% and did not vary between plants. Disappearance of bound fractions of condensed tannins was not associated with the degradability of plant fractions. The presence of tannins interfered with the microbial colonisation of plants. Each plant had distinct bacterial and archaeal communities after 3 and 12 h of incubation in the rumen and distinct protozoal communities at 3 h. Adherent communities in tannin-rich plants had a lower relative abundance of fibrolytic microbes, notably Fibrobacter spp. whereas, archaea diversity was reduced in high-tannin-containing Calliandra calothyrsus and Acacia nilotica at 12 h of incubation. Concurrently, in vitro methane production was lower for Calliandra calothyrsus, Acacia nilotica and Leucaena leucocephala although for the latter total volatile fatty acids production was not affected and was similar to control. Here, we show that the total amount of hydrolysable and condensed tannins contained in a plant govern the interaction with rumen microbes affecting degradability and fermentation. The effect of protein- and fibre-bound condensed tannins on degradability is less important.

Boar taint is an unpleasant odour and flavour released during heat treatment of pork from uncastrated male pigs. The two main compounds responsible for boar taint are androstenone and skatole. Androstenone is a steroid hormone formed in the testis during sexual maturity. Skatole is a product of microbial degradation of the amino acid tryptophan in the hindgut of pigs. Both of these compounds are lipophilic, which means that they can be deposited in adipose tissue. Several studies have reported heritability estimates for their deposition from medium (skatole) to high magnitudes (androstenone). In addition to efforts to influence boar taint through genetic selection, much attention has also been paid to reducing its incidence using various feeding strategies. From this point of view, research has focused especially on the reduction in skatole content by supplementation of feed additives into the nutrition of entire male pigs. Promising results have been achieved using hydrolysable tannins in the diet. To date, most studies have investigated the effects of tannins on the production and accumulation of skatole in adipose tissue, intestinal microbiota, growth rate, carcasses and pork quality. Thus, the objective of this study was, in addition to determining the effects of tannins on androstenone and skatole accumulation, to assess the effects of tannins on the sensory traits of meat from entire males. The experiment was performed on 80 young boars—progeny of several hybrid sire lines. Animals were randomly assigned to one control and four experimental groups (each numbering 16). The control group (T0) received a standard diet without any tannin supplementation. Experimental groups were supplemented with 1% (T1), 2% (T2), 3% (T3) or 4% (T4) SCWE (sweet chestnut wood extract) rich in hydrolysable tannins (Farmatan). Pigs received this supplement for 40 days prior to slaughter. Subsequently, the pigs were slaughtered, and sensory analysis was applied to evaluate the odour, flavour, tenderness and juiciness of the pork. The results showed a significant effect of tannins on skatole accumulation in adipose tissue (p = 0.052–0.055). The odour and flavour of the pork were not affected by tannins. However, juiciness and tenderness were reduced by higher tannin supplementation (T3–T4) compared to the controls (p < 0.05), but these results were sex-dependent (in favour of men compared to women). Generally, women rated tenderness and juiciness worse than men regardless of the type of diet.

Syzygium cumini (Myrtaceae) is a tropical tree used in traditional medicines to treat several diseases. All parts of S. cumini are used for medicinal purposes and present antioxidant potential. In this study, we evaluated the phytochemical composition of the ethanolic extract of S. cumini leaves (EESC) and its biological activity in vitro and in vivo regarding some effects on the central nervous system. Behavioral tests of anxiety, depression, and memory were performed with mice and the cerebral cortex used to evaluate lipoperoxidation and the acetylcholinesterase activity ex vivo. The EESC showed the presence of flavonoids, tannins, and gallic acid esters-4-O-glucurosides, detected for the first time in the species. The EESC presented antioxidant capacity in vitro with EC 50 of 82.8 μg/mL in the DPPH assay and IC 50 of 1.27 μg/mL in the lipoperoxidation test. The EESC inhibited the in vitro acetylcholinesterase and monoamine oxidase activities presenting IC 50 of 44.54 and 432.7 μg/mL, respectively. However, the EESC did not show significant effects on the behavioral tests and ex vivo assays. Our results confirm the potential of EESC as a source of bioactive compounds acting on important target enzymes for central nervous system disorders, but the in vivo effects must be better evaluated. [Display omitted] • First identification of gallic acid ester-4-O-glucurosides in leaves of S. cumini. • A potent in vitro antioxidant capacity was demonstrated in brain homogenate. • S. cumini leaves extract presented a mild inhibitory effect on MAO activity. • The extract inhibited AChE activity in vitro but not ex vivo in mice's frontal cortex. [ABSTRACT FROM AUTHOR]

