Methyl Salicylate Research Articles

Widely targeted volatileomics analysis reveals the typical aroma formation of Xinyang black tea during fermentation

Xinyang black tea (XYBT) is characterized by the honey sugar-like aroma which is produced during the fermentation process. However, the formation of this typical aroma is still unclear. We here performed widely targeted volatileomics analysis combined with GC–MS and detected 116 aroma active compounds (AACs) with OAV > 1. These AACs were mainly divided into terpenoids, pyrazine, volatile sulfur compounds, esters, and aldehydes. Among them, 25 significant differences AACs (SDAACs) with significant differences in fermentation processes were identified, comprising phenylacetaldehyde, dihydroactinidiolide, α-damascenone, β-ionone, methyl salicylate, and so forth. In addition, sensory descriptions and partial least squares discriminant analysis demonstrated that phenylacetaldehyde was identified as the key volatile for the honey sugar-like aroma. We further speculated that phenylacetaldehyde responsible for the aroma of XYBT was probably produced from the degradation of L-phenylalanine and styrene. In conclusion, this study helps us better understand the components and formation mechanism of the honey sugar-like aroma of XYBT, providing new insight into improving the processing techniques for black tea quality.

Identification of Essential Oils From The Bark of Balik Angin (Alphitonia Incana (Roxb.) Teijsm. & Binn. Ex Kurz)

One of the components that make up essential oils is phenolic compounds which are widely containedin the leaves and bark of the Balik Angin plant (Alphitonia incana (Roxb.) Teijsm. & Binn. ex Kurz).This study aimed to identify phenolic compounds and antioxidant activity of essential oils from thebark of the Balik Angin plant. The essential oils isolation using hydrodistillation and the compoundswere analyzed using gas chromatography-mass spectroscopy (GC-MS). Qualitatively antioxidantactivity test used thin layer chromatography (TLC) and quantitatively by measuring the absorbance of2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals residue that did not react against compounds reducer.The results showed the essential oils contain major compounds which are methyl salicylate followedby methyl palmitate, 2,2-Dimethyl-1,3-dioxane-4,6-dione, and methyl 12-acetoxyoleate. Qualitativetest results of antioxidant activity with TLC there were four yellow spots on a purple background. Thescavenging activity showed the essential oils had an IC50 of 229.056 ppm, while the gallic acid as acomparative standard obtained an IC50 of 0.618 ppm. The conclusion is the essential oils of BalikAngin bark that produces very weak antioxidant activity.

Monitoring Changes in the Volatile Compounds of Tea Made from Summer Tea Leaves by GC-IMS and HS-SPME-GC-MS.

Compared with spring tea, summer tea has the advantages of economy and quantity. However, research on the aroma characteristics of summer tea is currently limited. In this study, summer fresh tea leaves (castanopsis. sinensis, cv. Fuliangzhong) (FTLs) were processed intoblack tea (BT) and green tea (GT). The changes in the volatile compounds during the tea processing were quantified using gas chromatography-ion mobility spectrometry (GC-IMS) and head space-solid phase micro-extraction gas chromatography-mass spectrometry (HS-SPME-GC-MS), and then analyzed on the basis of relative odor activity value (ROAV). Results showed low amounts of flavor compounds, such as linalool oxides, geraniol, and sulcatone, were found in FTLs, but after processing, high amounts of the same in BT and GT. Summer BT and GT contained characteristic compounds similar to spring tea, including linalool, geraniol, (E,E)-2,4-decdienal, β-ionone, methyl salicylate, geranyl acetone, and decanal. All these compounds have high content and ROAV values, which give the same flavor to summer teas as spring tea. This study confirmed that summer fresh tea leaves were suitable to produce black and green tea with good flavor. Monitoring changes in aroma compounds by GC-IMS coupled with GC-MS, the quality of summer tea is expected to be promoted towards the quality of spring tea by improving processing methods for valuable-tea production.

