Catechin Content Research Articles

Grape seed phenolic extracts encapsulation in polymeric nanoparticles: Characterization and in vitro evaluation against skin melanoma

Nanocarrier platforms encapsulating plant-based natural extracts have emerged as an attractive tool to increase the safety and stability of phytomedicines and nutraceuticals. In this study, phenolic fractions were extracted from grape seed waste, spray dried, and characterized. Grape seed extracts (GSE) of Marselan, a red international variety, and Obeidi, a Lebanese autochthonous white variety, had a total phenolic content (TPC) of 301 and 206 mg gallic acid equivalents (GAE)/g of dry matter, respectively, along with a high content of catechins, gallic acid, epicatechins, caffeic acid, syringic acid, and protocatechuic acid. A nanocarrier formulation was developed using poly(ethylene glycol)-b-poly(lactide-co-glycolide) (PEG-PLGA), yielding GSE-loaded nanoparticles (NPs) with an average of 230 nm particle size and −35 mV zeta potential, 50% encapsulation efficiency, and sustained release over 96 h. GSE NPs exhibited high colloidal stability in terms of size and high chemical stability in terms of TPC and antioxidant activity for both Marselan and Obeidi when stored at 4 °C for 3 months. GSE NPs showed excellent biocompatibility in human dermal fibroblasts. Both NPs and crude extracts significantly suppressed the proliferation of B16–F10 melanoma cells, particularly Obeidi NPs. This study emphasizes the important role nanotechnology can play in the valorization of bioactive nutraceuticals by presenting GSE NPs as a promising nanoformulation against skin cancer.

A recoverable hydrophilic deep eutectic solvent for efficient extraction of polyphenolic compounds from raspberry root.

Green deep eutectic solvents (DESs) are widely used to extract bioactive components from plant biomass; however, hydrophilic DES and bioactive component isolation methods have not been developed. In this study, we synthesized hydrophilic DES (CL-CA-DES) using citric acid and choline chloride. We combined this with environmentally friendly anion- and cation-exchange resin column chromatographic isolation methods. This approach extracted and isolated four polyphenolic compounds (catechins, epicatechins, procyanidin B1, and procyanidin B2) from raspberry root and efficiently recovered the hydrophilic DES. CL-CA-DES extracted significantly higher contents of catechin and procyanidin B2 from raspberry root compared to other solvents. It also extracted substantially higher contents of epicatechin compared to butyl alcohol, 70% ethanol, and water, but there was no significant difference when compared with acetone and ethyl acetate. Additionally, CL-CA-DES extracted significantly higher contents of procyanidin B1 compared to butyl alcohol, water, and ethyl acetate, with no significant difference when compared with 70% ethanol and acetone. The isolation efficiency of the bioactive components in the raspberry root extract by anion- and cation-exchange resin column chromatography was higher than that of the organic solvent extraction and precipitation generation methods, and the method was effective in recovering CL-CA-DES with a recovery rate higher than 60%. In conclusion, this study developed a new method for the efficient recovery of hydrophilic CL-CA-DES, which can be used for isolating polyphenolic compounds from raspberry root.

Study on the Effect of Sooty Mould Disease in Tea Plants.

Sooty mould (SM) disease affects the growth, development and metabolism of plants and reduces the commodity and economic value of crops. SM disease is one of the important leaf diseases in tea plants. Nonetheless, studies on the effect of SM disease in tea plants are rare. Herein, we found that SM disease disrupted the cell morphology and structure and reduced the contents of caffeine, theanine, and catechins in the mature leaves of tea plants. Transcriptome analysis revealed that SM disease inhibited the biosynthesis of lignin, chlorophyll, catechin, caffeine, and theanine and affected the plant-pathogen interactions in the mature leaves of tea plants by downregulating gene expression. In addition, two fungal isolates, MTzyqA and MTzyqB, were obtained from the mature leaves of diseased tea plants. These strains were identified as Cladosporium pseudocladosporioides by mulitgene phylogenetic analysis, and they grew epiphytically on the leaves of tea plants. The biocontrol bacteria JT68, ZGT5, and BX1 had obvious inhibitory effect on MTzyqA and MTzyqB. These results provide a basis for understanding the effect of SM disease in tea plants.

