Search Results (273)

Aroma volatiles constitute the primary molecular basis of fruit flavor quality, governing sensory attributes and marketability. Based on their chemical states, aroma compounds are categorized into bound and free forms. Bound aroma compounds predominantly exist as non-volatile glycosides, which can be hydrolyzed enzymatically or through acid treatment to release volatile free aroma compounds, thereby enhancing fruit fragrance. Although the dynamic interconversion between free and bound aroma compounds is pivotal for fruit flavor development, the governing mechanisms, including the principal controlling factors, regulatory networks, and external influences, are still under investigation. This review primarily synthesizes recent advances regarding the structural diversity, analysis, biosynthesis, and regulation of bound aroma compounds. Additionally, it examines how key regulatory networks and environmental factors modulate the synthesis and transformation of these compounds. The integrated overview provides new insights for future regulation of aroma metabolism in fruits. Full article

This study aims to elucidate the molecular mechanisms underlying cyanogenic glycoside accumulation in flax. As an important oil and fiber crop, the nutritional value of flax is compromised by the toxicity of cyanogenic glycoside. To clarify the key genetic regulators and temporal patterns of cyanogenic glycoside biosynthesis, transcriptomic sequencing was performed on seeds from high- and low-cyanogenic glycoside flax varieties (‘MONTANA16’ and ‘Xilibai’) at three developmental stages: bud stage, full flowering stage, and capsule-setting stage. A total of 127.25 Gb of high-quality data was obtained, with an alignment rate exceeding 87.80%. We identified 31,623 differentially expressed genes (DEGs), which exhibited distinct variety- and stage-specific expression patterns. Principal component analysis (PCA) and hierarchical clustering demonstrated strong reproducibility among biological replicates and revealed the seed pod formation stage as the period with the most significant varietal differences, suggesting it may represent a critical regulatory window for cyanogenic glycoside synthesis. GO and KEGG enrichment analyses indicated that DEGs were primarily involved in metabolic processes (including secondary metabolism and carbohydrate metabolism), oxidoreductase activity, and transmembrane transport functions. Of these, the cytochrome P450 pathway was most significantly enriched at the full bloom stage (H2 vs. L2). A total of 15 LuCYP450 and 13 LuUGT85 family genes were identified, and their expression patterns were closely associated with cyanogenic glycoside accumulation: In high-cyanogenic varieties, LuCYP450-8 was continuously upregulated, and LuUGT85-12 was significantly activated during later stages. Conversely, in low-cyanogenic varieties, high expression of LuCYP450-2/14 may inhibit synthesis. These findings systematically reveal the genetic basis and temporal dynamics of cyanogenic glycoside biosynthesis in flax and highlight the seed pod formation stage as a decisive regulatory window for cyanogenic glycoside synthesis. This study provides new insights into the coordinated regulation of cyanogenic pathways and establishes a molecular foundation for breeding flax varieties with low CNG content without compromising agronomic traits. Full article

Anthocyanins are key pigments responsible for apple fruit coloration, influencing not only its appearance and marketability but also contributing significantly to its nutritional and health benefits. In their natural state, anthocyanins are chemically unstable. However, glycosylation modifies them into anthocyanin derivatives known as anthocyanin glycosides, which exhibit markedly enhanced stability and improved water solubility. As a result, most naturally occurring anthocyanins exist in the form of anthocyanin glycosides. The biosynthesis of anthocyanins involves a series of structural genes within the phenylpropanoid and flavonoid pathways (including PAL, C4H, 4CL, CHS, CHI, F3H, DFR, ANS/LDOX, and UFGT). The MYB–bHLH–WD40 transcriptional complex serves as the core regulatory mechanism controlling anthocyanin synthesis, with additional transcription factors also playing important roles. This review systematically summarizes recent advances in the structural characteristics, biosynthetic pathways, molecular regulatory mechanisms, and environmental factors affecting anthocyanin accumulation in apples. These insights are important both for consumer health and for breeding apple cultivars with enhanced anthocyanin content. Full article

d-Tagatose is a rare sugar that exhibits intriguing biological properties, such as its role as a low-calorie sweetener and its ability to reduce the glycemic response. Consequently, the synthesis of d-tagatose derivatives is a crucial endeavor for the advancement of their functionalities, as well as elucidation of their biological properties. In this study, we present the α-selective glycosidation of a 1,3,4,6-tetra-O-benzoylated d-tagatofuranosyl donor with various glycosyl acceptors. In contrast to d-allulose, which is the C3,C4-epimer of d-tagatose and does not exhibit the neighboring group effect, the current d-tagatofuranosyl donor demonstrated significant neighboring group participation, achieving high α-selectivity ratios up to α:β = 99:1. This method was also applicable to the synthesis of α-d-tagatofuranosylceramide, which has potential as a novel functional molecule. Meanwhile, the glycosylation of sterically congested glycosyl acceptors, such as 2-hydroxycumene, resulted in poor α-selectivity, which may be attributed to the interaction with the C1-benzoyloxy group of d-tagatofuranosyl donors in the transition state. Full article

