Non-targeted analysis of spatial metabolite composition in strawberry (Fragariaxananassa) flowers

Exploring Plants with Flowers: From Therapeutic Nutritional Benefits to Innovative Sustainable Uses

Flowers have played a significant role in society, focusing on their aesthetic value rather than their food potential. This study's goal was to look into flowering plants for everything from health benefits to other possible applications. This review presents detailed information on 119 species of flowers with agri-food and health relevance. Data were collected on their family, species, common name, commonly used plant part, bioremediation applications, main chemical compounds, medicinal and gastronomic uses, and concentration of bioactive compounds such as carotenoids and phenolic compounds. In this respect, 87% of the floral species studied contain some toxic compounds, sometimes making them inedible, but specific molecules from these species have been used in medicine. Seventy-six percent can be consumed in low doses by infusion. In addition, 97% of the species studied are reported to have medicinal uses (32% immune system), and 63% could be used in the bioremediation of contaminated environments. Significantly, more than 50% of the species were only analysed for total concentrations of carotenoids and phenolic compounds, indicating a significant gap in identifying specific molecules of these bioactive compounds. These potential sources of bioactive compounds could transform the health and nutraceutical industries, offering innovative approaches to combat oxidative stress and promote optimal well-being.

Antiinflammatory effect of the ethanolic extract of Korean native herb Potentilla rugulosa Nakai in Bisphenol-a-stimulated A549 cells

Potentilla rugulosa Nakai (P. rugulosa) is a perennial herb in the Rosaceae family and found in the Korean mountains. Previously, our findings demonstrated that P. rugulosa contains numerous polyphenols and flavonoids exhibiting important antioxidant and anti-obesity bioactivities. Bisphenol A (BPA) is a xenoestrogen that was shown to produce pulmonary inflammation in humans. However, the mechanisms underlying BPA-induced inflammation remain to be determined. The aim of this study was to examine whether ethanolic extract of P. rugulosa exerted an inhibitory effect on BPA-induced inflammation utilizing an adenocarcinoma human alveolar basal epithelial cell line A549. The P. rugulosa extract inhibited BPA-mediated cytotoxicity by reducing levels of reactive oxygen species (ROS). Further, P. rugulosa extract suppressed the upregulation of various pro-inflammatory mediators induced by activation of the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. In addition, inhibition of the NF-κB and MAPK signaling pathways by P. rugulosa extract was found to occur via decrease in the transcriptional activity of NF-κB. Further, blockade of phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and stress-activated protein kinase/Jun N-terminal kinase (SAPK/JNK) was noted. Thus, our findings suggest that the ethanolic extract of P. rugulosa may act as a natural anti-inflammatory therapeutic agent.

Kinetic Ultrasound-Assisted Extraction as a Sustainable Approach for the Recovery of Phenolics Accumulated through UVA Treatment in Strawberry By-Products

Ultrasound-assisted extraction (UAE) is an efficient and sustainable method for extracting bioactive compounds from agro-industrial by-products. Moreover, it has been reported that ultraviolet A (UVA) radiation can induce the biosynthesis and accumulation of bioactive phenolic compounds. This study optimized the efficiency of ultrasound-assisted extraction (UAE) for recovering ultraviolet A (UVA)-induced phenolic compounds in strawberry by-products (RF-N). The impact of three factors (solid-liquid ratio, ethanol concentration, and ultrasound power) on total phenolic compound (TPC) kinetics using Peleg's model was investigated. The developed model showed a suitable fit for both RF-N and strawberry by-products treated with UVA (RF-E). The optimal UAE conditions obtained were of a 1:30 ratio, 46% ethanol, and 100% ultrasound power, resulting in an average yield of 13 g total phenolics kg-1. The bioaccessibility of phenolic compounds during in-vitro digestion was 36.5%, with agrimoniin being the predominant compound. UAE combined with UVA treatment increased the bioactivity of RF extracts, displaying significant anti-proliferative effects on HT29 and Caco-2 cancer cell lines, as well as anti-inflammatory potential and cellular antioxidant activity. The ultrasound proved to be a sustainable and effective technique for extracting phenolic compounds from RF, contributing to the valorization of strawberry agro-industrial by-products, and maximizing their nutraceutical potential.

FaMYB5 Interacts with FaBBX24 to Regulate Anthocyanin and Proanthocyanidin Biosynthesis in Strawberry (Fragaria × ananassa)

MYB and BBX transcription factors play important roles in flavonoid biosynthesis. Here, we obtained transgenic woodland strawberry with stable overexpression of FaMYB5, demonstrating that FaMYB5 can increase anthocyanin and proanthocyanidin content in roots, stems and leaves of woodland strawberry. In addition, bimolecular fluorescence complementation assays and yeast two-hybridization demonstrated that the N-terminal (1-99aa) of FaBBX24 interacts with FaMYB5. Transient co-expression of FaBBX24 and FaMYB5 in cultivated strawberry 'Xiaobai' showed that co-expression strongly promoted the expression of F3'H, 4CL-2, TT12, AHA10 and ANR and then increased the content of anthocyanin and proanthocyanidin in strawberry fruits. We also determined that FaBBX24 is also a positive regulator of anthocyanin and proanthocyanidin biosynthesis in strawberry. The results reveal a novel mechanism by which the FaMYB5-FaBBX24 module collaboratively regulates anthocyanin and proanthocyanidin in strawberry fruit.

Impact of particle size on the nutrition release and antioxidant activity of rape, buckwheat and rose bee pollens

In this study, the effects of particle size on the microstructure, nutrient components and antioxidant activities of bee pollen were evaluated. Moreover, the in vitro simulated digestion model was used to explore whether there was a size effect on the release behavior of phenolic compounds from the bee pollen matrix. Results showed that the greater the damage degree of the bee pollen wall, the smaller the bee pollen particle became. The decrease in the bee pollen particle size promoted the release and extractability of sugar, protein, phenolics and flavonoids, and improved their antioxidant activities. In addition, during simulated digestion, the dissolution of total phenolics and flavonoids, as well as the antioxidant activities of bee pollen, increased with the decrease in the particle size. Results showed that minimizing the particle size of bee pollen was not always beneficial for bioaccessible phenolic compounds because their content and bioavailability decreased when the particle size became smaller than 200 μm.

