Metabolomic kinetics investigation of Camellia sinensis kombucha using mass spectrometry and bioinformatics approaches.

Kombucha is created through the fermentation of Camellia sinensis tea leaves, along with sucrose, utilizing a symbiotic consortium of bacteria and yeast cultures. Nonetheless, there exists a dearth of comprehensive information regarding the spectrum of metabolites that constitute this beverage. To explore this intricate system, metabolomics was used to investigate fermentation kinetics of Kombucha. For that, an experimental framework was devised to assess the impact of varying sucrose concentrations and fermentation temperatures over a ten-day period of kombucha fermentation. Following fermentation, samples were analyzed using an LC-QTOF-MS system and a distinctive metabolomic profile was observed. Principal component analysis was used to discriminate between metabolite profiles. Moreover, the identified compounds were subjected to classification using the GNPS platform. The findings underscore notable differences in compound class concentrations attributable to distinct fermentation conditions. Furthermore, distinct metabolic pathways were identified, specially some related to the biotransformation of flavonoids. This comprehensive investigation offers valuable insights into the pivotal role of SCOBY in driving metabolite production and underscores the potential bioactivity harbored within Kombucha.

Hirsutinolide- and Cadinanolide-type Sesquiterpene Lactones from Lessingianthus rubricaulis (Vernonieae, Asteraceae).

Sesquiterpene lactones are an important class of secondary metabolites frequently isolated from Lessingianthus genus that present a variety of biological properties, such as antimalarial, anti-inflammatory, antileishmanial, antitrypanosomal and anticancer. The limited phytochemical studies and the importance of this class of compounds isolated from Lessingianthus led us to study this genus. In this work, we focused on the phytochemical investigation and dereplication based on UHPLC-HRMS/MS and molecular networking of L. rubricaulis. Chemical investigation resulted in the isolation of several hirsutinolide-type sesquiterpene lactones including a new hirsutinolide derivative, 8,10α-hydroxy-1,13-bis-O-methylhirsutinolide, besides a cadinanolide and flavonoids. The dereplication study resulted in the identification of three known flavonoids, six known hirsutinolides and two known cadinanolides. Moreover, a fragmentation pathway for cadinanolide-type sesquiterpene lactones was proposed. These results contribute to chemotaxonomic studies and demonstrates the potential of Lessingianthus genus.

Bioactive compounds by UHPLC-MS/MS and molecular networking from Myrceugenia foveolata.

Myrceugenia foveolata, commonly known as 'guamirim', was analysed using UHPLC-MS/MS and molecular networking. Hydroalcoholic extracts of leaves and stem bark were obtained using ethanol:water (70:30) as solvent. Chemical composition of the extracts was identified using UHPLC-MS/MS and tested for antioxidant activity and growth inhibition against E. coli, S. aureus, L. monocytogenes and S. enterica. Ten compounds were tentatively identified in the extracts including myricitrin, quercitrin, and betulin (in leave extracts), and avicularin, kaemferol-3-O-arabinopyroniside, 2"-O-galloylquercitrin and the acid triterpenes ursolic, sumaresinolic, asiatic and maslinic (in both extracts). Both extracts showed similar antioxidant activities, phenolic composition, and growth inhibition. The most pronounced response was observed against L. monocytogenes, with a growth inhibition rate of 73% to leaves extract and 65% do stem bark extract.

Socio-historical representations of a disease: a study of posters from campaigns against Hansen's disease during the second half of the twentieth century. / Representações sócio-históricas de uma doença: um estudo sobre cartazes de campanhas para o combate à hanseníase na segunda metade do século XX.

This article analyzes the use of iconographic sources in the context of educational campaigns to combat Hansen's disease from a socio-historical perspective at four points in time: the 1950s, 1960s, 1980s, and 1990s. Four posters are analyzed to identify the elements (textual, visual or graphic) used to develop discourse on this disease and those it affected and transformations and permanences in this discourse, as well as to verify how they became part of a narrative of institutional memory linked to public health in the state of São Paulo. These were produced by various public health institutions and are part of the Health Campaign Poster Collection held by the Emílio Ribas Public Health Museum.

