How did plants evolve the prenylation of specialized phenolic metabolites by means of UbiA prenyltransferases?

Prenylated phenolics occur in over 4000 species in the plant kingdom, most of which are known as specialized metabolites with high chemical diversity. Many of them have been identified as pharmacologically active compounds from various medicinal plants, in which prenyl residues play a key role in these activities. Prenyltransferases (PTs) responsible for their biosynthesis have been intensively studied in the last two decades. These enzymes are membrane-bound proteins belonging to the UbiA superfamily that occurs from bacteria to humans, and in particular those involved in plant specialized metabolism show strict specificities for both substrates and products. This article reviews the enzymatic features of plant UbiA PTs, including C- and O-prenylation, molecular evolution, and application of UbiA PTs in synthetic biology.

Bioactive Compound Profiling and Antioxidant Activity of Phytelephas tenuicaulis and Other Amazonian Fruits.

The Amazon region is home to many plant species, many of which have not been studied. The objective was to evaluate the physicochemical properties, bioactive compounds, and antioxidant activity of Phytelephas tenuicalis (tintiuk), Grias neuberthii (apai), Euterpe oleracea (acai), and Mauritia flexuosa (brown moriche). Physicochemical analyses were carried out on fresh fruit from local markets. Bioactive compounds (carotenoids, phenolics, vitamin C, and organic acids) were quantified in the freeze-dried pulp by rapid-resolution liquid chromatography (RRLC), and antioxidant activity was determined by ABTS and DPPH assays. The results showed high soluble solids (10.7 °Brix) and ascorbic acid (67.3 mg/100 g DW) in tintiuk; ß-carotene (63.4 mg/100 g DW) and malic acid (19.6 g/100 g DW) in brown moriche; quercetin (944.2 mg/100 g DW) and antioxidant activity by ABTS (6.7 mmol ET/100 g DW) in apai; and citric acid (2.1 g/100 g DW) in acai. These results indicate interesting bioactive properties that could increase the consumption of these fruits nationally and internationally, benefiting local farmers and stimulating the development of new products in functional food, medicine, and cosmetics.

Effects of Ultra-High-Pressure Treatment on Chemical Composition and Biological Activities of Free, Esterified and Bound Phenolics from Phyllanthus emblica L. Fruits.

Phyllanthus emblica L. fruits (PEFs) were processed by ultra-pressure (UHP) treatment and then extracted by the ultrasonic-assisted extraction method. The influence of UHP on the phenolic composition, enzyme inhibitory activity and antioxidant activity of the free, esterified, and bound phenolic fractions from PEFs were compared. UHP pretreatment of PEFs significantly increased the total phenolic and flavonoid contents (p < 0.05). A total of 24 chemical compositions were characterized in normal and UHP-treated PEFs by UHPLC-ESI-HRMS/MS. Compared with normal PEFs, these three different phenolic fractions had stronger antioxidant activities and inhibitory effects on the intracellular reactive oxygen species (ROS) production in H2O2-induced HepG2 cells (p < 0.05). The ROS inhibition might be due to an up-regulation of the expressions of superoxide dismutase (SOD) and glutathione (GSH) activities. In addition, these three different phenolic fractions also significantly inhibited the activities of metabolic enzymes, including α-glucosidase, α-amylase and pancreatic lipase. This work may provide some insights into the potential economics and applications of PEFs in food and nutraceutical industries.

The Impact of ZnO and Fe2O3 Nanoparticles on Sunflower Seed Germination, Phenolic Content and Antiglycation Potential.