In this study, we present data on the effects of condensed tannins (CTs) and hydrolysable tannins (HTs), polyphenols extracted from plants, at different concentrations on zebrafish development to identify the range of concentrations with toxic effects. Zebrafish embryos were exposed to CTs and HTs at two different concentration ranges (5.0-20.0 μgL -1 and 5.0-20.0 mgL -1 ) for 72 h. The toxicity parameters were observed up to 72 h of treatment. The uptake of CTs and HTs by the zebrafish larvae was assessed via HPLC analysis. A qRT-PCR analysis was performed to evaluate the expressions of genes cd63 , zhe1 , and klf4 , involved in the hatching process of zebrafish. CTs and HTs at 5.0, 10.0, and 20.0 μgL -1 were not toxic. On the contrary, at 5.0, 10.0, and 20.0 mgL -1 , HTs induced a delay in hatching starting from 48 h of treatment, while CTs showed a delay in hatching mainly at 48 h. The analysis of gene expression showed a downregulation in the group exposed to HTs, confirming the hatching data. We believe that this study is important for defining the optimal doses of CTs and HTs to be employed in different application fields such as the chemical industry, the animal feed industry, and medical science.

Terminalia catappa and Terminalia subspathulata are two species of the Combretaceae family of medium to large forest trees. The fruits of T. catappa are known for the edible nuts commonly known as tropical almonds due to their similarity in taste with almonds of commerce. Therefore, the chemical profiles of the fruits of the two Terminalia species were examined to ascertain their potential value for food or health uses. Gas chromatographymass spectrometry (GCMS) and ultrahigh-pressure liquid chromatography-electrospray ionisation tandem mass spectrometry (UHPLC-ESI-MS/MS) techniques were employed to profile the extracts to ensure good coverage of the classes of metabolites of the fruit extracts. The GCMS results revealed that T. catappa nuts were rich in palmitic acid (33.2%), linoleoyl chloride (29.1%), and oxacyclohexadecan-2-one commonly known as pentadecanolide (16.2%). In comparison, the major constituents of T. subspathulata fruits were palmitic acid (18.1%) and its methyl ester, methyl palmitate (9.3%). Furthermore, a total of 38 compounds were putatively identified in the 70% aqueous methanolic extracts of both species via UHPLC-ESI-MS/MS analysis, comprising three organic acids, sixteen hydrolysable tannins, ten phenolic acids, eight flavonoids, and a diarylheptanoid. The GCMS- and liquid chromatography-mass spectrometry- (LCMS-) LCMS-based metabolite profiles obtained in the present study have revealed the diversity of chemical constituents in the T. catappa nuts and T. subspathulata fruits, potentially valorised as functional foods nutraceutical ingredients for plant-based health products. [ABSTRACT FROM AUTHOR]

ABSTRACT: The present study was conducted to evaluate the efficacy of the dietary inclusion of commercial hydrolysable tannins (HT) on the growth performance and haemato-immunological parameters of Pacific white shrimp (Litopenaeus vannamei). Four isonitrogenous and isolipidic practical diets were formulated to contain 0; 0,1; 0,2 and 0,3% of HT obtained from the sweet chestnut (Castanea sativa). The 0,3% HT was designed to be included in a diet with a low level of fish meal (FM) (7,5%), while others included 10% FM. A total of 240 post larvae shrimp with an average initial body weight of 4.24 ± 0,03 g were randomly stocked in four groups, with four replicates per treatment and 15 shrimp per aquaria tank. Results showed that there were no significant differences in terms of final biomass, final mean weight, survival, weight gain (WG), feed conversion ratio (FCR) and thermal growth coefficient (TGC). However, biologically, a better performance was observed when the diets had higher inclusion levels of HT. Shrimp fed diets with 0,2 and 0,3% HT had a significantly higher total haemocytes count, and those fed the diet with 0,2% HT also had a significantly higher lysozyme activity, compared to shrimp from the control group. These results indicated that 0,2 and 0,3% HT could remarkably improve the growth performance and the haemato-immunological parameters of Pacific white shrimp, and have potential functional properties when included in commercial diets for shrimp.

