Plant Secondary Metabolites Research Articles

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

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. 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. 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. 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.

Understory growth of Paris polyphylla accumulates a reservoir of secondary metabolites of plants.

Paris polyphylla is an important traditional medicinal plant of the Himalayan region. It is extensively used for the production of natural steroidal saponins and flavonoids. Although seed dormancy of wild plants can be broken to be artificially maintained and regenerated through micropropagation in the laboratory, the success of secondary metabolite production in higher quantities and the synthesis of superior plant metabolites have been very limited. In this study, we present differential metabolic profiling of P. polyphylla plants maintained for 8 years in natural and greenhouse conditions. Untargeted profiling of the metabolites through ultra-performance liquid chromatography-mass spectrometry/mass spectrometry (UPLC-MS/MS), followed by statistical analysis, identified secondary metabolites that were enriched in the naturally occurring plant roots compared with the greenhouse plant roots. A multivariate statistical analysis revealed the differential distribution of the compounds between the two groups. Overall, we identified 1,182 secondary metabolites, with 116 metabolites being differentially upregulated and 256 metabolites being downregulated. Moreover, 810 metabolites showed no significant variation under both growing conditions. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the naturally forest-grown P. polyphylla plants were significantly enriched in steroidal saponins, lipids, vitamins, flavonoids, and flavonols. An analysis of the top 10 differentially upregulated secondary metabolites indicated a significantly enriched quantity of spirost-5-en-3,12-diol and kaempferol synthesis pathways, which are known to reduce the effect of free radicals scavengers inside the cell. In addition, veratramine alkaloids were also enriched under natural conditions. Our findings indicated that naturally maintained P. polyphylla plants are suitable for the extraction of medicinally important compounds. Our study established a causal relationship between the metabolic composition of the roots and their natural growth condition. This study highlighted the importance of environmental conditions in the biosynthesis of secondary metabolites of plants.

Exploring the Antibacterial and Antibiofilm Efficacy of Psammogeton biternatum Edgew and Identification of a Novel Quinoline Alkaloid using X-ray Crystallography.

The prevalence of resistance to harmful human pathogens is steadily rising, emphasizing the urgent need to identify novel antimicrobial compounds. For this purpose, plants stand out as a significant source of bioactives worthy of exploration. Among these, alkaloids, a vast and structurally diverse category of plant secondary metabolites, have emerged as a foundation for crucial antibacterial medications such as metronidazole and the quinolones. In the current work, the crude methanol leaf extract of Psammogeton biternatum Edgew collected from District Bannu, Pakistan, was subjected to TLC (indirect) bioautography and X-ray crystallography for the isolation of potential antibacterial agents. From the crude extract, a novel quinoline alkaloid called quinoline dione ((3R,3aS,5aR)-3,5a,9-trimethyl-3a,4,5,5a-tetrahydro-2H-isoxazolo[2,3-a] quinoline-2,8(3H)-dione (C14H17NO3)) was isolated. The crystal information (M = 247.296 g/mol) is as follows: orthorhombic, P212121, a = 7.7339(14) Å, b = 10.7254(19) Å, c = 15.730(2) Å, V = 1304.8(4) Å3, Z = 4, T = 296 K, μ(Mo Kα) = 0.088 mm-1, ρ calc = 1.259 g/cm3, 13928 reflections measured (5.86° ≤ 2Θ ≤ 51.98°), 2478 unique (R int = 0.1613, R σ = 0.1335). The final R 1 was 0.1098 (I ≥ 2u(I)), and wR 2 was 0.2183. The antibacterial activity for both crude extract of leaves and quinoline dione was determined by a well diffusion method. The quinoline dione alkaloid demonstrated excellent inhibition zones against methicillin-resistant Staphylococcus aureus (18 mm), Bacillus subtills (17 mm), Escherichia coli (20 mm), and Pseudomonas aeruginosa (23 mm) compared to the crude extract. The antibiofilm potential was recorded against Pseudomonas aeruginosa by the 96-well microtiter plate method. A dose-dependent biofilm inhibition response was recorded, which increased with the increase in concentration. Moreover, quinoline dione showed a greater antibiofilm effect as compared to the crude extract, which may be linked to the presence of a particular active functional group positioned on the compound isolated in its pure form. Through in silico studies, i.e., molecular docking, quinoline dione shows strong binding energies with the LasR transcriptional regulator (6MVN) at -9.3 and LasR transcriptional activator (3IX4) at -9.2 kcal/mol, as well as moderate affinities with other targets such as AHL synthase LasI (PDB ID 1RO5) and OprM channel (PDB ID 3D5K), indicating its potential as a quorum sensing inhibitor. Thus, the antibacterial and antibiofilm potential of quinoline dione was confirmed.