Quality-controlled LC-ESI-MS food metabolomics of fenugreek (Trigonella foenum-graecum) sprouts: Insights into changes in primary and specialized metabolites

Fenugreek (Trigonella foenum-graecum L.) is an important food and spice with bioactive compounds against diabetes. In this study, fenugreek seeds germinating in darkness for 72 h were studied using quantification of trigonelline and 4-hydroxyisoleucine and an LC-ESI-MS/MS-based metabolomic approach capable of accurately estimating 237 features from various primary and specialized compound classes.During germination, the concentrations of trigonelline and 4-hydroxyisoleucine rose by 33.5% and 33.3%, respectively. At the same time, untargeted metabolomics revealed 9 putative flavonoids increasing 1.19- to 2.77-fold compared to the dormant seeds. A set of 19 steroid saponins rose by 1.08- to 31.86-fold. Primary metabolites however showed much more variability: abundance changes in amino acid derivatives, peptides and saccharides fell in the 0.09- to 22.25-fold, 0.93- to 478.79-fold and 0.36- to 941.58-fold ranges, respectively.To increase biosynthesis of specialized metabolites during germination, sprouts were exposed to 1–100 mM methyl jasmonate (MeJA) and methyl salicylate (MeSA). The hormone treatments affected normal metabolism: 67.1–83.1 % and 64.1–83.5 % of compounds showed a reduction compared to the controls in 100 mM MeJA and MeSA treatments at different sampling time points. Contrary to expectations, the abundance of flavonoids decreased, compared to the control sprouts (0.75- and 0.68-fold change medians, respectively). The same was observed for most, but not all steroid saponins.The quality-controlled untargeted metabolomics approach proved to yield excellent insight into the metabolic changes during germination of fenugreek. The results suggest that although fenugreek germination causes major shifts in plant metabolism, there are no major qualitative changes in bioactive specialized metabolites during the first three days. This stability likely translates into good bioactivity that is similar to that of the seeds. Because the large changes in the primary metabolites likely alter the nutritive value of the seed, further studies are warranted.

Designable peptides on graphene field-effect transistors for selective detection of odor molecules

Gas sensing based on graphene field-effect transistors (GFETs) has gained broad interest due to their high sensitivity. Further progress in gas sensing with GFETs requires to detection of various odor molecules for applications in the environmental monitoring, healthcare, food, and cosmetic industries. To develop the ubiquitous odor-sensing system, establishing an artificial sense of smell with electronic devices by mimicking olfactory receptors will be key. Although the application of olfactory receptors to GFETs is straightforward for odor sensing, synthetic molecules with a similar function to olfactory receptors would be desirable to realize the robust performance of sensing. In this work, we designed three new peptides consisting of two domains: a bio-probe to the target molecules and a molecular scaffold. These peptides were rationally designed based on a motif sequence in olfactory receptors and self-assembled into a molecular thin film on GFETs. Limonene, methyl salicylate, and menthol were employed as representative odor molecules of plant flavors to demonstrate the biosensing of odor molecules. The conductivity change of GFETs against the binding to odor molecules with various concentrations and the dynamic response revealed a distinct signature of three different peptides against individual species of the target molecules. The kinetic response of each peptide exhibited characteristic time constants in the adsorption and desorption process, also supported by the principal component analysis. Our demonstration of the graphene odor sensors with the designed peptides opens a way to establish future peptide-array sensors with multi-sequence of peptide, realizing an odor sensing system with higher selectivity.

Geraniol: A Potential Defense-Related Volatile in “Baiye No. 1” Induced by Colletotrichum camelliae

Plants produce and emit a large variety of volatiles that have multiple defense-related functions in response to abiotic or biotic stresses. In comparison with studies on plant volatile–herbivore interactions, little research has been carried out on plant volatile–microbe interactions. In the present paper, tea volatile–Colletotrichum camelliae interactions were studied. The results of emitted volatiles following infection with C. camelliae in “Baiye No. 1” showed that healthy tea plants contained 68 kinds of volatiles, while infected tea plants contained 76 kinds of volatiles. Five volatiles, namely, geraniol, linalool, methyl salicylate, (E)-3-hexen-1-ol, and α-farnesene, were found to have a relatively large content variation in infected tea plants, with increments of 7.903%, −2.247%, 2.770%, −6.728%, and 3.848%, respectively. The fungicidal activity results of the five volatiles against C. camelliae showed that geraniol had the best activity, with MIC and MBC values of 0.5 and 1 mg·mL−1, respectively. Thus, geraniol was selected for subsequent studies. The effects of geraniol on the mycelia and cell structures of C. camelliae were investigated by scanning electron microscopy (SEM) and transmission electron microscope (TEM). The results showed that the mycelia were significantly disrupted, and the cell structures were damaged. The effects of geraniol on the related enzymes of C. camelliae were assessed. The results showed that cellulase activity increased, malondialdehyde content increased, and the activity of defense enzymes was inhibited, thereby inhibiting the growth of pathogens. This study provides the first evidence that geraniol is a defense-related function volatile of “Baiye No. 1” in response to C. camelliae stress. It also provides valuable information and enriches the chemical ecology of tea plant diseases for the research field on defensive substances of microbe-induced plant volatiles.

