Synthesis Of Bioactive Compounds Research Articles

Inoculation of Arthrobacter sp. improves the growth of Acanthocalycium sp. and the fruits nutraceutical quality and the flowers longevity

Research objective: The aim of this work is on the inoculation in the growing medium of Arthrobacter sp. and its effects on the growth, flower quality and longevity of cactus plants. To this end, the study of biometric parameters, i.e. plants and flowers (height, weight, number and duration), as well as root growth (weight), and the presence of disease were quantified as measures of plant productivity and compared with those obtained from non-inoculated plants. The use of alginate microspheres as a means of bacterial inoculation was also considered. Materials and Methods: Seedlings of Acanthocalycium (2 years old) Ferrarii, A. Glaucum and A. Violaceum were immediately planted in pots after purchase, in substrate containing (sand 20%, pumice 20% and peat 60%; pH 7; electrical conductivity 0.7 dS/m; total porosity 80% (v/v). A randomised complete block design was applied for the experiments: the pots were randomly divided into two series, one series was inoculated with the bacteria and the other non-inoculated was used as a control. Each month, plant growth was assessed according to (1) plant height, (2) vegetative and root weight, (3) number of flowers per plant (4) flower duration. In addition, the occurrence of possible diseases, in particular Fusarium sp. and Verticillium sp., was assessed. Total flavonoids, total phenols and antioxidant activity were also analysed. Results and Discussion: The experiment showed that the use of Arthrobacter sp. can indeed significantly improve the vegetative and root growth of Acanthocalycium sp. cacti. In addition, there was a significant improvement in the number and floral longevity as well as in the phenol, flavonoid and antioxidant content of the fruits of the inoculated plants compared to the untreated control. The experiment also showed that mortality due to the pathogens Fusarium sp. and Verticillium sp. was significantly reduced in the treated plant. In agreement with these authors, we found that PGPB treatments increased agronomic parameters and improved Fusarium and Verticillium resistance. In general, the application of biostimulants can increase the synthesis of bioactive compounds in plants by increasing resistance to phytopathologies. Inoculation with Arthrobacter sp. led to a significant reduction in the number of dead plants with respect to the diseases analysed. As a result of the stimulating action demonstrated in Acanthocalycium, bioproducts suitable for nutraceutical purposes may be developed in the future. Therefore, new microbe-assisted technologies can help plants to resist stress conditions, improving their tolerance and productivity. Conclusions: Due to its ‘multifunctionality’, the genus Acanthocalycium is considered as one of the species of the future, for ornamental use and medicinal aspects, and new results may help reveal its potential in the context of the bio-economy and circular economy. As natural resources and cultural practices are crucial in defining the quality of flowers when destined for food/nutraceutical applications, the inoculation of Acanthocalycium with Arthrobacter sp. can be envisaged to provide better plant growth under conditions of environmental stress, or as a soil fertiliser, but also to improve the synthesis of natural products used for therapeutic applications.

In vitro and in silico effect of meldrum's acid-derived compounds on Staphylococcus aureus strains as NorA efflux pump inhibitors

The misuse of antibiotics has led to an alarming increase in bacterial strains resistant to these drugs. Efflux pumps, which expel antibiotics from bacterial cells, have emerged as one of the key mechanisms of bacterial resistance. In the quest to combat and mitigate bacterial resistance, researchers have turned their attention to efflux pump inhibitors as a potential solution. Meldrum's acid, a synthetic molecule widely utilized in the synthesis of bioactive compounds, has garnered significant interest in this regard. Hence, this study aims to investigate the antibacterial activity and evaluate the efficacy of three derivatives of meldrum's acid in inhibiting efflux mechanisms, employing both in silico and in vitro approaches. The antibacterial activity of the derivatives was assessed through rigorous broth microdilution testing. While the derivatives themselves did not exhibit direct antibacterial activity, they demonstrated remarkable potential in potentiating the effects of antibiotics. Additionally, fluorescence emission assays using ethidium bromide (EtBr) revealed fluorescence levels comparable to the positive control, indicating a possible blockade of efflux pumps. Molecular docking studies conducted in silico further supported these findings by revealing binding interactions similar to norfloxacin and CCCP, known efflux pump inhibitors. These results underscore the potential of meldrum's acid derivatives as effective inhibitors of efflux pumps. By inhibiting these mechanisms, the derivatives hold promise in enhancing the effectiveness of antibiotics and combatting bacterial resistance. This study contributes valuable insights into the development of novel strategies to address the pressing issue of bacterial resistance and paves the way for further research and exploration in this field.