The post-harvest processing of strawberries generates considerable amounts of by-products that consist of the inedible parts of the fruit (sepal, calyx, stem, and non-marketable portion of the fruit), which is an environmental problem for local producers and industries. This study aimed to revalue these kinds of tissues through identifying and quantifying the genotype influence on the total phenolic content, phenolic profile, and the antioxidant activity of the by-products from three strawberry cultivars: 'Festival' (FE), 'San Andreas ' (SA), and 'Camino Real' (CR). The total phenolic content was determined by the Folin–Ciocalteu method, in-vitro antioxidant activity by the DPPH* radical scavenging method and the phenolic profile by PAD–HPLC. The different genotypes showed significant differences (p < 0.05) in total phenolic content (TPC), FE being the one with the highest TPC (14.97 g of gallic acid equivalents < GAE > /Kg of by-product < R >), followed by SA and CR cultivars. The antioxidant capacity of the SA and FE tissues were similar (p > 0.05) and higher (15.1–16.3 mmol Trolox equivalents < TE > /Kg R) than CR. Eight main phenolic compounds were identified and quantified on the three cultivars. Agrimoniin was the principal polyphenol (0.38–1.56 g/Kg R), and the cultivar FE had the highest concentration. This compound showed the highest correlation coefficient with the antioxidant capacity (R2 0.87; p < 0.001). This study highlighted the impact of the multi-cultivar systems in strawberry production on the bioactive potential and the diversity of secondary metabolites obtained from strawberry agro-industrial by-products at a low cost. [ABSTRACT FROM AUTHOR]

[Display omitted] The escalation of many coronavirus variants accompanied by the lack of an effective cure has motivated the hunt for effective antiviral medicines. In this regard, 18 Saudi Arabian medicinal plants were evaluated for SARS CoV-2 main protease (Mpro) inhibition activity. Among them, Terminalia brownii and Acacia asak alcoholic extracts exhibited significant Mpro inhibition, with inhibition rates of 95.3 % and 95.2 %, respectively, at a concentration of 100 µg/mL. Bioassay-guided phytochemical study for the most active n -butanol fraction of T. brownii led to identification of eleven compounds, including two phenolic acids (1 , and 2), seven hydrolysable tannins (3 – 10), and one flavonoid (11) as well as four flavonoids from A. asak (12 – 15). The structures of the isolated compounds were established using various spectroscopic techniques and comparison with known compounds. To investigate the chemical interactions between the identified compounds and the target Mpro protein, molecular docking was performed using AutoDock 4.2. The findings identified compounds 4 , 5 , 10 , and 14 as the most potential inhibitors of Mpro with binding energies of −9.3, −8.5, −8.1, and −7.8 kcal mol−1, respectively. In order to assess the stability of the protein–ligand complexes, molecular dynamics simulations were conducted for a duration of 100 ns, and various parameters such as RMSD, RMSF, Rg, and SASA were evaluated. All selected compounds 4 , 5 , 10 , and 14 showed considerable Mpro inhibiting activity in vitro , with compound 4 being the most powerful with an IC 50 value of 1.2 µg/mL. MM-GBSA free energy calculations also revealed compound 4 as the most powerful Mpro inhibitor. None of the compounds (4 , 5 , 10 , and 14) display any significant cytotoxic activity against A549 and HUVEC cell lines. [ABSTRACT FROM AUTHOR]