New Type of Tannins Identified from the Seeds of Cornus officinalis Sieb. et Zucc. by HPLC-ESI-MS/MS

There is a lack of information on the compound profile of Cornus officinalis Sieb. et Zucc. seeds. This greatly affects their optimal utilization. In our preliminary study, we found that the extract of the seeds displayed a strong positive reaction to the FeCl₃ solution, indicating the presence of polyphenols. However, to date, only nine polyphenols have been isolated. In this study, HPLC-ESI-MS/MS was employed to fully reveal the polyphenol profile of the seed extracts. A total of 90 polyphenols were identified. They were classified into nine brevifolincarboxyl tannins and their derivatives, 34 ellagitannins, 21 gallotannins, and 26 phenolic acids and their derivatives. Most of these were first identified from the seeds of C. officinalis. More importantly, five new types of tannins were reported for the first time: brevifolincarboxyl-trigalloyl-hexoside, digalloyl-dehydrohexahydroxydiphenoyl (DHHDP)-hexdside, galloyl-DHHDP-hexoside, DHHDP-hexahydroxydiphenoyl(HHDP)-galloyl-gluconic acid, and peroxide product of DHHDP-trigalloylhexoside. Moreover, the total phenolic content was as high as 79,157 ± 563 mg gallic acid equivalent per 100 g in the seeds extract. The results of this study not only enrich the structure database of tannins, but also provide invaluable aid to its further utilization in industries.

Metabolite Profiling of Antioxidant Rich Fractions of Punica granatum L. Mesocarp and CD36 Expression Regulation

OBJECTIVE

It was aimed at determining which polyphenolic compound(s) in pomegranate mesocarp extract (PME) is liable for the antioxidant, anti-glycation and anti-CD36 activities.

METHODS

The PME was fractionated using liquid-liquid extraction method. The fractions were tested for their polyphenolic content, antioxidant potency, anti-glycation activity and anti-CD36 potential. The metabolite compositions of PME and derived fractions were investigated in an untargeted manner using metabolomics in relation to its antioxidant and anti-glycation activities.

RESULTS

The ethyl acetate and n-butanol fractions of the pomegranate mesocarp demonstrated highest antioxidant and anti-glycation potencies. These fractions, represented by gallic and ellagic acids monomers, were enriched in tannins and phenolic acids. Orthogonal partial least squares discriminate analysis (OPLS-DA) modeling of ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) metabolite profiles from the different pomegranate mesocarp fractions indicated that gallic and ellagic acids were potential contributors to the antioxidant and anti-glycation effects of the pomegranate mesocarp. At cellular level, the polyphenolic-rich crude extract as well as the ethyl acetate, n-butanol and aqueous residual fractions suppressed the protein expression of CD36. The anti-CD36 activity of these extracts and fractions was attributed to the presence of punicalagin, the ellagitannins that occurred in equal amount in the different fractions.

CONCLUSION

This work demonstrated the protective effect of the non-edible part of the pomegranate fruit and showed that gallic and ellagic acids account for the antioxidant and anti-glycation activities while punicalagin is liable for the anti-CD36 activity of PME.

Role of metabolites in flower development and discovery of compounds controlling flowering time

Flowering is one of the most important physiological processes of plants that ensures continuity of genetic flow from one generation to the next and also maintains food security. Therefore, impact of various climate-related abiotic stresses on flowering have been assessed to evaluate the long-term impact of global climate change. In contrast to the enormous volume of research that has been conducted at the genetic, transcriptional, post-transcriptional, and protein level, much less attention has been paid to understand the role of various metabolites in flower induction and floral organ development during normal growth or in stressed environmental condition. This review article aims at summarizing information on various primary (e.g., carbohydrates, lipids, fatty acid derivatives, protein and amino acids) and secondary metabolites (e.g., polyamines, phenolics, neuro-indoles, phenylpropanoid, flavonoids and terpenes) that have so far been identified either during flower induction or in individual floral organs implying their possible role in organ development. Specialized metabolites responsible for flower colour, scent and shape to support plant-pollinator interaction have been extensively reviewed by many research groups and hence are not considered in this article. Many of the metabolites discussed here may be used as metabolomarkers to identify tolerant crop genotypes. Several agrochemicals have been successfully used to release endodormancy in temperate trees. Along the same line, a strategy that combines metabolite profiling, screening of small-molecule libraries, and structural alteration of selected compounds has been proposed in order to identify novel lead compounds that can regulate flowering time when applied exogenously.

Fragaria × ananassa cv. Senga Sengana Leaf: An Agricultural Waste with Antiglycation Potential and High Content of Ellagitannins, Flavonols, and 2-Pyrone-4,6-dicarboxylic Acid

Strawberry leaves are considered a valuable waste material; so far, mainly due to their antioxidant properties. Since the annual production of this crop is high, our study aimed to thoroughly examine the chemical composition and antidiabetes-related bioactivity of Fragaria × ananassa leaf of its popular and productive cultivar Senga Sengana. Leaves from three different seasons, collected after fruiting, were extensively analyzed (UHPLC-qTOF-MS/MS, HPLC-DAD). Some individual components were isolated and quantified, including specific flavonol diglycosides (e.g., 3-O-[β-xylosyl(1‴→2″)]-β-glucuronosides). The separated quercetin glycosides were tested in an antiglycation assay, and their methylglyoxal uptake capacity was measured. In addition, the biodegradable polyester precursor 2-pyrone-4,6-dicarboxylic acid (PDC) was confirmed at relatively high levels, providing further opportunity for strawberry leaf utilization. We want to bring to the attention of the food, pharmaceutical, and cosmetic industries the Senga Sengana strawberry leaf as a new botanical raw material. It is rich in PDC, ellagitannins, and flavonols—potent glycation inhibitors.