Harnessing Nature's Toolbox: Naturally Derived Bioactive Compounds in Nanotechnology Enhanced Formulations.

The vast diversity of plants in nature offers a rich reservoir of bioactive compounds that have historically played an integral role in pharmacotherapy and continue to serve as a primary source of novel therapeutic agents. Medicinal plants contain a multitude of secondary metabolites with pharmacological potential, making them indispensable in drug discovery and development. These bioactive constituents, inherent in herbal remedies, exhibit a wide range of medicinal properties due to their complex chemical compositions and structural diversity. Despite their therapeutic potential, the clinical application of crude plant extracts is often hindered by limitations, such as poor bioavailability, low biostability, and variable efficacy. These issues can diminish the therapeutic impact of plant-derived compounds. Nanotechnology presents an innovative approach to addressing these challenges through the development of nanoformulations that enhance the efficacy of bioactive compounds. This review examines both historical and recent studies on the synthesis and characterization of bioactive compounds, focusing on their effectiveness in treating various diseases. Additionally, it addresses the risks associated with the direct use of crude plant extracts in medicine, explores extraction and isolation techniques, and reviews research from the past five years on the development of bioactive compounds, their nanoformulations, and their applications in disease treatment. The review also presents recent clinical trials conducted over the last five years on crude extracts and their nanoformulated counterparts, providing insights into the clinical translation of these natural therapeutics.

Cu(II)-Catalyzed Reaction of Ethynyl Methylene Cyclic Carbamates and Amines: Synthesis of Polysubstituted Pyrroles.

A copper-catalyzed efficient, operationally simple, general method for straightforward syntheses of polysubstituted pyrroles employing ethynyl methylene cyclic carbamates as precursors reacting with commercially available amines was first reported. A wide variety of polysubstituted pyrroles were obtained in acceptable to good yields under mild conditions. This protocol features broad substrate scope, high functional group tolerance, and easy operation, therefore enabling late-stage functionalization and rapid synthesis of bioactive compounds, including structurally complex marketed drugs and natural products. In addition, a scale-up experiment further highlighted the synthetic utility.

Synergistic Effect of Arbuscular Mycorrhizal Fungi and Germanium on the Growth, Nutritional Quality, and Health-Promoting Activities of Spinacia oleracea L.

Arbuscular mycorrhizal fungi (AMF) and the antioxidant germanium (Ge) are promising tools for boosting bioactive compound synthesis and producing healthier foods. However, their combined effect remains unexplored. This study demonstrates the synergistic impact of AMF and Ge on the growth, metabolite accumulation, biological activities, and nutritional qualities of Spinacia oleracea L. (spinach), a globally significant leafy vegetable. Individually, Ge and AMF increased biomass by 68.1% and 22.7%, respectively, while their combined effect led to an 86.3% increase. AMF and Ge also improved proximate composition, with AMF-Ge interaction enhancing crude fiber and mineral content (p < 0.05). Interestingly, AMF enhanced photosynthesis-related parameters (e.g., total chlorophyll) in Ge treated plants, which in turn increased carbohydrate accumulation. This accumulation could provide a route for the biosynthesis of amino acids, organic acids, and fatty acids, as evidenced by increased essential amino acid and organic acid levels. Consistently, the activity of key enzymes involved in amino acids biosynthesis (e.g., glutamine synthase (GS), methionine biosynthase (MS), lysine biosynthase (LS)) showed significant increments. Furthermore, AMF improved fatty acid levels, particularly unsaturated fatty acids in Ge-treated plants compared to the control. In addition, increased phenylalanine provided a precursor for the production of antioxidants (e.g., phenols and flavonoids), through the action of the enzyme phenylalanine ammonia-lyase (PAL), resulting in improved antioxidant activity gains as indicated by FRAP, ABTS, and DPPH assays. This study is the first to show that Ge enhances the beneficial effect of AMF on spinach, improving growth and nutritional quality, with promising implications for agricultural practices.

