Phenolic Compounds Research Articles

Implications of Ultrasonication-assisted Extraction with Response Surface Methodology on Phytochemical Compositions and Antioxidant Activity of Polysaccharide Extract from Phellinus rimosus (Berk.) Pilát Cultivated Mycelia in Northeastern Thailand

Background: Polysaccharides from the medicinal mushroom Phellinus rimosus (Berk.) Pilát (PR) are the major functional bioactive ingredients. However, there has been a marked natural decrease in the number of PR fruit bodies, leading to their increased cost. Moreover, the natural growth and development of mature PR fruit bodies takes several decades. Objective: The objective of this study was to produce a polysaccharide extract from cultured PR mycelia (PEPRM) by using ultrasonic-assisted extraction with response surface methodology (RSM), and determine its physicochemical composition and antioxidant potential. Methods: Polysaccharide and monosaccharide composition analyses were carried out by Fouriertransform infrared spectroscopy (FT-IR) and High-performance liquid chromatography (HPLC). Total contents of polysaccharides, beta-glucans, phenolic compounds, and flavonoids were investigated utilizing the phenol-sulfuric acid method, enzymatic-based commercial test kit, Folin-Ciocalteu method, and aluminium chloride colorimetric method, respectively. Antioxidant activity was determined by using 2,2-diphenyl-1-picrylhydrazyl-hydrate (DPPH) radical scavenging assay and 2,2- azino-bis (3-ethylbenzothiazol-6-sulfonic acid) (ABTS) radical cation decolorization assay. Results: Optimal conditions for the production of PEPRM included a ratio of 51.29 mL water to 1 g PR mycelia and an extraction time of 46.23 minutes, resulting in a total polysaccharide content of 577.5 mg/g of PEPRM. FT-IR spectra of PEPRM showed two broad bands at 3272.08 cm-1 and 2924.8 cm-1 in the carbohydrate region and the peaks at 1078.44, 1019.05, and 853.0 cm-1 indicated the presence of the pyranose ring skeleton, glycosidic linkage, and glucans. PEPRM had molar ratios of glucose: mannose: rhamnose: fucose, i.e., 21.86: 1.00: 2.08: 3.40, respectively. PEPRM had total contents of beta-glucans, phenolic compounds, and flavonoids as percentages of dry weight, i.e., 21.22, 2.51, and 5.71, respectively. PEPRM showed better inhibitory activity against ABTS radicals than DPPH radicals. result: Optimal conditions for the production of PEPRM were a ratio of 51.29 ml water to 1 g PR mycelia and extraction time of 46.23 min, yielding a total polysaccharide content of 577.5 mg/g of PEPRM. FT-IR spectra of PEPRM showed two broad bands at 3272.08 cm-1 and 2924.8 cm-1 in the carbohydrate region and the peaks at 1078.44, 1019.05, and 853.0 cm-1 indicated the presence of the pyranose ring skeleton, glycosidic linkage, and glucans. PEPRM had molar ratios of glucose: mannose: rhamnose: fucose, i.e., 21.86: 1.00: 2.08: 3.40, respectively. PEPRM had total contents of beta-glucan, phenolic compounds, and flavonoids as percentages of dry weight, i.e., 21.22, 2.51, and 5.71, respectively. PEPRM showed better inhibitory activity against ABTS radicals than DPPH radicals. Conclusion: This is the first finding to reveal that ultrasonic-assisted extraction with RSM was an environmentally friendly alternative to produce antioxidant polysaccharides from cultured PR mycelia. conclusion: This is the first finding to reveal that ultrasonic-assisted extraction with RSM was an environmentally friendly alternative to produce antioxidant polysaccharides from cultured PR mycelia.

