Search Results (52)

Recently, as a result of growing interest in diatoms as sources of energy (biofuel) and valuable food components for humans and aquaculture organisms, new data on the structures and properties of diatom natural products have been obtained, including both endo- and exometabolites. Information about their biosynthesis, biological activity and roles, and their beneficial and hazardous properties has also emerged. The application of modern methods of molecular biology, metabolomics, and chemical ecology to the study of diatom natural products has improved the understanding of many important natural phenomena associated with diatoms, such as photosynthesis, harmful algal blooms, interactions of diatoms with other organisms of marine biota, and their impact on biogeochemical cycles and climate regulation. In this paper, we discuss various aspects of research on natural compounds from diatoms, covering the last decade, as well as prospects for their further development, which have become apparent in recent years. Full article

Background: The genus Arthrophytum Schrenk (Amaranthaceae Juss.) is a relict systematic group restricted to the desert regions of northern Turan. Its species are narrowly endemic, stenotopic, and poorly studied, with virtually no available data on their phytochemical composition. Objectives: This study aimed to conduct the first comparative phytochemical analysis of five Arthrophytum species—A. lehmannianum, A. iliense, A. longibracteatum, A. subulifolium, and A. betpakdalense—to reveal their metabolite profiles and assess chemotaxonomic and functional features. Methods: Phytochemical profiling was performed using gas chromatography–mass spectrometry (GC–MS) to identify volatile and semi-volatile metabolites in the studied species. Results: GC–MS analysis revealed a predominance of terpenes in all species, along with significant contributions from fatty acids, esters, and other oxygen-containing compounds. The taxa were characterized by a rich pool of isoprenoids, including terpenes, sterols, tocopherols, and squalene, as well as lipid components of cuticular coatings such as fatty acids and long-chain alcohols. Isoprenoids dominated particularly in A. subulifolium and A. longibracteatum. A. iliense showed a high content of carbonyl and aromatic compounds, whereas A. longibracteatum and A. lehmannianum were distinguished by elevated levels of fatty acids and long-chain alcohols. Common metabolites—β-sitosterol, stigmasterol, vitamin E, squalene, and caryophyllene—constituted the conservative biochemical core of the genus. Conclusions: The results obtained for the first time demonstrate distinct chemotaxonomic and functional features of relict Arthrophytum species and highlight their potential for further research and application in the pharmaceutical, cosmetic, and aromatic industries. Full article

Heavy metal (HM) contamination in agricultural soils poses a significant threat to soil health and plant productivity. This study investigates the impact of cadmium (Cd) and zinc (Zn) stress on tomato plants (Solanum lycopersicum) and explores the mitigation potential of microbial biostimulants (MBs), including arbuscular mycorrhizal fungi (AMF) and Pseudomonas fluorescens So_08 (PGPR), over a 52-day period using multi-omics approaches. Root exudate profiling revealed distinct metabolic changes under HM stress, which compromised soil–plant interactions. Cd stress reduced the secretion of phenylpropanoids (sum LogFC: −45.18), lipids (sum LogFC: −27.67), and isoprenoids (sum LogFC: −11–67), key metabolites in antioxidative defense, while also suppressing rhizosphere fungal populations. Conversely, Zn stress enhanced lipid exudation (such as sphingolipids and sterols, as sum LogFC of 8.72 and 9.99, respectively) to maintain membrane integrity and reshaped rhizobacterial communities. The MBs application mitigated HM-induced stress by enhancing specialized metabolite syntheses, including cinnamic acids, terpenoids, and flavonoids, which promoted crop resilience. MBs also reshaped microbial diversity, fostering beneficial species like Portibacter spp., Alkalitalea saponilacus under Cd stress, and stimulating rhizobacteria like Aggregatilinea spp. under Zn stress. Specifically, under Cd stress, bacterial diversity remained relatively stable, suggesting their resilience to Cd. However, fungal communities exhibited greater sensitivity, with a decline in diversity in Cd-treated soils and partial recovery when MBs were applied. Conversely, Zn stress caused decline in bacterial α-diversity, while fungal diversity was maintained, indicating that Zn acts as an ecological filter that suppresses sensitive bacterial taxa and favors Zn-tolerant fungal species. Multi-omics data integration combined with network analysis highlighted key features associated with improved nutrient availability and reduced HM toxicity under MB treatments, including metabolites and microbial taxa linked to sulfur cycling, nitrogen metabolism, and iron reduction pathways. These findings demonstrate that MBs can modulate plant metabolic responses and restore rhizosphere microbial communities under Cd and Zn stress, with PGPR showing broader metabolomic recovery effects and AMF influencing specific metabolite pathways. This study provides new insights into plant–microbe interactions in HM-contaminated environments, supporting the potential application of biostimulants for sustainable soil remediation and plant health improvement. Full article