The enhancement of seed germination by using nanoparticles (NPs) holds the potential to elicit the synthesis of more desired compounds with important biomedical applications, such as preventing protein glycation, which occurs in diabetes. Here, we used 7 nm and 100 nm ZnO and 4.5 nm and 16.7 nm Fe2O3 NPs to treat sunflower seeds. We evaluated the effects on germination, total phenolic content, and the anti-glycation potential of extracted polyphenols. Sunflower seeds were allowed to germinate in vitro after soaking in NP solutions of different concentrations. Polyphenols were extracted, dosed, and used in serum albumin glycation experiments. The germination speed of seeds was significantly increased by the 100 nm ZnO NPs and significantly decreased by the 4.5 nm Fe2O3 NPs. The total phenolic content (TPC) of seeds was influenced by the type of NP, as ZnO NPs enhanced TPC, and the size of the NPs, as smaller NPs led to improved parameters. The polyphenols extracted from seeds inhibited protein glycation, especially those extracted from seeds treated with 7 nm ZnO. The usage of NPs impacted the germination speed and total polyphenol content of sunflower seeds, highlighting the importance of NP type and size in the germination process.

Untargeted metabolomic profiling of Prinsepia utilis Royle leaves by Ultra-Performance Liquid Chromatography-Quadrupole-Time of Flight-Mass Spectrometry.

Prinsepia utilis Royle, native to the Himalayas, is esteemed in Chinese and Indian folk medicine for its diverse medicinal benefits, targeting arthritis, pain relief, bone disorders, and joint discomfort. This study examined the 25% aqueous methanol extract of P. utilis leaves using UPLC-Q-TOF-MS/MS, identifying 78 metabolites, 76 of which were reported for the first time in P. utilis. These included 64 phenolics represented by 56 flavonoids, 5 phenolic acids, 3 phenolic glycosides, 4 terpenoids, 2 lignan glycosides, and 8 other compounds, expanding the knowledge of its chemical composition. These findings lay a foundation for further research, providing insights into potential bioactive compounds and opening avenues for applications in natural product drug discovery, traditional medicine, and nutraceutical development, leveraging the plant's established traditional uses.

Amelioration activity of the high bioaccessible chrysanthemum (Gongju) phenolics on alcohol-induced oxidative injury in AML-12 cells.

The main bioavailable phenolics from of Gongju (GJ) and their mechanism for hepato-protection remain unclear. To select the GJ phenolics with high bioavailability, chrysanthemum digestion and Caco-2 cells were used and their hepato-protective potential were examined by using AML-12 cells. The digestive recovery and small intestinal transit rate of the main phenolic compounds ranged from 28.52 to 69.53% and 6.57% âˆ¼ 15.50%, respectively. Among them, chlorogenic acid, 3,5-dicaffeoylquinic acid, and 1,5-dicaffeoylquinic acid, showed higher small intestinal transit rates and digestive recoveries. Furthermore, we found that by increasing intracellular Catalase (CAT) and Superoxide dismutase (SOD) viability and lowering Malondialdehyde (MDA) level (P < 0.05), 3,5-dicaffeoylquinic acid significantly mitigated the oxidative damage of AML-12 liver cells more than the other two phenolics. Our results demonstrated that 3,5-dicaffeoylquninic acid was the primary phenolic compounds in GJ that effectively reduced liver damage, providing a theoretical basis for the development of GJ as a potentially useful resource for hepatoprotective diet.

Liberated bioactive bound phenolics during in vitro gastrointestinal digestion and colonic fermentation boost the prebiotic effects of triticale insoluble dietary fiber.

Phenolics in bound form extensively exist in cereal dietary fiber, especially insoluble fiber, while their release profile in gastrointestinal tract and contribution to the potential positive effects of dietary fiber in modulating gut microbiota still needs to be disclosed. In this work, the composition of bound phenolics (BPs) in triticale insoluble dietary fiber (TIDF) was studied, and in vitro gastrointestinal digestion as well as colonic fermentation were performed to investigate BPs liberation and their role in regulating intestinal flora of TIDF. It turned out that most BPs were unaccessible in digestion but partly released continuously during fermentation. 16 s rRNA sequencing demonstrated that TIDF possessed prebiotic effects by promoting anti-inflammatory while inhibiting proinflammatory bacteria alongside boosting SCFAs production and antioxidative BPs contributed a lot to these effects. Results indicated that TIDF held capabilities to regulate intestinal flora and BPs were important functional components to the health benefits of cereal dietary fiber.