Insights into Characteristic Volatiles in Wuyi Rock Teas with Different Cultivars by Chemometrics and Gas Chromatography Olfactometry/Mass Spectrometry.

Wuyi rock tea (WRT) is one of the most famous subcategories of oolong tea, exhibiting distinct aroma characteristics with the application of different cultivars. However, a comprehensive comparison of the characteristic volatiles among WRTs with different cultivars has rarely been carried out. In this study, non-targeted analyses of volatile fragrant compounds (VFCs) and targeted aroma-active compounds in WRTs from four different cultivars were performed using chemometrics and gas chromatography olfactometry/mass spectrometry (GC-O/MS). A total of 166, 169, 166, and 169 VFCs were identified for Dahongpao (DHP), Rougui (RG), Shuixian (SX), and Jinfo (JF), respectively; and 40 components were considered as the key differential VFCs among WRTs by multivariate statistical analysis. Furthermore, 56 aroma-active compounds were recognized with predominant performances in "floral & fruity", "green & fresh", "roasted and caramel", "sweet", and "herbal" attributes. The comprehensive analysis of the chemometrics and GC-O/MS results indicated that methyl salicylate, p-cymene, 2,5-dimethylpyrazine, and 1-furfurylpyrrole in DHP; phenylethyl alcohol, phenethyl acetate, indole, and (E)-β-famesene in RG; linalool, phenethyl butyrate, hexyl hexanoate, and dihydroactinidiolide in JF; and naphthalene in SX were the characteristic volatiles for each type of WRT. The obtained results provide a fundamental basis for distinguishing tea cultivars, recombination, and simulation of the WRT aroma.

Comparison of skin decontamination strategies in the initial operational response following chemical exposures

In mass casualty incidents including hazardous chemical skin exposure, decontamination is the primary intervention to avoid systemic uptake of the toxic compound. The protocol needs to be both simple and efficient to enable a rapid response and avoid delay of patient management. In the present study, decontamination strategies included in the initial operational response were evaluated following human skin exposure in vitro to four different contaminants.Results demonstrated that the efficacy of selected decontamination procedures was highly dependent on the chemical contaminant used. Dry removal of the sulfur mustard simulant methyl salicylate prior to wet decontamination was found beneficial compared to wet decontamination alone. Rapidly initiated wet decontamination was more efficient compared to dry and wet removal of the industrial chemical 2-butoxyethanol and the nerve agent tabun. Following VX-exposure, all wet decontamination procedures resulted in increased agent penetration compared to the control.In conclusion, challenges in establishing simple and efficient decontamination procedures for a broad-spectrum of chemicals have been demonstrated. The impact of including a dry removal step during decontamination was evidently agent specific. Despite the variation in efficacy, immediately initiated dry removal may facilitate patient management until wet decontamination resources are available and to reduce the risk of secondary contamination.

Arbuscular Mycorrhizal Fungus Alters Alfalfa (Medicago sativa) Defense Enzyme Activities and Volatile Organic Compound Contents in Response to Pea Aphid (Acyrthosiphon pisum) Infestation.