Background: Potential advantages for improving plant growth, stress tolerance, and valuable metabolites generation are provided by the implementation of nanotechnology into plant biotechnology. A recently discovered technique with significant promise for agricultural practices is the use of biopolymer-based nanomaterials, like peptidomimetics, as insecticides, growth regulators, and nutrient carriers. This study explores the impact of biopolymer-based organic nanofibers—specifically peptidomimetics formed through the self-assembly of L-valine and nicotinic acid (NA) (denoted as M6) on Stevia rebaudiana in vitro propagation and specialized metabolite production. The central hypothesis was that such nanofibers, particularly when used as hormone carriers, can beneficially influence plant morphology, physiology, and biochemistry, thereby promoting the synthesis of antioxidant compounds with therapeutic potential. Methods: The nanofibers were tested either alone (M6) or as carriers of the plant hormone indole-3-acetic acid (IAA) (M6+IAA), supplemented to the cultivation MS medium at variable concentrations (0, 1, 10, and 50 mg L⁻¹). Results: The results revealed that treatment with 10 mg L⁻¹ M6 significantly enhanced shoot growth parameters, including the highest fresh weight (0.249 g), mean shoot height (9.538 cm), shoot number (1.95), and micropropagation rate. Plants treated with M6 alone outperformed those treated with M6+IAA in terms of shoot growth, total soluble sugars, and steviol glycoside content. Conversely, M6+IAA treatment more effectively promoted root initiation, the increased accumulation of mono- and dicaffeoylquinic acids, and boosted antioxidant enzyme activity. Conclusions: These findings highlight the potential of organic nanofibers, both with and without hormone loading, as novel tools for optimizing micropropagation and metabolite enhancement in Stevia rebaudiana. Full article

A rational synthesis of the branched decaarabinofuranoside with 4-(2-azidoethoxy)phenyl aglycone (a Janus aglycone) related to the non-reducing terminal fragments of the arabinogalactan and lipoarabinomannan from Mycobacterium tuberculosis was proposed. Since the most challenging step is the formation of a 1,2-cis glycosidic linkage, we have significantly simplified access to a library of oligoarabinofuranosides derived from Mycobacterium tuberculosis polysaccharides using a silylated Ara-β-(1→2)-Ara disaccharide as the glycosyl donor. The application of a Janus aglycone also allowed us to reduce the number of reaction steps in glycoside synthesis. The obtained arabinans can be useful to further prepare conjugates as antigens for creating tuberculosis screening assays. Full article

To explore the potential seed compounds from natural products as anticancer agents against small-cell lung cancer (SCLC), the underground parts of Agapanthus africanus, a plant commonly used for ornamental purposes, were investigated. Three spirostan-type steroidal glycosides (1–3) were isolated and identified by nuclear magnetic resonance spectral analysis. Compounds 1–3 exhibited cytotoxicity against SBC-3 human SCLC cells, with IC₅₀ values of 0.56, 1.4, and 7.4 µM, respectively. Compound 1, also known an agapanthussaponin A, demonstrated the most potent cytotoxicity among the isolated compounds and was evaluated for its apoptosis- and ferroptosis-inducing activities. Compound 1 arrested the cell cycle of SBC-3 cells in the G₂/M phase and induced apoptosis primarily via the mitochondrial pathway, characterized by caspases-3 and -9 activation, loss of mitochondrial membrane potential, and overproduction of reactive oxygen species. Additionally, 1 triggered ferroptosis via a dual mechanism consisting of enhanced cellular iron uptake through upregulation of transferrin and transferrin receptor 1 expression and impaired glutathione synthesis via downregulation of both xCT and glutathione peroxidase 4 expression. Compound 1 induces cell death via the apoptosis and ferroptosis pathways, suggesting its promise as a seed compound for the development of anticancer therapeutics against SCLC. Full article

Ganoderma lucidum polysaccharides (GLPs) are natural compounds with a broad spectrum of biological activities. β-1,3-glucosyltransferase (GL20535) plays an important role in polysaccharide synthesis by catalyzing the transfer of UDP-glucose to extend sugar chains, but its underlying mechanism remains unclear. In this study, the regulatory mechanism of GL20535 in polysaccharide synthesis was elucidated by overexpressing and silencing gl20535 in G. lucidum. Overexpression of gl20535 resulted in maximum increases of 18.08%, 79.04%, and 18.01% in intracellular polysaccharide (IPS), extracellular polysaccharide (EPS), and β-1,3-glucan contents, respectively. In contrast, silencing gl20535 resulted in maximum reductions of 16.97%, 30.20%, and 23.56% in IPS, EPS, and β-1,3-glucan contents, respectively. These phenomena in the overexpression strains were attributed to gl20535-mediated promotion of UDP-glucose synthesis in the sugar donor pathway and upregulation of the expression of glycoside hydrolase genes. The opposite trend was observed in the silenced strains. In mycelial growth studies, neither overexpression nor silencing of gl20535 affected biomass and cell wall thickness. Furthermore, the GL20535 isozyme gene gl24465 remained unaffected in gl20535-overexpressed strains but was upregulated in gl20535-silenced strains, suggesting a compensatory regulatory relationship. These findings reveal the regulatory role of GL20535 on gene expression in the GLPs synthesis pathway and deepen our understanding of GL20535 function in the polysaccharide network of edible and medicinal fungi. Full article