Sustainable methods for producing food-derived bioactive compounds

Background: Pursuing alternative starting materials has gained significant importance in the food and drug industries, driven by the global shift towards sustainable and renewable resources. Terpenes, naturally occurring hydrocarbons derived from plants, present a promising solution due to their abundant availability and range of physiological activities, including antioxidant, anti-inflammatory, antimicrobial, and anticancer properties. Objective: This study aims to develop a waste-free synthesis methodology for functionalizing limonene and myrcene, two notable terpenes, through Atom Transfer Radical Reactions (ATRR). The objective is to achieve high yields and purities while enhancing the therapeutic potential of these compounds and adhering to green chemistry principles. Methods: A catalytic complex of Cu(I)Br and dimethyl sulfoxide (DMSO) was used to facilitate the coupling of limonene and myrcene with various trichloroacetic acid derivatives. Reactions were performed at 80°C for 90 minutes, and products were purified by column chromatography. The synthesized compounds were characterized using Gas Chromatography-Mass Spectrometry (GC-MS) and Nuclear Magnetic Resonance (NMR). Microbiological analyses were conducted using the disk-diffusion method, and statistical analyses were performed to assess the reliability of the experiments. Results: The ATRR methodology enabled the efficient functionalization of limonene and myrcene, achieving high yields and purities. The best yield for limonene was 70%, and for myrcene, 82%, both using trichloroacetonitrile. The Cu(I) catalytic system showed dualistic biological effects, with 3% concentration exhibiting strong bactericidal and fungicidal activity, while 0.03% promoted growth. These results demonstrate the potential of the methodology and the catalytic system for bioactive compound synthesis and agricultural applications. Conclusion: This study demonstrates the viability of ATRR for efficiently functionalizing limonene and myrcene, achieving high yields and purities. The synthesized compounds show promise for pharmaceutical development. The dual antibacterial and antifungal activities of the Cu(I) catalytic system also suggest potential applications in wastewater reutilization. Future work should explore the biological effects and environmental impact of this process. Keywords: Terpenes, ATR reactions, Green Chemistry, Bioactive compounds, Therapeutic potential.

Electric fields to support microalgae growth with a differentiated biochemical composition

Microalgae are a group of microorganisms well-known for their high metabolic plasticity and biomass with commercial interest for several industries. In the present work, the influence of in-situ electric field application (INEF) on the growth and biochemical composition of Pavlova gyrans was, for the first time, assessed. Electrical protocols were tested, namely by applying INEF in different growth stages, in varying treatment times and even by combining it with dark phase of cells' photoperiod. INEF did not promote a stimulatory effect on growth but influenced the biochemical composition of P. gyrans – maximum increases of 74.9 and 66.2 % in the chlorophyll a and carotenoid content and of 4.72, 18.7 and 5.41 % in the lipid, carbohydrate and protein content were observed in independent experiments. Hence, with this study, the potential of INEF application as a strategy to modulate growth and to promote biochemical composition alterations was proven. Industrial relevanceMicroalgae, with their unique ability to efficiently convert sunlight and carbon dioxide into biomass, offer a sustainable platform for the synthesis of diverse bioactive compounds. By subjecting microalgae to controlled electric stress conditions, their metabolic pathways can be redirected towards the production of specific target compounds. This strategy has the potential to enhance the yield of high-value molecules, including biofuels, pharmaceuticals, nutraceuticals, and pigments, whilst minimizing resource inputs. Additionally, metabolic stress responses in microalgae often trigger the accumulation of secondary metabolites with bioactive properties. Harnessing the metabolic plasticity of microalgae through controlled stress manipulation represents a cutting-edge strategy for sustainable and economically viable bioproduction systems that align with the goals of green chemistry and circular economy principles.