Abstract Background The outer peels of pomegranate (Punica granatum L.) possess two groups of polyphenols that have health beneficial properties: anthocyanins (ATs, which also affect peel color); and hydrolysable tannins (HTs). Their biosynthesis intersects at 3-dehydroshikimate (3-DHS) in the shikimate pathway by the activity of shikimate dehydrogenase (SDH), which converts 3-DHS to shikimate (providing the precursor for AT biosynthesis) or to gallic acid (the precursor for HTs biosynthesis) using NADPH or NADP+ as a cofactor. The aim of this study is to gain more knowledge about the factors that regulate the levels of HTs and ATs, and the role of SDH. Results The results have shown that the levels of ATs and HTs are negatively correlated in the outer fruit peels of 33 pomegranate accessions, in the outer peels of two fruits exposed to sunlight, and in those covered by paper bags. When calli obtained from the outer fruit peel were subjected to light/dark treatment and osmotic stresses (imposed by different sucrose concentrations), it was shown that light with high sucrose promotes the synthesis of ATs, while dark at the same sucrose concentration promotes the synthesis of HTs. To verify the role of SDH, six PgSDHs (PgSDH1, PgSDH3–1,2, PgSDH3a-1,2 and PgSDH4) were identified in pomegranate. The expression of PgSDH1, which presumably contributes to shikimate biosynthesis, was relatively constant at different sucrose concentrations. However, the transcript levels of PgSDH3s and PgSDH4 increased with the accumulation of gallic acid and HTs under osmotic stress, which apparently accumulates to protect the cells from the stress. Conclusions The results strongly suggest that the biosynthesis of HTs and ATs competes for the same substrate, 3-DHS, and that SDH activity is regulated not only by the NADPH/NADP+ ratio, but also by the expression of the PgSDHs. Since the outer peel affects the customer’s decision regarding fruit consumption, such knowledge could be utilized for the development of new genetic markers for breeding pomegranates having higher levels of both ATs and HTs.

Little information is available on the effects of different sources of tannins on ruminant product quality. Nowadays several tannin-rich extracts, produced from different plants, are available and contain tannins belonging to different chemical groups, but most of these have not been used so far as feed supplements. The present study aimed at comparing the effects of feeding three tannin extracts (one containing condensed tannins and two containing hydrolysable tannins) to lambs on growth performances and meat oxidative stability. Comisana male lambs were divided into four groups (n=9 each) and were fed for 75 days: a concentrate-based diet (CON), or CON supplemented with 4% tannin extracts from either mimosa (MI; Acacia mearnsii, De Wild; condensed tannins), chestnut (CH; Castanea sativa, Mill; hydrolysable ellagitannins) or tara (TA; Cesalpinia spinosa, (Molina) Kuntze; hydrolysable gallotannins). Only CH reduced growth rate, final weight, carcass weight and feed intake (P0.05). The TA diet increased (P

In the thermal-drying processing of astringent persimmon fruit, the tissue-specific changes in the key antioxidants have hardly been investigated, while they have been well investigated in the flesh. We report here the different patterns of the antioxidant activities in the thermally processed flesh and peel of astringent persimmon, with analyses of the carotenoids, the condensed and hydrolysable tannins, and the total phenolics and flavonoids. The persimmon powders presented different colors on the basis of the drying temperatures: brown in 30 °C; light yellow in 60 °C; and dark brown in 90 °C, respectively. Non-maillard reaction and reduction of carotenoids caused the light-yellow color of 60 °C dried persimmon. Thermal drying reduced the antioxidant activities of the flesh in a temperature-dependent manner, with decreases in the carotenoids, the condensed and hydrolysable tannins, and the total phenolics and flavonoids, whereas it enhanced the antioxidant activities of the peel. The increase in the antioxidant activities in the peel were mainly the result of the increase in the total phenolics by the thermal effect, and especially in the content of the hydrolysable tannins, although the thermal processing decreased the other components. The heat-induced increase of antioxidant activity in the peel showed a strong significant correlation only with the contents of total phenolics (r2 = 0.9493) and total hydrolysable tannins (r2 = 0.9288), suggesting that the main antioxidant contributors differ from the flesh.