Impact of different processing methods on the phenolics and neuroprotective activity of Fragaria ananassa Duch. extracts in a D-galactose and aluminum chloride-induced rat model of aging

Age-related diseases, including dementia, are a major health concern affecting daily human life. Strawberry (Fragaria ananassa Duch.) is the most eaten fruit worldwide due to its exceptional aroma and flavor. However, it's rapid softening and decay limit its shelf-life. Freezing and boiling represent the well-known conservation methods to extend its shelf-life. Therefore, we aimed to discover the phytochemical content differences of fresh and processed strawberries associated with investigating and comparing their neuroprotective effects in a rat model of aging. Female Wistar rats were orally pretreated with fresh, boiled, and frozen F. ananassa methanolic extracts (250 mg kg-1) for 2 weeks, and then these extracts were concomitantly exposed to D-galactose [65 mg kg-1, subcutaneously (S/C)] and AlCl3 (200 mg kg-1, orally) for 6 weeks to develop aging-like symptoms. The results of UPLC/ESI-MS phytochemical profiling revealed 36 secondary metabolites, including phenolics, flavonoids, and their glycoside derivatives. Compared with boiled and frozen extracts, the fresh extract ameliorated the behavioral deficits including anxiety and cognitive dysfunction, upregulated brain HO-1 and Nrf2 levels, and markedly reduced caspase-3 and PPAR-γ levels. Moreover, LDH and miRNA-9, 124 and 132 protein expressions were reduced. The histological architecture of the brain hippocampus was restored and glial fibrillary acidic protein (GFAP) immunoexpression was downregulated. In conclusion, the fresh extract has neuroprotective activity that could have a promising role in ameliorating age-related neurodegeneration.

Metabolome dynamics during wheat domestication

One of the most important crops worldwide is wheat. Wheat domestication took place about 10,000 years ago. Not only that its wild progenitors have been discovered and phenotypically characterized, but their genomes were also sequenced and compared to modern wheat. While comparative genomics is essential to track genes that contribute to improvement in crop yield, comparative analyses of functional biological end-products, such as metabolites, are still lacking. With the advent of rigorous mass-spectrometry technologies, it is now possible to address that problem on a big-data scale. In attempt to reveal classes of metabolites, which are associated with wheat domestication, we analyzed the metabolomes of wheat kernel samples from various wheat lines. These wheat lines represented subspecies of tetraploid wheat along primary and secondary domestications, including wild emmer, domesticated emmer, landraces durum, and modern durum. We detected that the groups of plant metabolites such as plant-defense metabolites, antioxidants and plant hormones underwent significant changes during wheat domestication. Our data suggest that these metabolites may have contributed to the improvement in the agricultural fitness of wheat. Closer evaluation of specific metabolic pathways may result in the future in genetically-engineered high-yield crops.

Time Course Metabolite Profiling of Fusarium Head Blight-Infected Hard Red Spring Wheat Using Ultra-High-Performance Liquid Chromatography Coupled with Quadrupole Time of Flight/MS

Wheat is an important food crop, yet its value is reduced by fungal infections (ex. Fusarium graminearum). Metabolite profiling is a useful tool for explaining resistance mechanisms. By analyzing near-isogenic lines (NILs) with contrasting Fhb1 alleles and three wheat varieties, a time course resulting in 61 relevant metabolites was studied. The presence of one metabolite as resistant related constitutive late in the time course was detected. Results confirm the presence of hydroxycinnamic acid amides conjugated with polyamine derivatives (hydroxycinnamic acid amides, HCAAs), which have been shown to induce thickening of cell walls. These compounds are shared by resistant and susceptible genotypes with no difference in intensities but vary in time as early- or late-occurring, suggesting that for the NIL studied here, HCAAs were a normal part of the host reaction. Overall, metabolites synthesized as a result of infection were observed regardless of susceptibility but occurred at different times after infection.

Unique distribution of ellagitannins in ripe strawberry fruit revealed by mass spectrometry imaging

Ellagitannins (ETs) are hydrolysable tannins composed of a polyol core, primarily glucose, which is esterified with hexahydroxydiphenic acid (HHDP), and in some cases, gallic acid. ETs are the major phenolic compounds found in strawberries and may contribute to the health-related properties of strawberries, because of their strong antioxidative activity. However, their distribution in the strawberry fruit remains unclear. In this study, matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI–MSI) was used to visualize ETs in ripe strawberry fruits. Five peaks, corresponding to the m/z values of ET [M−H]⁻ ions detected in the MALDI–MS spectrum of strawberry extracts, were identified as strictinin, pedunculagin, casuarictin, davuriicin M₁, and an unknown ET using MALDI–tandem MS (MS/MS). In addition, liquid chromatography–electrospray ionization–MS/MS of the extracts revealed the presence of pedunculagin isomers and the unknown ET. Ion images of these five ETs were reconstructed using MALDI–MSI. Strictinin was widely distributed in and around the achene seed coats, while the other ETs were dispersed in and around the seed coats, and at the bottom of the receptacle; pedunculagin was distributed in the epidermis and pith, whereas casuarictin, the unknown ET, and davuriicin M₁ were distributed in the pith. Moreover, MALDI–MSI of a casuarictin standard indicated that in-source fragmentation weakly affected the ion images. The results suggest that the distribution of ETs depends on the presence or absence of their constituents, namely galloyl units, HHDP, and bis-HHDP. To the best of my knowledge, this is the first report on the visualization of ETs in plant tissues using MSI, MALDI–MSI may be a useful tool for analyzing the distribution of ETs in the strawberry fruit.

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The ellagitannins (ETs) in strawberry fruits were identified.

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MALDI-MS/MS and LC-MS/MS were used.

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The ETs identified in the fruits were visualized using MALDI-MSI.

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The ETs showed unique distributions in the seeds and the lower receptacle.

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The distribution of ETs depends on their constituents: galloyl units and HHDP.

Changes in "natural antibiotic" metabolite composition during tetraploid wheat domestication

Gramineous plants protect their seeds from a variety of biotic stresses by producing toxic and deterrent secondary metabolites such as benzoxazinoids. It is unclear how the composition and abundance of these natural toxins has changed over the course of crop-plant domestication. To address this uncertainty, we characterized differences in metabolic levels of benzoxazinoids and their derivatives, between four lines of tetraploid wheat: wild emmer wheat (WEW), the direct progenitor of modern wheat; non-fragile domesticated emmer wheat (DEW), which was first domesticated about 11,000 years ago; the subsequently developed non-fragile and free-threshing durum landraces (LD); and modern durum (MD) varieties. Three-dimensional principal component analysis of mass spectrometry data of wheat metabolites showed with high resolution clear differences between metabolic profiles of WEW, DEW, and durum (LD + MD) and similarity in the metabolic profiles of the two durum lines (LD and MD) that is coherent with the phylogenetic relationship between the corresponding wheat lines. Moreover, our results indicated that some secondary metabolites involved in plant defense mechanisms became significantly more abundant during wheat domestication, while other defensive metabolites decreased or were lost. These metabolic changes reflect the beneficial or detrimental roles the corresponding metabolites might play during the domestication of three taxonomic subspecies of tetraploid wheat (Triticum turgidum).