Pea aphid (Acyrthosiphon pisum) infestation leads to withering, reduced yield, and lower quality of the host plant. Arbuscular mycorrhizal (AM) fungi have been found to enhance their host plants' nutrient uptake, growth, and resistance to biotic stresses, including pathogen infection and insect pest infestation. Therefore, we evaluated the effects of AM fungus Rhizophagus intraradices on alfalfa defense responses to pea aphid infestation. Aphid infestation did not affect the colonization of AM fungus. The inoculation of AM fungus, on average, enhanced alfalfa catalase and the contents of salicylic acid and trypsin inhibitor by 101, 9.05, and 7.89% compared with non-mycorrhizal alfalfa, respectively. In addition, polyphenol oxidase activities significantly increased by six-fold after aphid infestation in mycorrhizal alfalfa. Moreover, the fungus significantly (p < 0.05) improved alfalfa shoot N content, net photosynthetic and transpiration rates, and shoot dry weight in aphid infected treatment. The aphid infestation changed the total volatile organic compounds (VOCs) in alfalfa, while AM fungus enhanced the contents of methyl salicylate (MeSA). The co-expression network analysis of differentially expressed genes (DEGs) and differentially expressed VOCs analysis showed that three DEGs, namely MS.gene23894, MS.gene003889, and MS.gene012415, positively correlated with MeSA both in aphid and AM fungus groups. In conclusion, AM fungus increased alfalfa's growth, defense enzyme activities, hormones, and VOCs content and up-regulated VOC-related genes to enhance the alfalfa's resistance following aphid infestation.

In Vitro Assessment of Antimicrobial Activity of Phytobiotics Composition towards of Avian Pathogenic Escherichia coli (APEC) and Other E. coli Strains Isolated from Broiler Chickens.

Escherichia coli infections (including APEC) in broiler chickens are not only a health and economic problem of the flock, but also a significant health threat to poultry meat consumers. The prophylactic and therapeutic effects of the phytobiotic composition on E. coli in broiler chickens were previously described. However, most of the data were related to the reference strains (for both in vitro and in vivo models). Based on the previous studies in human and animals, E. coli strains seem to be multidrug resistance. This, in turn, makes it necessary to develop effective alternative methods of treating this type of infection already at the stage of poultry production. In the present study, the antibacterial activity against various strains of E. coli (including APEC) was assessed for two innovative phytobiotics mixtures: H1, containing thymol, menthol, linalool, trans-anethole, methyl salicylate, 1,8-cineol, and p-cymene; H2, in addition to compounds from H1, containing terpinen-4-ol and γ-terpinene. The unique mixtures of phytobiotics used in the experiment were effective against various strains of E. coli, also against APEC, isolated from broiler chickens from traditional industrial breeding, as well as against those showing colistin resistance. The minimum inhibitory concentration (MIC) values for these unique mixtures were: For H1 1:512 for APEC and non-APEC E. coli strains isolated from day old chicks (DOCs), 1:512 for non-APEC, and 1:1024 for non-APEC isolated from broilers sample. For mixture H2, MIC for APEC from both type of samples (DOCs and broilers) was 1:1024 and for non-APEC (DOCs and broilers) was 1:512. The results suggest that phytobiotic compositions used in this study can be successfully used as a natural alternative to antibiotics in the treatment of E. coli infections in broiler chickens. The promising results may be a crucial point for further analyses in broiler flocks exposed to E. coli infections and where it is necessary to reduce the level of antibiotics or completely eliminate them, thus reducing the risk of foodborne infections.

Heterologous expression and functional characterization of Drosophila suzukii OR69a transcript variants unveiled response to kairomones and to a candidate pheromone

Drosophila suzukii is a main pest of berries on all continents. Population control relies on insecticides and a current research challenge is to develop alternative strategies. Methods based on behavior-modifying semiochemicals are widely used against other horticultural insects, and the functional characterization of chemoreceptors facilitates the identification of active compounds. Following heterologous expression of single olfactory receptors (ORs) in ab3A olfactory sensory neurons of D. melanogaster, we screened three transcript variants from the OR69a-locus (DsuzOR69aA, DsuzOR69aB, DsuzOR69aC), demonstrating binding to two possible kairomones (3-octanol and R-carvone) and to a possible fly-emitted volatile compound [(Z)-4-nonenal], although with different pharmacological qualities. By coupling Gas Chromatography to SSR (GC-SSR), these ligands enhanced ab3A-spiking at nanogram-aliquots in a complementary fashion among the different OR69a-variants, and we identified another possible kairomone, methyl salicylate, as the most active and specific ligand for the sole DsuzOR69aB. In testing headspaces collected from D. suzukii females and from the fly-associated yeast Hanseniaspora uvarum we did not observe activation from female headspaces but activation from yeast headspaces. In situ hybridization analysis on D. suzukii antennae suggests unique expression of OR69a-subunits in specific neurons, and points toward co-expression within the same neurons. The OR69a-subunits of D. suzukii constitute cation channels, which binding suggests kairomone specificity, even if effects coexist for a complementary binding of (Z)-4-nonenal. Methyl salicylate is the most active ligand and is specific to the sole DsuzOR69aB, inspiring future investigation to validate potentials of this compound for D. suzukii control strategies.