3-Acetyl Indole in the Synthesis of Natural Bioactive Compounds

Natural products, with their various sources from plants, marine organisms, and microorganisms, are considered a key source and inspiration for medicines and continue to be so. Indole alkaloids are a class of alkaloids and represent a large subunit of natural prod-ucts. Indole alkaloids of biological importance are numerous and cover a wide range of phar-maceutical applications, including anticancer, antiviral, antimicrobial, anti-inflammatory, and antioxidant. Obtaining natural, biologically active indole compounds involves isolating them from their natural sources or preparing them synthetically. 3-Substituted indoles repre-sent an emerging structural class of marine alkaloids based on their high degree of biological activity. 3-Acetyl indole is an important core used as a starting material for synthesizing many bioactive indole alkaloids. (5-Indole)oxazole alkaloids, β-carboline alkaloids, bis-in-dole alkaloids, chuangxinmycin, meridianine, and (±) indolemycin are the most important indole alkaloids that are prepared starting from 3-acety indole. The present review provides comprehensive information on the structures and the synthesis of bioactive indole alkaloids utilizing 3-acetyl indole and its derivatives as starting compounds. Additionally, it also spot-lights the diverse biological activities of these compounds.

Inoculation with Jeotgalicoccus sp. improves nutritional quality and biological value of Eruca sativa by enhancing amino acid and phenolic metabolism and increasing mineral uptake, unsaturated fatty acids, vitamins, and antioxidants.

Plant growth-promoting bacteria (PGPB) are considered a promising tool for triggering the synthesis of bioactive compounds in plants and to produce healthy foods. This study aimed to demonstrate the impact of PGPB on the growth, accumulation of primary and secondary metabolites, biological activities, and nutritional qualities of Eruca sativa (arugula), a key leafy vegetable worldwide. To this end, Jeotgalicoccus sp. (JW0823), was isolated and identified by using partial 16S rDNA-based identification and phylogenetic analysis. The findings revealed that JW0823 significantly boosted plant biomass production by about 45% (P<0.05) and enhanced pigment contents by 47.5% to 83.8%. JW0823-treated plants showed remarkable improvements in their proximate composition and vitamin contents, with vitamin E levels increasing by 161.5%. JW0823 induced the accumulation of bioactive metabolites including antioxidants, vitamins, unsaturated fatty acids, and essential amino acids, thereby improving the nutritional qualities of treated plants. An increase in the amounts of amino acids was recorded, with isoleucine showing the highest increase of 270.2%. This was accompanied by increased activity of the key enzymes involved in amino acid biosynthesis, including glutamine synthase, dihydrodipicolinate synthase, cystathionine γ-synthase, and phenylalanine ammonia-lyase enzymes. Consequently, the total antioxidant and antidiabetic activities of the inoculated plants were enhanced. Additionally, JW0823 improved antimicrobial activity against several pathogenic microorganisms. Overall, the JW0823 treatment is a highly promising method for enhancing the health-promoting properties and biological characteristics of E. sativa, making it a valuable tool for improving the quality of this important leafy vegetable.

A comprehensive review on microbial diversity and anticancer compounds derived from seaweed endophytes: a pharmacokinetic and pharmacodynamic approach.