Terpenoid and lipid profiles vary in different Phytophthora cactorum - strawberry interactions

Specialized metabolites are essential components in plant defence systems, serving as signalling molecules and chemical weapons against pathogens. The manipulation of plant defence metabolome or metabolites can thus be an important virulence strategy for pathogens. Because of their central role, metabolites can give valuable insights into plant-pathogen interactions. Here, we have conducted nontargeted metabolite profiling with UPLC-ESI-qTOF-MS to investigate the metabolic changes that have taken place in the crown tissue of Fragaria vesca L. (woodland strawberry) and Fragaria × ananassa (Weston) Duchesne ex Rozier (garden strawberry) during 48 h after Phytophthora cactorum challenge. Two P. cactorum isolates were compared: Pc407 is highly virulent to F. × ananassa and causes crown rot, whereas Pc440 is mildly virulent. In total, 45 metabolites differentially accumulated between the treatment groups were tentatively identified. Triterpenoids and various lipid compounds were highly represented. The levels of several triterpenoids increased upon inoculation, some of them showing distinct accumulation patterns in different interactions. Triterpenoids could either inhibit or stimulate P. cactorum growth and, therefore, triterpenoid profiles might have significant impact on disease progression. Of the lipid compounds, lysophospholipids, linoleic acid and linolenic acid were highly accumulated in the most compatible Pc407 - F. × ananassa interaction. As lysophospholipids promote cell death and have been linked to susceptibility, these compounds might be involved in the pathogenesis of crown rot disease. This metabolite analysis revealed potential factors contributing to the outcome of P. cactorum - strawberry interactions. The information is highly valuable, as it can help to find new breeding strategies and new solutions to control P. cactorum in strawberry.

Revealing floral metabolite network in tuberose that underpins scent volatiles synthesis, storage and emission

The role of central carbon metabolism in the synthesis and emission of scent volatiles in tuberose flowers was revealed through measurement of changes in transcripts and metabolites levels. Tuberose or Agave amica (Medikus) Thiede & Govaerts is a widely cultivated ornamental plant in several subtropical countries. Little is known about metabolite networking involved in biosynthesis of specialized metabolites utilizing primary metabolites. In this study, metabolite profiling and gene expression analyses were carried out from six stages of maturation throughout floral lifespan. Multivariate analysis indicated distinction between early and late maturation stages. Further, the roles of sugars viz. sucrose, glucose and fructose in synthesis, glycosylation and emission of floral scent volatiles were studied. Transcript levels of an ABC G family transporter (picked up from the floral transcriptome) was in synchronization with terpene volatiles emission during the anthesis stage. A diversion from phenylpropanoid/benzenoid to flavonoid metabolism was observed as flowers mature. Further, it was suggested that this metabolic shift could be mediated by isoforms of 4-Coumarate-CoA ligase along with Myb308 transcription factor. Maximum glycosylation of floral scent volatiles was shown to occur at the late mature stage when emission declined, facilitating both storage and export from the floral tissues. Thus, this study provides an insight into floral scent volatiles synthesis, storage and emission by measuring changes at transcripts and metabolites levels in tuberose throughout floral lifespan.

Comparative metabolomics analysis of different sesame (Sesamum indicum L.) tissues reveals a tissue-specific accumulation of metabolites

BACKGROUND

Sesame (Sesamum indicum L.) leaves, flowers, especially seeds are used in traditional medicine to prevent or cure various diseases. Its seed's market is expanding. However, the other tissues are still underexploited due to the lack of information related to metabolites distribution and variability in the plant. Herein, the metabolite profiles of five sesame tissues (leaves, fresh seeds, white and purple flowers, and fresh carpels) have been investigated using ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS/MS)-based widely targeted metabolomics analysis platform.

RESULTS

In total, 776 metabolites belonging to diverse classes were qualitatively and quantitatively identified. The different tissues exhibited obvious differences in metabolites composition. The majority of flavonoids predominantly accumulated in flowers. Amino acids and derivatives, and lipids were identified predominantly in fresh seeds followed by flowers. Many metabolites, including quinones, coumarins, tannins, vitamins, terpenoids and some bioactive phenolic acids (acteoside, isoacteoside, verbascoside, plantamajoside, etc.) accumulated mostly in leaves. Lignans were principally detected in seeds. 238 key significantly differential metabolites were filtered out. KEGG annotation and enrichment analyses of the differential metabolites revealed that flavonoid biosynthesis, amino acids biosynthesis, and phenylpropanoid biosynthesis were the main differently regulated pathways. In addition to the tissue-specific accumulation of metabolites, we noticed a cooperative relationship between leaves, fresh carpels, and developing seeds in terms of metabolites transfer. Delphinidin-3-O-(6"-O-p-coumaroyl)glucoside and most of the flavonols were up-regulated in the purple flowers indicating they might be responsible for the purple coloration.

CONCLUSION

This study revealed that the metabolic processes in the sesame tissues are differently regulated. It offers valuable resources for investigating gene-metabolites interactions in sesame tissues and examining metabolic transports during seed development in sesame. Furthermore, our findings provide crucial knowledge that will facilitate sesame biomass valorization.

Metabolomics, a Powerful Tool for Understanding Plant Abiotic Stress

Metabolomics is a technology that generates large amounts of data and contributes to obtaining wide and integral explanations of the biochemical state of a living organism. Plants are continuously affected by abiotic stresses such as water scarcity, high temperatures and high salinity, and metabolomics has the potential for elucidating the response-to-stress mechanisms and develop resistance strategies in affected cultivars. This review describes the characteristics of each of the stages of metabolomic studies in plants and the role of metabolomics in the characterization of the response of various plant species to abiotic stresses.