Seasonal changes in the phenolic compound contents and bioactivities in Betula platyphylla bark determined by soil properties

The white birch (Betula platyphylla Suk.) is widespread in eastern Asia, and its bark is a valuable resource for secondary metabolite extraction. Limited information is available regarding seasonal variations of secondary metabolites in white birch bark. In our study, we analyzed the phenolic compound contents and bioactivities of white birch bark in different seasons and their relationship to climatic factors and soil properties. The data suggested that the levels of total phenol, total flavonoid, seven individual phenolic compounds, and bioactivities all peaked in September. The antioxidant activity was positively correlated with the contents of phenolic compounds. Soil microbial properties like microbial biomass nitrogen (MBN) and soil urease activities (URE) explained more than 40% of the variation in phenolic compound contents. This study highlighted that seasons regulate the contents of phenolic compounds and bioactivities by influencing soil microbial properties. The soil with low microbial activity was more favorable for the accumulation of secondary metabolites.

Natural Phenolic Compounds with Antithrombotic and Antiplatelet Effects: A Drug-likeness Approach.

Thrombosis is one of the major causes of morbidity and mortality in a wide range of vessel diseases. Several studies have been conducted to identify antithrombotic agents from medicinal plants, and phenolic compounds (PCs) have been shown to effectively inhibit plasma coagulation and platelet aggregation. This study aimed to conduct a survey of the natural PCs with proven antithrombotic and antiplatelet activities, as well as to evaluate by computational modeling the physicochemical and toxicological properties of these compounds using drug-likeness approaches. The data were collected from the scientific database: 'Web of Science', 'Scifinder', 'Pubmed', 'ScienceDirect' and 'Google Scholar', the different classes of PCs with antithrombotic or antiplatelet effects were used as keywords. These molecules were also evaluated for their Drug-Likeness properties and toxicity to verify their profile for being candidates for new antithrombotic drugs. In this review, it was possible to register 85 lignans, 73 flavonoids, 28 coumarins, 21 quinones, 23 phenolic acids, 8 xanthones and 8 simple phenols. Activity records for tannins were not found in the researched databases. Of these 246 compounds, 213 did not violate any of Lipinski's rules of five, of which 125 (59%) showed non-toxicity, being promising candidates for new potential antithrombotic drugs. This review arouses interest in the isolation of phenolic compounds that may allow a new approach for the prevention of both arterial and venous thrombosis, with the potential to become alternatives in the prevention and treatment of cardiovascular diseases.

The Golden Spice for Life: Turmeric with the Pharmacological Benefits of Curcuminoids Components, Including Curcumin, Bisdemethoxycurcumin, and Demethoxycurcumins.

Turmeric (Curcuma longa L.), belonging to the Zingiberaceae family, is a perennial rhizomatous plant of tropical and subtropical regions. The three major chemical components responsible for the biological activities of turmeric are curcumin, demethoxycurcumin, and bisdemethoxycurcumin. The literature search included review articles, analytical studies, randomized control experiments, and observations, which have been gathered from various sources, such as Scopus, Google Scholar, PubMed, and ScienceDirect. A review of the literature was carried out using the keywords: turmeric, traditional Chinese medicine, traditional Iranian medicine, traditional Indian medicine, curcumin, curcuminoids, pharmaceutical benefits, turmerone, demethoxycurcumin, and bisdemethoxycurcumin. The main components of the rhizome of the leaf are α-turmerone, β-turmerone, and arturmerone. The notable health benefits of turmeric are antioxidant activity, gastrointestinal effects, anticancer effects, cardiovascular and antidiabetic effects, antimicrobial activity, photoprotector activity, hepatoprotective and renoprotective effects, and appropriate for the treatment of Alzheimer's disease and inflammatory and edematic disorders. Curcuminoids are phenolic compounds usually used as pigment spices with many health benefits, such as antiviral, antitumour, anti-HIV, anti-inflammatory, antiparasitic, anticancer, and antifungal effects. Curcumin, bisdemethoxycurcumin, and demethoxycurcumin are the major active and stable bioactive constituents of curcuminoids. Curcumin, which is a hydroponic polyphenol, and the main coloring agent in the rhizomes of turmeric, has anti-inflammatory, antioxidant, anti-cancer, and anticarcinogenic activities, as well as beneficial effects for infectious diseases and Alzheimer's disease. Bisdemethoxycurcumin possesses antioxidant, anti-cancer, and anti-metastasis activities. Demethoxycurcumin, which is another major component, has anti-inflammatory, antiproliferative, and anti-cancer activities and is the appropriate candidate for the treatment of Alzheimer's disease. The goal of this review is to highlight the health benefits of turmeric in both traditional and modern pharmaceutical sciences by considering the important roles of curcuminoids and other major chemical constituents of turmeric.