Antibiotic growth promoters in livestock nutrition cause microbial resistance which produces threats to human health. Therefore, tannins have been considered as natural alternative antibiotic feed additives which possess various biological properties including antimicrobial, anti-inflammatory, antioxidant and immunomodulatory. Additionally, these plants also have antiparasitic and anti-bloat characteristics which contribute to inhibit the enteric methane emission in order to improve nutrient digestibility, milk and meat quality, fatty acids composition and ruminant production. Antibiotic growth promoters have been practiced in animals feeding to increase feed intake, growth rate, weight gain as well as reduce metabolic disorders and energy losses in the rumen. In 2006, the European Union banned the usage of antibiotic growth promoters in the feeding of livestock. This antibiotic resistance issue has increased demand to explore the natural feed additives that might be useful for animal production system. Consequently, natural forages have been categorized as potential feed additives in animal production since it improves nutritive value, protein digestibility, increase amino acid absorption and growth rate. But, some plant materials are usually rich in tannins known as anti-nutritional factors. Therefore, the application of tannin-rich plants in ruminant nutrition needs great precaution due to its possible injurious effects (dose dependent) on animal health such as metabolic disorders. Hence, there is need to give attention to the usage of tannins in ruminant nutrition as an alternative to antibiotics feed additives to investigate its effects on enteric methane emissions and ruminants production. In addition, safety and risk associated with tannins feeding have also been briefly discussed. [ABSTRACT FROM AUTHOR]

Summary: Although tannins have been an important focus of studies of plant–animal interactions, traditional tannin analyses cannot differentiate between the diversity of structures present in plants. This has limited our understanding of how different mixtures of these widespread secondary metabolites contribute to variation in biological activity.We used UPLC‐MS/MS to determine the concentration and broad composition of tannins and polyphenols in 628 eucalypt (Eucalyptus, Corymbia and Angophora) samples, and related these to three in vitro functional measures believed to influence herbivore defence: protein precipitation capacity, oxidative activity at high pH and capacity to reduce in vitro nitrogen (N) digestibility.Protein precipitation capacity was most strongly correlated with concentrations of procyanidin subunits in proanthocyanidins (PAs), and late‐eluting ellagitannins. Capacity to reduce in vitro N digestibility was affected most by the subunit composition and mean degree of polymerisation (mDP) of PAs. Finally, concentrations of ellagitannins and prodelphinidin subunits of PAs were the strongest determinants of oxidative activity.The results illustrate why measures of total tannins rarely correlate with animal feeding responses. However, they also confirm that the analytical techniques utilised here could allow researchers to understand how variation in tannins influence the ecology of individuals and populations of herbivores, and, ultimately, other ecosystem processes. [ABSTRACT FROM AUTHOR]

Light exposure of white wine can cause a light-struck taste (LST), a fault induced by riboflavin (RF) and methionine (Met) leading to the formation of volatile sulfur compounds (VSCs), including methanethiol (MeSH) and dimethyl disulfide (DMDS). The study aimed to investigate the impact of different antioxidants, i.e., sulfur dioxide (SO2), glutathione (GSH) and chestnut tannins (CT), on preventing LST in model wine (MW) and white wine (WW), both containing RF and Met. Both MW and WW samples were added with the antioxidants, either individually or in different combinations, prior to 2-h light exposure and they were stored in the dark for 24 months. As expected, the light induced the degradation of RF in all the conditions assayed. Met also decreased depending on the antioxidants added. The presence of antioxidants limited the formation of LST as lower concentrations of VSCs were found in both MW and WW samples. In the latter matrix, neither MeSH nor DMDS were detected in the presence of CT, while only DMDS was found in WW+GSH, WW+SO2+GSH and WW+CT+SO2 samples at a concentration lower than the perception thresholds. Considering the antioxidants individually, the order of their effectiveness was CT ≥ GSH > SO2 in WW under the adopted experimental conditions. The results indicate tannins as an effective enological tool for preventing LST in white wine and their use will be further investigated in different white wines under industrial scale.