Nitrogen Fertilization Influences the Quantity, Composition, and Tissue Association of Foliar Phenolics in Strawberries

Unlike quantitative changes, the compositional changes of plant phenolics and changes in their tissue association as influenced by the nutrient supply are less well understood. We evaluated the quantity, composition, and tissue association of phenolics in leaves of two Fragaria ananassa cultivars in response to different levels of nitrogen (N) fertilization using global metabolomic approaches. Influence of N supply on phenolic content in both cultivars was similar, but the magnitude of this response was compound specific. Ellagitannins, the most abundant class of phenolic oligomers, were less responsive to the applied N treatments, whereas proanthocyanidins, the less abundant class of phenolic oligomers, exhibited higher fold change. Within mono-phenolics, the hydroxycinnamates were more abundant but showed lower fold change than the hydroxybenzoates. Among flavonoids, the hydroxylated flavonols showed higher abundances than the flavones, with a preferential accumulation of dihydroxylated flavonol at lower N levels. Furthermore, glycosylated flavonols were higher than the acylated forms. The extractable fraction of phenolics was more influenced by the N treatment than the fiber-bound fraction. The extensive compositional modification of phenolics and a greater response of non-bound fractions in response to N rates highlight the potential to use precise management of N supply as an effective strategy to enhance the bioactive compounds in crops.

Cross-Species Metabolic Profiling of Floral Specialized Metabolism Facilitates Understanding of Evolutional Aspects of Metabolism Among Brassicaceae Species

Plants produce a variety of floral specialized (secondary) metabolites with roles in several physiological functions, including light-protection, attraction of pollinators, and protection against herbivores. Pigments and volatiles synthesized in the petal have been focused on and characterized as major chemical factors influencing pollination. Recent advances in plant metabolomics have revealed that the major floral specialized metabolites found in land plant species are hydroxycinnamates, phenolamides, and flavonoids albeit these are present in various quantities and encompass diverse chemical structures in different species. Here, we analyzed numerous floral specialized metabolites in 20 different Brassicaceae genotypes encompassing both different species and in the case of crop species different cultivars including self-compatible (SC) and self-incompatible (SI) species by liquid chromatography-mass spectrometry (LC-MS). Of the 228 metabolites detected in flowers among 20 Brassicaceae species, 15 metabolite peaks including one phenylacyl-flavonoids and five phenolamides were detected and annotated as key metabolites to distinguish SC and SI plant species, respectively. Our results provide a family-wide metabolic framework and delineate signatures for compatible and incompatible genotypes thereby providing insight into evolutionary aspects of floral metabolism in Brassicaceae species.

Chemical composition of Prunus padus L. flower extract and its anti-inflammatory activities in primary bone marrow-derived macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Prunus padus L. has been traditionally used in European ethnomedicine as a treatment for internal and external purposes and is mainly used to reduce inflammation, pain and fever. The activities of P. padus flower extracts are not well characterized, and additional experimental studies at the molecular level are needed to confirm the ethnobotanical findings.

AIM OF THE STUDY

To assess the potential of P. padus flower extract (PPFE) as a source of bioactive compounds through the characterization of its chemical composition and antioxidant, anti-collagenase, and anti-inflammatory activities.

MATERIALS AND METHODS

The ethanolic extract (1:10 w/v in ethanol solution) from P. padus flowers was subjected to phytochemical analysis and evaluation of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Anti-collagenase activity was determined using a spectrophotometric method in vitro. The effect of PPFE on inflammation was evaluated by measuring specific markers using flow cytometry and assessing pro-inflammatory cytokine (IL-6) release by bone marrow-derived macrophages (BMDMs) ex vivo.

RESULTS

The major components of the ethanolic extract of P. padus flowers were quercetin diglycosides, chlorogenic acid and N',N″-dicaffeoyl,N‴-coumaroyl spermidine. The total phenolic content of PPFE was 85.19 mg GAE/g extract, and the EC₅₀ value in the DPPH assay was 0.55 mg/ml. PPFE exhibited the ability to inhibit collagenase activity in a dose-dependent manner. Preincubation of BMDMs with PPFE reduced the population of M1 (pro-inflammatory) and increased the population of M2 (anti-inflammatory) macrophages. Furthermore, PPFE decreased pro-inflammatory cytokine IL-6 release from BMDMs.

CONCLUSIONS

PPFE is a rich source of bioactive compounds and possesses considerable anti-inflammatory properties, supporting its use in ethnomedicine for the reduction of inflammatory processes.

LC-MS based metabolic fingerprinting of apricot pistils after self-compatible and self-incompatible pollinations

KEY MESSAGE

LC-MS based metabolomics approach revealed that putative metabolites other than flavonoids may significantly contribute to the sexual compatibility reactions in Prunus armeniaca. Possible mechanisms on related microtubule-stabilizing effects are provided. Identification of metabolites playing crucial roles in sexual incompatibility reactions in apricot (Prunus armeniaca L.) was the aim of the study. Metabolic fingerprints of self-compatible and self-incompatible apricot pistils were created using liquid chromatography coupled to time-of-flight mass spectrometry followed by untargeted compound search. Multivariate statistical analysis revealed 15 significant differential compounds among the total of 4006 and 1005 aligned metabolites in positive and negative ion modes, respectively. Total explained variance of 89.55% in principal component analysis (PCA) indicated high quality of differential expression analysis. The statistical analysis showed significant differences between genotypes and pollination time as well, which demonstrated high performance of the metabolic fingerprinting and revealed the presence of metabolites with significant influence on the self-incompatibility reactions. Finally, polyketide-based macrolides similar to peloruside A and a hydroxy sphingosine derivative are suggested to be significant differential metabolites in the experiment. These results indicate a strategy of pollen tubes to protect microtubules and avoid growth arrest involved in sexual incompatibility reactions of apricot.

Strawberry pollen as a source of UV-B protection ingredients for the phytoseiid mite Neoseiulus californicus (Acari: Phytoseiidae)

BACKGROUND

A new physical control method using ultraviolet-B (UV-B) lamps and light-reflecting sheets (UV method) significantly suppressed a spider mite population on greenhouse strawberries. Although UV-B radiation may adversely affect the survival of phytoseiid mites, previous research has suggested that Neoseiulus californicus can improve its survival on exposure to UV-B irradiation by consuming antioxidants contained in tea and peach pollen. In this study, we evaluated strawberry pollen as an alternative food source for N. californicus and examined whether antioxidants in the pollen mitigated UV-B damage to N. californicus.

RESULTS

The fecundity of N. californicus females reared on Tetranychus urticae decreased on shifting their diet to pollen. By contrast, females reared continuously on strawberry pollen produced as many eggs as females reared continuously on T. urticae. Survival and fecundity after UV-B irradiation were higher in females on the pollen diet. Oxygen radical absorbance capacity analysis revealed that the high antioxidant activity of strawberry pollen was due to four hydroxycinnamoyl spermidine derivatives.