Seaweed endophytes are a rich source of microbial diversity and bioactive compounds. This review provides a comprehensive analysis of the microbial diversity associated with seaweeds and their interaction between them. These diverse bacteria and fungi have distinct metabolic pathways, which result in the synthesis of bioactive compounds with potential applications in a variety of health fields. We examine many types of seaweed-associated microorganisms, their bioactive metabolites, and their potential role in cancer treatment using a comprehensive literature review. By incorporating recent findings, we hope to highlight the importance of seaweed endophytes as a prospective source of novel anticancer drugs and promote additional studies in this area. We also investigate the pharmacokinetic and pharmacodynamic profiles of these bioactive compounds because understanding their absorption, distribution, metabolism, excretion (ADMET), and toxicity profiles is critical for developing bioactive compounds with anticancer potential into effective cancer drugs. This knowledge ensures the safety and efficacy of proposed medications prior to clinical trials. This study not only provides promise for novel and more effective treatments for cancer with fewer side effects, but it also emphasizes the necessity of sustainable harvesting procedures and ethical considerations for protecting the delicate marine ecology during bioprospecting activities.

Ozonation: Post-harvest processing of different fruits and vegetables enhancing and preserving the quality

Daily ingestion of fresh produce has increased tremendously due to a rise in awareness of its nutritional benefits that contribute to reducing health risks and disease. However, these commodities are highly perishable and prone to significant post-harvest losses. Conventional methods have been scrutinized in the production of undesirable by-products. Ozone technology has emerged as an efficient sterilization technique. Additionally, it stimulated the synthesis of bioactive and antioxidant compounds by activating secondary metabolic pathways. However, there are conflicting findings in the literature related to their impact on the quality and physiological processes of fruits and vegetables (F&V). This scientific literature review focuses on key studies examining the effects of ozonation on the growth of microorganisms and the quality preservation of different F&V. This review also enlarges our understanding of eco-friendly technologies which not only extend the shelf life of F&V but also uphold their quality without introducing harmful chemicals.

Chemoenzymatic Synthesis of Plant‐Derived Kavalactone Natural Products by Dynamic Resolution Using a Biosynthetic O‐Methyltransferase Tailoring Enzyme

Biosynthetic enzymes have enormous potential for the chemoenzymatic synthesis of natural products and other bioactive compounds. Methyltransferases are promising tools for the selective enzymatic modification of complex structures. This paper describes the production, purification and biochemical characterization of the O‐methyltransferase JerF, which catalyzes unique 4‐methoxy‐5,6‐dihydropyranone formation in jerangolid A biosynthesis. Isolation problems had hitherto prevented detailed studies on JerF and were solved by the production of the maltose‐binding protein fusion protein. The differentiation of JerF between styryl‐substituted dihydropyrandion enantiomers was investigated. In combination with a spontaneous racemization occurring with this type of substrates, a new enzymatic dynamic kinetic resolution was observed, which was used for the enantioselective chemoenzymatic synthesis of kavalactone natural products and new derivatives. In combination with an HMT‐based SAM regeneration system, (+)‐kavain, (+)‐11,12‐dimethoxykavain and (+)‐12‐fluorokavain were prepared in 3‐4 steps on the 100 µmol scale with overall yields of 37‐57% and ees of 70‐86%. A mutational study based on an AlphaFold 2 model provided indications for active site residues with an influence on the performance of the enzyme that could be targets for engineering. This example illustrates how the exceptional enzymatic activities and specificities of biosynthetic enzymes can be exploited for the development of new synthesis approaches.

Postbiotic emissaries: a comprehensive review on the bioprospecting and production of bioactive compounds by Enterococcus species

SummaryEnterococcus species have been acknowledged for their diverse metabolic capabilities, resulting in a wide array of bioactive compounds that show promise for therapeutic use. This article presents a thorough examination of the exploration and synthesis of bioactive compounds by Enterococcus species. It encompasses the taxonomy, natural habitat, and significance in the biotechnology of Enterococcus, emphasising the various bioactive compounds it produces, including antibacterial, immunomodulatory, and antioxidant agents. Strategies for exploring potential bioactivities, encompassing isolation methodologies and screening techniques, are discussed. The biotechnological synthesis of bioactive compounds derived from Enterococcus via fermentation processes, optimisation approaches, and scaling methodologies is expounded. Moreover, the utilisation of these bioactive compounds in functional foods, pharmaceuticals, and agriculture, alongside considerations of safety and regulatory aspects, is examined. The review concludes with future perspectives and challenges in the field of Enterococcus‐derived bioactive compounds.