Este artigo analisa o uso de fontes iconográficas no contexto das campanhas educativas para o combate à hanseníase numa perspectiva sócio-histórica em quatro momentos: décadas de 1950, 1960, 1980 e 1990. São analisados quatro cartazes para identificar os elementos (textuais, visuais ou gráficos) utilizados para elaborar um discurso sobre a doença e os doentes; suas transformações discursivas e permanências, além de verificar como se tornaram parte de uma narrativa de memória institucional ligada à saúde pública paulista. As fontes estudadas fazem parte da coleção Cartazes de Campanhas de Saúde, cujos itens foram produzidos por diversas instituições ligadas à saúde pública e integram o acervo do Museu de Saúde Pública Emílio Ribas.

Representações sócio-históricas de uma doença: um estudo sobre cartazes de campanhas para o combate à hanseníase na segunda metade do século XX / Socio-historical representations of a disease: a study of posters from campaigns against Hansen's disease during the second half of the twentieth century

Resumo Este artigo analisa o uso de fontes iconográficas no contexto das campanhas educativas para o combate à hanseníase numa perspectiva sócio-histórica em quatro momentos: décadas de 1950, 1960, 1980 e 1990. São analisados quatro cartazes para identificar os elementos (textuais, visuais ou gráficos) utilizados para elaborar um discurso sobre a doença e os doentes; suas transformações discursivas e permanências, além de verificar como se tornaram parte de uma narrativa de memória institucional ligada à saúde pública paulista. As fontes estudadas fazem parte da coleção Cartazes de Campanhas de Saúde, cujos itens foram produzidos por diversas instituições ligadas à saúde pública e integram o acervo do Museu de Saúde Pública Emílio Ribas.

Abstract This article analyzes the use of iconographic sources in the context of educational campaigns to combat Hansen's disease from a socio-historical perspective at four points in time: the 1950s, 1960s, 1980s, and 1990s. Four posters are analyzed to identify the elements (textual, visual or graphic) used to develop discourse on this disease and those it affected and transformations and permanences in this discourse, as well as to verify how they became part of a narrative of institutional memory linked to public health in the state of São Paulo. These were produced by various public health institutions and are part of the Health Campaign Poster Collection held by the Emílio Ribas Public Health Museum.

Improved Sustainability in Wine Industry Byproducts: A Scale-up and Economical Feasibility Study for High-Value Compounds Extraction Using Modified SC-CO2.

The objective of the present work was to optimize the operating conditions (P, T cosolvent %) and to study the scale-up and the feasibility of the supercritical fluid extraction (SFE) process for polyphenols from grape pomace, the main solid byproduct of the wine industry. Pilot-scale equipment (1 L extraction vessel) was used to study the scale-up prediction for extraction vessels of 50, 100, 500, and 1000 L capacity. The adopted scale-up criteria consisted of maintaining and keeping constant the solvent mass-to-feed mass ratio and the bed geometry dimension. The results indicated an excellent predictive level obtained by Sovová's model and success of the adopted scale-up criteria. At industrial scale, yields were close to 2.3 gGAE/100 gDM, a value obtained using the pilot-scale equipment. High concentrations of high-added-value phenols such as cis-resveratrol glucoside, cis-coutaric acid, trans-p-coumaric acid, quercetin, and proanthocyanidins were found in the extract. An economic evaluation of the process indicated the feasibility of an industrial SFE plant with a capacity of 500 L for producing in 60 min an extract with an expected phenolics' concentration of approximately 133 gGAE/kg extract at an estimated 67€ /kgextract cost of manufacturing. Notably, all values are better than those currently reported in the literature.

Molecular network-guided chemical profile and mass spectrometry, volatile compounds, and antimicrobial activity of Scaptotrigona depilis propolis.