Effect of preharvest biofilm application regimes on cracking and fruit quality traits in '0900 Ziraat' sweet cherry cultivar.

BACKGROUND: Fruit cracking impacts the quality of sweet cherry, significantly affecting its marketability due to increased susceptibility to injury, aesthetic flaws, and susceptibility to pathogens. The effect of 1% biofilm (Parka™) application regimes on fruit cracking and other quality parameters in the '0900 Ziraat' cherry cultivar was investigated in this study. Fruit sprayed with water were served as control (U1). Fruit treated only once with biofilm three, two and one week before the commercial harvest were considered as U2, U3 and U4, respectively. Fruit treated with biofilm three, two, and one week before harvest were considered as U5; three and two week before harvest as U6; two and one week before harvest as U7; and fruit treated three and one week before harvest as U8. RESULTS: In both measurement periods, the lower cracking index was obtained in biofilm-treated sweet cherry fruit. However, the firmness of biofilm-treated fruit was higher than that of the control fruit. The lowest respiration rate was observed in U7, while the highest weight was recorded in U4 and U5 than the control. The biofilm application decreased fruit coloration. The biofilm application also increased the soluble solids content of the fruit. The U2, U3 and U4 applications at harvest showed higher titratable acidity than the control. In both measurement periods, the vitamin C content of the U2, U5, U6, U7 and U8 applications was found to be higher than that of the control. The total monomeric anthocyanin of the U3 and U8 applications was higher than that of the control. Furthermore, the antioxidant activity of the U2, U3 and U5 in the DPPH, and the U7 and U8 in FRAP were measured higher thanthat of the control. CONCLUSIONS: The application of biofilms has the potential to mitigate fruit cracking, prolong postharvest life of sweet cherries, and enhance fruit firmness.

Identification and Evaluation of Olive Phenolics in the Context of Amine Oxidase Enzyme Inhibition and Depression: In Silico Modelling and In Vitro Validation.

The Mediterranean diet well known for its beneficial health effects, including mood enhancement, is characterised by the relatively high consumption of extra virgin olive oil (EVOO), which is rich in bioactive phenolic compounds. Over 200 phenolic compounds have been associated with Olea europaea, and of these, only a relatively small fraction have been characterised. Utilising the OliveNetTM library, phenolic compounds were investigated as potential inhibitors of the epigenetic modifier lysine-specific demethylase 1 (LSD1). Furthermore, the compounds were screened for inhibition of the structurally similar monoamine oxidases (MAOs) which are directly implicated in the pathophysiology of depression. Molecular docking highlighted that olive phenolics interact with the active site of LSD1 and MAOs. Protein-peptide docking was also performed to evaluate the interaction of the histone H3 peptide with LSD1, in the presence of ligands bound to the substrate-binding cavity. To validate the in silico studies, the inhibitory activity of phenolic compounds was compared to the clinically approved inhibitor tranylcypromine. Our findings indicate that olive phenolics inhibit LSD1 and the MAOs in vitro. Using a cell culture model system with corticosteroid-stimulated human BJ fibroblast cells, the results demonstrate the attenuation of dexamethasone- and hydrocortisone-induced MAO activity by phenolic compounds. The findings were further corroborated using human embryonic stem cell (hESC)-derived neurons stimulated with all-trans retinoic acid. Overall, the results indicate the inhibition of flavin adenine dinucleotide (FAD)-dependent amine oxidases by olive phenolics. More generally, our findings further support at least a partial mechanism accounting for the antidepressant effects associated with EVOO and the Mediterranean diet.

Potential Large-Scale CO2 Utilisation for Salicylic Acid Production via a Suspension-Based Kolbe-Schmitt Reaction in Toluene.