The membranes of halophilic archaea are a source of novel biomaterials, mainly of isoprenoid nature, with therapeutic properties practically unraveled. Here, we explored the antitumoral activity of neutral archaeolipids (NAs, such as bacterioruberin, astaxanthin, and dihydrosqualene) present in the total archaeolipids (TAs) (a fraction from the first step of lipid extraction by the modified Blight and Dyer technique) extracted from halophilic archaea Halorubrum tebenquichense, and formulated as TA-nanoarchaeosomes (TA: polar archaeolipids (PAs): Tween 80, 5:5:4 w:w:w, TA-nanoARC). The structure of 300.3 ± 84.2 nm TA-nanoARC of 0.59 ± 0.12 polydispersity index and −20 ± 3.7 mV ζ potential as determined by SAXS modelling, revealed that NA reduced the hydrophobic core and enlarged its hydrophilic section in comparison to TA-lacking bilayers (nanoARC), while preserving the width (~50 Å) and unilamellarity. Stable to storage and nebulization, TA-nanoARC was cytotoxic on A549 cells after 48 h, with an IC50 expressed as [bacterioruberin] of 0.15 μg/mL (~0.20 µM), comparable to or lower than the IC50 of docetaxel or cisplatin. Such cytotoxicity was exerted at a concentration harmless to macrophages (mTHP-1 cells). Besides, the conditioned medium from TA-nanoARC nebulized on A549 cells reduced the expression of the CD204/SRA-1, an M2 phenotype marker, and induced pro-inflammatory activity, comparable to or to a greater extent than that induced by lipopolysaccharide, including IL-6 and TNF-α, in mTHP-1 as a model of tumor-associated macrophages. The endocytosis of TA-nanoARC by A549 cells induced Lysotracker red fluorescence to fade and blur. This suggested the internalization of the highly viscous and ordered TA-nanoARC rich in NAs and subsequent lysosomal dysfunction (and not its antioxidant activity), as responsible for the selective damage on A549 cells. These are the first results showing that nebulized TA-nanoARC, lethal to A549 cells and modulating mTHP-1 cell phenotype, may act as antitumorals in the absence of cytotoxic drugs. Full article

Protein prenylation is a crucial post-translational modification that involves the formation of a covalent bond between isoprenoid lipids and the cysteine residues of specific proteins. This modification plays a significant role in determining protein localization, facilitating protein–protein interactions, and ultimately influencing protein function within the cellular context. Prenylation is a conserved process observed across various kingdoms of life, including plants, animals, fungi, and protists. This review aims to consolidate existing knowledge regarding the mechanisms underlying protein prenylation, encompassing the biosynthetic pathways of isoprenoids in plants and the processing involved in the prenylation modification. Furthermore, it highlights the implications of alterations in protein prenylation on plant development, signaling pathways, and stress responses. The review also addresses the similarities in modification mechanisms between plants and animals, as well as the diversity of their functional implications. Finally, it outlines prospective research directions of the plant prenylation mechanisms and the potential applications in the field of biotechnology. Full article

Carotenoids are part of a diverse group of isoprenoid compounds. Due to the many properties they possess, they may become an alternative to synthetic additives in various industrial sectors. The increase in consumer demand and awareness determines research into extracting them from plants, algae and microorganisms. The extraction of carotenoids from plants is an inefficient method and generates additional production costs. On the other hand, the carotenoid potential of microorganisms, especially among yeasts, has not been fully exploited. The diversity of yeast species and strains influences the extraction of many fractions of carotenoids, including the less known ones such as thorulene and tholuradine. The developed adaptability of yeast enables the optimisation of their culture, which facilitates the understanding of their metabolic pathways. At the same time, the coordination of carotenoid and lipid synthesis may prevent their degradation or the loss of their bioactive properties. Application research has been conducted mainly in the feed industry, where their colouring and antimicrobial or immunomodulating properties are used. In the medical and pharmaceutical fields, there is not much research due to safety restrictions and the necessity of the high purity of the fractions. This review also highlights the overlooked aspect of carotenoids’ biodegradability, which is required to exploit the bioactive properties of microbial carotenoids. Full article