Jaboticaba is a Brazilian native berry described as a rich source of phenolic compounds (PC) with health promoting effects. PC from jaboticaba peel powder (JPP) have low intestinal bio-accessibility and are catabolized by gut microbiota. However, the biological implication of PC-derived metabolites produced during JPP digestion remains unclear. This study aimed to evaluate the antiproliferative effects of colonic fermented JPP (FJPP) in a 3D model of colorectal cancer (CRC) composed by HT29 spheroids. JPP samples fermented with human feces during 0, 2, 8, 24 or 48 h were incubated (10,000 µg mL−1) with spheroids, and cell viability was assessed after 72 h. Chemometric analyses (cluster and principal component analyses) were used to identify the main compounds responsible for the bioactive effect. The antiproliferative effect of FJPP in the CRC 3D model was increased between 8 h and 24 h of incubation, and this effect was associated with HHDP-digalloylglucose isomer and dihydroxyphenyl-γ-valerolactone. At 48 h of fermentation, the antiproliferative effect of FJPP was negligible, indicating that the presence of urolithins did not improve the bioactivity of JPP. These findings provide relevant knowledge on the role of colonic microbiota fermentation to generate active phenolic metabolites from JPP with positive impact on CRC.

Hydrolysable tannins (HTs) are useful secondary metabolites that are responsible for pharmacological activities and astringent taste, flavor, and quality in fruits. They are also the main polyphenols in Canarium album L. (Chinese olive) fruit, an interesting and functional fruit that has been cultivated for over 2000 years. The HT content of C. album fruit was 2.3–13 times higher than that of berries with a higher content of HT. 1-galloyl-β-d-glucose (βG) is the first intermediate and the key metabolite in the HT biosynthesis pathway. It is catalyzed by UDP-glucosyltransferases (UGTs), which are responsible for the glycosylation of gallic acid (GA) to form βG. Here, we first reported 140 UGTs in C. album. Phylogenetic analysis clustered them into 14 phylogenetic groups (A, B, D–M, P, and Q), which are different from the 14 typical major groups (A~N) of Arabidopsis thaliana. Expression pattern and correlation analysis showed that UGT84A77 (Isoform0117852) was highly expressed and had a positive correlation with GA and βG content. Prokaryotic expression showed that UGT84A77 could catalyze GA to form βG. These results provide a theoretical basis on UGTs in C. album, which will be helpful for further functional research and availability on HTs and polyphenols.

1,2,3,4,6-Penta-O-Galloyl-β-d-Glucose (PGG) is a hydrolysable tannin that belongs to the group of gallotannins but also participates in the formation of ellagitannins. PGG is composed of five galloyl groups with a glucose at its core and has structural characteristics that confer a high biological power. In this paper, we describe the chemistry of PGG, which is analyzed from a critical point regarding the types of synthesis, new sources of production from plants and by-products, highlighting the PGG obtaining, and its main functional properties recently reported in scientific literature. PGG has attracted attention because of its therapeutic potential and has shown functional properties as antimicrobial, anti-inflammatory, anti-carcinogenic, antidiabetic and antioxidant. Bioconversion from tannic acid can be potentialized with the use of biotechnological techniques. PGG can be obtained from natural sources as by-products. Research should continue to obtain pure molecules, in adequate quantity and with great biological activity.

Nanomaterials are widely used in health and biomedical applications, however, only a few studies investigate their toxic effects. The present report signifies a contribution to the study of the toxic effects of silver nanoparticles on E. coli cells, which is a model organism of anthropogenic pollution. The toxicity of nanoparticles depends on their chemical and surface properties, shape and size. Nanoparticles that have the same chemical composition but different shapes or sizes might have different effects on cells. In this work, Ag nanoparticles were biosynthesized with an Eichhornia crassipes biomass, and it was demonstrated for the first time, that the amounts of hydrolysable tannins in this plant, are directly related to the size, shape, structure and composition of the Ag nanoparticles ; furthermore, the toxic effect was studied using E. coli cell culture. The EC was divided in three sections, i.e. roots, stems and leaves. Particle aggregation seems to be influenced by the amount of tannins present in the biomass. For each plant part, the amounts of hydrolysable tannins were determined, the highest amounts of these chemicals were present in the leaves, and hence these Ag nanoparticles dissolutions were used for the nanotoxicity experiments. . The cytotoxicity of Ag nanoparticles in a suspension was tested using the Ag nanoparticles synthesized with leaves, against Escherichia Coli ATCC 25992 where the concentration that inhibited 100% of bacterial growth, was 5 mg/L in contrast with a commercial solution which needed 10mg/L of Ag. For the most part, the Ag nanoparticles seemed to be of a nearly spherical shape, although on closer examination were determined to be mainly polyhedral. Leaves biomass, produced mainly quantum dot nanoparticles with sizes below 10 nm and the Ag nanoparticles were mostly AgO. The cytotoxicity of Ag NPs in a suspension tested using the Ag nanoparticles on E. coli was highly effective towards inhibition of bacterial growth.