Conversion of CO2 into organic chemicals offers a promising route for advancing the circularity of carbon capture, utilisation, and storage in line with the international 2050 Net Zero agenda. The widely known commercialised chemical fixation of CO2 into organic chemicals is the century-old Kolbe-Schmitt reaction, which carboxylates phenol (via sodium phenoxide) into salicylic acid. The carboxylation reaction is normally carried out between the gas-solid phases in a batch reactor. The mass and heat transfer limitations of such systems require rather long reaction times and a high pressure of CO2 and are often characterised by the low formation of undesirable side products. To address these drawbacks, a novel suspension-based carboxylation method has been designed and carried out in this present study, where sodium phenoxide is dispersed in toluene to react with CO2. Importantly, the addition of phenol played a critical role in promoting the stoichiometric conversion of phenoxide to salicylic acid. Under the optimal conditions of a phenol/phenoxide molar ratio of 2:1 in toluene, a reaction temperature of 225 °C, a CO2 pressure of 30 bar, a reaction time of 2 h, and stirring at 1000 rpm, an impressive salicylic acid molar yield of 92.68% has been achieved. The reaction mechanism behind this has been discussed. This development provides us with the potential to achieve a carboxylation reaction of phenoxide with CO2 more effectively in a continuous reactor. It can also facilitate the large-scale fixing of CO2 into hydroxy aromatic carboxylic acids, which can be used as green organic chemical feedstocks for making various products, including long-lived polymeric materials.

Comparing Nutritional Values and Bioactivity of Kefir from Different Types of Animal Milk.

The growing interest in fermented dairy products is due to their health-promoting properties. The use of milk kefir grains as a starter culture made it possible to obtain a product with a better nutritional and biological profile depending on the type of milk. Cow, buffalo, camel, donkey, goat, and sheep milk kefirs were prepared, and the changes in sugar, protein, and phenol content, fatty acid composition, including conjugated linoleic acids (CLAs), as well as antioxidant activity, determined by ABTS and FRAP assays, were evaluated and compared. The protein content of cow, buffalo, donkey, and sheep milk increased after 24 h of fermentation. The fatty acid profile showed a better concentration of saturated and unsaturated lipids in all fermented milks, except buffalo milk. The highest content of beneficial fatty acids, such as oleic, linoleic, and C18:2 conjugated linoleic acid, was found in the cow and sheep samples. All samples showed a better antioxidant capacity, goat milk having the highest value, with no correlation to the total phenolic content, which was highest in the buffalo sample (260.40 ± 5.50 µg GAE/mL). These findings suggested that microorganisms living symbiotically in kefir grains utilize nutrients from different types of milk with varying efficiency.

Multiplexed colorimetric assay of antioxidants in wines with paper-based sensors fabricated by pen plotting.

This work reports the development of low-cost and rapid multiplexed colorimetric assay of antioxidants (total phenolics, antioxidant capacity, flavonoids and anthocyanins) in wines at daisy-shaped fluidic paper-based analytical devices (PADs). The desired fluidic patterns were formed on paper by pen drawing and colorimetric reagents were immobilized at the 6 peripheral test zones. The sample was added at the central sample zone, migrated to the test zones and reacted with the immobilized reagents producing characteristic colors that were captured and analyzed. The paper-based approach was applied to the analysis of several wine samples and the results were statistically correlated to standard solution-based colorimetric assays, indicating that it could be reliably used for ranking wines according to their antioxidants content. In addition, the paper-based analytical methodology is simple, instrument-free, portable, cost-effective, rapid and environment friendly.

RNA-Seq transcriptome profiling of Nile rat livers reveals novel insights on the anti-diabetic mechanisms of Water-Soluble Palm Fruit Extract.