RATIONALE: Propolis has a great diversity in its composition due to numerous factors; therefore, each study is an important contribution to the knoFwledge of its composition and biological action. The objective of this study was to determine the chemical profile and biological activity of propolis produced by Scaptotrigona depilis. METHODS: Extracts with 70% ethanol (EPE70) and with cereal alcohol (CAPE) were elaborated, and then characterized using UHPLC-ESI(+)-MS/MS. Volatile compounds were extracted and then characterized using gas chromatography mass spectrometry (GC-MS). In addition, antimicrobial activities were verified against resistant strains. RESULTS: The volatile compounds of propolis predominantly consist of sesquiterpenes. Using the exploratory metabolomic approach, compounds of different classes were putatively identified in the ethanolic extracts, of which the most representative were terpenes, and some of the sesquiterpenes identified among the volatiles were also detected. The extracts were shown to be active against Escherichia coli and Staphylococcus aureus bacteria with a minimum inhibitory concentration (MIC) of 0.5 and 1.0 mg mL-1 , respectively. CONCLUSIONS: The molecular network approach proved to be determining the chemical profile of S. depilis propolis rapidly and accurately, and led to the identification of lipophilic compounds. The identification of compounds using GC-MS and UHPLC-ESI(+)-MS/MS is complementary and useful for the characterization of propolis.

Ultra-high-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight mass spectrometry and molecular networking analysis to investigate the chemodiversity of bioactive extracts of Annona jahnii Saff. fungi from the Brazilian Amazon.

RATIONALE: Annona species are of interest for the isolation of bioactive molecules; however, studies of Annona jahnii Saff. are limited. The exploration of bioactive metabolites of endophytes isolated from this species is unprecedented and allows the preservation of the host plant, in addition to enabling the discovery of compounds with promising biological activities. METHODS: Ethyl acetate extracts from the cultured media of five fungi were obtained. The antioxidant capacity of the extracts was measured using the 1,1-diphenyl-2-picrylhydrazyl free radical method. Antimicrobial activity was determined using the microdilution method in broth in 96-well plates. The exploration of the metabolic profile of the extracts and dereplication of the compounds were performed using ultra-high-performance liquid chromatography/electrospray ionization/tandem mass spectrometry (UHPLC/ESI-MS/MS) combined with analysis using molecular networking (MN). RESULTS: A total of 1818 MS features were detected in the five selected extracts, of which 39 compounds were putatively identified. The secondary metabolites with the highest abundance were alkaloids, naphthopyrons, and cytochalasins. Other secondary metabolites include fumonisins, coumarin, and a meroterpenoid. Most of these compounds are related to specific biological properties such as antioxidant, anti-inflammatory, antimicrobial, antiviral, and antitumor activities. Extracts F398 and F403 showed inhibitory activity of the four pathogens tested. Extracts F475 and F506 did not inhibit the growth of Staphylococcus aureus, and F407 did not inhibit the growth of Escherichia coli in addition to having potent antioxidant activity, with IC50 values of 10 µg/mL or less. CONCLUSIONS: The use of UHPLC/ESI-MS/MS data combined with MN proved useful in the dereplication of bioactive molecules of complex extracts that are still unexplored. These initial investigations should significantly assist in further research and increase the efficiency and speed in the discovery of new sources of secondary metabolites and new natural products.

The relation between columbiform birds (Columba livia) age and gender and infection indices of rhinonyssid and ereynetid mites.