ABA and MeJA Induced Catechin and Epicatechin Biosynthesis and Accumulation in Camellia oleifera Fruit Shells.

Camellia oleifera Abel, one of the most valuable woody oil plants, has been widely cultivated for extracting edible oil. The shell of C. oleifera is a by-product generated in the processing of edible oil extraction. However, there is still limited research on the maturity and high-value resource utilization of shell by-products. We found that the C. oleifera 'Huashuo' (HS) fruit shells contained a high content of catechins. Abscisic acid (ABA) and methyl jasmonate (MeJA) enhanced the accumulation of catechins in C. oleifera fruit shells, providing a basis for production and application of the catechins in fruit shells of C. oleifera. We further found that 500 μM ABA and 900 μM MeJA significantly promoted the accumulation of catechin (C) and epicatechin (EC) in fruit shells. Following treatment with 900 μM MeJA, the expressions of CoPAL1, CoC4H1, CoC4H2, CoC4H3, Co4CL1, Co4CL2, CoF3'H1, CoLAR1, CoLAR2, CoLAR3, CoANR2, and CoANRL2 were significantly upregulated, while after 500 μM ABA treatment the expressions of CoPAL3, CoCHS1, CoCHS4, CoF3'H1, CoDFR, CoLAR1, CoLAR2, CoLAR3, CoANS1, CoANR1, and CoANR2 increased dramatically. These results indicate that appropriate concentrations of ABA and MeJA activate C and EC biosynthesis and promote their accumulation in fruit shells. Our results provide new ideas and guidance for promoting the resource utilization of C. oleifera fruit shells.

Основные группы биологически активных веществ в растениях видов Hemerocallis L.

Abstract. Wild species of the genus Hemerocallis L. – family Hemerocallidaceae Br. – are of value as ornamental, food and medicinal plants. Biologically active substances of the species composition of lilies growing in natural habitats have not been studied enough. There is no information on the quantitative content of the main groups of biologically active substances in the five types of lilac cultivated in the forest-steppe zone of the Novosibirsk region over the two growing seasons, which determines the originality and significance of this work. The purpose of the study is a comparative study of the content of the main groups of biologically active substances (BAS) in plants of five species of lilac cultivated in the forest-steppe zone of Western Siberia. Methods. A spectrophotometric method was used to determine flavonols, catechins, carotenoids; carbazole-free – for the determination of pectins and protopectins; titrimetric – for the determination of tannins. Results. Comparative analysis of BAV in flowers and leaves of five species of lilac allowed to establish that in leaves the content of catechins (1.1–1.3 times), flavonols (2.0 times), tannins (1.6–2.3 times) is higher than in flowers. The content of pectins is higher in flowers (1.7–3.3 times), protopectins (1.4 times), carotenoids (3.7–34.4 times). The concentration of protopectins in leaves and flowers of all species is 1,4–5.1 times higher compared to pectins. H. minor (flavonols, pectins), H. middendorffii (tannins, catechins, carotenoids), H. citrina (catechins), H. fulva (tannins), H. lilio-asphodelus (pectins) were distinguished by high indications for individual components in various organs. Species specificity of accumulation of these components in flowers and leaves during the period of mass flowering and specificity of their content over two growing periods has been established. Scientific novelty. For the first time in the conditions of the forest-steppe zone of the Novosibirsk region, a comparative quantitative analysis of the content of phenolic compounds, pectin substances, carotenoids in the aboveground organs of H. lilio-asphodelus, H. minor, H. middendorffii, H. citrina, H. fulva during the growing season of 2019–2020 was carried out.