Water-Soluble Palm Fruit Extract (WSPFE) has been shown to confer anti-diabetic effects in the Nile rat (NR) (Arvicanthis niloticus). Liquid and powder WSPFE both deterred diabetes onset in NRs fed a high-carbohydrate (hiCHO) diet, but the liquid form provided better protection. In this study, NRs were fed either a hiCHO diet or the same diet added with liquid or powder WSPFE. Following feeding of the diets for 8 weeks, random blood glucose levels were measured to categorize NRs as either diabetes-resistant or diabetes-susceptible, based on a cut-off value of 75 mg/dL. Livers were then obtained for Illumina HiSeq 4000 paired end RNA-sequencing (RNA-Seq) and the data were mapped to the reference genome. Consistent with physiological and biochemical parameters, the gene expression data obtained indicated that WSPFE was associated with protection against diabetes. Among hepatic genes upregulated by WSPFE versus controls, were genes related to insulin-like growth factor binding protein, leptin receptor, and processes of hepatic metabolism maintenance, while those downregulated were related to antigen binding, immunoglobulin receptor, inflammation- and cancer-related processes. WSPFE supplementation thus helped inhibit diabetes progression in NRs by increasing insulin sensitivity and reducing both the inflammatory effects of a hiCHO diet and the related DNA-damage compensatory mechanisms contributing to liver disease progression. In addition, the genetic permissiveness of susceptible NRs to develop diabetes was potentially associated with dysregulated compensatory mechanisms involving insulin signaling and oxidative stress over time. Further studies on other NR organs associated with diabetes and its complications are warranted.

Impact of Lactic Acid Bacteria Fermentation Based on Biotransformation of Phenolic Compounds and Antioxidant Capacity of Mushrooms.

Mushrooms contain phenolic compounds that possess health-promoting properties, including antioxidant effects. However, the low solubility and form of phenolic compounds affect their bioactivity and bioaccessibility. To overcome this limitation, our study investigates the fermentation of mushrooms to increase their free phenolic content and enhance their bioactivity. Our research focused on the impact of fermentation on both free and bound phenolic fractions (FPs and BPs, respectively) in Lentinula edodes and Lactarius deliciosus, which were successively fermented with Lactiplantibacillus plantarum LMG 17673 for 72 h. We examined the total phenolic content (TPC), phenolic profile, and antioxidant activity of both FPs and BPs. Our results showed that the TPC of BPs was higher than that of FPs in both mushrooms, with strong antioxidant capabilities. Fermentation significantly increased the TPC of FPs in both mushrooms, particularly after 24 h of fermentation. The TPC of BPs in mushrooms decreased during fermentation, indicating their release from the matrix. Additionally, we identified 30 bioactive compounds using UPLC-Q-TOF-MS/MS. Our study demonstrates for the first time that lactic acid bacteria fermentation of mushrooms with high phenolic content leads to the liberation of bound phenolics, enhancing their bioactivity and bioaccessibility.

Influence of Mulberry Leaf Powder Additive on Chemical and Physical Characteristics of Wheat and Rice Flour Butter Cookies.

People of all age groups consume cookies every day. Consumers' preferences for cookies supplemented with functional plant raw materials have recently increased. Therefore, this research aimed to investigate the influence of a mulberry leaf additive on the proximate and mineral compositions, total phenolic and total chlorophyll content, antioxidant activity, and the hardness and color properties of butter cookies. Wheat and rice flour butter cookies were prepared by replacing the flour with mulberry leaf powder at 0, 4, 8, and 12% (w/w). The results revealed that the investigated chemical and physical characteristics of butter cookies depend on the flour used (rice or wheat) and the addition of mulberry leaf powder. Wheat and rice flour cookies with 12% mulberry leaf powder had the significantly highest contents of fiber (20.34 and 20.23%, respectively), ash (1.73 and 1.75%, respectively), K (170.22 and 160.22 mg 100 g-1, respectively), and Ca (170.45 and 160.68 mg 100 g-1, respectively). The rice flour cookies enriched with 12% leaf powder had the greatest amounts of total phenolics (1.48 mg 100 g-1), Zn (12.25 mg kg-1), Mn (6.28 mg kg-1), Cu (1.95 mg kg-1), and antioxidant activity (67.98%). However, the wheat cookies without mulberry leaf powder contained the most B (9.12 mg kg-1), while the no-added rice cookies contained the most Fe (14.30 mg kg-1). Replacing flour with leaf powder increased the cookies' hardness and decreased their lightness. In conclusion, enriching butter cookies with freeze-dried mulberry leaves can improve their nutritional value and antioxidant activity.

Comparative Antioxidant Activity and Untargeted Metabolomic Analyses of Sour Cherry Cultivars Based on Ultra-Performance-Time of Flight-Mass Spectrometry.