Respiratory systems of birds may be parasitized by rhinonyssid and ereynetid mites, which are commonly found in their nasal cavities. Levels of infection caused by mites in relation to maturity and gender of birds have been poorly investigated. Although Columba livia is the host of both Tinaminyssus and Trispeleognathus species worldwide, there are no data on prevalence and mean intensity of infection by mites in immature and adult males and females. Therefore, this study aims to analyze infections in relation to characteristics of hosts in southern Brazil. In the sample of 160 birds under study, 24.38% were parasitized by rhinonyssid mites (Tinaminyssus melloi and Tinaminyssus columbae) while 5.0% were infested with ereynetid ones (Trispeleognathus striatus). Infections by rhinonyssid mites in immature and adult birds, as well as in male and female ones, were similar and there were no significant differences in prevalence and mean intensity of infection. However, when infections were analyzed separately, prevalence of T. melloi was significantly higher in immature (19.77%) than in adult (6.76%) birds (p = 0.021). Ereynetid mites, which parasitized only males, were more prevalent in adult (9.46%) than in immature (1.16%) birds (p = 0.025). Reproductive and behavioral characteristics of C. livia (e.g., year-round breeding and social behavior) may enable transmission and maintenance of mite populations, since direct contact among hosts and the presence of mites in their nests are considered forms of transmission. Even though information on the life history of mites is important to understand parasite-host relations, there is a gap in the biology of species commonly found in C. livia, which constitutes an area to be explored.

Chemical constituents and dereplication study of Lessingianthus brevifolius (Less.) H.Rob. (Asteraceae) by UHPLC-HRMS and molecular networking.

Chemical investigation of Lessingianthus brevifolius (Less.) H.Rob. aerial parts resulted in the isolation of the hirsutinolide-type sesquiterpene lactones piptocarphol, spicatolide D, piptocarphin D and 8α-acetoxy-10α-hydroxy-13-O-methylhirsutinolide, and also of a cadinanolide identified as 13-O-methylvernojalcanolide 8-O-acetate. Flavonoids, triterpenes and chlorogenic acids were also isolated. In addition, a dereplication study was carried out using UHPLC-HRMS and molecular networking, resulting in the identification of fifteen known compounds, being two sesquiterpene lactones and thirteen flavonoids. Some of the compounds are being described for the first time in L. brevifolius, and also in the Lessingianthus genus.

Soybean Metabolomics Based in Mass Spectrometry: Decoding the Plant's Signaling and Defense Responses under Biotic Stress.

Metabolomics is an omics technology that is extremely valuable to analyze all small-molecule metabolites in organisms. Recent advances in analytical instrumentation, such as mass spectrometry combined with data processing tools, chemometrics, and spectral data libraries, allow plant metabolomics studies to play a fundamental role in the agriculture field and food security. Few studies are found in the literature using the metabolomics approach in soybean plants on biotic stress. In this review, we provide a new perspective highlighting the potential of metabolomics-based mass spectrometry for soybean in response to biotic stress. Furthermore, we highlight the response and adaptation mechanisms of soybean on biotic stress about primary and secondary metabolism. Consequently, we provide subsidies for further studies of the resistance and improvement of the crop.

Untargeted Metabolomics Analysis by UHPLC-MS/MS of Soybean Plant in a Compatible Response to Phakopsora pachyrhizi Infection.

Phakopsora pachyrhizi is a biotrophic fungus, causer of the disease Asian Soybean Rust, a severe crop disease of soybean and one that demands greater investment from producers. Thus, research efforts to control this disease are still needed. We investigated the expression of metabolites in soybean plants presenting a resistant genotype inoculated with P. pachyrhizi through the untargeted metabolomics approach. The analysis was performed in control and inoculated plants with P. pachyrhizi using UHPLC-MS/MS. Principal component analysis (PCA) and the partial least squares discriminant analysis (PLS-DA), was applied to the data analysis. PCA and PLS-DA resulted in a clear separation and classification of groups between control and inoculated plants. The metabolites were putative classified and identified using the Global Natural Products Social Molecular Networking platform in flavonoids, isoflavonoids, lipids, fatty acyls, terpenes, and carboxylic acids. Flavonoids and isoflavonoids were up-regulation, while terpenes were down-regulated in response to the soybean-P. pachyrhizi interaction. Our data provide insights into the potential role of some metabolites as flavonoids and isoflavonoids in the plant resistance to ASR. This information could result in the development of resistant genotypes of soybean to P. pachyrhizi, and effective and specific products against the pathogen.

