Search Results (224)

Geranyl diphosphate synthase (GPPS) is a key enzyme in the plant isoprenoid metabolic pathway and regulates the biosynthesis of volatile monoterpenes. It plays an important role in the biosynthesis of floral volatile terpenoids (FVTs) and inter-cultivar variation in snapdragon. Despite its importance in floral scent formation, the GPPS/GGPPS gene family in snapdragon (Antirrhinum majus L.) has not been systematically characterized. In this study, nine GPPS/GGPPS family members were identified at genome-wide level. These include six AmGPPS and three AmGGPPS genes. Phylogenetic analysis grouped them into distinct subfamilies. We further analyzed their chromosomal locations, gene structures, conserved protein motifs, and promoter cis-acting elements. These results revealed both conservation and functional divergence within the gene family. To explore their functional roles, we compared gene expression profiles at the full flowering stage. This comparison was performed between strongly scented cultivar (Am3) and the weakly scented cultivar (Am5). Among all candidates, AmGPPS6 showed the most significant differential expression. Further, functional validation was conducted using transient overexpression and virus-induced gene silencing (VIGS). Overexpression of AmGPPS6 significantly increased terpenoid production. Total floral volatile terpenoids (FVTs) increased by 1.4 fold. Both monoterpene and sesquiterpene emissions were enhanced. In contrast, silencing of AmGPPS6 markedly reduced the emission of key monoterpenes such as ocimene and its isomers. Sequence analysis showed that AmGPPS6 shares 67.04% identity with canonical GPPS small subunit (GPPS.SSU). However, it lacks the conserved catalytic DDx2-D motif. This suggests that AmGGPPS2 is not catalytically active. Instead, it likely functions through heterodimer with AmGGPPS2. This interaction is supported by coordinated transcriptional expression patterns. Additionally, natural sequence polymorphisms were identified in GPPS.SSU. These variations, rather than those in GPPS.LSU, appear to drive differences in monoterpense emission between cultivars. In conclusion, AmGPPS6 in a key regulator of floral scent biosynthesis in snapdragon. This study provides new insights into functional roles of GPPS/GGPPS genes. It also offers valuable gene targets for the molecular breeding of aromatic traits in ornamental plants. Full article

This study evaluated the effects of light spectral quality on shoot yield and essential oil of Tagetes erecta L. cultivated in controlled growth chambers under three LED lighting treatments with different red, blue, and white wavelength ratios and a constant 16 h photoperiod for up to 101 days. The F2 treatment (5 red:1 blue) produced yields of fresh shoots, early blooming flowers, and oils of 1586 ± 164 g/m², 569.77 ± 76.81 g/m², and 307 ± 31.7 mg/m², respectively. These values were significantly higher (p < 0.05) than those of the F1 treatment (white:red-phosphor), and represented increases of 1.37-, 1.26-, and 1.38-fold, respectively. Gas chromatography identified 30–31 compounds in the oil with three major constituents—(E)-β-ocimene (22.9–28.8%, highest under F3), (E)-myroxide (13.9–20.6%, highest under F1), and piperitone (7.3–9.6%, highest under F3). Essential oils inhibited from four to five of the seven tested microbial strains, with the notable activity against Escherichia coli and Candida albicans recorded in F2 and F1, respectively. These findings confirm that light spectral quality is a critical factor regulating flower, essential oil, and antimicrobial efficacy in T. erecta, demonstrating that optimized LED spectra offer a practical strategy to improve plant yield and phytochemical quality. Full article