Oxidation characteristics of catechins in suspended fermentation of different varieties’ tea leaves

This study focused on the efficiency of enzymatic synthesis for theaflavins (TFs) and SII types of thearubigins (SII-TRs) in suspended fermentation of different varieties of tea leaves. The results showed that the content of catechins in tea variety-Xiaoxianghong 21–3 (XXH21–3) was the highest among the five kinds of fresh tea leaves, and it had the strongest ability of transforming catechins to TFs and SII-TRs. The total amount of catechins for XXH 21–3 decreased rapidly and the conversion ratio of TFs reached the highest level of 13.96 % after 20 min, the residual catechins was the lowest (3.27 %) and the conversion rate of SII-TRs was the highest (13.02 %) after 120 min during the suspended fermentation of five varieties tea leaves. Among six types of catechins, epicatechin gallate (ECG), epigallocatechin gallate (EGCG) and epigallocatechin (EGC) were consumed in large quantities, and the residues were all less than 5 % in the final stage of fermentation, of which ECG consumption was the fastest, followed by EGCG. These results demonstrated that the concentration of catechins and PPO activities were positively correlated with the formation of TFs and SII-TRs, POD activity was positive correlation with synthesis of SII-TRs and negative correlation with TFs.

Enhancing catechins, antioxidant and sirtuin 1 enzyme stimulation activities in green tea extract through pulse electric field-assisted water extraction: Optimization by response surface methodology approach

Green tea is an economic resource in Thailand because it is derived from smallholder agriculture and has expanded into food production. The purpose of this study is to optimize the parameters of pulsed electric field (PEF) assisted green tea extraction to produce a natural health product. A central composite design was involved to determine the effect of independent variables, including the intensity of electric field (I; 3–5 kV/cm), number of pulses (Np; 1000 to 3000 pulses) and green tea-to-water ratio (GT/W; 0.05–0.15 g/mL) on catechin (C), epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC) and epigallocatechin gallate (EGCG), total phenolic compound, antioxidant and sirtuin 1 enzyme stimulating activities. The results indicated that the Np had the most significant impact (p < 0.05) on the content of catechin and its derivatives and sirtuin 1 enzyme stimulating activity. The observations revealed that the I had a greater impact on antioxidant activities compared to the Np. The optimal conditions for PEF using the response surface method were determined to be I of 5 kV/cm, Np of 3000 pulses, GT/W of 0.14 g/mL and specific energy of 27 kJ/kg. Under the optimized conditions, the content of C, EC, ECG, EGC and EGCG were 7.34 ± 0.33, 11.26 ± 0.25, 3.75 ± 0.13, 7.53 ± 0.77 and 37.78 ± 0.58 mg/g extract, respectively. Furthermore, it was observed that green tea extract exhibited the ability to modulate the deacetylation activity of the sirtuin 1 enzyme, with a value of 22.63 ± 0.17 FIR. The results emphasized that the PEF led to achieving better responses compared to without pre-treatment using the PEF. Therefore, innovative technologies as PEF can be utilized for green tea extraction to produce natural ingredients, which can contribute to improved accessibility to healthcare. Additionally, the implementation of innovation techniques, such as PEF, in the extraction industry can enhance productivity growth and economic development.

Mechanisms of single and mixed microbial fermentation to improve summer-autumn green tea