Plant Extract-Mediated Synthesis of Silver Nanoparticles and Their Anticancer Potentials

Five plant extracts (Ardisia argentea, Aegiceras corniculatum, Polycarpaea corymbosa, Maesa perlaria, and Schima wallichii) were utilized as reducing agents in the synthesis of silver nanoparticles (AgNPs) through a green route. As the reducing power and total content of phenolic compounds in the extract increased, the absorbance of the surface plasmon resonance of the resulting AgNPs also increased. The characteristic surface plasmon resonance was clearly observed at 400∼500 nm. The AgNPs were spherical, as shown by field emission transmission electron microscopy images, with an average size between 10.4±0.3 nm and 22.2±0.8 nm. The cytotoxicity in A549 (lung cancer) and HeLa (cervical cancer) cells increased in a dose-dependent manner. Specifically, at the highest dose, the AgNPs synthesized with the A. corniculatum extract exhibited the highest cytotoxicity and induced high levels of reactive oxygen species (ROS). Interestingly, it was observed that smaller AgNPs tended to generate higher levels of ROS. Cell death was clearly observed in the treatment with the AgNPs. A G2/M phase arrest occurred in cell cycle analysis, which induced cell death. The results obtained herein support the potential of natural product-mediated synthesis of AgNPs as a promising anticancer nanomedicine.

Chia (Salvia hispanica L.), a functional 'superfood': new insights into its botanical, genetic and nutraceutical characteristics.

Chia (Salvia hispanica L.) seeds have become increasingly popular among health-conscious consumers due to their high content of ω-3 fatty acids, which provide various health benefits. Comprehensive chemical analyses of chia seeds' fatty acids and proteins have been conducted, revealing their functional properties. Recent studies have confirmed the high ω-3 content of chia seed oil and have hinted at additional functional characteristics. This review article aims to provide an overview of the botanical, morphological, and biochemical features of chia plants, seeds, and seed mucilage. Additionally, we discuss the recent developments in genetic and molecular research on chia, including the latest transcriptomic and functional studies that examine the genes responsible for chia fatty acid biosynthesis. In recent years, research on chia seeds has shifted its focus from studying the physicochemical characteristics and chemical composition of seeds to understanding the metabolic pathways and molecular mechanisms that contribute to their nutritional benefits. This has led to a growing interest in various pharmaceutical, nutraceutical, and agricultural applications of chia. In this context, we discuss the latest research on chia, as well as the questions that remain unanswered, and identify areas that require further exploration. Nutraceutical compounds associated with significant health benefits including ω-3 PUFAs, proteins, and phenolic compounds with antioxidant activity have been measured in high quantities in chia seeds. However, comprehensive investigations through both in vitro experiments and in vivo animal and controlled human trials are expected to provide greater clarity on the medicinal, antimicrobial, and antifungal effects of chia seeds. The recently published genome of chia and gene editing technologies, such as CRISPR, facilitate functional studies deciphering molecular mechanisms of biosynthesis and metabolic pathways in this crop. This necessitates development of stable transformation protocols and creation of a publicly available lipid database, mutant collection, and large-scale transcriptomic datasets for chia.

Protective potential of onion eco-extract: safeguarding chicken patties from oxidative deterioration.

