Analysis Of Mass Spectral Data Research Articles

A Targeted and an Untargeted Metabolomics Approach to Study the Phytochemicals of Tomato Cultivars Grown Under Different Salinity Conditions.

In this study, we evaluated the effect of increasing the salinity of irrigation water on the metabolic content and profiles of two tomato cultivars ('Jaune Flamme' (JF) and 'Red Pear' (RP)) using targeted and untargeted metabolomics approaches. Irrigation of tomato plants was performed with four different salt concentrations provided by chloride (treatment 1) and sulfate (treatment 2) salts. Targeted analysis of the methanolic extract resulted in the identification of nine major polyphenols. Among them, chlorogenic acid, rutin, and naringenin were the prominent compounds in both cultivars. In addition, the quantification of 18 free amino acids from both tomato cultivars showed that different salinity treatments significantly enhanced the levels of glutamine, glutamic acid, and γ-aminobutyric acid (GABA). Using the untargeted metabolomic approach, we identified 129 putative metabolites encompassing a diverse array of phytochemicals including polyphenols, organic acids, lipids, sugars, and amino acids. Principal component analysis (PCA) of mass spectral data acquired under positive and negative ionization modes showed a clear separation between the two cultivars. However, only positive ionization showed separation among different salinity treatments. Unsupervised and supervised learning algorithms were applied to mine the generated data and to pinpoint metabolites different from the two cultivars. These findings suggest that different salinity conditions significantly influenced the accumulation of phytochemicals in tomato cultivars. This study will help tomato breeding programs to develop value-added tomato cultivars under varying environmental conditions.

Mining the chemical diversity of the hemp seed (Cannabis sativa L.) metabolome: discovery of a new molecular family widely distributed across hemp.

Hemp (Cannabis sativa L.) is a widely researched industrial crop with a variety of applications in the pharmaceutical, nutraceutical, food, cosmetic, textile, and materials industries. Although many of these applications are related to its chemical composition, the chemical diversity of the hemp metabolome has not been explored in detail and new metabolites with unknown properties are likely to be discovered. In the current study, we explored the chemical diversity of the hemp seed metabolome through an untargeted metabolomic study of 52 germplasm accessions to 1) identify new metabolites and 2) link the presence of biologically important molecules to specific accessions on which to focus on in future studies. Multivariate analysis of mass spectral data demonstrated large variability of the polar chemistry profile between accessions. Five main groups were annotated based on their similar metabolic fingerprints. The investigation also led to the discovery of a new compound and four structural analogues, belonging to a previously unknown chemical class in hemp seeds: cinnamic acid glycosyl sulphates. Although variability in the fatty acid profiles was not as marked as the polar components, some accessions had a higher yield of fatty acids, and variation in the ratio of linoleic acid to α-linolenic acid was also observed, with some varieties closer to 3:1 (reported as optimal for human nutrition). We found that that cinnamic acid amides and lignanamides, the main chemical classes of bioactive metabolites in hemp seed, were more concentrated in the Spanish accession Kongo Hanf (CAN58) and the French accession CAN37, while the Italian cultivar Eletta Campana (CAN48) demonstrated the greatest yield of fatty acids. Our results indicate that the high variability of bioactive and novel metabolites across the studied hemp seed accessions may influence claims associated with their commercialization and inform breeding programs in cultivar development.

Database Creator for Mass Analysis of Peptides and Proteins, DC-MAPP: A Standalone Tool for Simplifying Manual Analysis of Mass Spectral Data to Identify Peptide/Protein Sequences.