Reliability and robustness of optimization properties for stabilization of the upright stance as determined using posturography.

Diagnostic value of static posturography depends on its methodological features, measurement properties, and on computational methods that extract meaningful information from the postural sway i.e. the center-of-pressure (CoP) displacements. In this study, we assessed the reliability and robustness of the postural system based on the optimization properties of the CoP signal: descending, local and global stability, and convergence. For the analysis, we used CoP data from 146 participants (104 [71%] female, age 46 ± 23 years, body mass index 23.6 ± 3.4 kg/m2) recorded while standing quietly on a foam surface without visual input. Reliability was estimated using the intraclass correlation coefficient from a single (ICC2,1) and averaged (ICC2,3) measurements. Robustness was assessed through main and interaction effects for the signal duration (60, 30 s), sampling frequency (100, 50 Hz), and lowpass filtering cutoff frequency (10, 5 Hz). The observed reliability depended on the use of average or single measurements as it was excellent for the stability property (ICC2,k ≥ 0.772); excellent-to-acceptable (ICC2,3 ≥ 0.540) or excellent-to-unacceptable (ICC2,1 ≥ 0.281) for the descending property; and excellent-to-unacceptable (ICC2,3 > 0.295; ICC2,1 > 0.122) for the convergence property. Robustness analysis showed large main effects of signal duration (ω2 ≤ 0.834, p < 0.001), sampling frequency (ω2 ≤ 0.526, p < 0.001), and the lowpass filter cutoff frequency (ω2 ≤ 0.523, p < 0.001) on the optimization properties; but all two-way and three-way effects varied from medium to trivial. Reliability is thus excellent to acceptable for deriving the descending, stability, and convergence properties from the average of three measurements. Those optimization properties are robust to the interaction but not the main effects of methodological sources of variation of posturography.

Lower limb muscle fatigability is not associated with changes in movement strategies for balance control in the upright stance.

BACKGROUND: Fatigue is a distressing symptom inversely related to postural stability in adults with neuromuscular and systemic diseases. However, there is no information about the effects of lower limb muscles fatigability on the movement strategies for balance control in the upright standing. METHODS: This study enrolled 41 healthy subjects (female/male: 22/19; age 23 ± 3 years; body mass index 25.4 ± 3.7 kg/m2). Participants underwent posturography and surface electromyography of the gastrocnemius medialis muscle during a sustained, fatiguing voluntary contraction of the gastrocnemius preceded and followed by quiet standing (120 s). Amplitude of electromyograms and fatigability were evaluated using the root mean square (RMS) value and both the RMS and spectral median frequency (fmed) slopes. Balance control was evaluated using the center-of-pressure elliptic area (Area) and average velocity (Vavg). Movement strategies for balance control were evaluated using the number of high-density regions (nHDR) and spatial patterns of the three-dimensional statokinesigram. RESULTS: Mean time to muscle fatigability was 258 ± 190 s. Area and Vavg but not nHDR increased after the fatiguing task. Single-centered spatial patterns were predominant in both tasks (pre-fatigue: n = 22/41; post-fatigue: n = 19/41), with no evidence of an association between the spatial patterns and tasks (γ = 0.237, 95%CI = [-0.338; 0.542]). CONCLUSIONS: Lower limb muscle fatigability increases postural instability, but it is not associated with changes in movement strategies for balance control in the upright stance.

Unraveling Asian Soybean Rust metabolomics using mass spectrometry and Molecular Networking approach.