Hormonomics represents an innovative approach to plant physiology and biochemistry. We utilized hormonomics to analyze the hormone profiles of three lily bulbs. The hormones specifically enriched in BiFeng7 lily show a strong response to secondary metabolism pathways, while the Diwanghuang lily profile was predominantly focused on growth. Physiological experiments demonstrated that Diwanghuang exhibited higher levels of primary nutrients, whereas BiFeng7 displayed a greater concentration of secondary metabolites and enhanced antioxidant capacity. Through untargeted metabolomic analysis, it was revealed that BiFeng7 highly enriched four flavonoid glycosides, two flavones, one flavan, one pyranoflavonoid, two isoflavonoid O-glycosides and one rotenoid. These findings provide valuable information for developing breeding strategies and cultivation practices aimed at achieving ornamental quality, nutritional value, or stress resilience outcomes. This research demonstrates the practical application of hormone profiling in plant evaluation and offers insights into the mechanisms underlying flavonoid synthesis in lilies, serving as a reference for breeding stress-resistant lily varieties. Full article

The sorghum aphid (Melanaphis sacchari (Zehntner, 1897)), a globally destructive pest, severely compromises sorghum yield and quality. This study compared aphid-resistant (HX133) and aphid-susceptible (HX37) sorghum (Sorghum bicolor (L.) Moench) cultivars, revealing that HX133 significantly suppressed aphid proliferation through repellent and antibiotic effects, while aphid populations increased continuously in HX37. Transcriptome analysis identified 2802 differentially expressed genes (DEGs, 45.9% upregulated) in HX133 at 24 h post-infestation, in contrast with only 732 DEGs (21% upregulated) in HX37. Pathway enrichment highlighted shikimate-mediated phenylpropanoid/flavonoid biosynthesis and glutathione metabolism as central to HX133’s defense response, alongside photosynthesis-related pathways common to both cultivars. qRT-PCR validation confirmed activation of the shikimate pathway in HX133, driving the synthesis of dhurrin—a cyanogenic glycoside critical for aphid resistance—and other tyrosine-derived metabolites (e.g., benzyl isoquinoline alkaloids, tocopherol). These findings demonstrate that HX133 employs multi-layered metabolic regulation, particularly dhurrin accumulation, to counteract aphid infestation, whereas susceptible cultivars exhibit limited defense induction. This work provides molecular targets for enhancing aphid resistance in sorghum breeding programs. Full article

Marine-derived compounds represent a rich source of structurally diverse molecules with therapeutic potential for cancer, renal disorders, metabolic-associated fatty liver disease (MAFLD), and atherosclerosis. This review systematically evaluates recent advances, highlighting compounds such as Microcolin H, Benzosceptrin C, S14, HN-001, Equisetin, glycosides (e.g., cucumarioside A₂-2), ilimaquinone, and Aplidin (plitidepsin). Key mechanisms include autophagy modulation, immune checkpoint inhibition, anti-inflammatory effects, and mitochondrial homeostasis. Novel findings reveal glycosides’ dual role in cytotoxicity and immunomodulation, ilimaquinone’s induction of the DNA damage response, and Aplidin’s disruption of protein synthesis via eEF1A2 binding. Pharmacokinetic challenges and structure–activity relationships are critically analyzed, emphasizing nanodelivery systems and synthetic analog development. This review bridges mechanistic insights with translational potential, offering a cohesive framework for future drug development. Full article