Proteomic studies typically involve the use of different types of software for annotating experimental tandem mass spectrometric data (MS/MS) and thereby simplifying the process of peptide and protein identification. For such annotations, these softwares calculate the m/z values of the peptide/protein precursor and fragment ions, for which a database of protein sequences must be provided as an input file. The calculated m/z values are stored as another database, which the user usually cannot view. Database Creator for Mass Analysis of Peptides and Proteins (DC-MAPP) is a novel standalone software that can create custom databases for "viewing" the calculated m/z values of precursor and fragment ions, prior to the database search. It contains three modules. Peptide/Protein sequences as per user's choice can be entered as input to the first module for creating a custom database. In the second module, m/z values must be queried-in, which are searched within the custom database to identify protein/peptide sequences. The third module is suited for peptide mass fingerprinting, which can be used to analyze both ESI and MALDI mass spectral data. The feature of "viewing" the custom database can be helpful not only for better understanding the search engine processes, but also for designing multiple reaction monitoring (MRM) methods. Post-translational modifications and protein isoforms can also be analyzed. Since, DC-MAPP relies on the protein/peptide "sequences" for creating custom databases, it may not be applicable for the searches involving spectral libraries. Python language was used for implementation, and the graphical user interface was built with Page/Tcl, making this tool more user-friendly. It is freely available at https://vit.ac.in/DC-MAPP/.

New Sesterterpenoid from the Marine Fungus Penicillium oxalicum M893

Objectives The aim of the project was the isolation, structural elucidation, and antimicrobial and antifungal activities of compounds from the culture broth of the marine fungus Penicillium oxalicum M893 (isolated from the marine brown alga Spatoglossum sp.). Methods Combined chromatographic techniques were used to isolate antibacterial and antifungal compounds from the MeOH extract Penicillium oxalicum M893. The structures were elucidated by analyses of high-resolution electrospray ionization mass spectral and nuclear magnetic resonance data. The antimicrobial and antifungal effects of compounds were evaluated using the dilution turbidimetric broth method. Results One new sesterterpenoid, oxaliterpenoid (1), and six known compounds, aspergillusidone C (2), nidulin (3), emeguisin B (4), aspergillusether A (5), aspergillusether J (6), and guisinol (7) were isolated from the methanol extract of the culture broth of Penicillium oxalicum M893. All compounds showed potent antibacterial activities against Gram-(+) bacteria, E. faecalis (ATCC299212), S. aureus (ATCC25923), and B. cereus (ATCC14579), and the yeast Candida albicans (ATCC10231), with MIC values ranging from 2 to 128 µg/mL.

Reducing the matrix effect in mass spectral imaging of biofilms using flow-cell culture.

The interactions between soil microorganisms and soil minerals play a crucial role in the formation and evolution of minerals and the stability of soil aggregates. Due to the heterogeneity and diversity of the soil environment, the under-standing of the functions of bacterial biofilms in soil minerals at the microscale is limited. A soil mineral-bacterial biofilm system was used as a model in this study, and it was analyzed by time-of-flight secondary ion mass spectrometry (ToF-SIMS) to acquire molecular level information. Static culture in multi-wells and dynamic flow-cell culture in microfluidics of biofilms were investigated. Our results show that more characteristic molecules of biofilms can be observed in SIMS spectra of the flow-cell culture. In contrast, biofilm signature peaks are buried under the mineral components in SIMS spectra in the static culture case. Spectral overlay was used in peak selection prior to performing Principal component analysis (PCA). Comparisons of the PCA results between the static and flow-cell culture show more pronounced molecular features and higher loadings of organic peaks of the dynamic cultured specimens. For example, fatty acids secreted from bacterial biofilm extracellular polymeric substance are likely to be responsible for biofilm dispersal due to mineral treatment up to 48h. Such findings suggest that the use of microfluidic cells to dynamically culture biofilms be a more suitable method for reducing the matrix effect arisen from the growth medium and minerals as a perturbation fac-tor for improved spectral and multivariate analysis of complex mass spectral data in ToF-SIMS. These results show that the interaction mechanism between biofilms and soil minerals at the molecular level can be better studied using the flow-cell culture and advanced mass spectral imaging techniques like ToF-SIMS.