Cork is a renewable, non-wood high valued forest product, with relevant ecological and economic impact in the Mediterranean-type ecosystems. Currently, cork is ranked according to its commercial quality. The most valuable planks are chosen for cork stoppers production. Cork planks with adequate thickness and porosity are classified as stoppable quality cork (SQC). The chemical composition of cork is known, but the regulation of metabolic pathways responsible of cork production and composition, hence of cork quality, is largely unknown. Here, we tested the hypothesis that post-genomic events may be responsible for the development of SQC and N-SQC (non-stoppable quality cork). Here, we show that combined proteomics and targeted metabolomics (namely soluble and cell wall bound phenolics) analyzed on recently formed phellem allows discriminate cork planks of different quality. Phellem cells of SQC and N-SQC displayed different reducing capacity, with consequential impact on both enzymatic pathways (e.g., glycolysis) and other cellular functions, including cell wall assembly and suberization. Glycolysis and respiration related proteins were abundant in both cork quality groups, whereas the level of several proteins associated to mitochondrial metabolism was higher in N-SQC. The soluble and cell wall-bound phenolics in recently formed phellem clearly discriminated SQC from N-SCQ. In our study, SQC was characterized by a high incorporation of aromatic components of the phenylpropanoid pathway in the cell wall, together with a lower content of hydrolysable tannins. Here, we propose that the level of hydrolysable tannins may represent a valuable diagnostic tool for screening recently formed phellem, and used as a proxy for the quality grade of cork plank produced by each tree.

Both condensed and hydrolysable tannins represent versatile natural polyphenolic structures exhibiting a broad range of activities that could be exploited in various fields including nutraceutics, cosmesis, consumer care, household and pharmaceutical applications. Various tannins are commercially available nowadays for use in such application fields. We have analysed a representative selection of commercially available condensed and hydrolysable tannins for structural features and purity. Using a combination of quantitative 31P NMR spectroscopy, HSQC measurements, MALDI-ToF analyses, gel permeation chromatography and wet chemical analysis, detailed structural characterisations and descriptions were possible, allowing for verification and falsification of claimed structural features.

Cork is a renewable, non-wood high valued forest product, with relevant ecological and economic impact in the Mediterranean-type ecosystems. Currently, cork is ranked according to its commercial quality. The most valuable planks are chosen for cork stoppers production. Cork planks with adequate thickness and porosity are classified as stoppable quality cork (SQC). The chemical composition of cork is known, but the regulation of metabolic pathways responsible of cork production and composition, hence of cork quality, is largely unknown. Here, we tested the hypothesis that post-genomic events may be responsible for the development of SQC and N-SQC (non-stoppable quality cork). Here, we show that combined proteomics and targeted metabolomics (namely soluble and cell wall bound phenolics) analyzed on recently formed phellem allows discriminate cork planks of different quality. Phellem cells of SQC and N-SQC displayed different reducing capacity, with consequential impact on both enzymatic pathways (e.g., glycolysis) and other cellular functions, including cell wall assembly and suberization. Glycolysis and respiration related proteins were abundant in both cork quality groups, whereas the level of several proteins associated to mitochondrial metabolism was higher in N-SQC. The soluble and cell wall-bound phenolics in recently formed phellem clearly discriminated SQC from N-SCQ. In our study, SQC was characterized by a high incorporation of aromatic components of the phenylpropanoid pathway in the cell wall, together with a lower content of hydrolysable tannins. Here, we propose that the level of hydrolysable tannins may represent a valuable diagnostic tool for screening recently formed phellem, and used as a proxy for the quality grade of cork plank produced by each tree. The shikimate and the core phenylpropanoid pathways are involved in the synthesis of the polyphenols identified in cork producing cells. Stoppable cork quality producing cells are characterized by higher incorporation of aromatic components of the phenylpropanoid pathway in the cell wall, together with a lower content of hydrolysable tannins. [ABSTRACT FROM AUTHOR]