Archaeal lipids, defining a primordial life domain alongside Bacteria and Eukarya, are distinguished by their unique glycerol-1-phosphate backbone and ether-linked isoprenoid chains. Serving as critical geochemical biomarkers, archaeal lipids like glycerol dialkyl glycerol tetraethers (GDGTs) underpin paleoclimate proxies, while their phylum-specific distributions illuminate phylogenetic divergence. Despite the maturity of Mass Spectrometry-based quantitative biomarkers—predominantly those with established structures—becoming well-established in geochemical research, systematic investigation of archaeal lipids as natural products has notably lagged. This deficit manifests across three key dimensions: (1) Extraction methodology lacks universal protocols adapted to diverse archaeal taxa and sample matrices. While comparative studies exist, theoretical frameworks guiding method selection remain underexplored. (2) Purification challenges persist due to the unique structures and complex isomerization profiles of archaeal lipids, hindering standardized separation protocols. (3) Most critically, structural characterization predominantly depends on decades-old foundational studies. However, the existing reviews prioritize chemical structural, biosynthetic, and applied aspects of archaeal lipids over analytical workflows. This review addresses this gap by adopting a natural product chemistry perspective, integrating three key aspects: (1) the clarification of applicable objects, scopes, and methodological mechanisms of various extraction technologies for archaeal lipids, encompassing both cultured and environmental samples; (2) the elucidation of separation principles underlying polar-gradient lipid fractionation processes, leveraging advanced chromatographic technologies; (3) the detailed exploration of applications for NMR in resolving complex lipid structures, with specialized emphasis on determining the stereochemical configuration. By synthesizing six decades of methodological evolution, we establish a comprehensive analytical framework, from lipids extraction to structural identification. This integrated approach constructs a systematic methodological paradigm for archaeal lipid analysis, bridging theoretical principles with practical implementation. Full article

The biosynthesis of isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), which are essential for sesquiterpenes and triterpenes, respectively, is primarily governed by the mevalonate pathway, wherein farnesyl pyrophosphate synthase (FPS) plays a pivotal role. This study identified eight members of the FPS gene family in Euphorbia hirta, designated EhFPS1–EhFPS8, through bioinformatics analysis, revealing their distribution across several chromosomes and a notable tandem gene cluster. The genes exhibited strong hydrophilic properties and key functional motifs crucial for enzyme activity. An in-depth analysis of the EhFPS genes highlighted their significant involvement in isoprenoid metabolism and lipid biosynthesis, with expression patterns influenced by hormones such as jasmonic acid and salicylic acid. Tissue-specific analysis demonstrated that certain FPS genes, particularly EhFPS1, EhFPS2, and EhFPS7, showed elevated expression levels in latex, suggesting their critical roles in terpenoid biosynthesis. Furthermore, subcellular localization studies have indicated that these proteins are primarily found in the cytoplasm, reinforcing their function in metabolic processes. These findings provide a foundational understanding of the FPS genes in E. hirta, including their gene structures, conserved domains, and evolutionary relationships. This study elucidates the potential roles of these genes in response to environmental factors, hormone signaling, and stress adaptation, thereby paving the way for future functional analyses aimed at exploring the regulation of terpenoid biosynthesis and enhancing stress tolerance in this species. Full article

Two strains, M1 and H32 with nitrogen-fixing ability, were isolated from the rhizospheres of different plants. Genome sequence analysis showed that a nif (nitrogen fixation) gene cluster composed of nine genes (nifB nifH nifD nifK nifE nifN nifX hesA nifV) was conserved in the two strains. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strains M1 and H32 are members of the genus Paenibacillus. Strains M1 and H32 had 97% similarity in the 16S rRNA gene sequences. Strain M1 had the highest similarity (97.25%) with Paenibacillus vini LAM 0504T in the 16S rRNA gene sequences. Strain H32 had the highest similarity (97.48%) with Paenibacillus faecis TCIP 101062T in the 16S rRNA gene sequences. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between strain M1 and its closest member P. vini were 78.17% and 22.3%, respectively. ANI and dDDH values between strain H32 and its closest member P. faecis were 88.94% and 66.02%, respectively. The predominant fatty acid of both strains is anteiso-C15:0. The major polar lipids of both strains are DPG (diphosphatidylglycerol) and PG (phosphatidylglycerol). The predominant isoprenoid quinone of both strains is MK-7. With all the phylogenetic and phenotypic divergency, two novel species Paenibacillus haidiansis sp. nov and Paenibacillus sanfengchensis sp. nov are proposed with the type strain M1^T [=GDMCC (Guangdong Culture Collection Centre of Microbiology) 1.4871 = JCM (Japan Collection of Microorganisms) 37487] and with type strain H32^T (=GDMCC 1.4872 = JCM37488). Full article