Onions contain valuable phytochemical compounds, including quercetin derivatives. This study explores the potential of onion extract as a natural additive in chicken patties. The optimized conditions involved sonication at 80% for 5 min with a 75% ethanol concentration. The onion extract exhibited total phenolic and flavonoid compound values of 255.63 mg GAE g-1 DR and 196.87 mg QE g-1 DR, respectively. The antioxidant activity of the onion extract was characterized by an IC50 of 12.74 µg/mL. This onion extract was dominated by quercetin derivatives (quercetin 4'-O-β-glycoside and quercetin-3-O-β-glycoside and quercetin-3,4'-O-β-diglycoside). Chicken patties treated with 2% onion extract exhibited superior pH stability, lowest thiobarbituric acid reactive substances level (0.40 mg/kg) and peroxide index (0.77 mEq O2/kg meat) and maintained color stability. Comparative analysis with BHT demonstrated the efficacy of onion extract in reducing lipid oxidation. These findings highlight the potential of a 2% onion extract as effective ingredient for enhancing the quality of chicken products.

Antioxidant Activities and Laxative Effect of Bioactive Compounds from Cynara cardunculus var. sylvestris

The present study aims to investigate the antioxidant and anti-constipation activities of the derived phenolic extracts in ribs wild cardoon (Cynara sylvestris). Analysed extracts (acetone, methanol and aqueous) exhibited high level of phenolic compounds and excellent antioxidant activities with significant IC50 values (p ≤0.05), as assessed by the DPPH radical-scavenging activity (0.84±0.08 - 2.44±0.007 μg/mL), ABTS cationic radical test (0.96 ±0.01- 136.67±6.75 μg/mL) and β-carotene bleaching assay (2.09±0.02-51.12±1.32 μg/mL). Also, higher levels of insoluble dietary fibers were found (56.18 ± 0.91% DW of neutral detergent fiber). The in vivo investigation was performed on Wistar rats to explore the ability of C. sylvestris aqueous extract (CSAE) in the enhancement of the gastrointestinal transit and the treatment of induced constipation by Loperamide (commercialized as Idium). A significant increase of 15, 24.5 and 32.4% in gastrointestinal motility was recordedwhen doses of CSAE increased (75, 150 and 300 mg/kg b.w, respectively). Food intake, water consumption, number and weight of stools were also increased in a dose-dependent manner, compared to the positive control (untreated). Moreover, CSAE provided significantly (p ≤0.05) and dose-dependently protection against oxidative stress by preserving normal antioxidant enzymes activities (SOD and GPx) in intestinal and colonic mucosa, and resorted hepatic enzymes (AST and ALT) and renal (urea and creatinine) levels to normal values. These results can be explained by the abundance of phenolic compounds and insoluble fibers in this plant. Therefore, its use can be encouraged in alimentary and pharmaceutical applications as antioxidant and laxative food supplements.

Evaluation of six phenolic compounds content and antifungal activity against wood-decay fungi of tobacco waste extracts obtained by ultrasound-assisted extraction

The tobacco industry produces substantial amounts of biomass waste that contains bioactive substances that may serve as renewable energy sources. This study reports an efficient and environmentally friendly method for the simultaneous extraction of gallic, protocatechuic, vanillic, chlorogenic, caffeic, and ferulic acids from tobacco waste. The ultrasound-assisted extraction (UAE) parameters were optimized using one-factor-at-a-time method and response surface methodology (RSM), in combination with Box-Behnken design (BBD). The optimal extraction conditions were an extraction temperature of 62 °C, a solvent-to-solid ratio of 19 mL/g, an ethanol-to-water ratio of 62%, and an extraction time of 38 min. The composition and content of phenolic compounds extracted using this optimized method were identified by ultra-performance liquid chromatography coupled with electrospray ionization quadrupole-time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS). The extraction yield and antifungal activity against wood-decay fungi using the extracts obtained with the UAE method were much higher than those obtained using maceration and heat reflux extraction. The results demonstrated that the UAE method extracted six phenolic compounds in tobacco waste, which could then be quantitatively analyzed. This study provides a green and efficient method for extracting active ingredients from waste tobacco and offers a new perspective for utilizing tobacco waste as an antifungal agent against wood-decay fungi.

