Plant Secondary Metabolites Research Articles

Synthesis, characterization and photo catalytic activity of silver nano particle derived from Arachis hypogaea L. seed peel extracts

Abstract The study focuses on the green synthesis of silver nanoparticles (AgNPs) using Arachis hypogaea L. seed peel extract (AHSPE) and evaluates their photocatalytic activity against Rhodamine B and Congo Red dyes. The synthesis involved reducing aqueous silver metal ions with AHSPE, characterized by various techniques including UV–visible spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and FT-Raman spectroscopy. UV–visible spectroscopy indicated characteristic absorption peaks at 428 and 439 nm, confirming the formation of AgNPs. XRD analysis revealed an average particle size of 4.77–5.6 nm. FT-IR spectra identified biomolecules such as amines, peptides, amides, lactones, and polyphenols in the extract, acting as reducing and capping agents, thereby stabilizing the AgNPs. SEM analysis showed pristine silver nanoparticles with diameters ranging from 1 to 10 µm. The biosynthesized AgNPs demonstrated strong photocatalytic activity in degrading Rhodamine B and Congo Red dyes. This method did not use any synthetic reagents, making it an environmentally safe and cost-effective alternative for synthesizing silver nanoparticles. The process aligns with green chemistry principles, offering potential applications in photocatalysis and environmental cleanup. The study underscores the importance of biosynthesized nanoparticles due to their unique biological properties and the role of plant secondary metabolites in facilitating green synthesis.

The Use of Thyme (Thymus vulgaris) Essential Oil for Controlling Cercospora Leaf Spot (Cercospora beticola) on Sugar Beets (Beta vulgaris)

Decreasing efficacy of fungicides and the withdrawal of further hazardous active ingredients in pesticides from use have prompted the search for alternative methods of crop protection. Essential oils (EOs) are secondary metabolites of plants and have been proven to show antibacterial, antifungal, and pest-repellent properties. This study was undertaken to determine the activity of grapefruit, rosemary, pine, sage, and thyme EOs against the fungus Cercospora beticola, which is the most dangerous pathogen of sugar beet and the causal agent of Cercospora leaf spot. According to the determined Minimum Inhibitory Concentration (MIC), thyme EO was found the most effective against C. beticola. For most of the fungal isolates tested, the MIC of this EO was 0.313 mL/L. Thyme EO also inhibited the growth of multi-resistant isolates. Based on the results obtained, thyme EO was subjected to further testing in field conditions, where its efficiency in controlling C. beticola was also proven. The results indicate that the use of thyme EO may be a promising method for the protection of sugar beets, although it requires further optimization in the context of its inclusion in sustainable protection programs assuming a reduced number of synthetic fungicide treatments.

Metabolomic profiling and 16 S rRNA metabarcoding of endophytes of two Aloe species revealed diverse metabolites

Aloe species are often used interchangeably for medicinal and cosmeceutical applications, presenting a challenge to the biological efficacy consistency of some herbal preparations. Sustainable production of high-quality commonly used medicinal plants remains a limitation for commercialisation. Thus, this study investigated the potential for plant substitution by examining bacterial endophytes capable of producing similar host plant secondary metabolites. The metabolite profiles and endophytic bacterial communities of endangered Aloe lettyae were compared with those of Aloe longibracteata using nuclear magnetic resonance spectroscopy and 16 S rRNA gene sequencing. Only 15 metabolites were significantly different between A. lettyae and A. longibracteata based on metabolite concentrations. However, both plants’ functionality and potential application remain comparable. Phytohormones, including indole-3-acetate and 5-hydroxyindole-3-acetate, were more concentrated in A. lettyae than A. longibracteata. Metabolites such as tyrosine, allantoin, and myo-inositol, with human health benefits, were annotated in both species. Aloe lettyae harboured a phylogenetically diverse bacteria community compared to A. longibracteata, with a higher richness of bacterial species, indicating a likelihood of diverse metabolic capabilities among the bacteria. Dominant endophytes, including Bacillus, Comamonas, and Pseudomonas, possess enzymes contributing to various metabolic pathways. The enzymes have the potential to impact the synthesis, or breakdown of plant metabolites, consequently influencing the overall metabolic composition of the host plant. Therefore, this study supports the interchangeability of A. lettyae and A. longibracteata due to their ability to produce similar metabolites, and although the Aloe species exhibit phylogenetically diverse endophytic communities, the feasibility of utilizing their endophytes as producers of secondary metabolites remains viable.Graphical abstract