Asian Soybean Rust (ASR), caused by the biotrophic fungus Phakopsora pachyrhizi, is a devastating disease with an estimated crop yield loss of up to 90%. Yet, there is a nerf of information on the metabolic response of soybean plants to the pathogen Untargeted metabolomics and Global Natural Products Social Molecular Networking platform approach was used to explore soybean metabolome modulation to P. pachyrhizi infection. Soybean plants susceptible to ASR was inoculated with P. pachyrhizi spore suspension and non-inoculated plants were used as controls. Leaves from both groups were collected 14 days post-inoculation and extracted using different extractor solvent mixtures. The extracts were analyzed on an ultra-high performance liquid chromatography system coupled to high-definition electrospray ionization-mass spectrometry. There was a significant production of defense secondary metabolites (phenylpropanoids, terpenoids and flavonoids) when P. pachyrhizi infected soybean plants, such as putatively identified liquiritigenin, coumestrol, formononetin, pisatin, medicarpin, biochanin A, glyoceollidin I, glyoceollidin II, glyoceollin I, glyoceolidin II, glyoceolidin III, glyoceolidin IV, glyoceolidin VI. Primary metabolites (amino acids, peptides and lipids) also were putatively identified. This is the first report using untargeted metabolomics and GNPS-Molecular Networking approach to explore ASR in soybean plants. Our data provide insights into the potential role of some metabolites in the plant resistance to ASR, which could result in the development of resistant genotypes of soybean to P. pachyrhizi, and effective and specific products against the pathogen.

Metabolomics of soybean green stem and foliar retention (GSFR) disease using mass spectrometry and molecular networking.

RATIONALE: The nematode Aphelenchoides besseyi is the causal agent of green stem and foliar retention, a soybean disease recently described in Brazil. This condition can reduce soybean yield by up to 100%. However, little is known about chemical interactions between the plant and pathogen. Therefore, this work aimed to investigate metabolites from healthy soybean roots and from soybean roots that were inoculated with A. besseyi. METHODS: A. besseyi were multiplied in vitro with Fusarium sp. colonies in Petri dishes for 25 days, and were axenically inoculated into hydroponics healthy soybean plants. The metabolites were extracted from the roots of healthy and A. besseyi-infected plants 16 days post-inoculation. These extracts were analyzed using an untargeted metabolomic method with an ultra-high-performance liquid chromatography/electrospray ionization /tandem mass spectrometry (UHPLC/ESI-MS/MS) and molecular networking approach. RESULTS: Roots from infected plants showed morphological alterations such as shrinkage, darkening, and arching. Similarly, they also showed an increased presence of flavonoids, compared with healthy roots. Compounds such as neobavaisoflavone, glycitin, genistin, and genistein were putatively identified and had greater intensity in inoculated roots. These compounds are linked to the defensive mechanisms in plants against nematodes. Moreover, coumaric acid, also exclusively putatively identified in inoculated roots, shows activity related to inhibition of root growth. CONCLUSIONS: Liquid chromatography, mass spectrometry, and molecular networking approaches proved to be a powerful tool for the metabolomic study of GSFR. This study showed metabolomics differences of protective substances in the roots, evidencing a quick response of the plant to the attack of A. besseyi.

[Writing about oneself and a disease: a study on biographical and autobiographical work by survivors of Hansen's disease]. / Escritas de si e de uma doença: um estudo sobre produções de caráter biográfico e autobiográfico de ex-portadores do mal de Hansen.

This article investigates some elements of representation in literary work based on memoirs of people with Hansen's disease (formerly known as leprosy) who lived the confinement forced upon people with this disease in Brazil until the mid-1980s. In addition to the stigma associated with leprosy, this policy traumatized patients, who faced social exclusion and loss of relationships; these experiences yielded autobiographies, biographies, and even romances inspired by their memories of life in isolation. Our objective is to understand, through the study of some of these records, how these people saw themselves and how they viewed the disease and their places of confinement.

Este artigo investiga alguns dos elementos de representação em produções literárias baseadas em memórias de ex-portadores de lepra (atualmente denominada hanseníase) que viveram o regime de isolamento, em vigor no país até meados da década de 1980. Além do estigma de maldição que a lepra já carregava, a medida causou inúmeros traumas àqueles que sofreram a exclusão social e a perda de seus vínculos afetivos. Essas experiências resultaram na escrita de autobiografias, biografias ou, ainda, romances inspirados nas memórias da vida em isolamento. Busca-se, portanto, compreender, a partir do estudo de alguns desses registros, como essas pessoas se viam e como viam a doença e os locais de isolamento.