Isoprenoids and their derivatives, essential for all cellular life on Earth, are particularly crucial in archaeal membrane lipids, suggesting that their biosynthesis pathways have ancient origins and play pivotal roles in the evolution of early life. Despite all eukaryotes, archaea, and a few bacterial lineages being known to exclusively use the mevalonate (MVA) pathway to synthesize isoprenoids, the origin and evolutionary trajectory of the MVA pathway remain controversial. Here, we conducted a thorough comparison and phylogenetic analysis of key enzymes across the four types of MVA pathway, with the particular inclusion of metagenome assembled genomes (MAGs) from uncultivated archaea. Our findings support an archaeal origin of the MVA pathway, likely postdating the divergence of Bacteria and Archaea from the Last Universal Common Ancestor (LUCA), thus implying the LUCA’s enzymatic inability for isoprenoid biosynthesis. Notably, the Asgard archaea are implicated in playing central roles in the evolution of the MVA pathway, serving not only as putative ancestors of the eukaryote- and Thermoplasma-type routes, but also as crucial mediators in the gene transfer to eukaryotes, possibly during eukaryogenesis. Overall, this study advances our understanding of the origin and evolutionary history of the MVA pathway, providing unique insights into the lipid divide and the evolution of early life. Full article

The term vitamin K refers to a group of similarly structured fat-soluble compounds. One of the vitamin K forms is phylloquinone, known as vitamin K1. The main nutritional sources of vitamin K1 are green, leafy vegetables like kale, beetroot, spinach and broccoli. Other forms of vitamin K are menaquinones (vitamin K2) that can further be divided into a few subtypes depending on the number of isoprenoid residues in the side chain (MK-n). Besides MK-4, bacteria synthesize all menaquinones. As such, the main dietary sources of vitamin K2 are natto, dairy (especially fermented products, e.g., cheese), meat and eggs. Until recently, vitamin K was associated with the regulation of the coagulation system. Interest in the biological activity of these compounds increased once it was discovered that vitamin K2 affects the processes of the calcification of both bones and soft tissues. Vitamin K can reduce oxidative stress and inflammation. The objective of the present study was to verify the hypothesis about the effectiveness of dietary vitamin K2 as an anti-atherosclerotic agent. An in vivo experiment on ApoE/LDLR^−/− mice was conducted to verify this hypothesis. Two month-old mice were fed AIN-93G modified diets containing vitamin K-rich products, i.e., natto, cheese (Munster), sauerkraut and synthetic vitamin K2 MK-7 (100 μg/kg b.w./day) for 8 weeks. The body weight, weight of organs and glucose concentration were determined. Blood was taken and the aorta dissected. The investigation included both the area of lesions and biochemical parameters such as lipid profile. Quantification of the atherosclerotic area in entire aorta was performed by an en face method. The lipid profile was determined automatically by ABX Pentra 400 (Horiba Medical, Kyoto, Japan). The concentration of vitamins K was determined using UHPLC-MS/MS technique in feaces. Body weights of mice fed MK-7 and Munster were significant decreased compared to Control (respectively, 20.01 and 19.98 vs 21.45 [g]). Liver’s weight of mice fed Munster was significantly increased in comparison to other groups (5.70 vs 4.53 [g/100g] in Control). Glucose concentration was unchanged. Significant changes in plasma lipid profile of mice fed modified diets, especially in groups fed Munster and Sauerkraut, were observed. Total cholesterol and LDL concentrations were significantly increased in Munster and Sauerkraut compared to Control (respectively, for TC 20.45 and 19.80 vs 15.95 [mmol/L]; for LDL 17.15 and 11.94 vs 7.85 [mmol/L]). Moreover, TAG level was significantly increased in Sauerkraut in comparison to Control (2.87 vs 2.23 [mmol/L]). The main forms of vitamin K identified in mouse feaces were menaquinones MK-6. Nutritional factors with an alleviating effect on the development of atherosclerotic plaques are still being investigated. Full article