Cytotoxic Effects of Plant Secondary Metabolites and Naturally Occurring Bioactive Peptides on Breast Cancer Model Systems: Molecular Mechanisms

Breast cancer is the second leading cause of death among women, and the number of mortal cases in diagnosed patients is constantly increasing. The search for new plant compounds with antitumor effects is very important because of the side effects of conventional therapy and the development of drug resistance in cancer cells. The use of plant substances in medicine has been well known for centuries, but the exact mechanism of their action is far from being elucidated. The molecular mechanisms of cytotoxicity exerted by secondary metabolites and bioactive peptides of plant origin on breast cancer cell lines are the subject of this review.

Genome-wide investigation of MYB gene family in Areca catechu and potential roles of AcTDF in transgenic Arabidopsis.

MYB protein, a crucial transcription factor, holds crucial importance in plant growth, development, stress responses, and secondary metabolite regulation. While MYB proteins have been extensively studied, research on MYBs within the palm family, particularly in Areca catechu, remains limited. This study identified 259 MYB genes in Areca catechu, including 105 1R-MYBs, 150 R2R3-MYBs, 3 3R-MYBs, and 1 4R-MYBs. Physicochemical properties, collinearity, and gene structure of these genes were analyzed. The AcMYB is distributed across 16 chromosomes of A.catechu and has 119 and 195 homologs in Arabidopsis and rice, respectively. Cis-acting elements in the promoter region suggest roles in plant hormones, growth, development, and stress. R2R3-MYB genes were divided into eight groups based on tissue expression profiles. The flowering-related gene AcTDF is highly expressed in male flowers. Overexpression of AcTDF in Arabidopsis promotes early flowering, upregulates AtSOC1 and AtFUL, and enhances tolerance to drought and salt stress. These results provide valuable insights for the identification and analysis of the MYB gene family in Areca catechu and offer a basis for the subsequent verification of its related functions and the role and significance of its role in the evolution of palms.

Phthalate exposure and reproductive effects in rodents: a model for approaches on the protective role of natural products.

This review article summarizes the experimental findings in rodents published between 2014 and 2024 concerning phthalates exposure and reproductive outcomes. Rodents were chosen for this review since most studies that have developmental aspects in different phases of exposure and that address more in-depth reproductive mechanisms have been carried out in mice and rats. The evidence of adverse effects of phthalates on fetal development and human and animal reproduction is extensive, with impacts ranging from gene expression to physiological alterations. Despite the large volume of scientific papers pointing out the harmful effects of exposure to phthalates, isolated or in mixtures, at different developmental periods, most of them are associated with the maternal exposure and long-term effects in the offspring. Regular vegetables, fruits, fish, dairy products, and whole grains intake rich in bioactive compounds can mitigate the adverse effects of EDCs in humans and animals at different developmental periods. Various food bioactive compounds (FBCs) such as genistein, resveratrol, lycopene, vitamin E, curcumin, selenium, and plant secondary metabolites (PSMs) present antioxidant, anti-inflammatory, anti-tumor, and other biological properties with the potential to reduce of deleterious effects of phthalates on the reproductive tract. In this review, we aimed to summarize the main studies produced in the last decade about phthalate exposure and reproductive disorders in males and females (at different developmental critical windows). Additionally, we proposed some FBCs and PSMs that could attenuate the main adverse effects caused by phthalate exposure on male reproduction since there is a lack of studies with females.

Trivalent chromium stress trigger accumulation of secondary metabolites in rice plants: Integration of biochemical and transcriptomic analysis