CONCLUSION

Strawberry pollen was an adequate alternative food source for N. californicus. Feeding on strawberry pollen, which contains spermidine derivatives with high antioxidant activity, mitigated UV-B damage. This shows the potential of combining the UV-method with N. californicus for controlling T. urticae in strawberries.

Chemical and pharmacological evaluation of the non-flowering aerial parts of Acacia modesta Wall. cultivated in Egypt

Background

Acacia modesta Wall. (A. modesta), often recognized as Phulai, is belonging to family Fabaceae and sub-family Mimosaceae. A. modesta has many beneficial uses. Leaves, wood, flowers, and gum of A. modesta have been used frequently for multiple therapeutic purposes.

Results

The chemical investigation of butanol fraction of A. modesta non-flowering aerial parts yielded Vitexin-2′′-β-D-glucopyranoside and Apigenin-6,8-di-C-β-D-glucopyranoside in a flavone mixture as well as (β-D-glucopyranosyl (1-3)-β-D-glucopyranosyl)-3-β-hydroxy-11-oxo-olean-12-en-28-oic acid) an oleanane-type triterpenoidal saponin. Metabolite profiling via ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS) of the ethyl acetate fraction resulted in recognizing of eighteen compounds tentatively compared with previously published data. Quantitative measurement of the overall value of flavonoids of A. modesta was found to be 2.824 μg/100 μg ± 0.01 calculated as quercetin. The acute toxicity study of the ethanol extract proved that the plant under investigation is safe and nontoxic to the male albino mice used. The anti-hyperglycemic activity of the ethanol extract performed on type 2 diabetic rats proved that the most potent dosage was 200 mg/kg b. wt. after 4 and 4 weeks of treatment respectively compared to metformin. Furthermore, evaluation of the hepato-protective activity of the ethanol extract of the plant under investigation showed that the most potent extract was with a dose level of 200 mg/kg b. wt. after 3 and 10 days of continuous treatment compared to silymarin.

Conclusion

It can be concluded that A. modesta Wall. cultivated in Egypt could be used as a promising anti-diabetic agent and a hepato-protective agent against hepatocellular damage induced by hepatotoxins.

Cornus mas L. Stones: A Valuable By-Product as an Ellagitannin Source with High Antioxidant Potential

The stone of Cornus mas L. remains the least known morphological part of this plant, whereas the fruit is appreciated for both consumption purposes and biological activity. The stone is considered to be a byproduct of fruit processing and very little is known about its phytochemical composition and biological properties. In this study, the complete qualitative determination of hydrolyzable tannins, their quantitative analysis, total polyphenolic content, and antioxidant properties of the stone of C. mas are presented for the first time. The 37 identified compounds included the following: various gallotannins (11), monomeric ellagitannins (7), dimeric ellagitannins (10), and trimeric ellagitannins (7). The presence of free gallic acid and ellagic acid was also reported. Our results demonstrate that C. mas stone is a source of various bioactive hydrolyzable tannins and shows high antioxidant activity which could allow potential utilization of this raw material for recovery of valuable pharmaceutical or nutraceutical substances. The principal novelty of our findings is that hydrolyzable tannins, unlike other polyphenols, have been earlier omitted in the evaluation of the biological activities of C. mas. Additionally, the potential recovery of these bioactive chemicals from the byproduct is in line with the ideas of green chemistry and sustainable production.

Activity-guided isolation of α-amylase, α-glucosidase, and pancreatic lipase inhibitory compounds from Rhus coriaria L

The leaves and fruits of Rhus coriaria are traditionally used in Turkey for the treatment of diabetes. The aim of the present study is to determine α-amylase, α-glucosidase, and pancreatic lipase inhibitory activities of R. coriaria leaf and fruit ethanol extracts (80%), and to isolate active compounds against these enzymes. As a result of the activity-guided isolation, the active compounds were determined as the amentoflavone, agathisflavone, and 1,2,3,4,6-penta-O-galloyl-β-glucopyranose. Agathisflavone, amentoflavone, and penta-O-galloyl-β-glucopyranose inhibited α-glucosidase with 11.4 ± 0.9, 11.3 ± 0.7, and 4.1 ± 0.1 µM IC₅₀ values, respectively. Furthermore, penta-O-galloyl-β-glucopyranose inhibited α-amylase with 6.32 ± 0.18 µM IC₅₀ . These three compounds also significantly inhibited (P < 0.05) pancreatic lipase. The results of high-performance liquid chromatography analysis showed that penta-O-galloyl-β-D-glycopyranose was one of the main compounds in both fruit and leaf extracts. Therefore, it may be considered that R. coriaria fruit and leaf extracts can be standardized on this substance and used in the development of both medicinal products and functional food for diabetes. PRACTICAL APPLICATION: Rhus coriaria (Sumac) is one of the plants that is well known and used around the world as a spice. It is also used against diabetes traditionally. The determination of effective compounds can lead to the standardization and development of both medicinal products and functional foods for diabetes. While the fruits of the plant are used as a spice all around the world, the leaves are generally throw away; therefore, the usage of the leaves to the food and medical industry can lead to beneficial effects on the economy.

Strategies for Drawing Quantitative Conclusions from Nontargeted Liquid Chromatography-High-Resolution Mass Spectrometry Analysis

This Feature aims at giving an overview of different possibilities for quantitatively comparing the results obtained from LC-HRMS-based nontargeted analysis. More specifically, quantification via structurally similar internal standards, different isotope labeling strategies, radiolabeling, and predicted ionization efficiencies are reviewed.

Characterization of metabolite profiles of white and green spears of asparagus officinalis L. from Caoxian, East China

China is the largest planting country of asparagus (Asparagus officinalis L.) in the world. Caoxian, as the famous asparagus township in China, enjoys a reputation for producing asparagus with high yield and good quality, due to its unique geological characteristic. In this study, a method of reverse-phase ultraperformance liquid chromatography coupled with electrospray tandem mass spectrometry (RP-UPLC-ESI-MS/MS) was established for profiling metabolites from three segments (tip, mid, and base) of 'Caoxian white and green Asparagus'. A total of 114 metabolites were identified, among them, 43 were found for the first time in this vegetable. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) was applied to provide an overview of the metabolite profiles of Caoxian asparagus and to separate different segments of spears. The variables most decisive to discriminate among segments included 9 of the metabolites tentatively identified. This study will help to improve the protection of Caoxian asparagus geographical indication.