To investigate the effect of individual and collaborative fermentation on summer-autumn green tea (SAGT) quality. Liquid fermentation with individual inoculation of Aspergillus cristatus (ACFT), Aspergillus niger (ANFT) and mixed inoculation of A. cristatus/A. niger (MFT), respectively, with SAGT extracts (CT) as raw materials. The volatile organic compounds (VOCs), characteristic non-volatile compounds and sensory evaluation of tea samples were determined. The results showed a significant decrease in the content of tea polyphenols, carbohydrates and nongalloylated catechins (C, EC) and a significant increase in the amount of VOCs in MFT compared to ANFT and ACFT. The results of metabolic pathway analysis and sensory evaluation showed that ACFT went through the terpene and phenylpropanoic acid metabolic pathway, which produced large amounts of α-terpineol, phenethyl alcohol, and methyl salicylate, which in turn conferred ACFT with distinctly sweet, floral, and herbal aroma. ANFT produces large amounts of linalool oxides I and II, mainly through the linalool oxide metabolic pathway, making ANFT a distinctive aged and woody aroma. MFT may be due to the strong woody aroma of linalool oxides masking other weaker and better aromas, thus giving MFT a significant woody, herbal and stale aroma. This study provides new insights and a theoretical basis for mixed fungal fermentation to improve the quality of SAGT.

Sensory evaluation and chemical composition of Solanum nigrum and Solanum torvum herbal tea and spice.

Herbal teas are ingested for various purposes and by diverse populations across the globe. There is a growing recognition among individuals of the advantages associated with the use of this beverage, leading to a heightened demand for the manufacture of herbal tea derived from therapeutic plants. Spices on the other hand add flavour to food but could pose harm if it is high in phytates and oxalates. The objective of this study was to develop natural spices and herbal tea with health beneficial properties using Solanum nigrum and Solanum torvum berries. Herbal tea samples from S. nigrum were prepared by sorting berries, maceration, divided into two (fermenting at 18 °C and non-fermenting) and dried at 60 °C for 12 h in a hot oven. Spices from S. torvum and S. nigrum were prepared by removing the berries from the stalk, freeze-drying and smooth milling into fine powder. In addition, antinutrient, phytochemical and sensory evaluation studies were conducted on these spices and herbal teas. A nine-point hedonic scale was utilized for the purpose of conducting a consumer acceptability sensory evaluation test using 101 untrained panelists. Data was then analyzed by t-test, one-way analysis of variance (ANOVA) and the level of significance (p < 0.05) was assessed using Tukey's and Dunnett's multiple comparison tests. The panellists expressed a favourable perception towards Solanum nigrum unripe unfermented green herbal tea (6.65 ± 2.08) as compared to the other formulated teas due to the components working together in a way that produces a nice tea sample. Both Solanum nigrum and Solanum torvum spices contained various levels of catechins, saponins, flavonoids, oxalates, phytates and tannins comparable to literature. The herbal tea samples exhibited a range of catechin content, varying from 0.255 to 0.756 mg/g. The antioxidant activity of the various herbal tea samples ranged from 66.37 ± 0.24 to 78.53 ± 0.18 µg/mL GAE as determined by the DPPH free radical assay Fermented black herbal teas recorded higher total phenols (2.80 ± 0.09d), total flavonoids (21.84 ± 1.84c) and showed greater antioxidant activity (78.53 ± 0.18a) as compared to the unfermented green herbal teas. The process of fermentation resulted in a decrease in pH from 7.22 to 6.53 within a period of 12 h. The Total Titratable Acidity (TTA) grew as the fermentation period progressed, whereas the Total Soluble Solids (TSS) decreased. Phytates were the least antinutrients among the two Solanum species accounting for 0.02 mg/100 g and 0.03 mg/100 g in S. torvum berries (STBs) and (S. nigrum berries) SNBs respectively.

Enzymatic quality enhancement of oolong tea based on grade difference analysis

The quality of oolong tea in summer and autumn is generally lower than in spring, resulting in a loss of economic benefits. We found that this was due to the higher tea polyphenol content and lower sugar and amino acid content of summer and autumn oolong teas. Here, we used cellulase, protease and tannase for targeted enzymatic hydrolysis of low-quality teas to reduce the tea polyphenol content while increasing the soluble sugar and amino acid contents. By optimizing the ratio, concentration and treatment temperature of the added enzymes, the soluble sugar and amino acid contents of low- and middle- quality tea were increased by 6%-128% and 12%-88%, respectively. The ester catechin content was reduced by 12% and the total catechin content was reduced by 41%. The aroma of middle- and low-quality tea was transformed into the characteristics of high-quality tea. Therefore, directed enzymatic degradation is a promising technology for tea quality improvement.