Trivalent chromium [Cr (III)] is a frequently detected environmental contaminant that negatively affects plant metabolism, growth, and yield. Plant secondary metabolites are non-nutrient compounds involved in diverse physiological functions in response to abiotic stresses. This study performed biochemical and transcriptomic analyses to clarify the protective role and mechanism of secondary metabolites in rice seedlings under Cr(III) stress. The content of measured secondary metabolites i.e., total soluble phenolics, flavonoids, lignin, and anthocyanin in rice tissues was significantly enhanced under Cr(III) exposure. Additionally, the activities of several enzymes including chalcone synthase, phenylalanine ammonialyase, peroxidase, and anthocyanidin synthase, were positively activated. Transcriptomic analysis revealed a number of differentially expressed genes (DEGs) in Cr(III)-treated rice seedlings and their expression patterns are tissue-specific. Additionally, the DEGs involved in secondary metabolism pathways were evident after KEGG enrichment analysis. Cr(III) exposure resulted in distinct genetic regulation strategies in rice tissues, with different DEGs activating various sub-pathways in the secondary metabolism pathways to cope with Cr(III) stress. Furthermore, the integrated correlation analysis of the secondary metabolites and transcriptome data identified key genes involved in different steps of the sub-pathways of secondary metabolism pathway in rice plants under Cr(III) stress. This study indicates that the accumulation of secondary metabolites in rice plants is a survival and detoxification strategy to reduce the adverse effects of toxic compounds. Future research should explore how key genes in secondary metabolism pathways aid in Cr(III) detoxification and enhance crop stress tolerance.

Molecular Mechanics Demonstrate S-COMT as promising therapeutic receptor when analyzed with secondary plant metabolites.

Major depressive disorder (MDD) and other psychiatric conditions are debilitating illnesses affecting millions globally. Catechol-O-methyltransferase (COMT), an enzyme that regulates dopamine and norepinephrine breakdown in the brain, has emerged as a potential therapeutic target for these disorders. This study explores the inhibitory potential of plant secondary metabolites against S-COMT using computational techniques. COMT exists in two isoforms: membrane-bound COMT (MB-COMT), primarily found in brain neurons, and soluble COMT (S-COMT), present in peripheral tissues. S-COMT, particularly in the prefrontal cortex, is crucial for regulating neurotransmitters and maintaining cognitive function. Studies suggest S-COMT variants might be linked to the development of depression, schizophrenia, and other psychiatric disorders. Current COMT inhibitors often suffer from limitations, necessitating the exploration of novel therapeutic strategies. This study employed in-silico methods to investigate plant secondary metabolites as potential S-COMT inhibitors. Here, we describe the S-COMT protein structure retrieval and validation, followed by molecular docking simulations to identify plant compounds with the strongest binding affinity to the receptor's active site. Key amino acid residues involved in these interactions were also analysed. Furthermore, molecular dynamics simulations were conducted to assess the stability of the top-scoring protein-ligand complexes over a 100-nanosecond timeframe. The results explored the stability of ligand binding within the active site and its impact on the overall conformation of the S-COMT receptor. Our findings highlight promising therapeutic potential for these plant-derived compounds. Further in vitro and in vivo studies are warranted to validate their efficacy and safety for potential clinical applications in treating S-COMT-related disorders. SubjectsBioinformatics and Computational Biology, Proteomics, Neurogenerative Diseases

Harvesting Light: The Interrelation of Spectrum, Plant Density, Secondary Metabolites, and Cannabis sativa L. Yield

The approaching legalisation and associated increasing demand for medicinal and recreational Cannabis sativa L. will lead to a growing relevance for lighting systems designed for Cannabis sativa L. The interplay between plant density, light spectrum, light distribution, yield, and secondary metabolite distribution within the plant has not yet been studied. To fill this knowledge gap, a CBD-dominant Cannabis sativa L. strain was grown in a greenhouse experiment with two plant densities (2.66 and 12 plants −1 m−2) under two different light spectra. The chosen light spectra were two LED fixtures, Solray385 (SOL) and AP67, with an R: FR ratio of 12.9 and 3.7, respectively. The results indicated that light-induced effects on individual plants can be transferred to the plant stock. A low R: FR ratio induced a 16% increase in dry flower yield in the last ten days of flowering, while a change in the light spectrum could increase the potential maximum plant density per square metre. The two spectra did not affect (CBD + CBDA) yield, as a lower flower yield compensated for a higher concentration. CBDA concentration was not significantly affected by plant density. In contrast, the higher density led to an increased total cannabidiol concentration (CBD + CBDA) and altered the distribution of terpenes. Here, the light distribution over the plant stock is particularly decisive, as a more homogenous illumination led to an increased terpene concentration of up to 41%. A Photon Conversion Efficacy (PCE) of 0.05 g mol−1 under SOL and 0.06 g mol−1 under AP67 was achieved. Plants in the centre under the highest light intensity of 1200 PAR showed up to 48% reduced efficacy. These results strongly suggest that light intensity needs to be fine-tuned to the cultivation system to prevent a reduction in efficacy, resulting in yield and quality losses.