Centaurea pumilio L. extract and nanoparticles: A candidate for healthy skin

Centaurea pumilio was the subject of phytochemical and biological studies, and its extract was used in the green synthesis of silver nanoparticles (AgNPs). Liquid chromatography/electrospray ionization mass spectrometry allowed the tentative identification of twenty-nine phytoconstituents of C. pumilio methanolic extract (CME), while column chromatography led to the identification of eight phenolic compounds. The neutral red uptake method showed the safety of CME and AgNPs on skin cells (HaCaT cell lines), while their high antioxidant potentials were demonstrated based on their oxygen radical absorbance capacity, and these results were confirmed in vivo. Additionally, CME and AgNPs had promising abilities to retard the ageing process and combat dark spots by potently inhibiting collagenase, elastase and tyrosinase, in addition to antimicrobial activity against skin infection-causing strains, especially Staphylococcus aureus, which was further confirmed by the significant phagocytic activity of neutrophils via engulfment. This study presents C. pumilio as a candidate for healthy skin.

Swift metabolite changes and leaf shedding are milestones in the acclimation process of grapevine under prolonged water stress

BACKGROUND

Grape leaves provide the biochemical substrates for berry development. Thus, understanding the regulation of grapevine leaf metabolism can aid in discerning processes fundamental to fruit development and berry quality. Here, the temporal alterations in leaf metabolism in Merlot grapevine grown under sufficient irrigation and water deficit were monitored from veraison until harvest.

RESULTS

The vines mediated water stress gradually and involving multiple strategies: osmotic adjustment, transcript-metabolite alteration and leaf shedding. Initially stomatal conductance and leaf water potential showed a steep decrease together with the induction of stress related metabolism, e.g. up-regulation of proline and GABA metabolism and stress related sugars, and the down-regulation of developmental processes. Later, progressive soil drying was associated with an incremental contribution of Ca²⁺ and sucrose to the osmotic adjustment concomitant with the initiation of leaf shedding. Last, towards harvest under progressive stress conditions following leaf shedding, incremental changes in leaf water potential were measured, while the magnitude of perturbation in leaf metabolism lessened.

CONCLUSIONS

The data present evidence that over time grapevine acclimation to water stress diversifies in temporal responses encompassing the alteration of central metabolism and gene expression, osmotic adjustments and reduction in leaf area. Together these processes mitigate leaf water stress and aid in maintaining the berry-ripening program.

Genetic diversity of strawberry germplasm using metabolomic biomarkers

High-throughput metabolomics technologies can provide the quantification of metabolites levels across various biological processes in different tissues, organs and species, allowing the identification of genes underpinning these complex traits. Information about changes of metabolites during strawberry development and ripening processes is key to aiding the development of new approaches to improve fruit attributes. We used network-based methods and multivariate statistical approaches to characterize and investigate variation in the primary and secondary metabolism of seven domesticated and seven wild strawberry fruit accessions at three different fruit development and ripening stages. Our results demonstrated that Fragaria sub-species can be identified solely based on the gathered metabolic profiles. We also showed that domesticated accessions displayed highly similar metabolic changes due to shared domestication history. Differences between domesticated and wild accessions were detected at the level of metabolite associations which served to rank metabolites whose regulation was mostly altered in the process of domestication. The discovery of comprehensive metabolic variation among strawberry accessions offers opportunities to probe into the genetic basis of variation, providing insights into the pathways to relate metabolic variation with important traits.

Metabolomic Approach for the Authentication of Berry Fruit Juice by Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry Coupled to Chemometrics

Berry fruit juice, which is represented by blueberry and cranberry juice, has become increasingly popular due to its reported nutritional and health benefits. However, in markets, adulteration of berry fruit juice with cheaper substitutes is frequent. In the present study, a metabolomic approach for authentication of berry fruit juices by liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) was established. The global characterization of the berry fruit metabolome by information dependent acquisition directed LC-MS/MS coupled to a peak mining workflow by isotope pattern matching was reported. Targeted metabolomics analysis of known juice biomarkers, such as flavonoids, anthocyanins, etc. exhibited a good separation of berry fruit juices from adulterant juices. Moreover, untargeted metabolomics analysis was carried out and subjected to chemometrics analysis. Discrimination of blueberry juice, cranberry juice, and its adulterant apple juice and grape juice was obtained by principal component analysis-discriminant analysis. Eighteen characteristic markers discriminating berry fruit juice and its adulterants were selected by comparison of marker abundances in different juice samples. Identification of characteristic markers was accomplished by elemental formula prediction and online database searches based on accurate MS information. These results suggested that the combination of untargeted and targeted metabolomics approach has great potential for authentication of berry fruit juice.

Insights into Tissue-specific Specialized Metabolism in Tieguanyin Tea Cultivar by Untargeted Metabolomics

Tea plants produce extremely diverse and abundant specialized metabolites, the types and levels of which are developmentally and environmentally regulated. However, little is known about how developmental cues affect the synthesis of many of these molecules. In this study, we conducted a comparative profiling of specialized metabolites from six different tissues in a premium oolong tea cultivar, Tieguanyin, which is gaining worldwide popularity due to its uniquely rich flavors and health benefits. UPLC-QTOF MS combined with multivariate analyses tentatively identified 68 metabolites belonging to 11 metabolite classes, which exhibited sharp variations among tissues. Several metabolite classes, such as flavonoids, alkaloids, and hydroxycinnamic acid amides were detected predominantly in certain plant tissues. In particular, tricoumaroyl spermidine and dicoumaroyl putrescine were discovered as unique tea flower metabolites. This study offers novel insights into tissue-specific specialized metabolism in Tieguanyin, which provides a good reference point to explore gene-metabolite relationships in this cultivar.