Comparative assessment of nutritional composition, phenolic compounds, antioxidative and antidiabetic properties of pilosocereus gounellei and Cereus Jamacaru: two unexplored cactus fruits from the Brazilian semi-arid

ABSTRACT In this study, we determine the chemical composition, bioactive compounds profile, antioxidant capacity and antidiabetic potential of two cactus fruits. Pilosocereus gounellei had the highest contents of ash (6.84%), lipid (7.79%), maltose (1.02 mg g−1), soluble fiber (10.85%) and minerals such as Mg. Thirteen volatile compounds (alcohols, terpenes, aldehydes and esters) were found in the fruits. Although higher amounts of quinic acid and quercetrin were found in Cereus Jamacaru, Pilosocereus gounellei had a higher content of p-coumaric acid and rutin. Regarding the functional potential, Cereus Jamacaru had the highest content of total phenolics (65.17 GAE g−1), total flavonoids (26.06 mg EC g−1), antioxidant capacity (28.67; 49.86; 158.79 µM TE g−1 for DPPH, ABTS and ORAC, respectively) and highest inhibition for α-amylase (84.84 ± 0.41%) and protein glycation. In view of their nutritional and bioactive characteristics, these species have great potential to be used in preparations with functional claims.

Metabolic Profiling Reveal Changes in Shoots and Roots of Nitrogen-Deficient Tea Plants (Camellia sinensis cv. Jinxuan)

Tea plants require high levels of nitrogen for optimal growth. However, delayed or insufficient nitrogen supply often induces nitrogen deficiency stress. This stress can adversely affect the plant's growth, development, and metabolic processes. Therefore, studying how tea plants respond to nitrogen deficiency conditions is crucial for enhancing our understanding and management of their growth environment. In this study, we utilized High-Performance Liquid Chromatography (HPLC), Gas Chromatography-Mass Spectrometry (GC-MS), and Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS) techniques to analyze the non-volatile and volatile components of both shoots and roots of the 'Jing Xuan (JX)' tea variety under nitrogen deprivation for 30 days (Nd). The results revealed that nitrogen deprivation led to a deceleration in shoot growth of 'JX', accompanied by reduced chlorophyll and water-soluble extract contents, with nitrogen accumulating predominantly in the roots. Significant decreases were observed in caffeine content in shoots and in the total amounts of theanine and catechins in both shoots and roots, while epigallocatechin gallate (EGCG) accumulation increased in shoots. Moreover, we identified 65 volatile components in shoots, including a notable decrease in floral and fruity compounds such as trans-β-Ionone, Geranylacetone, and α-Ionone. The biosynthesis of amino acids and phenylpropane metabolism are more active pathways under nitrogen stress. Nitrogen deficiency led to reduced levels of amino acids, carboxylic acids, flavonoids, steroids, and their derivatives in roots, with the most notable decline observed in carboxylic acids, typified by Leucine, L-Aspartate, and L-histidine. In contrast, shoots accumulate carbohydrates and phenolic compounds, mainly sucrose. Additionally, metabolites such as Myristic acid and 3-Dehydroshikimate could be a critical indicator of stress levels. These findings enhance our understanding of tea plant growth and metabolism under nitrogen deficiency, providing valuable insights for breeding nitrogen-efficient tea varieties.

Transformation of sedimentary dissolved organic matter in electrokinetic remediation catalogued by FT-ICR mass spectrometry

In electrokinetic remediation (EKR), the sedimentary dissolved organic matter (DOM) could impede remediation by scavenging reactive species and generating unintended byproducts. Yet its transformation and mechanisms remained largely unknown. This study conducted molecular-level characterization of the water-extractable DOM (WEOM) in EKR using negative-ion electrospray ionization coupled to 21 tesla Fourier transform ion cyclotron resonance mass spectrometry (21 T FT-ICR MS). The results suggested that ∼55 % of the ∼7,000 WEOM compounds identified were reactive, and EKR lowered their diversity, molecular weight distribution, and double-bond equivalent (DBE) through a combination of electrochemical and microbial redox reactions. Heteroatom-containing WEOM (CHON and CHOS) were abundant (∼ 35% of the total WEOM), with CHOS generally being more reactive than CHON. Low electric potential (1 V/cm) promoted the growth of dealkylation and desulfurization bacteria, and led to anodic CO2 mineralization, anodic cleavage of -SO and -SO3, and cathodic cleavage of -SH2; high electric potential (2 V/cm) only enriched desulfurization bacteria, and differently, led to anodic oxygenation and cathodic hydrogenation of unsaturated and phenolic compounds, in addition to cathodic cleavage of -SH2. The long-term impact of these changes on soil quality and nitrogen-sulfur-carbon flux may be need to studied to identify unknown risks and new applications of EKR.