Enhanced Curculigoside and Phenolic Compounds Elevate Antioxidant Activity in C. orchioides Gaertn In Vitro Under Exogenous Augmentation with Elicitors Salicylic Acid (SA) and Polyethylene Glycol (PEG) 6000

Abstract Introduction Curculigo orchioides Gaertn, an endangered medicinal plant, possesses a bioactive compound known as curculigoside (phenolic glycoside) in addition to other phenolic compounds. Curculigoside has multifunctional pharmacological properties including antioxidant and anti-inflammatory. Advances in plant tissue culture provide us with tools for the in vitro propagation of medicinal plants in addition to a well-founded system to enhance pharmacologically bioactive compounds through the use of elicitors. Objective The study evaluates the effect of exogenous application of salicylic acid (SA) and polyethylene glycol 6000 (PEG 6000) to in vitro cultures of C. orchioides for enhanced curculigoside, phenolic compounds production followed by an increase in antioxidant activity (AA). Method Eight-week-old subcultured plants grown in one-fourth strength Murashige and Skoog media were subjected to elicitors treatment. SA (10, 100, and 1,000 ppm) and a PEG 6000 (1,000, 5,000, and 10,000 ppm) were used as elicitors for a period of 1, 2, and 4 weeks. Plants without treatment were considered as control. The treated plants were subjected to 80% acetone solvent for efficient phenolic extract preparation. High-performance liquid chromatography was used for the analysis of curculigoside content (CC), and total phenolic content (TPC) was determined using the Folin–Ciocalteu colorimetric method. AA was evaluated by 1,1-diphenyl-2-picrylhydrazyl assay. Results SA treatment increased CC, TPC, and biological activity of AA properties compared to the control, with the maximum value observed at 10 ppm treatment after week 1 elicitation. CC, TPC, and AA gradually decreased after week 2 elicitation, and the lowest values were observed after week 4 elicitation. In the PEG 6000 treatment, 10,000 ppm elicited the highest CC and TPC, with the maximum AA observed after week 2 elicitation. The treatment also elicited higher CC, TPC, and AA in both the 1st and 4th weeks compared to the control. Conclusion SA and PEG 6000 successfully enhanced CC, TPC, and improved AA in C. orchioides in vitro. The study also offers insightful information for the neutraceutical, cosmeceutical, and pharmaceutical industries about how to potentially manipulate medicinal plants in vitro to increase the synthesis of bioactive compounds.

Elicitation and precursor induced approaches for the enhancement of α−tocopherol production using suspension cultures of Solanum lycopersicum

Elicitation and precursor feeding are the effective strategies for enhancing the synthesis of bioactive compounds in plant cell suspension cultures. The present study aimed to explore an efficient elicitation and precursor feeding protocol and its effect on inducing the accumulation of α-tocopherol in Solanum lycopersicum (tomato) suspension cell culture. The tomato cell suspension cultures were treated with different elicitors (Methyl Jasmonate, Salicylic acid and Yeast extract) and precursors (Homogentisic acid, Tyrosine, Hydroxypyruvic acid and Phytol) and the effect of α-tocopherol production was studied. Significant increase in the α-tocopherol was observed on day 5 upon methyl jasmonate treatment which represented 17.7 fold increase in comparison to the control. The treatment of precursor in combination viz., 150 μM Homogentisic acid + 150 μM Phytol showed the maximum enhancement of α-tocopherol up to 22 fold on day 10 compared to the untreated control. These results suggested that the suspension cultures combining with the optimal precursor feeding and elicitors enhanced the production of α-tocopherol in economically important tomato cell cultures.