The chemical composition of basil essential oil is influenced by plant developmental stage, which alters the relative distribution of volatile constituents and their functional properties. In this study, we investigated developmental-stage-dependent changes in the essential oil composition of Ocimum basilicum and evaluated their relationship with nitric oxide (NO) inhibitory activity and estragole exposure. Essential oils were obtained by hydrodistillation and analyzed by gas chromatography–tandem mass spectrometry (GC–MS/MS), resulting in the identification of 54 volatile compounds representing 98.13–98.97% of the total composition. Estragole remained the dominant constituent, ranging from 70.58% to 85.55%, with the lowest proportion at the flowering stage (Day 85). In contrast, minor constituents, including eucalyptol (2.41–3.77%), β-ocimene (0.52–1.98%), and methyleugenol (~2.00%), increased during flowering. NO inhibitory activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages was strongest at Day 85. Estimated Daily Intake (EDI) ranged from 0.4215 to 1.1005 µg kg⁻¹ bw day⁻¹, and Margin of Exposure (MOE) ranged from 2999 to 7830. These findings indicate that developmental stage influences composition, activity, and exposure. From a compositional perspective, the observed redistribution among major chemical groups reflects a structured balance that can be interpreted within a symmetry-related framework in multicomponent systems. Full article

Leaves from California yerba santa (Eriodictyon californicum) have been used historically by indigenous peoples for medicinal purposes. Recent research has ascribed potential pharmaceutical effects to leaf polyphenols, without a consideration of other constituents. Based on prior analyses of polyphenols in leaves sampled in nature, five accessions known to be rich in sterubin and five accessions known to be rich in eriolic acid C were grown from seeds in Ontario, Oregon, and samples of their leaves were harvested and evaluated for their essential oil and polyphenol contents. The major essential oil components in E. californicum were 1,8-cineole (0.6–35.5%), (Z)-β-ocimene (6.8–15.7%), terpinen-4-ol (8.3–16.1%), α-pinene (2.6–13.6%), β-phellandrene (1.9–11.7%), γ-terpinene (4.6–7.9%), ethyl (E)-cinnamate (0.2–8.9%), α-terpineol (1.5–5.2%), p-cymene (2.0–5.3%), and β-pinene (0.6–6.8%). Fifteen polyphenols with a prominence of eriolic acid C, rosmarinic acid, sterubin, homoeriodictyol, 6-methoxynaringenin, hesperetin, and eriodictyol were identified. Essential oils may contribute to the medicinal properties of the leaves of California yerba santa. Results from the ten samples were evaluated for both polyphenols and essential oils; the variations in several essential oils may be correlated to variations in some of the polyphenols. Full article

Background/Objectives: Microbial infections represent a major challenge in the food processing chain. Postharvest fungal control has historically relied on chemical control; however, their use is increasingly restricted due to environmental and health risks. Therefore, the aim of this study was to evaluate the antifungal potential of essential oils obtained from high-yield plant species and characterize the potential mechanisms of action of their major volatiles, with the goal of proposing a prospective formulation for the control of postharvest fungi. Methods: Cinnamon, rosemary, allspice, and Peruvian pepper essential oils were extracted by hydrodistillation, tested against Botrytis cinerea and Colletotrichum sp., and analyzed by gas chromatography-mass spectrometry. Finally, in silico bioactivity analyses were performed on the most abundant volatiles. Results: Cinnamon and rosemary produced the most effective oils against both fungal species. Cinnamaldehyde, cinnamyl acetate, eugenol, methyleugenol, (+)-2-bornanone, eucalyptol, α-phellandrene, and β-myrcene were some of the most abundant volatiles in the analyzed oils. In silico analyses predicted 56 antifungal mechanisms, including inhibition of cell membrane and wall synthesis, affectation of primary metabolism, inhibition of molecular processes, redox homeostasis, and protein degradation and cutinase inhibition. The last one is a specific mechanism mediating in vivo plant-fungal interactions found exclusively in β-terpinene and β-ocimene. Conclusions: Compounds with cutinase inhibition activity such as β-terpinene and β-ocimene are of great potential to complement the activity of other bioactive compounds. According to literature and in silico analyses the mixture of cinnamaldehyde, eugenol, β-terpinene and β-ocimene could be a potential formulation for the management of postharvest fungi. Full article