Gallic acid modified aminated cellulose integrated polyethyleneimine to construct a phenol-amine chemical network for bonding wood

Cellulose-based adhesives are becoming increasingly popular in the wood industry as an environmentally friendly alternative to formaldehyde-based resins. However, the development of highly water-resistant polymer structures is crucial for achieving reliable bonding with bio-based adhesives. Gallic acid (GA) was grafted onto aminated cellulose by covalent modification to obtain gallic acid functionalized cellulose (AC-GA). Using Schiff base reactions and Michael addition, phenolic amine networks were constructed by mixing AC-GA with polyethyleneimine (PEI) in a manner similar to insect cuticle sclerotization. The phenol-amine chemical network greatly facilitated the anchoring of rigid cellulose molecular chains, leading to a significant increase in crosslink density. Test results show that AC-GA/PEI has excellent bond strengths, with dry strengths of 2.05 MPa, hot water strengths of 1.76 MPa, and even boiling water strengths of 1.39 MPa. This work demonstrates that simulating the hardening process by using phenolic compounds and polyamine molecules can produce plywood with waterproof and stable bonding properties. Phenolamine networks offer interesting solutions for the development of green and aldehyde-free outstanding biomass wood adhesives.

Testing the joint effects of arbuscular mycorrhizal fungi and ants on insect herbivory on potato plants

Main conclusionAnts, but not mycorrhizae, significantly affected insect leaf-chewing herbivory on potato plants. However, there was no evidence of mutualistic interactive effects on herbivory.Plants associate with both aboveground and belowground mutualists, two prominent examples being ants and arbuscular mycorrhizal fungi (AMF), respectively. While both of these mutualisms have been extensively studied, joint manipulations testing their independent and interactive (non-additive) effects on plants are rare. To address this gap, we conducted a joint test of ant and AMF effects on herbivory by leaf-chewing insects attacking potato (Solanum tuberosum) plants, and further measured plant traits likely mediating mutualist effects on herbivory. In a field experiment, we factorially manipulated the presence of AMF (two levels: control and mycorrhization) and ants (two levels: exclusion and presence) and quantified the concentration of leaf phenolic compounds acting as direct defenses, as well as plant volatile organic compound (VOC) emissions potentially mediating direct (e.g., herbivore repellents) or indirect (e.g., ant attractants) defense. Moreover, we measured ant abundance and performed a dual-choice greenhouse experiment testing for effects of VOC blends (mimicking those emitted by control vs. AMF-inoculated plants) on ant attraction as a mechanism for indirect defense. Ant presence significantly reduced herbivory whereas mycorrhization had no detectable influence on herbivory and mutualist effects operated independently. Plant trait measurements indicated that mycorrhization had no effect on leaf phenolics but significantly increased VOC emissions. However, mycorrhization did not affect ant abundance and there was no evidence of AMF effects on herbivory operating via ant-mediated defense. Consistently, the dual-choice assay showed no effect of AMF-induced volatile blends on ant attraction. Together, these results suggest that herbivory on potato plants responds mainly to top-down (ant-mediated) rather than bottom-up (AMF-mediated) control, an asymmetry in effects which could have precluded mutualist non-additive effects on herbivory. Further research on this, as well as other plant systems, is needed to examine the ecological contexts under which mutualist interactive effects are more or less likely to emerge and their impacts on plant fitness and associated communities.