Comprehensive analysis of secondary metabolite biosynthetic gene clusters in Helianthus annuus L.: A bioinformatics approach

Plant secondary metabolite gene clusters are regions within the plant genome that encode enzymes and proteins involved in the biosynthesis of secondary metabolites. Helianthus annuus L. is a significant oilseed plant with economic importance. This study aims to comprehensively identify secondary metabolite biosynthetic gene clusters within H. annuus using bioinformatics tools, shedding light on the functions of the enzymes involved. In this study, the plantiSMASH software was utilized to predict secondary metabolite biosynthetic gene clusters in H. annuus. The results from plantiSMASH were analyzed to identify the biosynthetic gene clusters for secondary metabolites on each chromosome. The biological and molecular functions of the enzymes within these clusters were predicted using data from the relevant articles. According to the obtained data, H. annuus lacks a biosynthetic gene cluster on chromosomes four, seven, and fifteen. The identified gene clusters in this plant are polyketide, saccharide, saccharide-terpene, alkaloid, putative, and terpene. The enzyme categories found in secondary metabolite biosynthetic gene clusters include Methyltransferase, Ketosynthase, Glycosyltransferase, BAHD acyltransferase, Dioxygenase, CoA-ligase, Epimerase, PRISE enzymes, Prenyltransferase, Oxidoreductase, Aminotransferase, Copper amine oxidase, Cytochrome P450, Terpene synthase, and Pictet-Spengler enzyme (Bet v1). This comprehensive analysis provides a foundation for further investigations into the biosynthesis of secondary metabolites in H. annuus, offering valuable insights for researchers exploring the medicinal and pharmaceutical potential of this plant species.

Effect of Cashew Nutshell Extract, Saponins and Tannins Addition on Methane Emissions, Nutrient Digestibility and Feeding Behavior of Beef Steers Receiving a Backgrounding Diet

The beef industry contributes to greenhouse gas emissions through enteric methane emissions, exacerbating climate change. Anacardic acid in cashew nutshell extract (CNSE), saponins and tannins (ST) are plant secondary metabolites that show promise in methane mitigation via antimicrobial effects, potentially exerting changes in ruminal fermentation patterns. This study examined the impact of CNSE, ST, and their combination on methane emissions, digestibility, intake, and performance of sixteen Angus crossbred steers (347 ± 30 kg) receiving a backgrounding diet (70:30 corn silage: cottonseed burrs). The study used a 4 × 4 Latin square design (4 steers, 4 treatments, 4 periods) with a 2 × 2 factorial arrangement, including the main effects of additive (CNSE or ST) fed individually or combined. Thus, steers received the following treatments: (1) no additive, (2) CNSE only, (3) ST only, or (4) both (CNSEST). Non-supplemented steers registered eight more feedbunk visits/d than ST-steers and spent an extra 10 min/d on the feedbunk. The addition of ST tended to increase dry matter, organic matter, and neutral detergent fiber intake. Additives fed individually reduced CP digestibility. Intake of the carrier containing CNSE only was lesser and coincided with a greater methane yield in that treatment. Digestibility and methane mitigation were improved after CNSEST compared with individual inclusion, suggesting synergistic reactions enhanced methane mitigation effects in fibrous diets without affecting the digestibility of nutrients nor animal growth performance.

Assessment of loliolide extracted from Biserula pelecinus, present during in vitro oocyte maturation, on fertilisation and embryo development in sheep

Context As a ‘duty of care’, it is important to test whether new forage plants for ruminants contain secondary compounds (PSCs) that affect reproductive performance. We have previously observed, a posteriori, that the presence of a methanolic extract of Biserrula pelecinus during maturation of sheep oocytes increased fertilisation rate and blastocyst development. This result needed to be verified a priori and, if the outcome was repeated, we needed to identify the plant secondary metabolite responsible. Aims To test whether PSCs from B. pelecinus, when added to the oocyte maturation medium, improve fertilisation rate and blastocyst development; to test whether loliolide is the active molecule produced by B. pelecinus. Methods Methanol–chloroform extracts of B. pelecinus were fractionated using rapid silica filtration and solvents of increasing polarity. Fractions at final concentrations of 0, 100 or 200 μg mL−1 were added to the medium used to mature sheep cumulus–oocyte complexes (COCs) and effects were determined for maturation, subsequent cleavage rate, blastocyst rate, hatching rate, blastocyst efficiency and total blastocyst cell number (TCN). Results Fraction BP-6 at 100 μg mL−1 reduced blastocyst rate (P < 0.05), but had no effect when the dose was doubled to 200 μg mL−1. Further fractionation using semi-preparative high-performance liquid chromatography showed loliolide as the most abundant compound in BP-6. Supplementation of the in vitro maturation medium with loliolide (0, 2.5, 5, 10 and 25 μg mL−1) did not affect any measure of embryo development. All COCs treated with B. pelecinus fractions reached the final stage of embryo development, blastocyst hatching. Total blastocyst cell number was not affected. Conclusion The presence of fractions of B. pelecinus extract during in vitro oocyte maturation can reduce embryo development. Implications In vitro techniques can detect potential effects of forages on reproduction. Some fractions from an extract of B. pelecinus when present during oocyte maturation can reduce embryo development. The abundant PSC, loliolide, was not responsible. There was no indication that a PSC in B. pelecinus improves outcomes.