Synthesis, experimental and molecular dynamics simulation of the ESI-CID spectrum of the nerve agent Novichok analog O-2-methoxyethyl N- [bis(dimethylamino)methylidene]-P-methylphosphonamidate

The comprehensive and accurate analysis of mass spectral data is critical for the unequivocal identification of environmental samples containing compounds short-listed by the Chemical Weapons Convention (CWC). In particular, experiments with nerve agents are limited by the high risks involved in their handling. Therefore, the possibility of studying fragmentation pathways by a theoretical approach is especially welcome. In this work, for the first time, O-2-methoxyethyl N- [bis(dimethylamino)methylidene]-P-methylphosphonamidate, an analog of the Novichok nerve agent A-242, was synthesized employing a one-pot microscale synthesis. Electron ionization (EI) and electrospray ionization (ESI) mass spectra (MS) were measured to provide data for CWC verification purposes. Considering that ESI-MS/MS is a powerful method for analyzing non-volatile, highly polar, and very water-soluble compounds, such as degradation products of nerve agents, we extensively investigated for the first time the ESI-(collision-induced dissociation) CID fragmentation pathways of the selected molecule. For this purpose, molecular dynamics simulations using the Quantum Chemical Mass Spectrometry (QCxMS) method employing the semiempirical electronic structure method GFN2-xTB were compared with Triple Quadrupole electrospray ionization (ESI) experimental spectra in positive ion mode. The base peak of the EI spectrum for this molecule was found to be m/z 151, which strongly suggests a McLafferty +1 (ML+1) rearrangement involving the 2-methoxyethyl moiety. The formation of ion the m/z 106 in the ESI-CID spectrum, according to the simulations, results from the rearrangement involving a transfer of one dimethylamino group to the phosphorus atom, a mechanism that would be difficult to identify without employing theoretical methods.

Nematicidal Coumarins from Cnidium monnieri Fruits and Angelica dahurica Roots and Their Physiological Effect on Pine Wood Nematode (Bursaphelenchus xylophilus).

Pine wood nematode (PWN), Bursaphelenchus xylophilus, is a major pathogen of pine wilt disease (PWD), which is a devastating disease affecting pine trees. Eco-friendly plant-derived nematicides against PWN have been considered as promising alternatives to control PWD. In this study, the ethyl acetate extracts of Cnidium monnieri fruits and Angelica dahurica roots were confirmed to have significant nematicidal activity against PWN. Through bioassay-guided fractionations, eight nematicidal coumarins against PWN were separately isolated from the ethyl acetate extracts of C. monnieri fruits and A. dahurica roots, and they were identified to be osthol (Compound 1), xanthotoxin (Compound 2), cindimine (Compound 3), isopimpinellin (Compound 4), marmesin (Compound 5), isoimperatorin (Compound 6), imperatorin (Compound 7), and bergapten (Compound 8) by mass and nuclear magnetic resonance (NMR) spectral data analysis. Coumarins 1-8 were all determined to have inhibitory effects on the egg hatching, feeding ability, and reproduction of PWN. Moreover, all eight nematicidal coumarins could inhibit the acetylcholinesterase (AChE) and Ca2+ ATPase of PWN. Cindimine 3 from C. monnieri fruits showed the strongest nematicidal activity against PWN, with an LC50 value of 64 μM at 72 h, and the highest inhibitory effect on PWN vitality. In addition, bioassays on PWN pathogenicity demonstrated that the eight nematicidal coumarins could effectively relieve the wilt symptoms of black pine seedlings infected by PWN. The research identified several potent botanical nematicidal coumarins for use against PWN, which could contribute to the development of greener nematicides for PWD control.

Isolation, Characterization and Antibacterial Activity of 4-Allylbenzene-1,2-diol from Piper austrosinense.