Fermentation of Rice, Oat, and Wheat Flour by Pure Cultures of Common Starter Lactic Acid Bacteria: Growth Dynamics, Sensory Evaluation, and Functional Properties

Recent consumer demand for non-dairy alternatives has forced many manufacturers to turn their attention to cereal-based non-alcoholic fermented products. In contrast to fermented dairy products, there is no defined and standardized starter culture for manufacturing cereal-based products. Since spontaneous fermentation is rarely suitable for large-scale commercial production, it is not surprising that manufacturers have started to adopt centuries-known dairy starters based on lactic acid bacteria (LABs) for the fermentation of cereals. However, little is known about the fermentation processes of cereals with these starters. In this study, we combined various analytical tools in order to understand how the most common starter cultures of LABs affect the most common types of cereals during fermentation. Specifically, 3% suspensions of rice, oat, and wheat flour were fermented by the pure cultures of 16 LAB strains belonging to five LAB species—Lacticaseibacillus paracasei, Lactobacillus delbrueckii, Lactobacillus helveticus, Streptococcus thermophilus, and Lactococcus lactis. The fermentation process was described in terms of culture growth and changes in the pH, reducing sugars, starch, free proteins, and free phenolic compounds. The organoleptic and rheological features of the obtained fermented products were characterized, and their functional properties, such as their antioxidant capacity and angiotensin-converting enzyme inhibitory activity, were determined.

Blue light as an important factor increasing plant tolerance to acute photooxidative stress

Previous studies have confirmed the stimulating effect of blue light on phenolic compound accumulation and emphasized that sufficient dose of blue light is essential for biosynthesis of B-dihydroxylated flavonoids with enhanced antioxidant properties (under UV-lacking conditions). This study investigates the importance of blue light and complex role of phenolic compounds in plant tolerance against acute photooxidative stress. Hordeum vulgare (L. Cv. Bojos) seedlings were acclimated to different light spectra (blue, green:red 1:1, and white composed of blue:green:red 1:1:1) at total irradiance 400 µmol.m−2.s−1. Subsequently, they were subjected to a 3-hour combined stress induced by high photosynthetically active (850–950 µmol.m−2.s−1) and UV-B (2.0–2.5 W.m−2) radiation. Content of flavonoids, expression of genes involved in their biosynthesis (phenylalanine ammonia-lyase, chalcone synthase, flavonoid 3′-hydroxylase), and antioxidant activity of plant extracts were significantly highest in plants acclimated to blue light. As an indicator of reactive oxygen species interaction with biomolecules, the content of lipid hydroperoxides was estimated. It was demonstrated that plants acclimated to blue light revealed significantly lower extent of lipid peroxidation compared to those acclimated to white or green:red light. Plants exposed to combined light-induced stress for 3 hours exhibited pronounced disruption of PSII function: FV/FM tended to decrease proportionally with decreasing amount of blue photons in the treatments. Additionally, stress exposure upregulated the expression of genes related to phenolic compounds but not genes encoding antioxidant enzymes. We confirmed higher resistance of plants acclimated to blue light and presume that phenolic compounds are significantly involved in protection during the acute phase of stress.

The Production of Useful Phenol Compounds with Antioxidant Potential in Gametophytes and Sporophytes from In Vitro Cultures in Four Ornamental Ferns Species

Ferns are vascular plants with significant ornamental value, and in recent years, they have also been considered for the potential application in different economic sectors like nutrition, medicine and cosmetics. This study aimed to obtain in vitro fern gametophytes and sporophytes and evaluate their potential as secondary metabolites sources. For this study four fern species were used: Polypodium vulgare L. (PV), Asplenium trichomanes L. (AT), Athyrium filix-femina L. Roth (AF), and Osmunda regalis L. (OR). The polyphenols, flavonoids, tannins and terpenoids content and antioxidant activity were estimated by different colorimetric methods. For metabolite identification and their antioxidant activity, HP-TLC separations were used. Also, quantitative HPLC–DAD analysis was performed to estimate the content of certain metabolites. The results showed that in vitro generation of gametophytes registered higher growth rates in OR, PV, and AF, while the regeneration of sporophytes was better for PV, AT, and AF. The OR gametophyte produced the highest quantities in all analyzed metabolite classes and also had the highest antioxidant values. We report for the first time the presence of metabolites such as catechin, caffeic acid, gallic acid, ferulic acid, cinnamic acid, or rutin in OR. In this study, we demonstrated the possibility of producing potent antioxidant metabolites by in vitro cultures in ferns.