This study was conducted for the comparative analysis of antioxidant activity and untargeted metabolomics of dark- and light-colored sour cherry cultivars grown in Canada. Based on our previous study, we selected four cultivars-'Heimann R', 'Gorsemska', V70142, and 'Montmorency'-to determine the untargeted metabolites and their role in antioxidant activities. A total of 473 metabolites were identified from four sour cherry genotypes using UPLC-ToF-MS. Untargeted metabolomics revealed the dominant chemical groups present in sour cherries. PCA showed that the diversity in sour cherry metabolites was due to the genotype differences indicating iditol, malic acid, chlorobenzene, 2-mercaptobenzothiazole, and pyroglutamic acid as the predominant contributors. The variable importance in the projection (VIP > 1.0) in partial least-squares-discriminant analysis described 20 biomarker metabolites representing the cherry metabolome profiles. A heatmap of Pearson's correlation analysis between the 20 biomarker metabolites and antioxidant activities identified seven antioxidant determinants that displayed the highest correlations with different types of antioxidant activities. TPC and TAC were evaluated using the Folin-Ciocalteu method. The total antioxidant activity was performed using three different assays (ABTS, FRAP, and DPPH). This study of correlating metabolomics and antioxidant activities elucidated that the higher nutritional value and biological functions of sour cherry genotypes can be useful for the development of nutraceutical and functional foods.

Can Simulated Microgravity and Darkness Conditions Influence the Phytochemical Content and Bioactivity of the Sprouts?-A Preliminary Study on Selected Fabaceae Species.

Sprouts' consumption has become popular due to their wide availability, easy cultivation process, and proven biological activity. Moreover, stress factors, such as limited access to light or disturbed gravity during growth, may contribute to the increased activity and the synthesis of bioactive compounds. In this study, for the first time, the examination of the impact of darkness and simulated microgravity conditions on the white clover sprouts from the Fabaceae family was conducted. Among several species, used in the preliminary attempts, only white clover was satisfactory sprouting in the disturbed gravity conditions, and thus was chosen for further examination. A random positioning machine setup was used during the cultivation process to simulate microgravity conditions. Additionally, the sprouts were cultivated in total darkness. Simulated microgravity and/or darkness during the first few days of the sprouts' growth caused biomass reduction, the increased synthesis of bioactive compounds (isoflavones and phenolics), and changes in the level of abscisic acid and phenylalanine ammonia-lyase. Moreover, it increased the antioxidant properties of the sprouts, while the enhancement of their cytotoxic impact was observed only for androgen-dependent prostate cancer LNCaP cells. To conclude, the presented results are promising in searching for novel functional food candidates and further studies are necessary, directed at other plant families.

Green Separation by Using Nanofiltration of Tristerix tetrandus Fruits and Identification of Its Bioactive Molecules through MS/MS Spectrometry.

Membrane technology allows the separation of active compounds, providing an alternative to conventional methods such as column chromatography, liquid-liquid extraction, and solid-liquid extraction. The nanofiltration of a Muérdago (Tristerix tetrandus Mart.) fruit juice was realized to recover valuable metabolites using three different membranes (DL, NFW, and NDX (molecular weight cut-offs (MWCOs): 150~300, 300~500, and 500~700 Da, respectively)). The metabolites were identified by ESI-MS/MS. The results showed that the target compounds were effectively fractionated according to their different molecular weights (MWs). The tested membranes showed retention percentages (RPs) of up to 100% for several phenolics. However, lower RPs appeared in the case of coumaric acid (84.51 ± 6.43% (DL), 2.64 ± 2.21% (NFW), 51.95 ± 1.23% (NDX)) and some other phenolics. The RPs observed for the phenolics cryptochlorogenic acid and chlorogenic acid were 99.74 ± 0.21 and 99.91 ± 0.01% (DL membrane), 96.85 ± 0.83 and 99.20 ± 0.05% (NFW membrane), and 92.98 ± 2.34 and 98.65 ± 0.00% (NDX membrane), respectively. The phenolic quantification was realized by UHPLC-ESI-MS/MS. The DL membrane allowed the permeation of amino acids with the MW range of about 300~100 Da (aspartic acid, proline, tryptophan). This membrane allowed the highest permeate flux (22.10-27.73 L/m2h), followed by the membranes NDX (16.44-20.82 L/m2h) and NFW (12.40-14.45 L/m2h). Moreover, the DL membrane allowed the highest recovery of total compounds in the permeate during the concentration process (19.33%), followed by the membranes NFW (16.28%) and NDX (14.02%). Permeate fractions containing phenolics and amino acids were identified in the membrane permeates DL (10 metabolites identified), NFW (13 metabolites identified), and NDX (10 metabolites identified). Particularly, tryptophan was identified only in the DL permeate fractions obtained. Leucine and isoleucine were identified only in the NFW permeate fractions, whereas methionine and arginine were identified only in the NDX ones. Liquid permeates of great interest to the food and pharmaceutical industries were obtained from plant resources and are suitable for future process optimization and scale-up.