Isolation for antibacterial compounds from natural plants is a promising approach to develop new pesticides. In this study, two compounds were obtained from the Chinese endemic plant Piper austrosinense using bioassay-guided fractionation. Based on analyses of 1H-NMR, 13C-NMR, and mass spectral data, the isolated compounds were identified as 4-allylbenzene-1,2-diol and (S)-4-allyl-5-(1-(3,4-dihydroxyphenyl)allyl)benzene-1,2-diol. 4-Allylbenzene-1,2-diol was shown to have strong antibacterial activity against four plant pathogens, including Xanthomonas oryzae pathovar oryzae (Xoo), X. axonopodis pv. citri (Xac), X. oryzae pv. oryzicola (Xoc) and X. campestris pv. mangiferaeindicae (Xcm). Further bioassay results exhibited that 4-allylbenzene-1,2-diol had a broad antibacterial spectrum, including Xoo, Xac, Xoc, Xcm, X. fragariae (Xf), X. campestris pv. campestris (Xcc), Pectobacterium carotovorum subspecies brasiliense (Pcb) and P. carotovorum subsp. carotovorum (Pcc), with minimum inhibitory concentration (MIC) values ranging from 333.75 to 1335 μmol/L. The pot experiment showed that 4-allylbenzene-1,2-diol exerted an excellent protective effect against Xoo, with a controlled efficacy reaching 72.73% at 4 MIC, which was superior to the positive control kasugamycin (53.03%) at 4 MIC. Further results demonstrated that the 4-allylbenzene-1,2-diol damaged the integrity of the cell membrane and increased cell membrane permeability. In addition, 4-allylbenzene-1,2-diol also prevented the pathogenicity-related biofilm formation in Xoo, thus limiting the movement of Xoo and reducing the production of extracellular polysaccharides (EPS) in Xoo. These findings suggest the value of 4-allylbenzene-1,2-diol and P. austrosinense could be as promising resources for developing novel antibacterial agents.

New 2‐Phenylquinoline‐Based Bis‐Methoxymethyl‐1,2,3‐Triazoles as Potential Antimicrobial Agents: Synthesis and Molecular Docking Studies against COVID‐19

AbstractSynthesis of novel 2‐phenylqinoline conjugated bis‐triazole analogues 8(a–n) demonstrated by a series of reactions concerning Vilsmeier‐Haack reaction, Suzuki‐Miyaura cross coupling, reduction of carbonyl groups, and click reaction. The structure of final compounds predicted based on IR, 1H, 13C NMR and Mass spectral data analysis. The title compounds were screened for their in vitro antimicrobial activities against two‐gram positive (S. aureus and S. pyogens) and two‐gram negative (P. aeruginosa and E. coli) bacteria, and two fungal strains (S. rolfs and F. ricini) by employing Amoxicillin and Bavistin as standard drugs, respectively. The compound containing 3‐chlorophenyl, 4‐(trifluoromethyl)phenyl, 3,4‐dimethylphenyl and 3‐fluoro‐4‐chlorophenyl residues, indicated promising antibacterial activity and the best antifungal activity was reported for compounds containing 3‐chlorophenyl, 4‐methoxyphenyl and 4‐(trifluoromethyl)phenyl residues. Further, Insilco screening of these compounds against COVID‐19 main protease of corona virus had displayed good docking scores and binding interactions in its active site pocket.

Synthesis, Characterization, and Evaluation of Antioxidant Activities of 2-(1- (Substituted phenyl)Ethylidene)-1-(4,6-dimethylpyrimidin-2-yl)Hydrazines

Background: Pyrimidine and hydrazones are well known for their therapeutic applications. Objective: To investigate the antioxidant activities of compounds having pyrimidine and hydrazone motifs in hope of finding molecules with robust antioxidant activities Methods: Hydrazones were obtained by condensing pyrimidine hydrazine with aromatic ketones. The structures of these compounds were established on the basis of NMR, FTIR and mass spectral data analysis. Results: All compounds were assessed for their antioxidant potential against DPPH, hydrogen peroxide, nitric oxide and superoxide free radical Conclusion: A series of twelve 2-(1-(substituted phenyl)ethylidene)-1-(4,6-dimethylpyrimidin-2- yl)hydrazines was synthesized and compounds 6d, 6e, 6h, and 6j found to have good antioxidant activities.

Probe-based mass spectrometry approaches for single-cell and single-organelle measurements.