Silver Nanoparticles (AgNPs) Act as Nanoelicitors in Melissa officinalis to Enhance the Production of Some Important Phenolic Compounds and Essential Oils

ABSTRACTNanoparticles (NPs) are well‐known biostimulants in plant biotechnology, utilised to enhance the physical properties of plants and exhibit positive effects on them. The important key role is the most suitable type, effective dose and size of NP to be used in plant tissue culture systems. In this study, various concentrations of silver nanoparticles (AgNPs; 0, 25, 50, 75 and 100 μg L−1) were tested as elicitors in callus culture with the aim of enhancing secondary metabolite production in lemon balm (Melissa officinalis L.). According to the results obtained, callus formation rates have shown an increase in all applications compared to the control group. The highest callus formation, weight and diameter were observed in 50 μg L−1 application. In this application, the callus structure was compact and its colour was green. However, the aromatic compounds, neral and geranial increased significantly in 25 μg L−1 application. The maximum increase in phenolic compounds such as caffeic acid, chlorogenic acid, proto‐catechic acid, hesperidin and p‐coumaric acid was observed in the 75 μg L−1 AgNP and the highest increase in rosmarinic acid compound was determined in the 50 μg L−1 application. The study found that AgNP applications are an effective method for increasing the production of secondary metabolites in medicinal and aromatic plants, such as lemon balm, in vitro.

Beneficial Effects of a Freeze-Dried Kale Bar on Type 2 Diabetes Patients: A Randomized, Double-Blinded, Placebo-Controlled Clinical Trial

Background/Objectives: Type 2 diabetes (T2D) is one of the most common global diseases, with an ever-growing need for prevention and treatment solutions. Kale (Brassica oleracea L. var. acephala) offers a good source of fiber, minerals, bioavailable calcium, unsaturated fatty acids, prebiotic carbohydrates, vitamins, health-promoting secondary plant metabolites, as well as higher amounts of proteins and essential amino acids compared to other vegetables. The objective of this study was to investigate whether daily intake of freeze-dried kale powder can provide health benefits for T2D patients vs. placebo. Methods: This study was designed as a 12-week, blinded, randomized, controlled trial. Thirty T2D patients were randomly assigned to either a placebo bar (control) or a kale bar (intervention). Participants in the intervention group were instructed to consume three bars/day, each containing 26.25 g of freeze-dried kale (corresponding to approx. 341 g fresh kale/day). At baseline and 12 weeks, all participants underwent an oral glucose tolerance test (OGTT), 24 h blood pressure measurements, DEXA scans, and fasted blood samples were taken. Results: A significant reduction in HbA1c, insulin resistance, body weight, and calorie intake was observed in the intervention group compared to control. Positive trends were detected in fasted blood glucose and LDL-cholesterol for those in the kale intervention group. No significant differences were found in total body fat mass and area under the curve glucose 240 min OGTT. Conclusions: Given the positive effects of high daily kale intake observed in this study, further research with a larger sample size is needed to better understand the health benefits of kale bars. This could potentially lead to new dietary recommendations for patients with T2D.