Multi-omics analysis of soil microbiota and metabolites in dryland wheat fields under different tillage methods

No-tillage and subsoiling can improve soil aggregate structure and realize a synergistic effect of soil carbon and nitrogen retention compared with deep tillage. This study aimed to investigate the effects of different tillage methods on the microbiome and metabolites in wheat rhizosphere. Results indicated that no significant differences in the diversity of soil bacterial and fungal communities were observed among the tillage methods. Analysis revealed that no-tillage enriched specific genera such as Cryptosporangium, Crossiella, Rhodothermaceae, Leptothrix, Stilbella, Diutina, and Pyrenochaetopsis, while subsoiling was associated with Rubrobacter, Latescibacteraceae, Nitrospira, Rokubacteriales, and Ctenomyces. Deep tillage, on the other hand, showed significant associations with Nocardia, Aeromicrobium, Sphingopyxis, Cordyceps, and Subulicystidium. Metabolomic analysis identified differential metabolites involved in various pathways, including the biosynthesis of plant secondary metabolites, ABC transporters, and starch and sucrose metabolism. Correlation analysis revealed a significant interaction between microorganisms and metabolites in wheat rhizosphere. Bacteria at the genus level exhibited greater associations with differential metabolites. In conclusion, different tillage practices can alter the composition of microbial communities and metabolites in wheat rhizosphere, and their interactions may affect soil fertility and wheat growth.

Characterization and antibacterial application of peppermint essential oil nanoemulsions in broiler

In order to mitigate the risk of antibiotic resistance in poultry, scientists nowadays consider plant secondary metabolites to be a major organic antibacterial substitute. This study aimed to characterize and investigate the in silico, in vitro, and in vivo antibacterial effects of peppermint essential oil (PEO) in the form of a nanoemulsion (NE), termed PEONE. Menthol as a major compound of PEO has been identified by gas chromatography and mass spectroscopy (GCMS) analysis as 32.3 %, while lower droplet size, polydispersity Index (PDI), and optimum zeta potential values depicted the stability of PEONE have been observed and validated by transmission electron microscopy (TEM) micrograph image. In silico antibacterial activity was studied by molecular docking of menthol and enrofloxacin with Topoisomerase IV protein (PDB: 1s16;) of Escherichia coli K12 MG1655 and this effect was validated by in vitro and in vivo analysis. In vitro analysis, sustained release of PEONE has been observed against Escherichia coli and Staphylococcus aureus. In this study for in vivo experiments (n = 90) day-old broiler chicks were distributed into 6 dietary treatments with 5 replicates of 3 birds per replication. Dietary treatments included 1) Negative control (basal diet), 2) Positive control (basal diet + 200 µl enrofloxacin), 3) 25 µl PEONE + basal diet, 4) 50 µl PEONE + basal diet, 5) 75 µl PEONE + basal diet, and 6) 100 µl PEONE + basal diet. Analyzed data by different statistical tools confirmed that PEONE significantly affected body weight gain (BWG) with an improved feed conversion ratio (FCR) compared to the control group. A significant increase in cecal Lactobacillus count and a decrease in total coliform was observed. Positive effects on physiological parameters, visceral organs, and meat quality characteristics have been observed. In conclusion, our experiments suggest that PEONE can be used in the broiler industry as a substitute for antibiotics to minimize bacterial resistance.

The Effect of Adding Green and Black Tea Waste Extracts on Rumen Fermentation Parameters by In Vitro Techniques

The increase in global temperatures over the past few decades due to greenhouse gas emissions has raised concerns and necessitated further research in climate change mitigation and adaptation. Methane is a prominent greenhouse gas that significantly contributes to climate change, with a substantial amount generated through fermentation processes occurring in the rumen of ruminant animals. The potential of plant secondary metabolites, especially those derived from tannin-rich plants, warrants investigation to modify rumen fermentation and mitigate methane emissions in livestock diets. The objective of this study was to assess the impact of extracts obtained from green and black tea waste on rumen fermentation dynamics and gas (methane) production, utilizing in vitro methods. For this purpose, rumen fluid was collected from two fistulated sheep and subjected to three treatments: (1) a basal diet (control), (2) a basal diet + green tea waste extract (5% of dry matter), (3) a basal diet + black tea waste extract (5% of dry matter). The study assessed the effects of incorporating extracts from green and black tea waste on various parameters, including digestibility, protozoa population, ammonia nitrogen levels, volatile fatty acids, and methane gas production following a 24-h incubation period. Statistical analysis of the data was conducted using SAS software within a completely randomized design framework. The findings indicated that the addition of green and black tea waste extracts significantly decreased methane gas production (p &lt; 0.05), protozoa count (p &lt; 0.05), and ammonia nitrogen concentrations in rumen fluid (p &lt; 0.05) when compared to the control group. The addition of green and black tea waste extracts has significantly altered the concentration of VFAs in rumen fluid (p &lt; 0.05). Specifically, the addition of green tea waste extract has led to a highly significant reduction in acetic acid, (p &lt; 0.01) and the addition of both extracts has resulted in a significant increase in propionic acid (p &lt; 0.05). Consequently, the results suggest that the inclusion of green and black tea waste extracts in livestock diets may effectively mitigate methane emissions in the rumen, thereby reducing feed costs and reducing environmental pollution.