Exploring the chemical content of individual cells not only reveals underlying cell-to-cell chemical heterogeneity but is also a key component in understanding how cells combine to form emergent properties of cellular networks and tissues. Recent technological advances in many analytical techniques including mass spectrometry (MS) have improved instrumental limits of detection and laser/ion probe dimensions, allowing the analysis of micron and submicron sized areas. In the case of MS, these improvements combined with MS's broad analyte detection capabilities have enabled the rise of single-cell and single-organelle chemical characterization. As the chemical coverage and throughput of single-cell measurements increase, more advanced statistical and data analysis methods have aided in data visualization and interpretation. This review focuses on secondary ion MS and matrix-assisted laser desorption/ionization MS approaches for single-cell and single-organelle characterization, which is followed by advances in mass spectral data visualization and analysis.

Instrument-independent chemometric models for rapid, calibration-free NPS isomer differentiation from mass spectral GC-MS data

Chemometric analysis of mass spectral data for the purpose of differentiating positional isomers of novel psychoactive substances has seen a substantial increase in popularity in recent years. However, the process of generating a large and robust dataset for chemometric isomer identification is time consuming and impractical for forensic laboratories. To begin to address this problem, three sets of ortho/meta/para positional ring isomers (fluoroamphetamine (FA), fluoromethamphetamine (FMA), and methylmethcathinone (MMC)) were analyzed using multiple GC-MS instruments at three distinct laboratories. A diverse assortment of instrument manufacturers, model types, and parameters was utilized in order to incorporate substantial instrumental variation. The dataset was randomly split into 70% training and 30% validation sets, stratified by instrument. Following an approach based on Design of Experiments, the validation set was used to optimize the preprocessing steps performed prior to Linear Discriminant Analysis. Using the optimized model, a minimum m/z fragment threshold was determined to allow analysts to assess whether an unknown spectrum is of sufficient abundance and quality to be compared to the model. To assess the robustness of the models, a test set was developed utilizing two instruments from a fourth laboratory that was not involved in the generation of the primary dataset in addition to spectra from widely used mass spectral libraries. Of the spectra that reached the threshold, the classification accuracy was 100% for all three isomer types. Only two of the test and validation spectra that did not reach the threshold were misclassified. The results indicate that forensic illicit drug experts world-wide can use these models for robust NPS isomer identification on the basis of preprocessed mass spectral data without the need for acquiring reference drug standards and creating instrument specific GC-MS reference datasets. The continued robustness of the models could be ensured through international collaboration to collect data that captures all potential GC-MS instrumental variation encountered in forensic illicit drug analysis laboratories. This would allow every forensic institute to confidently assign isomeric structures without the need for additional chemical analysis.

The isotope distribution: A rose with thorns.

The isotope distribution, which reflects the number and probabilities of occurrence of different isotopologues of a molecule, can be theoretically calculated. With the current generation of (ultra)-high-resolution mass spectrometers, the isotope distribution of molecules can be measured with high sensitivity, resolution, and mass accuracy. However, the observed isotope distribution can differ substantially from the expected isotope distribution. Although differences between the observed and expected isotope distribution can complicate the analysis and interpretation of mass spectral data, they can be helpful in a number of specific applications. These applications include, yet are not limited to, the identification of peptides in proteomics, elucidation of the elemental composition of small organic molecules and metabolites, as well as wading through peaks in mass spectra of complex bioorganic mixtures such as petroleum and humus. In this review, we give a nonexhaustive overview of factors that have an impact on the observed isotope distribution, such as elemental isotope deviations, ion sampling, ion interactions, electronic noise and dephasing, centroiding, and apodization. These factors occur at different stages of obtaining the isotope distribution: during the collection of the sample, during the ionization and intake of a molecule in a mass spectrometer, during the mass separation and detection of ionized molecules, and during signal processing.

Unnatural tetradeoxy echinocandins produced by gene cluster design and heterologous expression.