Genome-wide computational analysis of the dirigent gene family in Solanum lycopersicum

BackgroundDirigent (DIR) genes play a key role in the development of organic products in plants. They confer conformational influence on processes that lack stereoselectivity and regioselectivity through processes that are mostly understood. They are required to produce lignans, which are a unique and widely distributed family of plant secondary metabolites with intriguing pharmacological characteristics and potential role in plant development. DIR genes are implicated in the process of lignification and protect plants from environmental stresses, including biotic and abiotic stresses. Nevertheless, no research has been performed on the DIR gene family in Solanum lycopersicum. This study provides detailed information on the DIR gene family in S. lycopersicum.Methods and resultsThe conserved domain analysis, phylogenetic analysis, evolutionary adaptation, cis-acting elements, proteomic analysis, signal peptide detection, transmembrane potential analysis, sequence identity and similarity analysis, gene assembly, genomic localization, duplication of gene analysis, and evolutionary linkage of 31 potential DIR genes were studied. All these analyses provide a deep understanding of DIR genes in the S. lycopersicum genome that will provide a useful reference for further functional analysis of the DIR genes in S. lycopersicum.ConclusionThis research provides an in-depth and comprehensive explanation of the detailed process and structural characterization of DIR genes in the genome of S. lycopersicum, laying the groundwork for future plant genetic engineering and crop development exploration. This work will provide valuable information for identifying DIR genes in higher plants and support future research on the DIR gene family.

Phytochemical screening and antioxidant evaluation of Agave angustifolia and Agave sisalana

Background: Agave angustifolia (AA) and Agave sisalana (AS) are used by local communities for medicinal purposes to treat skin conditions. Small companies add Agave leaf extracts to their cosmetic products, claiming calming and skin-rejuvenating qualities.Aim: The study aimed to assess the phytochemical profiles and antioxidant activities of AA and AS verifying the traditional therapeutic claims about the species and accordingly establishing the assertions of cottage industries.Setting: The AA leaves were collected from the eThekwini Metropolitan Municipality, while AS leaves were sourced from the iLembe district municipality.Methods: The phytochemical extracts were obtained by gradient solvent maceration of the leaves. Qualitative phytochemical screening established the presence of bioactive phytochemicals in the extract. The 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and the ferric reducing and/or antioxidant power (FRAP) methods measured the bioactive phytochemicals’ antioxidant activity.Results: Qualitative phytochemical evaluation confirmed the presence of secondary metabolites in both plants. AS extracts also contained alkaloids. The DPPH antioxidant activity indicated that Agave extracts had 20% to 80% scavenging activity. AS methanol extract had the maximum antioxidant activity among all the extracts. AA methanol and AS hexane extracts had no antioxidant activity. AA ethyl acetate extract had higher antioxidant activity (64%) than AS (52%). AA hexane extract had 70% activity while AS hexane extract had 30%.Conclusion: The detected phytochemicals indicate potential use for emulsifying, antioxidant, anti-ageing, anti-inflammatory, and broad-spectrum antimicrobial activities.Contribution: This study contributes to the existing knowledge of the therapeutic properties of AA and AS plants.

Flawonoidy – naturalne związki o potencjale przeciwwirusowym i przeciwnowotworowym

Flavonoids are a group of plant secondary metabolites that have a number of health-promoting properties and have both preventive and therapeutic effects. Research confirms that flavonoids work, among others: antiviral and anticancer. Apigenin, luteolin, isorhamnetin, kaempferol, myricetin, quercetin, hesperetin, naringenin, epicatechin and genistein have documented antiviral activity. The discovery of the anticancer activity of flavonoids (including apigenin, naringenin, hesperetin) initiated a number of studies to identify the most active compounds against various cancers and to understand the mechanism of their action. However, the relationship between flavonoid intake and cancer risk appears to be non-linear. Available literature data suggest that flavonoids may act as therapeutic agents in the early stages of virus infection and as an anticancer agent and should be included in the daily diet by increasing the consumption of primarily fruit (chokeberry, elderberry, cherry, mandarin), vegetables (parsley, celery, onion) and herbs and spices (mint, oregano, lovage, moringa, saffron). Flavonoids present in food are transported by passive diffusion (hydrophobic aglycones) and by active transport (hydrophilic glycosides). Individual classes of flavonoids differ in the amount they appear in food, the metabolites they produce and their possible impact on health. The aim of this review is to summarize the current knowledge on the potential use of selected flavonoids in the treatment of diseases of various etiologies, with an indication of their anticancer and antiviral effects. The perspectives and possibilities of using these compounds are presented, taking into account the problems resulting from their bioavailability.

Endophytic bacteria in Camellia reticulata pedicels: isolation, screening and analysis of antagonistic activity against nectar yeasts.