Cytokinins enhance the metabolic activity of in vitro-grown catmint (Nepeta nuda L.).

The phytohormones cytokinins are essential mediators of developmental and environmental signaling, primarily during cell division and endophytic interactions, among other processes. Considering the limited understanding of the regulatory mechanisms that affect the growth and bioactivity of the medicinal plant Nepeta nuda (Lamiaceae), our study aimed to explore how cytokinins influence the plant's metabolic status. Exogenous administration of active cytokinin forms on in vitro N. nuda internodes stimulated intensive callus formation and de novo shoot regeneration, leading to a marked increase in biomass. This process involved an accumulation of oxidants, which were scavenged by peroxidases using phenolics as substrates. The callus tissue formed upon the addition of the cytokinin 6-benzylaminopurine (BAP) acted as a sink for sugars and phenolics during the allocation of nutrients between the culture medium and regenerated plants. In accordance, the cytokinin significantly enhanced the content of polar metabolites and their respective in vitro biological activities compared to untreated in vitro and wild-grown plants. The BAP-mediated accumulation of major phenolic metabolites, rosmarinic acid (RA) and caffeic acid (CA), corresponded with variations in the expression levels of genes involved in their biosynthesis. In contrast, the accumulation of iridoids and the expression of corresponding biosynthetic genes were not significantly affected. In conclusion, our study elucidated the mechanism of cytokinin action in N. nuda in vitro culture and demonstrated its potential in stimulating the production of bioactive compounds. This knowledge could serve as a basis for further investigations of the environmental impact on plant productivity.

Compositional Consequences of Ultrafiltration Treatment of White and Red Wines.

Clarification and stabilisation processes are routinely performed post-fermentation to 'finish' wines, but traditional methods are slow and energy intensive, create waste, and can affect wine volume and quality. New methods that 'finish' wine rapidly, with higher recovery rates, and reduced waste and input costs, are therefore needed. Ultrafiltration is a separation process that fractionates liquids, nominally, according to molecular weight. By comparing the composition of permeate and retentate derived from pilot-scale fractionation of white and red wine using 75, 20, or 10 kDa membranes and different degrees of permeation (50, 80, 90, or 95%), this study sought to evaluate ultrafiltration as an innovative approach to the clarification and stabilisation of wine. Mass balance analysis confirmed that titratable acidity and alcohol were fractionated according to the degree of permeation; however, proteins, polysaccharides, and phenolic compounds (including anthocyanins for red wine) were concentrated in retentate due both to the membrane molecular weight cut-off (MWCO) specifications and degree of permeation. The retention of wine constituents smaller than the nominal MWCO suggests that interaction with other macromolecules or the membrane surface occurred. Red wine permeates were stripped of much of their essential character and were no longer considered commercially acceptable. In contrast, the removal of protein and phenolic compounds from white wine demonstrated the potential for ultrafiltration to remediate heat unstable or excessively phenolic wines. Findings enabled the identification of other winemaking applications of ultrafiltration technology that could enhance wine quality, process efficiency, and profitability.