The hydroxyl groups in the amino acid residues of echinocandin B were related to the biological activity, the instability, and the drug resistance. The modification of hydroxyl groups was expected to obtain the new lead compounds for next generation of echinocandin drug development. In this work one method for heterologous production of the tetradeoxy echinocandin was achieved. A reconstructed biosynthetic gene cluster for tetradeoxy echinocandins composed of ecdA/I/K and htyE was designed and successfully hetero-expressed in Aspergillus nidulans. The target product of echinocandin E (1) together with one unexpected derivative echinocandin F (2), were isolated from the fermentation culture of engineered strain. Both of compounds were unreported echinocandin derivatives and the structures were identified on the basis of mass and NMR spectral data analysis. Compared with echinocandin B, echinocandin E demonstrated superior stability and comparable antifungal activity.

Pharmacokinetic Study of Vadadustat and High-Resolution Mass Spectrometric Characterization of its Novel Metabolites in Equines for the Purpose of Doping Control.

Vadadustat, a hypoxia-inducible factor prolyl hydroxylase (HIF-PHD) inhibitor, is a substance which carries a lifetime ban in both horse racing and equestrian competition. A comprehensive metabolic study of vadadustat in horses has not been previously reported. Metabolism and elimination profiles of vadadustat in equine plasma and urine were studied for the purpose of doping control. A nasoesophageal administration of vadadustat (3 g/day for 3 days) was conducted on three thoroughbred mares. Potential metabolites were comprehensively detected by differential analysis of full-scan mass spectral data obtained from both in vitro studies with liver homogenates and post-administration samples using liquid chromatography high-resolution mass spectrometry. The identities of metabolites were further substantiated by product ion scans. Quantification methods were developed and validated for the establishment of the excretion profiles of the total vadadustat (free and conjugates) in plasma and urine. A total of 23 in vivo and 14 in vitro metabolites (12 in common) were identified after comprehensive analysis. We found that vadadustat was mainly excreted into urine as the parent drug together with some minor conjugated metabolites. The elimination profiles of total vadadustat in post-administration plasma and urine were successfully established by using quantification methods equipped with alkaline hydrolysis for cleavage of conjugates such as methylated vadadustat, vadadustat glucuronide, and vadadustat glucoside. Based on our study, for effective control of the misuse or abuse of vadadustat in horses, total vadadustat could successfully be detected for up to two weeks after administration in plasma and urine.

Study of biophysical properties, synthesis and biological evaluations of newer thiazolidine-2,4-dione conjugates

Thiazolidine-2,4-dione and its derivatives are acting as antimicrobial and antitubercular agents. Computational approach 2D-QSAR is used for prediction of antitubercular activity of the synthetic derivatives. 2D-QSAR generated model using PLSR method which predicted the statistically significant r 2 = 0.3333, q 2 = 0.4000, pred_r 2 = -1.9753 and F test = 3.0000. 2D-QSAR generated equation of pMICs is denoted the antitubercular activity correlated with thermodynamic descriptor T_2_2_O. Pharmacokinetic properties absorption, distribution, metabolism, excretion are also predicted which are useful for design the derivatives. A designed derivatives of ( Z )-2-(5-substituted-2,4-dioxothiazolidin-3-yl)- N -(4-methoxy-6-methyl-1,3,5-triazin-2-yl)acetamide (C 1 -C 10 ) are synthesized and spectrally characterized using IR, 1 H NMR, 13 C NMR and mass spectral data analysis as well as biologically evaluated against antitubercular and antimicrobial activities. From the biologically evaluated derivatives, compounds C 1 and C 4 were found to be active against the different antimicrobial species. Compounds C 7 and C 10 are more progressive than others against antitubercular species.

Identification of potential plasma protein biomarkers for feline pancreatic carcinoma by liquid chromatography tandem mass spectrometry.