The Potential of Glucosinolates and Their Hydrolysis Products as Inhibitors of Cytokine Storms

A cytokine storm is an intense inflammatory response characterized by the overproduction of proinflammatory cytokines, resulting in tissue damage, and organ dysfunction. Cytokines play a crucial role in various conditions, such as coronavirus disease, in which the immune system becomes overactive and releases excessive levels of cytokines, including interleukins, tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ). This anomalous response often leads to acute respiratory distress syndrome (ARDS), disseminated intravascular coagulation (DIC), and multiple organ injury (MOI). Glucosinolates are plant secondary metabolites predominantly found in Brassica vegetables, but are also present in other species, such as Moringa Adens and Carica papaya L. When catalyzed by the enzyme myrosinase, glucosinolates produce valuable products, including sulforaphane, phenethyl isothiocyanate, 6-(methylsulfinyl) hexyl isothiocyanate, erucin, goitrin, and moringin. These hydrolyzed products regulate proinflammatory cytokine production by inhibiting the nuclear factor kappa-light-chain-enhancer of activated B-cell (NF-κB) signaling pathway and stimulating the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. This action can alleviate hyperinflammation in infected cells and modulate cytokine storms. In this review, we aimed to examine the potential role of glucosinolates in modulating cytokine storms and reducing inflammation in various conditions, such as coronavirus disease. Overall, we found that glucosinolates and their hydrolysis products can potentially attenuate cytokine production and the onset of cytokine storms in diseased cells. In summary, glucosinolates could be beneficial in regulating cytokine production and preventing complications related to cytokine storms.

Application of Fe2O3 nanoparticles improves the growth, antioxidant power, flavonoid content, and essential oil yield and composition of Dracocephalum kotschyi Boiss.

Dracocephalum kotschyi Boiss., an endemic and endangered medicinal and aromatic plant in Iran, showcases distinct botanical characteristics and therapeutic promise. According to the IUCN grouping criteria, this plant is facing challenges due to overcollection from its natural habitats. To address this issue, there is an increasing inclination towards cultivating this species within agricultural systems. This study aimed to evaluate the impact of applying Fe2O3 nanoparticles (NPs) at varying concentrations (50, 100, and 200 mg L-1), as well as bulk Fe2O3 at the same concentrations, on the growth, essential oil production, antioxidant capacity, total phenol, and flavonoid content of D. kotschyi. The foliar application of 100 and/or 200 mg L-1 of Fe2O3 NPs resulted in the greatest leaf length and dry weight, while Fe2O3 NPs at the level of 100 mg L-1 led to the highest leaf/stem ratio. Additionally, spraying 200 mg L-1 of Fe2O3 NPs and all concentrations of bulk Fe2O3 positively impacted chlorophyll and carotenoid levels. Both nano and bulk Fe2O3 supplements stimulated H2O2 production and subsequently enhanced enzymatic antioxidant activity. The use of 50 mg L-1 of Fe2O3 NPs resulted in the highest flavonoid content and non-enzymatic antioxidant activity. Meanwhile, the highest essential oil content and yield was achieved by the application of 50 and/or 100 mg L-1 Fe2O3 NPs. The addition of low concentration of Fe2O3 NPs (50 mg L-1) resulted in a significant increase in the concentration of geranial, while a higher supply of Fe2O3 NPs (200 mg L-1) significantly decreased the percentage of neral in the essential oil. Overall, the application of Fe2O3 NPs demonstrated significant potential for increased biomass, enhanced yield, essential oil production, and phytochemical attributes. The findings highlight the versatility of Fe2O3 NPs at optimal concentrations, acting as both a nano-fertilizer and a nano-inducer, promoting the production and accumulation of valuable secondary metabolites in plants.