Escritas de si e de uma doença: um estudo sobre produções de caráter biográfico e autobiográfico de ex-portadores do mal de Hansen / Writing about oneself and a disease: a study on biographical and autobiographical work by survivors of Hansen's disease

Resumo Este artigo investiga alguns dos elementos de representação em produções literárias baseadas em memórias de ex-portadores de lepra (atualmente denominada hanseníase) que viveram o regime de isolamento, em vigor no país até meados da década de 1980. Além do estigma de maldição que a lepra já carregava, a medida causou inúmeros traumas àqueles que sofreram a exclusão social e a perda de seus vínculos afetivos. Essas experiências resultaram na escrita de autobiografias, biografias ou, ainda, romances inspirados nas memórias da vida em isolamento. Busca-se, portanto, compreender, a partir do estudo de alguns desses registros, como essas pessoas se viam e como viam a doença e os locais de isolamento.

Abstract This article investigates some elements of representation in literary work based on memoirs of people with Hansen's disease (formerly known as leprosy) who lived the confinement forced upon people with this disease in Brazil until the mid-1980s. In addition to the stigma associated with leprosy, this policy traumatized patients, who faced social exclusion and loss of relationships; these experiences yielded autobiographies, biographies, and even romances inspired by their memories of life in isolation. Our objective is to understand, through the study of some of these records, how these people saw themselves and how they viewed the disease and their places of confinement.

Rapid discrimination of fungal strains isolated from human skin based on microbial volatile organic profiles.

Studies of the microbiota of human skin have gained attention mainly because of its high complexity. Volatile metabolites that emerge from the microbiota play a significant role in fungus metabolism, acting on fungal development, defense, and protection against stress, communication, and pathogenicity. The present study evaluated volatile organic profiles, based on headspace-solid-phase microextraction-gas chromatography-mass spectrometry. We sought to define the optimal experimental conditions for such identification. Chromatograms from 15 fungi were evaluated and discriminated by principal component analysis. The volatile metabolite profiles that were putatively identified in the present study (e.g 2­isopropyl­5­methyl­cyclohex­3­en­1­one, 3/2­methyl­1­butanol, isopentyl ethanoate, phenyl ethanol) allowed the discrimination of different microorganisms from human skin. The present methodology may be a more rapid way of identifying microorganisms compared with conventional methods of microbiological identification.

Exploring the rumen fluid metabolome using liquid chromatography-high-resolution mass spectrometry and Molecular Networking.

The rumen primary and secondary metabolite content is intimately related to its community of bacteria, protozoa, fungi, archaea and bacteriophages, ingested feed and the host. Despite the myriad of interactions and novel compounds to be discovered, few studies have explored the rumen metabolome. Here, we present the first study using ultra-high performance liquid chromatography tandem mass-spectrometry and Molecular Networking approach, and various extraction methods on the cell-free rumen fluid of a non-lactating Holstein cow. Putative molecules were annotated based on accurate fragmentation matching the Global Natural Products Social Molecular Networking library, public spectral libraries, or annotated manually. The combination of five extraction methods resulted on 1,882 molecular features observed. Liquid-liquid extraction resulted on the highest molecular features abundance, 1,166 (61.96% of total). Sixty-seven compounds were annotated using Global Natural Products Social Molecular Networking library and public libraries, such as hydrocinnamic and azelaic acid, and monensin. Only 3.56% of molecular features (67) observed had positive match with available libraries, which shows the potential of the rumen as reservoir of novel compounds. The use of untargeted metabolomics in this study provided a snapshot of the rumen fluid metabolome. The complexity of the rumen will remain long unknown, but the use of new tools should be encouraged to foster advances on the rumen metabolome.