Camellia reticulata, an ancient plant species endemic to Yunnan Province, China, remains underexplored in terms of its endophytic bacterial communities. The plant tissue pedicel serves as the connection between the flower and the stem, not only delivers nutrients but also transmits metabolic substances from endophytic bacteria to the nectar during long-term microbial colonization and probably improves the antagonistic activity of nectar against yeast. Hence, 138 isolates of endophytic bacteria have been isolated in this study from the pedicels of 12- and 60-year-old C. reticulata. Comparative analysis revealed significantly higher density of endophytic bacteria in older trees. Among these isolates, 29 exhibited inhibitory effects against nectar yeasts. Most of the isolates displayed positive results for Gram staining, catalase reaction, gelatin liquefaction, and motility. Additionally, the isolates demonstrated the ability to utilize diverse substrates, such as glucose, nitrate, and starch. Based on 16S rRNA molecular biology analysis, these isolates were identified to be 11 different species of 6 genera, with the majority belonging to Bacillus genus. Notably, C1 isolate, identified as Bacillus spizizenii, exhibited strongest antagonistic effect against three yeasts, i.e., Metschnikowia reukaufii, Cryptococcus laurentii, and Rhodotorula glutinis, with minimum inhibitory concentration values below 250 μg/mL. Major metabolites of B. spizizenii were aminoglycosides, beta-lactams, and quinolones, which possess antimicrobial activities. Furthermore, KEGG enrichment pathways primarily included the synthesis of plant secondary metabolites, phenylpropanoids, amino acids, alkaloids, flavonoids, neomycin, kanamycin, and gentamicin. Therefore, antagonistic activity of B. spizizenii against yeasts could be attributed to these antibiotics. The findings highlight the diverse endophytic bacteria associated with C. reticulata, indicating their potential as a valuable resource of bioactive metabolites. Additionally, this study provides new insights into the role of endophytic bacteria of pedicels in enhancing nectar resistance against yeasts.

The HOMO-LUMO Gap as Discriminator of Biotic from Abiotic Chemistries.

Low-molecular-mass organic chemicals are widely discussed as potential indicators of life in extraterrestrial habitats. However, demarcation lines between biotic chemicals and abiotic chemicals have been difficult to define. Here, we have analyzed the potential utility of the quantum chemical property, HOMO-LUMO gap (HLG), as a novel proxy variable of life, since a significant trend towards incrementally smaller HLGs has been described in the genetically encoded amino acids. The HLG is a zeroth-order predictor of chemical reactivity. Comparing a set of 134 abiotic organic molecules recovered from meteorites, with 570 microbial and plant secondary metabolites thought to be exclusively biotic, we found that the average HLG of biotic molecules was significantly narrower (-10.4 ± 0.9 eV versus -12.4 ± 1.6 eV), with an effect size of g = 1.87. Limitation to hydrophilic molecules (XlogP < 2) improved the separation of biotic from abiotic compounds (g = 2.52). The "hydrophilic reactivity" quadrant defined by |HLG| < 11.25 eV and XlogP < 2 was populated exclusively by 183 biotic compounds and 6 abiotic compounds, 5 of which were nucleobases. We conclude that hydrophilic molecules with small HLGs represent valuable indicators of biotic activity, and we discuss the evolutionary plausibility of this inference.

Evaluation of methyl jasmonate as elicitor in the production of cycloartane saponins in Astragalus aitosensis in vitro root cultures

Methyl jasmonate (MeJA) treatment is known to increase the levels of plant secondary metabolites. The significant medicinal benefits of cycloartane type saponins, including immune modulation, antiviral properties, and antitumor activity, drive high global demand, making sustainable production methods economically, medically, and ecologically important. In this study the effect of MeJA as an elicitor for promoting higher accumulation of cycloartane saponins – astragaloside I, II and IV was evaluated. The experiment was conducted using biotechnological approaches for sustainable production using in vitro root cultures of the endemic plant species Astragalus aitosensis, which is known to produce rare cycloartane saponins. LC-HRESI-MS analysis was used to identify and quantify compounds. The content of astragaloside I increased significantly by 68% (118 ng/mg DW) compared to control group (70 ng/mg DW). Astragaloside II was found with 1.5 points increased amount (473 ng/mg DW), compared to control (331 ng/mg DW) and astragaloside IV production was also improved. The highest cost-efficacy concentration of the elicitor for all tested astragalosides was observed at 50 µL MeJA.