An Exploratory Randomized Controlled Study to Investigate Concentration-Dependence of Green Tea Catechin Gargling on Acute Upper Respiratory Tract Infections.

Green tea (GT) catechins exhibit antiviral effects in experimental studies. However, we lack clinical evidence on the preventive effects of catechin concentrations in gargling against acute upper respiratory tract infections (URTIs). Therefore, we aimed to investigate the concentration-dependence of GT catechins in gargling on the incidence of URTIs. We conducted an open-label randomized study. The target population consisted of 209 students from the University of Shizuoka and Meiji University, who were randomly assigned to high-catechin (approximate catechin concentration: 76.4 mg/dL), low-catechin (approximate catechin concentration: 30.8 mg/dL), and a control water gargling (catechin concentration: 0 mg/dL) group. All participants gargled water or GT daily for 12 weeks. The symptoms of URTIs were recorded on a daily survey form by participants. The incidences of URTIs occurred in 6 (9.1%), 7 (10.8%), and 11 (15.7%) participants in the high-catechin, low-catechin, and water groups, respectively. Cox proportional hazards analysis, using background factors and prevention status as covariates, revealed a hazard ratio of 0.57 (95% Confidence Interval (CI): 0.21-1.55, p = 0.261) for the high-catechin vs. water group and 0.54 (95% CI: 0.20-1.50, p = 0.341) for the low-catechin vs. water group. Our findings showed the incidence of URTIs in a concentration-dependent GT gargling was not significantly different, partly owing to the low event rates caused by intense precautions against the coronavirus disease 2019 pandemic. Our study would serve as a foundation for the development of an advanced protocol with optimal concentrations and a larger number of participants.

Enhancing bioactive phenolic extraction from unfermented Cabernet Sauvignon pomace through tailored synergies of pH, proteolysis, and microwave processing

The impact of enzyme-assisted (EAE), microwave-assisted (MAE), and microwave enzyme-assisted (MEAE) extractions using water were evaluated and compared to aqueous (AEP), conventional ethanolic (CSE), and microwave ethanolic (MSE) controls for the release of phenolics from Cabernet Sauvignon grape pomace. Optimization of extract total phenolic content (TPC) involved stepwise screening of time, temperature, slurry pH, solids-to-liquid ratio, and enzyme conditions. The use of 0.1 % alkaline protease in MEAE (1:10 g pomace/mL water, pH 11.5, 70 °C, 30 min) reduced extraction time by 50 % compared to AEP, EAE, and CSE methods, doubling the TPC of the extracts to 100.9 mg GAE/g dry weight pomace compared to ethanolic extractions. MAE and MEAE extracts exhibited in vitro antioxidant activities (ABTS and ORAC) similar to ethanolic extracts and had greater antioxidant activities than AEP/EAE extracts while boosting relative contents of catechins, procyanidins, trans-piceid, and malvidin-3,5-diglucoside as detected by untargeted metabolomics. Quantitation by HPLC showed increased levels of gallic acid, protocatechuic acid, syringic acid, p-coumaric acid, polymeric phenols, and polymeric pigments in MEAE compared to hydroethanolic methods. Scanning electron microscopy further supported the synergistic role of microwave processing and proteolysis in disrupting the grape cell structure to aid in releasing valuable bioactive phenolic compounds.