Amid the accelerating spread of antibiotic resistance, medicinal and aromatic plants stand out as powerful natural reservoirs of bioactive compounds, offering innovative prospects for next-generation antimicrobial therapies. To explore its therapeutic potential, this study evaluated the antimicrobial and antioxidant activities of Matricaria pubescens from Southeastern Morocco, supported by a thorough chemical profiling of its essential oils. The oils were obtained by steam distillation and analyzed using gas chromatography–mass spectrometry (GC–MS). The results revealed two distinct chemotypes, with isochrysanthemic ethyl ester (32.7%) as the dominant compound in chemotype EO1 and α-ocimene (19.62%) as the major constituent in chemotype EO2. Antioxidant activities were assessed using DPPH, ABTS, and reducing power assays, while antimicrobial activities were evaluated against bacteria, fungi, and yeasts using both disc diffusion and broth microdilution methods. Both oils exhibited notable antioxidant activities. Significant antimicrobial effects were observed, with Bacillus subtilis, Escherichia coli, and Staphylococcus aureus being the most sensitive strains, whereas Pseudomonas aeruginosa exhibited the highest resistance among all tested microorganisms, with the lowest MIC recorded for B. subtilis (0.612 mg/mL). These findings emphasize that M. pubescens could serve as a valuable source of biologically active compounds, particularly in the development of agents to combat microbial resistance, and further support its potential applications in pharmaceutical, cosmetic, and food industries. Full article

The genus Oncosiphon (Asteraceae), consisting of aromatic herbs, is indigenous to southern Africa. Oncosiphon species have been documented in Khoi-San ethnobotany as herbal remedies for typhoid fever, pneumonia, and as diuretics. Research on the biological properties and comprehensive phytochemical profiling of these important Oncosiphon species is currently limited. This study was therefore undertaken to address the knowledge void in chemical profiling, through the application of various analytical techniques to analyse the volatile and non-volatile constituents of three South African Oncosiphon species. The aerial parts of Oncosiphon suffruticosus (n = 28), O. grandiflorus (n = 16), and O. africanus (n = 4) were collected from various locations in the Western Cape Province of South Africa. The stems and leaves (SL) were separated from the flowers (F) and analysed as distinct samples. The methanol: chloroform (1:1, v/v) extracts were prepared and analysed using ultra–high–performance liquid chromatography quadrupole time-of-flight time–of–flight mass spectrometry (UHPLC–QToF–MS) and a semi–automated high–performance thin–layer chromatography (HPTLC) system. Multivariate data analysis was performed on the UHPLC–QToF–MS data to determine interspecies chemical variation. Two-dimensional (2D) gas chromatography (GCxGC–ToF–MS) was used to determine the headspace volatile profiles of the intact aerial parts. The results show that the non-volatile profiles of the Oncosiphon species are characterised by amino acids, phenolic acids, flavonoids, sesquiterpene lactones, and fatty acid derivatives. The HPTLC profiles of O. grandiflorus and O. africanus are chemically more closely related, and O. suffruticosus has a distinct profile, which is supported by the chemometrics results of the flowers. The major headspace volatile compounds in Oncosiphon flowers are α-pinene, α-ocimene, eucalyptol, o-cymene, and artemisia alcohol, whereas the stems and leaves mainly consist of α-ocimene, eucalyptol, and yomogi alcohol. Full article