UV-A treatment of phenolic extracts impacts colour, bioactive compounds and antioxidant activity.

The unintended co-extraction of chlorophylls during the recovery of polyphenols from plant sources yields green-coloured phenolic extracts with limited use in colour-sensitive foods. This study aimed at decolourizing the ethanolic extracts of sugar beet leaves using a UV-A treatment (390 nm). Exposure of the phenolic extracts to 30 UV-A LEDs at 8.64 J m-2 radiation dose decreased the total chlorophyll content by 69.23% and reduced the greenness parameter (-a*) significantly (P < 0.05) from 27.33 ± 0.32 to 8.64 ± 0.16. Additionally, UV-A treatment increased the content of most individual phenolic compounds (e.g. gallic acid, ferulic acid, etc.) significantly, resulting in an increase in the overall phenolic content in the extracts from 900.56 ± 14.11 μg g-1 fresh weight (FW) to a maximum of 975.09 ± 9.62 μg g-1 FW at 0.67 J m-2. However, rutin content had a significant decrease at the highest radiation dose (8.64 J m-2). The soluble sugar content (i.e. glucose and fructose) increased simultaneously with phenolic compounds after the UV-A treatment. Although the UV treatment reduced the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, it had no significant effect on the ferrous chelating activity and the extract's ability to delay lipid oxidation in corn oil. The antioxidant activity index of the treated extract was comparable to that of butylated hydroxytoluene, a synthetic antioxidant. Key findings of this study include successful decolourization of the extract, decomposition of bound polyphenols to their free form, and maintaining the antioxidant activity of the extract in the oil system after UV-A exposure. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Secondary compounds increase litter removal by termites across 23 savanna grass species

Abstract Termites—one of the most abundant animal groups in tropical ecosystems—are vital in nutrient recycling, contributing significantly to maintaining ecosystem functioning. However, how selective they are in their litter food choice, and whether they prefer nutritious or less nutritious litter substrates, are still important unresolved questions. Here, we test the effect of litter traits on the removal of litter by fungus‐growing termites, a dominant group of macrodetritivores in the Serengeti‐Mara ecosystem. We used metal‐mesh litterbags to measure the mass loss of stem and leaf litter from 23 grass species after an incubation period of 61 days. Sheeting—soil deposits indicating termite presence—strongly increased with tannin and phenolic compounds, especially in leaf litter (R2 = 0.54), where highly aromatic species like Cymbopogon caesius and Bothriochloa insculpta exhibited the highest sheeting rates. Litterbags with sheeting displayed 66% higher mass loss on average compared to those without. Once termites had selected the substrate, mass loss increased consistently irrespective of litter traits. Quantifying the combined effects of sheeting frequency and differential mass loss, we found that fungus‐growing termites predominantly increased the mass loss of high‐nutrient litter. This was mainly due to additional mass loss in leaf litter, not stem litter, with tannin concentration being the primary predictor of enhanced overall decomposition by termites. This suggests termites ameliorate the otherwise adverse influence of plant secondary compounds on litter decomposition. Synthesis: Our results support the idea that fungus‐growing termites are generalists, as termites collected organic substrates with varying quality. The strong effect of phenolic compounds on sheeting rate implies that secondary compounds play an important role in termite substrate selection. The selective removal of substrates high in secondary compounds suggests fungus‐growing termites lift important constraints to microbial breakdown, potentially enhancing ecosystem‐level carbon and nutrient recycling rates. Termites play crucial roles in recycling organic matter across tropical biomes and our study highlights that the role of secondary compounds in their selection and detection in decomposition studies needs more attention

UPLC-PDA Phenolic Compounds Profile of Mango Peel Extracts Obtained using Different Solvents and Ultrasound-Assisted Extraction

UPLC-PDA Phenolic Compounds Profile of Mango Peel Extracts Obtained using Different Solvents and Ultrasound-Assisted Extraction