Evaluation of hot-air drying conditions of ora-pro-nobis leaves: Effects on bioactive compounds and powder properties

This study aimed to evaluate the effect of hot-air drying conditions on the bioactive composition, antioxidant capacity, and technological properties of ora-pro-nobis (OPN) leaves. Drying time decreased from 300 min to 75 min, with increasing air temperature from 60 to 120 °C. There was an increase in total phenolic (1.2 to 2.4 times) and total flavonoid (1.2 to 2.1 times) contents when drying conditions were changed from 60 °C for 300 min to 100 °C for 105 min. The highest antioxidant activities were observed in samples dried at 100 or 110 °C, with positive correlations with kaempferol, catechin, trans-cinnamic acid, and hydroxybenzoic acid contents. Thus, drying at 100 °C for 105 min was considered the moist suitable condition for OPN leaves, because higher temperatures caused greater changes in color, technological properties, and powder microstructures.

Systematic study on date palm seeds (Phoenixdactylifera L.) extraction optimisation using natural deep eutectic solvents and ultrasound technique

Natural deep eutectic solvents (NADES) are emerging, environment-friendly solvents that have garnered attention for their application in extracting phenolic compounds. This study investigated the effects of four synthetic NADES on polyphenols extracted from date seeds (DS) using choline chloride (ChCl) as a hydrogen-bond acceptor and lactic acid (La), citric acid (Citri), glycerol (Gly), and fructose (Fruc) as hydrogen-bond donors, in comparison with DS extracts extracted by conventional solvents (water, 70% methanol, and 70% ethanol). The antioxidant activity (DPPH), total phenolic content (TPC) and 6 phenolic compounds were determined using HPLC. The results showed that the ChCl–La and ChCl–Citri systems exhibited a high extraction efficiency regarding TPC, and DPPH in the DS extracts extracted by NADES compare to those DS extracts extracted with conventional solvents (p ˂ 0.001). HPLC results demonstrated that DS extracted by ChCl–La contained all measured phenolic compounds. Also gallic acid and catechin were the major compounds identified in the DS extracts. In addition DS extracted by ChCl–Citri and ChCl–Gly had the highest concentration of catechin. In conclusion, combining NADES is a promising and environment-friendly alternative to the conventional solvent extraction of phenolic compounds from DS.

Fatty acid and nutrient profiles, diosgenin and trigonelline contents, mineral composition, and antioxidant activity of the seed of some Iranian Trigonella L. species

BackgroundFenugreeks (Trigonella L. spp.), belonging to the legume family (Fabaceae), are well-known multipurpose crops that their materials are currently received much attention in the pharmaceutical and food industries for the production of healthy and functional foods all over the world. Iran is one of the main diversity origins of this valuable plant. Therefore, the aim of the present study was to explore vitamins, minerals, and fatty acids profile, proximate composition, content of diosgenin, trigonelline, phenolic acids, total carotenoids, saponins, phenols, flavonoids, and tannins, mucilage and bitterness value, and antioxidant activity of the seed of thirty populations belonging to the ten different Iranian Trigonella species.ResultsWe accordingly identified notable differences in the nutrient and bioactive compounds of each population. The highest content (mg/100 g DW) of ascorbic acid (18.67 ± 0.85‒22.48 ± 0.60) and α–tocopherol (31.61 ± 0.15‒38.78 ± 0.67) were found in the populations of T. filipes and T. coerulescens, respectively. Maximum content of catechin was found in the populations of T. teheranica (52.67 ± 0.05‒63.50 ± 0.72 mg/l). Linoleic acid (> 39.11% ± 0.61%) and linolenic acid (> 48.78 ± 0.39%) were the main polyunsaturated fatty acids, with the majority in the populations of T. stellata (54.81 ± 1.39‒63.46 ± 1.21%). The populations of T. stellata were also rich in trigonelline (4.95 ± 0.03‒7.66 ± 0.16 mg/g DW) and diosgenin (9.06 ± 0.06‒11.03 ± 0.17 mg/g DW).ConclusionsThe obtained data provides baseline information to expand the inventory of wild and cultivated Iranian Trigonella species for further exploitation of rich chemotypes in the new foods and specific applications.