Common goldenrod (S. virgaurea L., Asteraceae) is recognised in traditional medicine as a folk remedy for kidney, urinary tract, and liver diseases, among others; however, its pharmaceutical potential remains largely unexplored. The pharmaceutical potential of the invasive species Canadian goldenrod (S. canadensis L.) in Europe is also of practical interest. The aim of the study was to compare the yield and composition of essential oils (EO) of flowering tops (20 cm long) of S. canadensis and S. virgaurea. The yield of EOs, hydrodistilled from S. canadensis (8 samples) and S. virgaurea (5 samples) herbs using the European Pharmacopoeia method, ranged from 2.7 to 14.9 mL/kg. The average EO yield in both goldenrod species was similar, but the composition differed. A total of 81 constituents were identified and semiquantified by GC-MS in the EOs of both Solidago species, eight of which have been found in these species for the first time. α-Pinene, limonene, and (E)-β-ocimene were the principal compounds in S. canadensis herb EO, and α-pinene, β-pinene, β-myrcene, and α-humulene were the principal compounds in S. virgaurea EO. It contained, on average, 39 times more benzyl salicylate than the EO from S. canadensis. Also, the amounts of viridiflorol (more in S. virgaurea) or β-bourbonene and (E)-β-ocimene (more in S. canadensis) can be used as a chemical fingerprint of both goldenrod species studied. The EO compositions were largely similar, with species-related differences supported by the presence of α-muurolene in S. virgaurea and its absence in S. canadensis. The pharmaceutical potential of V. canadensis as an invasive species is not yet sufficiently clear and requires further pharmacological studies. The composition of the EO seems to support the traditional use of goldenrod in the urological field. Full article

The genus Oenanthe L. (Apiaceae) comprises aquatic and semi-aquatic species widely distributed across the Northern Hemisphere, some of which are traditionally used as food or in folk medicine. Despite this ethnobotanical relevance and toxicological notoriety, phytochemical and pharmacological data on the genus remain limited, especially regarding their essential oils (EOs). Essential oils, extracted by hydrodistillation from aerial parts of Sicilian Oenanthe fistulosa L. (OF), Oenanthe aquatica (L.) Poir (OA), and Oenanthe pimpinelloides L. (OP), were analyzed by GC–MS. The EO of O. fistulosa was dominated by monoterpene hydrocarbons (59.8%), with β-cis-ocimene (21.6%), sabinene (9.3%), and β-trans-ocimene (8.4%) as the main metabolites. O. pimpinelloides also exhibited a monoterpene-rich profile (60.3%), characterized by β-cis-ocimene (15.5%), sylvestrene (12.8%), and β-trans-ocimene (10.3%) but distinguished by a high apiol content (21.0%), indicating a mixed monoterpene/phenylpropanoid chemotype. In contrast, O. aquatica revealed a markedly different profile dominated by phenylpropanoids (57.2%), particularly dill apiol (53.5%), alongside α-pinene (17.2%) and sabinene (6.5%), representing an uncommon chemotype within the genus. This study aimed to evaluate whether these chemo-diverse Sicilian Oenanthe EOs (dill-apio OA 53.5%; ocimene OF 59.9%; apiol OP 21%) differentially modulated LPS-induced epithelial redox stress in Caco-2. Caco-2 cells were treated for 24 h with lipopolysaccharide (LPS) and co-treated with two concentrations (12.5 and 25 µg/mL) of EOs from three different species of Oenanthe. Assessment of proliferating cell nuclear antigen (PCNA) and the stress response of enzyme heme oxygenase-1 (HO-1) expression was performed using Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR). EOs showed species- and concentration-dependent effects on LPS-induced stress in Caco-2 cells. O. aquatica and O. fistulosa EOs exerted cytoprotective and antioxidant activity at low concentrations (12.5 and 25 μg/mL), reducing 8-hydroxy-2′ -deoxyguanosine (8-OHdG) DNA damage and moderately upregulating HO-1. In contrast, O. pimpinelloides EO (apiol-rich) induced dose-dependent cytotoxicity, elevated 8-OHdG despite strong HO-1 induction, and lacked protection at higher doses. PCNA expression was reduced by LPS across all treatments, with no preservation of proliferation by any EOs. These findings reveal chemotype-specific modulation of oxidative stress and epithelial integrity. Full article