Effect of storage time on the volatile compounds and taste quality of Meixian green tea

Longer aging year affect the flavor characteristics and quality of Meixian green tea (MXGT); however, little is known about the quality and chemical characteristics of aged green tea. In the present study, the quality of MXGT stored for varying periods were compared by volatile compounds and sensory evaluation. Based on a random forest model, three volatile compounds (dihydroactinidiolide, methyl salicylate, and jasmon) were significantly related to the storage time, classification, and spectra of MXGT, with correlation coefficient of 0.99, respectively. Meanwhile, we found that the fermenter genus Muribaculaceae was involved in the changes of volatile compounds in MXGT after the 10th year of storage. These results may help promote the use of volatile compounds and microbial to stabilize and improve the quality of MXGT products.

Phonophoresis through Nonsteroidal Anti-Inflammatory Drugs for Knee Osteoarthritis Treatment: Systematic Review and Meta-Analysis.

Knee osteoarthritis (OA) is the most common joint disease. The administration of nonsteroidal anti-inflammatory drugs (NSAIDs) by phonophoresis is a therapeutic alternative to relieve pain in inflammatory pathologies. The main aim was to analyze the efficacy of the application of NSAIDs by phonophoresis in knee OA. A systematic review and meta-analysis of controlled clinical trials were performed between January and March 2021 in the following databases: Web of Science, Scopus, PubMed, Cinahl, SciELO, and PEDro. The PEDro scale was used to evaluate the level of evidence of the selected studies. The RevMan 5.4 statistical software was used to obtain the meta-analysis. Eight studies were included, of which five were included in the meta-analysis, involving 195 participants. The NSAIDs used through phonophoresis were ibuprofen, piroxicam, diclofenac sodium, diclofenac diethylammonium, ketoprofen, and methyl salicylate. The overall result for pain showed not-conclusive results, but a trend toward significance was found in favor of the phonophoresis group compared to the control group (standardized mean difference (SMD) = -0.92; 95% confidence interval: -1.87-0.02). Favorable results were obtained for physical function (SMD = -1.34; 95% CI: -2.00-0.68). Based on the selected studies, the application of NSAIDs by phonophoresis is effective in relieving the symptoms of knee OA. Future long-term studies are recommended.

Determination of ointments active ingredients and parabens by one analytical method – capillary GC with cool-on-column injection and FID detection

In the field of quality control of medicines every pharmaceutical is tested for compliance with the requirements of the normative document for this drug to assess the quality. Among the quality indicators are the content of active ingredients and the excipients content. The more analytical methods used in a normative document, the greater the time and effort of people in all areas where a drug is developed, manufactured and controlled. A fast, precise, accurate and sensitive method has been developed for the simultaneous determination of the active ingredients of ointments of camphor, L-menthol, methyl salicylate, benzyl nicotinate, nonivamide, capsaicin, dihydrocapsaicin, nordihydrocapsaicin together with excipients, which are often para-hydroxybenzoic acid esters (parabens). The proposed gas chromatographic technique was validated. Good sensitivity for the application area (fractions of µg/mL for active ingredients and units of µg/mL for parabens), high reproducibility (relative standard deviation (RSD) doesn’t significantly exceed 2%) and the accuracy of the proposed method were demonstrated. The practical application was shown on the example of commercially available ointments. Also several assumptions about retention mechanism of such compounds were given. It seemed interesting to us for adapting proposed GC method to other components of ointments (or another dosage forms).

Exogenous Application of a Plant Elicitor Induces Volatile Emission in Wheat and Enhances the Attraction of an Aphid Parasitoid Aphidius gifuensis.