Apricot is one of the most important Mediterranean fruits with high diversity and fruit quality properties, being an excellent raw material for polyphenol compounds. This study aimed to determine the anthocyanin, quercetin glycoside and phenolic acid contents in new apricot genotypes from the breeding program at the Instituto Valenciano de Investigaciones Agrarias, confirming the potential of the ‘Goldrich’ cultivar to be a parental donor for increasing the antioxidant content, which would, in turn, enhance fruit quality. Phenolic composition of the apricot accessions is strongly genotype-dependent, with the concentrations of overall total phenolic compounds ranging from 770 to 260 mg 100 g⁻¹ DW, reflecting significant genetic diversity. ‘Goldrich’ contributed to the polyphenol content; however, its influence varied across derived varieties, with ‘GG9310’ and ‘GG979’ enhancing the shikimic acid pathway and accumulating high levels of total phenolics. In contrast, ‘Mitger’ and ‘HG9850’ stood out for high anthocyanin synthesis, despite their lower levels of flavonols and phenolic acids. The predominant anthocyanin was cyanidin-3-O-rutinoside, followed by cyanidin-3-O-glucoside and peonidin-3-O-rutinoside in smaller amounts. Other phenolics were rutin and quercetin-3-O-glucuronide, as well as neochlorogenic and chlorogenic acids. The PCA model was applied to all data to identify the most attractive cultivars, and chromatographic analysis was performed in a short time using Ultra-High-Performance Liquid Chromatography (UHPLC) with diode array and mass spectrometric detection. Apricot peel is an excellent source of nutraceutical compounds with a chemical composition strongly determined by the cultivar. Results can help establish authenticity markers for apricot cultivars. Full article

Algal polysaccharides are a kind of bioactive compound with diverse pharmacological applications, yet their structure–activity relationships and therapeutic potential in chronic disease management remain systematically underexplored. This review comprehensively analyzes the structural characteristics of brown, red, and green algal polysaccharides, revealing how specific structural features—such as glycosidic linkage patterns and sulfate group positioning—dictate their biological activities. We also demonstrated their multifaceted roles in diabetes, cancer, and cardiovascular diseases through distinct mechanisms, including gut microbiota modulation via short-chain fatty acid production, antioxidant enzyme activation, and targeted inhibition of pathological signaling pathways like mTOR and JAK-STAT3. The work further evaluates extraction methodologies, highlighting the advantages of emerging techniques such as enzyme-assisted and ultrasonic extraction for preserving bioactive integrity. By integrating fundamental research with practical applications in functional foods, this synthesis provides critical insights for harnessing algal polysaccharides in precision nutrition and sustainable biomedicine, while identifying key challenges in standardization and environmental safety that warrant future investigation. Full article

The ester of caffeic acid with α-hydroxydihydrocaffeic acid, named rosmarinic acid (α-o-caffeoyl-3,4-dihydroxyphenyllactic acid; RA) can occur as oligomeric molecules, or in free, esterified, and glycosidic forms. Although it is commonly found among the members of the plants from the Lamiaceae (mints) and Boraginaceae (borages) families, only certain plant species produce a comparatively high concentration of RA. This valuable bioactive compound exhibits anti-cancer, anti-angiogenic, antioxidant, anti-inflammatory, antiviral, and antimicrobial properties, among others. As it is difficult to obtain high quantities of RA from natural sources, and since chemical manufacturing is costly and challenging, various biotechnological methods have recently been investigated to boost RA production. Plant cell tissue culture has been used to promote RA production in various plant species, particularly medicinal ones, with elicitation being the most commonly used technique. This review explores the main steps involved in RA biosynthesis in plants, including the molecular mechanisms and physiological alterations underlying its function, along with the primary mechanisms of RA accumulation in response to elicitation. Recent progress in synthetic biology-based RA synthesis, as well as metabolic engineering techniques to enhance the industrial production of this valuable bioactive constituent, are also discussed. Full article

With the rapid development of radical initiation technologies such as photocatalysis and electrocatalysis, radical reactions have become an increasingly attractive approach for constructing target molecules. However, designing efficient synthetic routes using radical reactions remains a significant challenge due to the inherent complexity and instability of radical intermediates. While computer-aided synthesis planning (CASP) has advanced retrosynthetic analysis for polar reactions, radical reactions have been largely overlooked in AI-driven approaches. In this study, we introduce RadicalRetro, the first deep learning-based retrosynthesis model specifically tailored for radical reactions. Our work is distinguished by three key contributions: (1) RadicalDB: A novel, manually curated database of 21.6 K radical reactions, focusing on high-impact literature and mechanistic clarity, addressing the critical gap in dedicated radical reaction datasets. (2) Model Innovation: By pretraining Chemformer on ZINC-15 and USPTO datasets followed by fine-tuning with RadicalDB, RadicalRetro achieves a Top-1 accuracy of 69.3% in radical retrosynthesis, surpassing the state-of-the-art models LocalRetro and Mol-Transformer by 23.0% and 25.4%, respectively. (3) Interpretability and Practical Utility: Attention weight analysis and case studies demonstrate that RadicalRetro effectively captures radical reaction patterns (e.g., cascade cyclizations and photocatalytic steps) and proposes synthetically viable routes, such as streamlined pathways for Tamoxifen precursors and glycoside derivatives. RadicalRetro’s performance highlights its potential to transform radical-based synthetic planning, offering chemists a robust tool to leverage the unique advantages of radical chemistry in drug synthesis. Full article