Background: Diabetes mellitus is a chronic metabolic disorder associated with persistent increased level of glucose in the blood. According to a report by World Health Organisation (WHO), prevalence of diabetes among adults over 18 years of age had reached to 8.5% in year 2014 which was 4.7% in 1980s. The Prolong increased level of glucose in blood leads to development of microvascular (blindness, nephropathy and neuropathy) and macrovascular (cardiovascular and stroke) degenerative complications because of uncontrolled level of glucose in blood. This also leads to the progression of oxidative stress and affecting metabolic, genetic and haemodynamic system by activation of polyol pathway, protein kinase C pathway, hexosamine pathway and increases advanced glycation end products (AGEs) formation. Diabetes mellitus and its associated complications are one of the major leading causes of mortality worldwide. Various natural products like alkaloids, glycosides, flavonoids, terpenoids and polyphenols are reported for their activity in management of diabetes and its associated diabetic complications. Tannins are systematically studied by many researchers in past few decades for their effect in diabetes and its complications.Aim: The present review was designed to compile the data of tannins and their beneficial effects in the management of diabetic complications.Method: Literature search was performed using various dataset like pubmed, EBSCO, proQuest Scopus and selected websites including the National Institutes of Health (NIH) and the World Health Organization (WHO).Results: Globally, more than 400 natural products have been investigated in diabetes and its complications. Tannins are the polyphenolic compounds present in many medicinal plants and various dietary sources like fruits, nuts, grains, spices and beverages. Various reports have shown that compounds like gallic acid, ellagic acid, catechin, epicatechin and procynidins from medicinal plants play major role in controlling progression of diabetes and its related complications by acting on molecular pathways and key targets involved in progression. Many chemists used above mentioned phyto-constituents as a pharmacophore for the developing new chemical entities having higher therapeutic benefits in management of diabetic complications.Conclusion: This review focuses on the role of various tannins in prevention and management of diabetic complications like diabetic nephropathy, diabetic neuropathy, diabetic retinopathy and diabetic cardiomyopathy. It will help researchers to find some leads for the development of new cost effective therapy using dietary source for the management of diabetic complications. [ABSTRACT FROM AUTHOR]

Little information is available on the effects of different sources of tannins on ruminant product quality. Nowadays several tannin-rich extracts, produced from different plants, are available and contain tannins belonging to different chemical groups, but most of these have not been used so far as feed supplements. The present study aimed at comparing the effects of feeding three tannin extracts (one containing condensed tannins and two containing hydrolysable tannins) to lambs on growth performances and meat oxidative stability. Comisana male lambs were divided into four groups (n =9 each) and were fed for 75 days: a concentrate-based diet (CON), or CON supplemented with 4% tannin extracts from either mimosa (MI ; Acacia mearnsii , De Wild; condensed tannins), chestnut (CH; Castanea sativa , Mill; hydrolysable ellagitannins) or tara (TA; Cesalpinia spinosa , (Molina) Kuntze; hydrolysable gallotannins). Only CH reduced growth rate, final weight, carcass weight and feed intake (P <0.05). Tannins did not affect the concentration of the main fatty acid classes and the peroxidability of the intramuscular fat (P >0.05). The TA diet increased (P <0.001) the concentration of γ -tocopherol in muscle and tended to increase that of α -tocopherol (P =0.058). Oxidative stability of raw and cooked meat, or of meat homogenates incubated with pro-oxidants, was not affected by the extracts. These results, compared with those reported in the literature, highlight that some effects of tannins cannot be easily generalized, but may strictly depend on their specific characteristics and on conditions inherent to the basal diet and the metabolic status of the animals. [ABSTRACT FROM AUTHOR]