Rosin, a renewable natural resin derived from pine trees, is a promising biomass material for sustainable product development, though its distinct intrinsic odor limits broader use. This study implemented a comprehensive analytical strategy to mitigate the odor by incorporating essential oils (EOs)—eucalyptus (EUC) and peppermint (MINT)—and to conduct a multi-analytical characterization of the modified rosin jewelry. By integrating complementary analytical techniques, including LC-Q/TOF-MS for non-volatile components and GC-Q/TOF-MS for volatile organic compounds (VOCs), we achieved a systematic chemical profiling of the materials. The core composition of rosin, dominated by abietic acid (>48%), remained stable across all samples. The incorporation of EOs significantly altered the VOC profiles: The total VOC signal (summed peak area) in MINT-modified rosin was 2.57-fold that of the EUC-modified sample, with monoterpenoids comprising 87.62% of its VOC signature. Eucalyptol and limonene were tentatively identified as the major components in the EUC sample, whereas menthone, menthol, and limonene predominated in the MINT sample. Multivariate statistical analysis highlighted that variations in specific VOCs—particularly menthone, menthol, eucalyptol, and allo-ocimene—were closely associated with differences in the scent profiles of each modification. This work illustrates how a multi-technique analytical strategy can both guide and assess the functional modification of sustainable biomass materials. The findings offer a practical approach to improving rosin’s functional properties while providing a methodological framework for the integrated characterization of complex biomaterials, supporting the development of eco-friendly products aligned with green chemistry and sustainable design principles. Full article

The essential oils obtained by steam distillation of leaves of Piper species have found several applications in bioeconomy due to their various biological properties. Nevertheless, the analysis of essential oils does not provide information regarding the ecologically relevant volatile organic compounds (VOCs) emitted by metabolically active leaves under real-world conditions, challenged or not by herbivore damage. In this study, P. arboreum growing in a highly diverse area was observed as the host of two generalist caterpillars—Gonodonta maria (Erebidae) and Dysodia spissicornis (Thyrididae)—and one Piper-specialist from the genus Eois (Geometridae). The effect of the leaf attack caused by the three different caterpillars on VOCs emission indicated significant and herbivore-specific changes in leaf-induced responses. The profiles of undamaged leaves showed that the two generalist herbivores induced a higher number of single VOCs and of total VOCs emissions by P. arboreum when compared to the herbivory of the specialist caterpillar. Many of the VOCs emitted by herbivore-damaged leaves contained terpenoids that have been previously shown to attract parasitoids, such as (E)-β-ocimene, linalool, DMNT and (E)-β-caryophyllene. All three herbivores significantly altered the VOC profile of P. arboreum leaves compared to undamaged controls, but specific composition signatures were observed, highlighting the complexity of chemical communication at multitrophic levels. Full article

Terpenes are diverse plant metabolites with essential ecological and physiological functions, yet their biosynthetic regulation in lettuce (Lactuca sativa L.) remains poorly understood. By integrating volatile profiling, genome-wide identification, and biochemical characterization of terpene synthase (TPS) genes, we elucidated how methyl jasmonate (MJ) induces terpene formation in lettuce seedlings. Headspace analysis of 10-day-old seedlings revealed that while mock-treated tissues emitted no detectable volatiles, MJ elicitation triggered the de novo production of a terpene blend dominated by (E)-β-ocimene (9.3–14.6%), (E)-β-caryophyllene (37.2–46.9%), and caryophyllene oxide (26.2–41.4%). A genome-wide search identified 54 putative LsTPS genes, often clustered with prenyl transferases or cytochrome P450 genes. Gene expression assays revealed 17 MJ-responsive LsTPS genes; among them, LsTPS21, LsTPS23, LsTPS28, LsTPS51, and LsTPS52 showed strong (>200-fold) induction, with LsTPS52 exceeding a 20,000-fold increase. Functional characterization of six recombinant enzymes demonstrated diverse substrate specificities: LsTPS8 as an α-copaene synthase, LsTPS16 as a linalool synthase, LsTPS24 as an (E)-nerolidol synthase, LsTPS21 and LsTPS23 as (E)-β-ocimene synthases, and LsTPS10 as an (E)-β-caryophyllene synthase. Phylogenetic analyses confirmed conserved domains characteristic of the TPS-a and TPS-b subfamilies. This study presents the first comprehensive framework for MJ-induced terpene biosynthesis in lettuce, offering new insights into Asteraceae terpenoid metabolism. Full article