In both humans and cats, pancreatic carcinoma is an aggressive cancer with a grave prognosis. Proteomics techniques have successfully identified several blood-based biomarkers of human pancreatic neoplasia. Thus, this study aims to investigate whether similar biomarkers can be identified in the plasma of cats with FePAC by using liquid chromatography tandem mass spectrometry (LC-MS/MS). To facilitate evaluation of the low abundance plasma proteome, a human-based immunodepletion device (MARS-2) was first validated for use with feline plasma. Marked reduction and/or complete removal of albumin and immunoglobulins was confirmed by analysis of electrophoretograms and mass spectral data. Subsequently, plasma collected from 9 cats with pancreatic carcinoma (FePAC), 10 cats with symptomatic pancreatitis, and 10 healthy control cats was immunodepleted and subjected to LC-MS/MS. Thirty-seven plasma proteins were found to be differentially expressed (p < .05 in one-way ANOVA, FC >2 in fold change analysis). Among these proteins, ETS variant transcription factor 4 (p < .05) was overexpressed, while gelsolin (p < .01), tryptophan 2,3-dioxygenase (p < .05), serpin family F member 1 (p < .01), apolipoprotein A-IV (p < .01) and phosphatidylinositol-glycan-specific phospholipase D (p < .05) were down-regulated in cats with FePAC. Further studies on these potential biomarkers are needed to investigate their diagnostic value.

Prato cheese with addition of Lactobacillus helveticus: Effect of culture preparation on peptide profile

This study evaluated the effect of the activation of Lactobacillus helveticus LH-B02 (40°C/18h), before its addition to Prato cheese manufacturing vat as an adjunct culture, on the cheese peptide profile. 62 peaks were detected in the cheese's peptide extracts by matrix-assisted laser ionization mass spectrometry (MALDI-MS) and the chemometric analysis of mass spectral data revealed that the addition of the adjunct culture to the cheese vat, either previously activated or not, modified the peptide profile of Prato cheese after 30 days of ripening. In general, the adjunct culture addition favored the release of β-casein derived peptides, particularly from β-casein C-terminal fraction, while reduced the relative intensity of αs1-casein derived peptides. The activation of the adjunct culture before its addition to the cheese vat resulted in higher differences in the peptides relative intensities than the direct addition of the adjunct culture without prior activation, when compared to the control Prato cheese.

Exploring Verrucosidin Derivatives with Glucose-Uptake-Stimulatory Activity from Penicillium cellarum Using MS/MS-Based Molecular Networking.

Under the guidance of LC-MS/MS-based molecular networking, seven new verrucosidin derivatives, penicicellarusins A-G (3–9), were isolated together with three known analogues from the fungus Penicillium cellarum. The structures of the new compounds were determined by a combination of NMR, mass and electronic circular dichroism spectral data analysis. The absolute configuration of penicyrone A (10) was corrected based on X-ray diffraction analyses. Bioactivity screening indicated that compounds 1, 2, and 4 showed much stronger promising hypoglycemic activity than the positive drug (rosiglitazone) in the range of 25–100 μM, which represents a potential new class of hypoglycemic agents. Preliminary structure-activity relationship analysis indicates that the formation of epoxy ring on C6-C7 in the structures is important for the glucose uptake-stimulating activity. The gene cluster for the biosynthesis of 1–12 is identified by sequencing the genome of P. cellarum and similarity analysis with the gene cluster of verrucosidins in P. polonicum.

Eupatorin 3′-O-glucopyranoside, a trimethoxyflavonoid glucoside from the aerial parts of Salvia mellifera

Salvia mellifera, native to California, Baja California, and Mexico, is a medicinal herb traditionally used to relieve pain, body aches, including chronic pain. A detailed phytochemical investigation of aerial parts of S. mellifera was accomplished to find species-specific markers and to differentiate the closely related, often (un)intentionally substituted with S. apiana. A total of 22 metabolites, including flavonoids (1–14), triterpenoids (15–18), diterpenoids (19–21), and phenylpropanoid (22), were isolated and characterized thoroughly. Among the isolates, eupatorin 3′-O-glucopyranoside (1) was identified as undescribed phytochemical and detailed structure elucidation was achieved through extensive NMR and mass spectral data analysis.