Effects of catechin on the malignant biological behavior of gastric cancer cells through the PI3K/Akt signaling pathway

Catechin is a kind of flavonoids, mainly derived from the plant Camellia sinensis. It has a strong antioxidant effect, and it also has significant therapeutic effects on anti-cancer, anti-diabetes, and anti-infection. This study was intended to look at how catechin affected the malignant biological activity of gastric cancer cells. We used databases to predict the targets of catechin and the pathogenic targets of gastric cancer. Venn diagram was used to find the intersection genes, the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses were performed on intersection genes. Using the STRING database, the Protein-Protein Interaction (PPI) network was built. The top 8 genes were screened by Cytoscape 3.9.1, then their binding was verified by molecular docking. The proliferation ability, cell cycle, apoptosis and migration of gastric cancer cells were detected, as well as the protein expression levels of PI3K, p-AKT, and AKT and the mRNA expression levels of AKT1, VEGFA, EGFR, HRAS, and HSP90AA1 in gastric cancer cells. Our research revealed that different concentrations of catechin could effectively inhibit the proliferation and migration of gastric cancer cells, regulate the cell cycle, and promote the death of these cells, and it's possible that the PI3K/Akt pathway was crucial in mediating this impact. Moreover, adding the PI3K/Akt pathway agonist significantly reduced the promoting effect of catechin on the apoptosis of gastric cancer cells. This study suggested that catechin was a potential drug for the treatment of gastric cancer.

Polyphenol composition and antioxidant activity of wine raw materials and pomace from hybrid grapes, aronia, and Japanese quince ia melanocarpa) and Japanese quince (Chaenomeles japonica)

Wine pomace contains high amounts of bioactive compounds, mainly polyphenols, with varying concentrations depending on multiple factors. This research aimed to determine differences in the content of polyphenols and antioxidant activity of the wine raw materials and pomace of Japanese quince (‘Rasa’), aronia (seedlings), and grape (‘Hasansky Sladky’) and between harvest years (2021, 2022), as well as between fruits and pomace. Pomace from aronia and Japanese quince was obtained after maceration for 5 and 7 days, respectively, while grape pomace was collected on the day of harvest. The polyphenol content of fruits and pomace varied significantly between harvest years. Aronia had the highest total polyphenol content in fruits (989 mg GAE 100 g-1) and pomace (1022 mg GAE 100 g-1), followed by Japanese quince (625 and 722 mg GAE 100 g-1) and grapes (390 and 481 mg GAE 100 g-1). Aronia fruits and pomace had higher antioxidant activity. Compared to the fruits, aronia pomace had less chlorogenic acid and neochlorogenic acid. Flavanols were the main polyphenols in the Japanese quince, showing lower content in the pomace when compared to fruits, except catechin content was higher. The content of anthocyanins and flavonols was higher in the rosé wine pomace than in the fruits of grapes.

Chemical composition, antioxidant and antimicrobial activities of Vaccinium macrocarpon (Ericaceae) and Camellia sinensis (Theaceae) extracts

In the modern scientific community, considerable attention is given to studying the pharmacological activity of catechin and anthocyanin derivatives. However, a comparative analysis of the antioxidant and antimicrobial activities of extracts rich in anthocyanins and catechins has not been previously conducted. So, the purpose of this work was to study and compare phytochemical composition, antimicrobial and antioxidant potential of Vaccinium macrocarpon L., Ericaceae fruit thick and Camellia sinensis L., Theaceae leaf liquid extracts. The quantification of biologically active substances (BAS) was accomplished with spectrophotometric, titrimetric and HPLC methods of analysis; antioxidant activity was determined by the potentiometric method; antimicrobial and anti-fungi effects was evaluated by the well method and minimum inhibition concentration. The total content of phenolic compounds was 0.47% and 10.10%, organic acids – 4.27% and 1.60% for V. macrocarpon fruit thick and C. sinensis leaf extract. The total content of catechins in the C. sinensis leaf extract was 105,000 mg/kg, where epicatechin-3-O-gallate dominated (37300 mg/kg). The total content of anthocyanins in the V. macrocarpon fruit thick extract was 1280 mg/kg, where peonidin-3-O-galactoside dominated (408 mg/kg). Both extracts possessed a high antioxidant potential, and effective antimicrobial and anti-fungi effects. The antioxidant, antimicrobial and anti-fungi activity of V. macrocarpon fruit extract was higher than C. sinensis leaf extract. In addition, we assumed that anthocyanins had higher antioxidant, antimicrobial and anti-fungi properties than catechins. These findings would promote application of V. macrocarpon fruits extract as pharmaceuticals and nutraceuticals.