Synthesis of New Glucose-containing 5-Arylisoxazoles and their Enzyme Inhibitory Activity

Abstract: Carbohydrates are an important group of biomolecules that have received special attention due to their significant role in the design and synthesis of new bioactive compounds. In this study, a new class of 5-arylisoxazole-glucose hybrids was designed and synthesized for evaluation of their inhibitory effects on α-glucosidase, α-amylase, and tyrosinase. The target compounds depicted selective α-glucosidase inhibitory activity over α-amylase, which is an important factor in reducing probable gastrointestinal problems in the treatment of type 2 diabetes. In this respect, compound 9a, possessing the phenylisoxazole group, was found to be the most potent α-glucosidase inhibitor (IC50 = 292.2 ± 0.1 μM) compared to acarbose (IC50 = 750.2 ± 0.1 μM) as the positive control. All compounds were also evaluated for their anti-tyrosinase effect, and among them, compound 9j, containing a fluoroaryl moiety, showed potent activity (IC50 = 50.1 ± 6.3 μM) in comparison to kojic acid (IC50 = 23.6 ± 2.6 μM). Also, docking studies were performed to investigate the probable mode of action, which indicated the construction of important H-bonding interactions between the sugar moiety and the enzyme’s active sites. According to the results, hybrids containing heterocycles attached to glucose can be used to inhibit α-glucosidase.

Low microbial diversity, yeast prevalence, and nematode-trapping fungal presence in fungal colonization and leaf microbiome of Serjania erecta

Medicinal plant microbiomes undergo selection due to secondary metabolite presence. Resident endophytic/epiphytic microorganisms directly influence plant’s bioactive compound synthesis. Hypothesizing low microbial diversity in Serjania erecta leaves, we assessed leaf colonization by epiphytic and endophytic fungi. Given its traditional medicinal importance, we estimated diversity in the endophytic fungal microbiome. Analyses included scanning electron microscopy (SEM), isolation of cultivable species, and metagenomics. Epiphytic fungi interacted with S. erecta leaf tissues, horizontally transmitted via stomata/trichome bases, expressing traits for nematode trapping. Cultivable endophytic fungi, known for phytopathogenic habits, didn’t induce dysbiosis symptoms. This study confirms low leaf microbiome diversity in S. erecta, with a tendency towards more fungal species, likely due to antibacterial secondary metabolite selection. The classification of Halicephalobus sp. sequence corroborated the presence of nematode eggs on the epidermal surface of S. erecta by SEM. In addition, we confirmed the presence of methanogenic archaea and a considerable number of methanotrophs of the genus Methylobacterium. The metagenomic study of endophytic fungi highlighted plant growth-promoting yeasts, mainly Malassezia, Leucosporidium, Meyerozyma, and Hannaella. Studying endophytic fungi and S. erecta microbiomes can elucidate their impact on beneficial bioactive compound production, on the other hand, it is possible that the bioactive compounds produced by this plant can recruit specific microorganisms, impacting the biological system.

PLANT-GROWTH-PROMOTING AND ANTIFUNGAL ASSET OF INDIGENOUS DROUGHT-TOLERANT RHIZOBACTERIA ISOLATED FROM OLIVE (Olea europaea L.) RHIZOSPHERE