Research on spicy anchovies lacks dedicated sensory frameworks, reliable aroma identification, and systematic processing–flavor insights. In this study, 21 spicy anchovy samples with different processing parameters were selected as research objects. The effects of process modifications on the sensory attributes and aroma composition of spicy anchovies were investigated through sensory evaluation and aroma analysis. A product-specific flavor wheel (5 modalities, 136 terms) with 17 key descriptors was built via Quantitative Descriptive Analysis. GC-O combined with AEDA/AECA identified 13 key aroma compounds in the commercial sample. HS-SPME-GC-MS detected 73 volatiles across all samples, among which olefins (34 species) were dominant and their formation was linked to lipid oxidation and high-temperature processing. Odor activity values and sensory data revealed that a frying temperature of 180 °C promoted nonanal and (E)-β-ocimene to enhance “fried seafood aroma”; Xiaomila chili pepper boosted “initial spiciness” via capsaicin; and high Sichuan pepper masked “fishy off-flavor” via linalyl acetate. A prediction model for aroma sensory attributes was established and the prediction correlations for “braised beef in soy sauce aroma” and “fried seafood aroma” were relatively high (r = 0.90 and 0.96, respectively). This study provides theoretical guidance for the flavor improvement of spicy anchovies. Full article

Global warming has increased outbreaks of the tea pest Ectropis grisescens. However, how water and nitrogen management modulates tea plant resistance against this pest through induced volatile organic compounds (VOCs) remains unclear. This study aimed to (1) characterize how water–nitrogen interactions alter the composition of VOCs in fresh leaves of Camellia sinensis cv. Rougui, and (2) identify key VOCs that mediate repellence against E. grisescens. Using gas chromatography–mass spectrometry (GC–MS) and olfactometry under three water and three nitrogen levels, we found that nitrogen effects on VOCs were contingent on water status. Four terpenoids—(+)-dihydrocarvone, myrcene, linalool, and β-ocimene—and one green-leaf volatile ((E)-3-hexenoic acid) significantly repelled E. grisescens, whereas hexanoic acid, 3-oxo-, ethyl ester acted as an attractant. Mechanistically, low-water–moderate-nitrogen and high-water–high-nitrogen treatments reduced repellent terpenoids and increased attractant VOCs, thereby elevating pest preference. These results demonstrate that water–nitrogen coupling shifts the balance between repellent and attractant volatiles, providing a physiological basis for manipulating tea plant resistance through agronomic management. Full article

Phalaenopsis is one of the most economically valuable genera in the Orchidaceae family. However, the common varieties of Phalaenopsis in the market rarely have fragrance, greatly limiting the sustainable development of the Phalaenopsis industry. Here, an integrated investigation was conducted on the patterns and determinants of aroma release in Phalaenopsis. GC-MS/MS analysis revealed that the primary volatile organic compounds (VOCs) in 10 fragrant Phalaenopsis cultivars are consistent. Terpenoids, alcohols, ketones, and esters collectively accounted for an average of 66.59% of the total VOCs across these 10 varieties. By performing metabolomic and transcriptomic analyses, we investigated the variation in 1532 VOCs in four different developmental stages of Phalaenopsis Formosa Sweet Memory. Metabolite analysis revealed that the levels of total volatiles, terpenoids, esters, and heterocyclic compounds were significantly upregulated during the flowering stages, and Linalool, β-Ocimene, and Methyl Benzoate were selected as key metabolites. While analyzing the correlation network between aroma components synthesis and differentially expressed genes, 33 key structural genes were detected and regulated by transcription factors. PAXXG356500_TPS, PAXXG333030_4CL, and PAXXG061420_SAM were key genes in the terpenoids and esters’ biosynthetic pathway, and they were co-expressed with aroma release. In summary, this study characterized the key metabolic pathways involved in aroma formation in Phalaenopsis and constructed the corresponding transcriptional regulatory network. These results laid a theoretical foundation for the subsequent research on aroma of Phalaenopsis and genetic engineering technology breeding. Full article