Growth and metabolism regulation of cinnamic acid and its derivatives to Auxenochlorella pyrenoidosa

Auxenochlorella pyrenoidosa's industrial utility is closely associated with the concentration of high-value products. This study focuses on the effects of cinnamic acid (CA) and its derivatives, which known as secondary metabolites in higher plants and effective plant growth regulators, on the growth and metabolic profiles of A. pyrenoidosa. It was discovered that CA and its derivatives significantly enhance the biomass of A. pyrenoidosa under conditions of 10 mg/L over 48 h or 100 mg/L over 120 h. Cells treated with 10 mg/L CA exhibited lower oxidative stress and maintained robust metabolic activity. Metabolic pathways, including those for carbohydrates, lipids, small peptides, and cofactors, were stimulated, leading to the accumulation of a wide array of bio-products, notably high-value products such as α-linolenic acid, cis-4,7,10,13,16,19-docosahexaenoic acid (DHA), nicotinamide adenine dinucleotide plus hydrogen (NADH), glutathione, and vitamins B2/B3. This study demonstrates that CA and its derivatives are good nutritional enhancers for cultivating A. pyrenoidosa, highlighting their potential for broad application in biotechnological industries.

Efficient Production of 4’-Hydroxydihydrochalcones Using Non-Conventional Yeast Strains

The quest for novel therapeutic agents has rekindled interest in natural products, particularly those derived from biotransformation processes. Dihydrochalcones, a class of plant secondary metabolites, exhibit a range of pharmacological properties. Chalcone and dihydrochalcone compounds with the characteristic 4’-hydroxy substitution are present in ‘dragon’s blood’ resin, known for its traditional medicinal uses and complex composition, making the isolation of these compounds challenging. This study investigates the efficient production of 4′-hydroxydihydrochalcones using non-conventional yeast strains. We evaluated the biotransformation efficiency of various 4′-hydroxychalcone substrates utilizing yeast strains such as Yarrowia lipolytica KCh 71, Saccharomyces cerevisiae KCh 464, Rhodotorula rubra KCh 4 and KCh 82, and Rhodotorula glutinis KCh 242. Our findings revealed that Yarrowia lipolytica KCh 71, Rhodotorula rubra KCh 4 and KCh 82, and Rhodotorula glutinis KCh 242 exhibited the highest conversion efficiencies, exceeding 98% within one hour for most substrates. The position of methoxy substituents in the chalcone ring significantly influenced hydrogenation efficiency. Moreover, we observed isomerization of trans-4′-hydroxy-2-methoxychalcone to its cis isomer, catalyzed by light exposure. This study underscores the potential of using yeast strains for the sustainable and efficient production of dihydrochalcones, providing a foundation for developing new therapeutic agents and nutraceuticals.

Elucidating the downstream pathways triggered by H2S signaling in Arabidopsis thaliana under drought stress via transcriptome analysis

ABSTRACT Hydrogen sulfide (H2S) is a crucial signaling molecule in plants. Recent studies have shown that H2S plays an equally important role as nitric oxide (NO) and hydrogen peroxide (H2O2) in plant signaling. Previous studies have demonstrated the involvement of H2S in regulating drought and other stressful environmental conditions, but the exact downstream molecular mechanisms activated by the H2S signaling molecule remain unclear. In this study, we conducted a comprehensive genome-wide transcriptomic analysis of both wild type (WT) and double mutant (lcd/des1). Arabidopsis thaliana plants were exposed to 40% polyethylene glycol (PEG) to induce drought stress and 20 µM sodium hydrosulfide (NaHS). The resulting transcriptome data were analyzed for differentially significant genes and their statistical enrichments in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The results indicated significant upregulation of genes related to photosynthesis, carbon fixation, plant secondary metabolite biosynthesis, inositol and phosphatidylinositol signaling pathways, and stress-responsive pathways in mutant plants under drought stress. Mutant plants with impaired H2S signaling mechanisms displayed greater susceptibility to drought stress compared to wild-type plants. In summary, all findings highlight the pivotal role of H2S signaling in stimulating other drought-responsive signaling pathways.

Characterization and quantification of peptaibol produced by novel Trichoderma spp: Harnessing their potential to mitigate moisture stress through enhanced biochemical and physiological responses in black pepper (Piper nigrum L.).