It is well known that plant elicitors can induce plant defense against pests. The herbivore-induced plant volatile (HIPV) methyl salicylate (MeSA), as a signaling hormone involved in plant pathogen defense, is used to recruit natural enemies to protect wheat and other crops. However, the defense mechanism remains largely unknown. Here, the headspace volatiles of wheat plants were collected and analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with electroantennographic detection (GC-EAD) and principal component analysis (PCA). The results showed that exogenous application of MeSA induced qualitative and quantitative changes in the volatiles emitted from wheat plants, and these changes were mainly related to Carveol, Linalool, m-Diethyl-benzene, p-Cymene, Nonanal, D-limonene and 6-methyl-5-Hepten-2-one. Then, the electroantennogram (EAG) and Y-tube bioassay were performed to test the physiological and behavioral responses of Aphidius gifuensis Ashmesd to the active volatile compounds (p-Cymene, m-Diethyl-benzene, Carveol) that identified by using GC-EAD. The female A. gifuensis showed strong physiological responses to 1 μg/μL p-Cymene and 1 μg/μL m-Diethyl-benzene. Moreover, a mixture blend was more attractive to female A. gifuensis than a single compound. These findings suggested that MeSA could induce wheat plant indirect defense against wheat aphids through attracting parasitoid in the wheat agro-ecosystem.

Solid Phase Microextraction-Multicapillary Column-Ion Mobility Spectrometry (SPME-MCC-IMS) for Detection of Methyl Salicylate in Tomato Leaves.

Methyl salicylate (MeSA) is a plant-signaling molecule that plays an essential role in the regulation of plant responses to biotic and abiotic pathogens. In this work, solid phase microextraction (SPME) and a multicapillary column (MCC) are coupled to ion mobility spectrometry (IMS) to detect MeSA in tomato leaves. The SPME-MCC-IMS method provides two-dimensional (2D) separation by both MCC and IMS, based on the retention and drift times. The effect of the IMS polarity on the separation efficiency of MCCs was also investigated. In the positive polarity, ionization of MeSA resulted in [MeSA + H]+ formation while, in the negative, deprotonated ions, [MeSA - H]-, and the O2- adduct ion, [MeSA + O2]-, were formed. In the real sample analysis, the negative polarity operation resulted in the suppression of many matrix molecules and thus in the reduction of interferences. Four different SPME fibers were used for head space analysis, and four MCC columns were investigated. In the negative polarity, complete separation was achieved for all of the MCCs columns. The limits of detection (LODs) of 0.1 μg mL-1 and linear range of 0.25-12 μg mL-1 were obtained for the measurement of MeSA in a standard solution (H2O/CH3OH, 50:50) by the SPME-IMS method with a 5 min extraction time using an SPME with a PDMS fiber, in the negative mode of IMS. The MeSA contents of fresh tomato leaves were determined as 1.5-9.8 μg g-1, 24-96 h after inoculation by tomato mosaic ringspot virus (ToRSV).

High-resolution transcriptome and volatile assays provide insights into flower development and aroma formation in single- and double-petal jasmines (Jasminum sambac)

Jasmine ( Jasminum sambac ) is one of the most popular ornamental plant species in the world, with diverse floral morphology, including single-petal (SP), double-petal (DP) and multi-petal (MP). Here, based on our recently published chromosome-level genome assemblies of SP and DP Jasmines, we generated high-resolution transcriptional profiles of SP and DP jasmine flowers at six developmental stages and identified key events and regulators contributing to the differences between the two jasmines. The upregulated genes of DP jasmine in early flower development were mainly related to photosynthesis and light reactions, which may contribute to its stronger energy metabolism and environmental adaptability compared with SP jasmine. AGL63 (GOA) and PLETHORA3 (PLT3) motifs involved in floral organogenesis in Arabidopsis were overrepresented at the initial stages in SP and DP, respectively, and may be involved in the development of different petal layers in jasmines. The specific high expression of volatile terpene and benzene/phenylpropane synthesis genes during flowering is an important factor why jasmines during bud development and other tissues are scentless. This factor is also responsible for the typical floral volatiles of jasmine, including terpenes ( α -farnesene, linalool , and ( E )- β -ocimene), and benzenoid lipids (benzyl acetate, methyl salicylate , and methyl benzoate). The high content of α -farnesene and the low content of other core volatiles may constitute the fresh and elegant fragrance of SP compared to DP jasmine. Only DP jasmine had high expression of benzoic acid/salicylic acid carboxyl methyltransferase (BMST), which resulted in its higher content of volatile methyl salicylate and methyl benzoate . Our findings lay the foundation for understanding the flower development and aroma formation mechanisms of different jasmine petal morphologies. • High-resolution transcriptome and volatile assays for single- and double-petal jasmine. • Identified key events and regulators contributing to the differences between two jasmines. • Determine why jasmines were scentless during bud development and other tissues. • The high content of α-farnesene may contribute to the fresh and sweet fragrance of single-petal jasmine. • The expression of BMST was only higher in DP jasmine, resulting in higher content of methyl salicylate and methyl benzoate.