The Gram-negative marine bacterium GXY010^T, which has been isolated from the surface seawater of the western Pacific Ocean, is aerobic, non-motile and non-flagellated. Strain GXY010^T exhibits growth across a temperature range of 10–42 °C (optimal at 37 °C), pH tolerance from 7.0 to 11.0 (optimal at 7.5) and a NaCl concentration ranging from 1.0 to 15.0% (w/v, optimal at 5.0%). Ubiquinone-8 (Q-8) was the predominant isoprenoid quinone in strain GXY010^T. The dominant fatty acids (>10%) of strain GXY010^T were iso-C_15:0 (14.65%), summed feature 9 (iso-C_17:1 ω9c and/or 10-methyl C_16:0) (12.41%), iso-C_17:0 (10.85%) and summed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c) (10.41%). Phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), unidentifiable glycolipid (GL) and four non-identifiable aminolipids (AL1-AL4) were the predominant polar lipids of strain GXY010^T. The genomic DNA G+C content was identified as a result of 48.0% for strain GXY010^T. The strain GXY010^T genome consisted of 2,766,857 bp, with 2664 Open Reading Frames (ORFs), including 2586 Coding sequences (CDSs) and 78 RNAs. Strain GXY010^T showed Average Nucleotide Identity (ANI) values of 73.4% and 70.6% and DNA–DNA hybridization (DDH) values of 19.2% and 14.5% with reference species Pseudidiomarina tainanensis MCCC 1A02633^T (=PIN1^T) and Pseudidiomarina taiwanensis MCCC 1A00163^T (=PIT1^T). From the results of the polyphasic analysis, a newly named species, Pseudidiomarina fusca sp. nov. within the genus Pseudidiomarina, was proposed. The type strain of Pseudidiomarina fusca is GXY010^T (=JCM 35760^T = MCCC M28199^T = KCTC 92693^T). Full article

Cholesterol (CHOL) is a multifaceted lipid molecule. It is an essential structural component of cell membranes, where it cooperates in regulating the intracellular trafficking and signaling pathways. Additionally, it serves as a precursor for vital biomolecules, including steroid hormones, isoprenoids, vitamin D, and bile acids. Although CHOL is normally uptaken from the bloodstream, cells can synthesize it de novo in response to an increased requirement due to physiological tissue remodeling or abnormal proliferation, such as in cancer. Cumulating evidence indicated that increased CHOL biosynthesis is a common feature of breast cancer and is associated with the neoplastic transformation of normal mammary epithelial cells. After an overview of the multiple biological activities of CHOL and its derivatives, this review will address the impact of de novo CHOL production on the promotion of breast cancer with a focus on mammary stem cells. The review will also discuss the effect of de novo CHOL production on in situ and invasive carcinoma and its impact on the response to adjuvant treatment. Finally, the review will discuss the present and future therapeutic strategies to normalize CHOL biosynthesis. Full article

Plants are exposed to a variety of abiotic and biotic stresses leading to increased formation of reactive oxygen species (ROS) in plant cells. ROS are capable of oxidizing proteins, pigments, lipids, nucleic acids, and other cell molecules, disrupting their functional activity. During the process of evolution, numerous antioxidant systems were formed in plants, including antioxidant enzymes and low molecular weight non-enzymatic antioxidants. Antioxidant systems perform neutralization of ROS and therefore prevent oxidative damage of cell components. In the present review, we focus on the biosynthesis of non-enzymatic antioxidants in higher plants cells such as ascorbic acid (vitamin C), glutathione, flavonoids, isoprenoids, carotenoids, tocopherol (vitamin E), ubiquinone, and plastoquinone. Their functioning and their reactivity with respect to individual ROS will be described. This review is also devoted to the modern genetic engineering methods, which are widely used to change the quantitative and qualitative content of the non-enzymatic antioxidants in cultivated plants. These methods allow various plant lines with given properties to be obtained in a rather short time. The most successful approaches for plant transgenesis and plant genome editing for the enhancement of biosynthesis and the content of these antioxidants are discussed. Full article

The novel bacterial strain MBLB1776^T was isolated from marine mud in Uljin, the Republic of Korea. Cells were Gram-positive, spore-forming, non-motile, and non-flagellated rods. Growth was observed at a temperature range of 10–45 °C, pH range of 6.0–8.0, and NaCl concentrations of 0–4% (w/v). Phylogenetic analysis of the 16S rRNA gene sequence revealed that MBLB1776^T belonged to the genus Paenibacillus and was closely related to Paenibacillus cavernae C4-5^T (94.83% similarity). Anteiso-C_15:0, iso-C_16:0, C_16:0, and iso-C_15:0 were the predominant fatty acids. Menaquinone 7 was identified as the major isoprenoid quinone. The major polar lipids included diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. Its whole genome was 6.3 Mb in size, with a G+C content of 55.8 mol%. Average nucleotide identity and in silico DNA–DNA hybridization values were below the species delineation threshold. Gene function analysis revealed the presence of a complete C₃₀ carotenoid biosynthetic pathway. Intriguingly, MBLB1776^T harbored carotenoid pigments, imparting an orange color to whole cells. Based on this comprehensive polyphasic taxonomy, the MBLB1776^T strain represents a novel species within the genus Paenibacillus, for which the name Paenibacillus aurantius sp. nov is proposed. The type strain was MBLB1776^T (=KCTC 43279^T = JCM 34220^T). This is the first report of a carotenoid-producing Paenibacillus sp. Full article