Trichoderma spp. is primarily applied to manage biotic stresses in plants. Still, they also can mitigate abiotic stresses by the stimulation of antioxidative protective mechanisms and enhanced synthesis of secondary metabolites. The study optimized the conditions to enhance peptaibol production by novel Trichoderma spp, characterized and quantified peptaibol- alamethicin using HPLC and LC MS-MS. The present study investigated these isolates efficacy in enhancing growth and the associated physio-biochemical changes in black pepper plants under moisture stress. Under in vitro conditions, out of 51 isolates studied, six isolatesviz., T. asperellum (IISR NAIMCC 0049), T. erinaceum (IISR APT1), T. harzianum (IISR APT2), T. harzianum (IISR KL3), T. lixii (IISR KA15) and T. asperellum (IISR TN3) showed tolerance to low moisture levels (5, 10 and 20%) and higher temperatures (35 and 40°C). In vivo evaluation on black pepper plants maintained under four different moisture levels (Field capacity [FC]; 75%, 50%, and 25%) showed that the plants inoculated with Trichoderma accumulated greater quantities of secondary metabolites viz., proline, phenols, MDA and soluble proteins at low moisture levels (50% and 25% FC). In the present study, plants inoculated with T. asperellum and T.harzianum showed significantly increased growth compared to uninoculated plants. The shortlisted Trichoderma isolates exhibited differences in peptaibol production and indicated that the peptide might be the key factor for their efficiency as biocontrol agents. The present study also demonstrated that Trichoderma isolates T. harzianum and T. asperellum (IISR APT2 & NAIMCC 0049) enhanced the drought-tolerant capabilities of black pepper by improving plant growth and secondary metabolite production.

Possibilities of using secondary plant metabolites as antitumor agents

The review summarized the literature data of recent years on the antitumor effect of secondary plant metabolites, as well as their immunotropic and anti-inflammatory effects as components of the antitumor response. The biological basis for the action of secondary plant metabolites was characterized in the form of influence on potential targets: transcription factors, signaling pathways and receptors responsible for proliferation and apoptosis. The ways of increasing the bioavailability of secondary plant metabolites to enhance the effectiveness and possibility of their medicinal use were considered, the effects of berberine, curcumin and their derivatives were described. The search for scientific publications was conducted in foreign (PubMed) and domestic (eLibrary) electronic libraries. It was found that the multiplicity of molecular targets of secondary plant metabolites and the pleiotropy of their effects suggest the possibility of their use for the regulation of various processes in tumor and normal cells. There was a connection between the antitumor effect of secondary plant metabolites and their anti-inflammatory and immunomodulatory action. However, a significant limitation of their use was the fact that most studies were conducted on cell cultures, which was insufficient to judge the antitumor effect. Clinical trials were few and their results were contradictory. In addition, a certain contradiction has been noted between the idea of a more effective action when using a pure substance or a complex composition of various plant components. An important problem was the low bioavailability of most secondary plant metabolites, for which various methods have been proposed. Despite the long history of phytotherapy in oncology, the development of new derivatives of secondary plant metabolites with high water solubility remains relevant, including modified molecules of known secondary plant metabolites and the search for new ones with unexplored biological activity. Modern methods of chemical synthesis and delivery systems of derivatives of secondary plant metabolites, as well as the study of their effects in model experiments, seem to be promising scientific directions for the creation of new drugs with antitumor activity.

Multitemporal UAV study of phenolic compounds in slash pine canopies

Phenolic compounds (PC) are important secondary metabolites in plants, playing a crucial role in plant defense mechanisms against pathogens and other plants. Monitoring PC levels is important for understanding tree stress and implementing effective breeding programs. However, traditional methods for monitoring PC are time-consuming, prone to altering the phenolic composition, and mostly applicable only on a small scale. In this study, we evaluated the performance of Unoccupied Aerial Vehicles (UAV) multispectral imaging in estimating the canopy phenolic content in slash pine over an 11-month period in 2021 and a seven-month period in 2022. Three machine learning models including Partial least squares regression (PLSR), Random forest (RF) and Support Vector Machine (SVM) were compared to determine the optimal predictive model for canopy PC. The RF model provided the best predictive results, with R2 values of 0.82 for the validation set and 0.94 for the calibration set. Additionally, the study assesses the heritable variation in canopy PC over time, with the monthly heritability (h2) of PC ranging from 0 to 0.26 in 2021 and from 0 to 0.35 in 2022; The highest h2 levels were observed in July and September 2021and July 2022. The findings demonstrate significant genetic control over the variation of PC. Furthermore, we observed higher breeding values and genetic gains in July and November, which further supports the strong correlation between PC and environmental factors such as temperature and light intensity. To the best of our knowledge, this is the first study to employ time-series UAV multispectral imaging to predict secondary metabolites in pine trees and estimate their genetic variation over time. As a proof of concept, these findings provide more reliable information for tree breeding programs, ultimately enhancing their overall performance.