Ultrasensitive methyl salicylate gas sensing determined by Pd-doped SnO2

Ultrasensitive methyl salicylate gas sensing determined by Pd-doped SnO2

Fabrication of mesoporous nanoprobe with molecularly imprinted fluorescent carbon dots embedded within silica network for the selective and sensitive detection of aspirin in ground water samples

In this work, a highly selective and sensitive protocol has been developed to detect aspirin (ASP) by using mesoporous silica nanoprobe equipped with molecular imprints and fluorescent carbon dots (ms-MIP-FCDs). The fabrication of nanoprobe is based on the reprocessing of rice straw to fluorescent carbon dots (FCDs) and their amalgamation with molecular imprinting within mesoporous silica network (ms). The molecular imprints for ASP were introduced via sol gel process. The nanoprobe displayed spectrofluorimetric signal due to photoinduced electron transfer between ms-MIP-FCDs and ASP. The synergistic action of mesopores, molecular imprints, and FCDs makes the spectrofluorimetric recognition of ASP quick (in 5 min), sensitive (LOD = 1.16 nM), and selective in the presence of potential competing interferents (such as salicylic acid, methyl salicylate, salsalate, 5-methylsalicyldehyde, naproxen, ketoprofen, diclofenac, mefenamic acid, carbamazepine, and levofloxacin). Furthermore, the method can be successfully applied to detect the ASP from ground water samples with the recoveries in the range of 94.1–104.2% and good precision (relative standard deviation (RSD) < 6.0%). The prepared fluorescent probe also displayed excellent performance with enhanced reusability/durability.

Methyl salicylate pretreatment maintains quality and antioxidant capacity of fresh-cut pitaya fruit by modulating phenylpropanoid metabolism and antioxidant system

The effect of 0.1 mmol L−1 methyl salicylate (MeSA) pretreatment on quality properties of fresh-cut pitaya fruit and their relationships with phenylpropanoid metabolism and antioxidant system were studied. Results revealed that MeSA pretreatment efficiently inhibited flesh browning, respiration rate, ethylene production, electrical conductivity (EC) and malondialdehyde (MDA) content of fresh-cut pitaya fruit compared with the control. Moreover, the contents of total phenolics and flavonoids, antioxidant system, and the major phenolic acids (protocatechuic acid, chlorogenic acid and gallic acid) and flavonoid compounds (phloridin, kaempferol, rutin and epicatechin) were overall higher in MeSA-pretreated group than those in the control. Meanwhile, the gene expressions and activities of key enzymes (phenylalanine ammonia lyase (PAL), 4-coumarate-CoA ligase (4CL), cinnamic acid 4-hydroxylase (C4H)) closely related with phenolic biosynthesis were induced by MeSA, while polyphenoloxidase (PPO) and peroxidase (POD), key enzymes closely related to phenolic oxidation, were suppressed at lower activities in MeSA-pretreated group. In addition, MeSA pretreatment stimulated higher superoxide anion (O2·−) generation rate and hydrogen peroxide (H2O2) content at the beginning of storage but led to lower levels of them afterwards. As for the antioxidant enzymes system and ascorbate-glutathione (AsA-GSH) cycle, superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) activities were all increased, while the losses of AsA and GSH were alleviated due to the application of MeSA. These results demonstrated that MeSA pretreatment maintained quality of fresh-cut pitaya fruit through modulating phenylpropanoid metabolism and antioxidant system.