Isolation of Intact Vacuoles from Petunia Petals and Extraction of Sequestered Glycosylated Phenylpropanoid Compounds

Plant vacuoles are the largest compartment in plant cells, occupying more than 80% of the cell volume. A variety of proteins, sugars, pigments and other metabolites are stored in these organelles ( Paris et al., 1996 ; Olbrich et al., 2007 ). Flowers produce a variety of specialized metabolites, some of which are unique to this organ, such as components of pollination syndromes, i.e., scent volatiles and flavonoids ( Hoballah et al., 2007; Cna'ani et al., 2015). To study the compounds stored in floral vacuoles, this compartment must be separated from the rest of the cell. To enable isolation of vacuoles, protoplasts were first generated by incubating pierced corollas with cellulase and macrozyme enzymes. After filtering and several centrifugation steps, protoplasts were separated from the debris and damaged/burst protoplasts, as revealed by microscopic observation. Concentrated protoplasts were lysed, and vacuoles were extracted by Ficoll-gradient centrifugation. Vacuoles were used for quantitative GC-MS analyses of sequestered metabolites. This method allowed us to identify vacuoles as the subcellular accumulation site of glycosylated volatile phenylpropanoids and to hypothesize that conjugated scent compounds are sequestered in the vacuoles en route to the headspace (Cna'ani et al., 2017).

Comparison of polyphenol content and antioxidant capacity of strawberry fruit from 90 cultivars of Fragaria × ananassa Duch

Strawberry fruit is a valuable resource, rich in vitamins and polyphenolic compounds. These compounds have a broad spectrum of biological activity. The aim of this study was to evaluate the qualitative and quantitative composition of polyphenols in strawberry fruit from 90 cultivars of Fragaria × ananassa Duch. from two growing seasons. Eighty of them were analyzed for the first time (to the best of our knowledge). The identification of polyphenolics and other compounds was performed using UPLC-qTOF-MS/MS. Nine compounds were recorded for the first time in mature strawberry fruit. Antioxidant properties were also determined using DPPH and ABTS methods. Statistical analysis of the results was performed using principal component analysis. Tannins, especially ellagitannins with agrimoniin, as well as the total polyphenols, had the greatest influence on antioxidant activity in the ABTS test. Cultivars characterized by a high content of tannins and high antioxidant capacity were selected.

Semi-Targeted Analysis of Complex Matrices by ESI FT-ICR MS or How an Experimental Bias may be Used as an Analytical Tool

Ammonia is well suited to favor deprotonation process in electrospray ionization mass spectrometry (ESI-MS) to increase the formation of [M - H]^-. Nevertheless, NH₃ may react with carbonyl compounds (aldehyde, ketone) and bias the composition description of the investigated sample. This is of significant importance in the study of complex mixture such as oil or bio-oil. To assess the ability of primary amines to form imines with carbonyl compounds during the ESI-MS process, two aldehydes (vanillin and cinnamaldehyde) and two ketones (butyrophenone and trihydroxyacetophenone) have been infused in an ESI source with ammonia and two different amines (aniline and 3-chloronaniline). The (+) ESI-MS analyses have demonstrated the formation of imine whatever the considered carbonyl compound and the used primary amine, the structure of which was extensively studied by tandem mass spectrometry. Thus, it has been established that the addition of ammonia, in the solution infused in an ESI source, may alter the composition description of a complex mixture and leads to misinterpretations due to the formation of imines. Nevertheless, this experimental bias can be used to identify the carbonyl compounds in a pyrolysis bio-oil. As we demonstrated, infusion of the bio-oil with 3-chloroaniline in ESI source leads to specifically derivatized carbonyl compounds. Thanks to their chlorine isotopic pattern and the high mass measurement accuracy, (+) ESI Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) unambiguously highlighted them from the numerous C_xH_yO_z bio-oil components. These results offer a new perspective into the detailed molecular structure of complex mixtures such as bio-oils. Graphical Abstract ᅟ.

Metabolite Profiling of 14 Wuyi Rock Tea Cultivars Using UPLC-QTOF MS and UPLC-QqQ MS Combined with Chemometrics

Wuyi Rock tea, well-recognized for rich flavor and long-lasting fragrance, is a premium subcategory of oolong tea mainly produced in Wuyi Mountain and nearby regions of China. The quality of tea is mainly determined by the chemical constituents in the tea leaves. However, this remains underexplored for Wuyi Rock tea cultivars. In this study, we investigated the leaf metabolite profiles of 14 major Wuyi Rock tea cultivars grown in the same producing region using UPLC-QTOF MS and UPLC-QqQ MS with data processing via principal component analysis and cluster analysis. Relative quantitation of 49 major metabolites including flavan-3-ols, proanthocyanidins, flavonol glycosides, flavone glycosides, flavonone glycosides, phenolic acid derivatives, hydrolysable tannins, alkaloids and amino acids revealed clear variations between tea cultivars. In particular, catechins, kaempferol and quercetin derivatives were key metabolites responsible for cultivar discrimination. Information on the varietal differences in the levels of bioactive/functional metabolites, such as methylated catechins, flavonol glycosides and theanine, offers valuable insights to further explore the nutritional values and sensory qualities of Wuyi Rock tea. It also provides potential markers for tea plant fingerprinting and cultivar identification.

Scent from Jasminum grandiflorum flowers: Investigation of the change in linalool enantiomers at various developmental stages using chemical and molecular methods

Jasminum species are among the most preferred fresh cut flowers in India since ancient times. The plant produces small and fragrant flowers, which are of great demand in the preparation of fragrant garlands and also in perfume industries. Floral volatile of Jasminum grandiflorum L. (Family: Oleaceae) was extracted using solid-phase microextraction and analyzed in enantioselective gas chromatography. Chemical classes of identified volatiles revealed the presence of terpenoids, phenylpropanoids, and fatty acid derivatives. Marker constituent of flower volatiles, linalool was selected for analytical characterization on ethyl- and acetyl-β-cyclodextrin stationary phase. (R)-(-)-Linalool was found as major enantiomer in volatiles of floral buds whereas (S)-(+)-linalool predominated in the volatiles of matured flowers. Simultaneously, a quantitative real-time PCR was performed to find the gene expression of linalool synthase to investigate the mechanism of enantiomeric inversion. The emission pattern of (R)-(-)-linalool at different flower developmental stages was well correlated (P = 0.01) with the gene expression of the cloned linalool synthase from J. grandiflorum. We observed that the successive change in (R)- to (S)-linalool ratio from bud to mature flower was mainly due to the enantio- specific transformation and temporal decline of (R)-linalool producing gene in J. grandiflorum. This enantiomeric change also leads to the difference in flower aroma. Furthermore, this is probably the reason behind consumer's acceptance for jasmine buds rather than bloomed flowers in cut flower segments.