Faced with global environmental challenges, the quest for sustainable food production has gathered momentum. While abiotic stresses adversely affect plant health and productivity, Verticillium wilt causes considerable yield losses worldwide, particularly in crops such as olive. Recently, drought-tolerant bacteria have been used to alleviate both abiotic stress and pathogen pressure in crops. In this context, our work focuses on the isolation of tolerant indigenous rhizobacteria to mitigate these challenges by investigating their role in biocontrol and abiotic stress tolerance. Thus, a total of 94 rhizobacterial strains were isolated from the rhizospheres of olive trees in southeastern Morocco and characterized to identify tolerant plant growth-promoting rhizobacteria that inhibit Verticillium dahliae. 24 strains demonstrated in vitro suppression of Verticillium dahliae Klebahn, and exhibited tolerance to different abiotic stresses (drought, salinity, and high temperature). In addition, they proved xerotolerant (Aw ≤ 0.91), halotolerant (≥10% NaCl), and thermotolerant (≥ 55°C) capabilities. Beyond, these isolates showcased multifaceted plant growth-promoting traits, such as phosphate solubilization and significant synthesis of essential bioactive compounds like siderophores, indole-3-acetic acid and hydrolytic enzymes. Evaluating outcomes, three standout rhizobacterial isolates emerged due to their exceptional stress tolerance, unique plant growth-promoting qualities, and potent antagonistic potential. Molecular analysis identified them as Bacillus paranthracis (OZ-60) and Bacillus licheniformis (OZ-48 and OZ-77) through 16S rRNA sequencing. Besides enhancing plant abiotic stress resistance, these isolates hold promise in bolstering the sustainability of olive cultivation and fortifying plant defenses against pathogens.

Unveiling the potential of native arbuscular mycorrhizal fungi for growth promotion and phytochemical enrichment in Valeriana jatamansi Jones.

Medicinal plants are rich sources of pharmaceutically important compounds and have been utilized for the treatment of various diseases since ancient times. Valeriana jatamansi Jones, also known as Indian valerian, holds a special place among temperate Himalayan medicinal plants and is renowned for its therapeutic properties in addressing a variety of ailments. The therapeutic potential of V. jatamansi is attributed to the presence of valuable compounds such as valepotriates, sesquiterpenoids, valeriananoids, jatamanins, lignans, cryptomeridiol, maaliol, xanthorrhizzol, and patchouli alcohol found in its rhizome and roots. This study employed various treatments, including the cultivation of V. jatamansi with the inoculation of Funneliformis mosseae, F. constrictus, and a consortium of arbuscular mycorrhizal fungi (AMF), to investigate their influence on biomass production, chlorophyll content, and the accumulation of bioactive compounds in V. jatamansi. The results revealed significant improvement in these parameters in the inoculated plants. The parameters of plants inoculated with F. mosseae were the highest, followed by those of plants inoculated with F. constrictus and a mixture of AMFs. This study not only underscores the potential of native AMF for promoting the growth of V. jatamansi but also elucidates their role in influencing the synthesis of bioactive compounds. The cultivation of V. jatamansi with native AMF has emerged as a sustainable and eco-friendly approach, providing the dual benefit of enhancing both the medicinal and economic value of this valuable plant. This research contributes valuable insights into the practical application of mycorrhizal associations for the cultivation of medicinal plants, bridging the realms of agriculture and pharmaceuticals.

Modular assembly of arenes, ethylene and heteroarenes for the synthesis of 1,2-arylheteroaryl ethanes.

The 1,2-arylheteroaryl ethane motif stands as a privileged scaffold with promising implications in drug discovery. Conventional de novo syntheses of these molecules have relied heavily on pre-functionalized synthons, entailing harsh conditions and multi-step processes. Here, to address these limitations, we present a modular approach for the direct synthesis of 1,2-arylheteroaryl ethanes using feedstock chemicals, including ethylene, arenes and heteroarenes. We disclosed a photo triplet-energy-transfer-initiated radical cascade process, leveraging homolytic cleavage of C-S bonds in aryl sulfonium salts as the key step to access aryl radicals with excellent regioselectivity. This method allows for rapid structural diversification of bioactive molecules, showcasing excellent functional group tolerance and streamlining the synthesis of bioactive compounds and their derivatives. Furthermore, our approach can be extended to propylene, non-gaseous terminal alkenes and various other electrophilic radical precursors, including heteroaryl radicals, hydroxyl radicals, trifluoromethyl radicals and α-carbonyl alkyl radicals. This study highlights the significance of radical polarity matching in designing selective multi-component couplings.