Dynamic DNA methylation modification in catechins and terpenoids biosynthesis during tea plant (Camellia sinensis) leaf development

DNA methylation plays important roles in regulating gene expression during development. However, little is known about the influence of DNA methylation on secondary metabolism during leaf development in the tea plant (Camellia sinensis). In this study, we combined the methylome, transcriptome, and metabolome to investigate the dynamic changes in DNA methylation and its potential regulatory roles in secondary metabolite biosynthesis. In this study, the level of genomic DNA methylation increased as leaf development progressed from tender to old leaf. It additionally exhibited a similar distribution across the genomic background at the two distinct developmental stages studied. Notably, integrated analysis of transcriptomic and methylomic data showed that DNA hypermethylation primarily occurred in genes of the phenylpropanoid, flavonoid, and terpenoid biosynthesis pathways. The effect of methylation on transcription of these secondary metabolite biosynthesis genes was dependent on the location of methylation (i.e., in the promoter, gene or intergenic regions) and the sequence context (i.e., CpG, CHG, or CHH). Changes in the content of catechins and terpenoids were consistent with the changes in gene transcription and the methylation state of structural genes, such as serine carboxypeptidase-like acyltransferases 1A (SCPL1A), leucoanthocyanidin reductase (LAR), and nerolidol synthase (NES). Our study provides valuable information for dissecting the effects of DNA methylation on regulation of genes involved in secondary metabolism during tea leaf development.

Investigating alterations of nutritional constituents, antioxidant abilities, and physicochemicals in aging processes of ginseng sprouts

This study was the first to document the fluctuations of nutritional constituents, antioxidant capacities, and physicochemical characteristics during the aging processes of red ginseng sprouts (RGS) and black ginseng sprouts (BGS) from dried ginseng sprouts (DGS). Total ginsenoside levels differed with 54.72 (DGS) → 57.15 (RGS) and 6.98 (BGS) mg/g, specifically, ginsenoside F2 and Rd2 in RGS remarkably increased with 1.97 → 5.88 and 2.41 → 5.49 mg/g, respectively. Phenolics increased dramatically as 297.02 → 1770.01 (6.0-fold); 1834.94 (6.2-fold) μg/g in DGS → RGS; BGS with abundance contents of benzoic acid (>15.3-fold), chlorogenic acid (>9.5-fold), and catechin (>4.2-fold), whereas amino acids markedly decreased (3686.81 → 1505.00; 364.64 mg/100 g), with arginine showing a significant decrease. Moreover, beneficial factors (total phenolic content: TPC; total flavonoid content: TFC; maillard reaction products: MRP) displayed increase tendencies (approximately 2.0-fold) with BGS > RGS > DGS, and antioxidant patterns significantly increased with potential capacities as follows: ABTS (48.3: DGS → 65.8: RGS; 70.2 %: BGS) > DPPH (18.5 → 44.6; 59.2 %) > hydroxyl (23.2 → 35.4; 39.9 %) > FRAP (0.6 → 1.8; 1.8 %) at 500 μg/mL. In particular, DNA protection exhibited excellent rates of 100 %, in the order of BGS (25 μg/mL) > RGS (50 μg/mL) > DGS (500 μg/mL). These findings suggest that processed ginseng sprouts can be excellent agents for natural antioxidants.