Melon is a pollinator-dependent crop that relies mainly on bees to set fruits. However, man-selected varieties vary in their attractiveness to flower visitors, and some flower genders and melon types may be less visited than others, harming pollination. We investigated the nectar composition of male, female and hermaphrodite flowers of 270 individuals of five commercial melons Cucumis melo (Cantaloupe, Charentais, Galia, Piel de Sapo, and Yellow), and its role in flower visit by Apis mellifera foragers. We found that melon nectar is composed mainly of sugars and amino acids such as tyrosine, phenylalanine, tryptophan, and flavonoids kaempferol-3-O-neohesperidoside, luteolin hexoside, and kaempferol rhamnoside. But the amount of these chemical compounds varies among the flower genders. We also developed an accurate regression model to predict the number of bee visits to melon flowers based on the nectar composition. Our results indicate that nectar composition plays little role in bee discrimination among flowers of different melon types but is essential to the honeybee choice between flower gender. The amounts of phenylalanine (49.40%) and tryptophan (12.05%) in the nectar are related to bee preference for hermaphrodite flowers. More visits to hermaphrodite flowers contribute to setting and developing well-formed fruits, increasing productivity.

Metabolomics, together with analytical methods and chemometric tools, point to new paths for selecting species that are resistant to pests and diseases. In this work, the forage palm species' metabolomic profile was investigated, and the relation between the chemical composition and resistance to Dactylopius opuntiae (carmine cochineal). The study was performed in cladodes of different non-susceptible cultivars (Nopalea cochenillifera (L.) Salm-Dyck, Opuntia stricta (Haw.), Nopalea cochenillifera and susceptible cultivar (Opuntia ficus-indica (L.) Mill.)). Metabolic profile showed 28 metabolites detected in the four species. From these total, 18 metabolites were annotated using UPLC-QTOF-MSE (ultra-performance liquid chromatography coupled with an electrospray ionization quadrupole time-of-flight mass spectrometry operating in MSE mode). By comparing the chemical profiles of non-susceptible and susceptible species through the application of chemometric tools, it was possible to obtain biomarkers (quercetin-3-O-2',6'-dirhamnosylglucoside, quercetin rhamnosyl dihexoside, and isorhamnetin-3-sophoroside-7-rhamnoside) that may be associated with resistance to carmine cochineal. Metabolomics based on UPLC-QTOF-MSE and chemometric allowed to establish the biomarkers knowledge of the resistance present in forage palm species. These results contribute to developing the initial understanding of flavonoids' role in the defense mechanisms of cactaceans and can be useful for application in breeding programs; it can increase the chances of success in creating new varieties of plants not susceptible to carmine cochineal.

The collection time could be an important target for optimizing technological processes in obtaining essential oils of interest to agribusiness. The objective of this study was to distinguish the time for the collecting of Achillea millefolium L. leaves, which provides the highest yield and quality of the essential oil. Also, identify the type of polyethylene packaging and leaf storage period during the one-year period that would maintain the essential oil characteristics. Gas chromatography-mass spectrometry and chemometric studies were performed into two steps trial to detect changes in chemical profile induced by different conditions. First, an analysis of the leaf collection time was performed using chromatographic data from six different gathering times throughout the day. After determining the best time to collect from the leaves, the essential oil was extracted in five storage periods over a year. The highest oil content was observed in leaves harvested between 11 and 15 h, with a maximum of 39 min after 13 h. Therefore, it is recommended to perform extraction in the early afternoon. There was no significant statistical differentiation related to polyethylene packages. In addition, it is recommended that the essential oil can be stored without significant changes for up to six months.

Agroindustrial residues, such as leaves of fruit plants, can be sources of bioactive molecules, thus adding value to co-products that are rarely explored in agroindustry. In this context, this study aimed to look into the phytochemical profiles in detail and to explore the antitumor potential of S. tuberosa and S. mombin leaves. We observed that, S. tuberosa leaf extract was cytotoxic in both tumor and healthy cells. S. mombin extracts selectively inhibited cell proliferation in the tumor cell line for prostate cancer (PC3) and did not significantly affect healthy cells. The metabolic profiles of the extracts were evaluated by gas chromatography coupled with mass spectrometry and twenty-three metabolites were identified. The correlation of metabolic profiles with cytotoxic tests indicated possible chemical markers that may be responsible for the inhibition of cell proliferation. This study revealed that the unexplored co-products in agroindustry may have great therapeutic potential, and therefore should be screened for biologically active compounds.

The industrial development, urbanization and agriculture play a major role in the degradation of the global environmental. Thus, the wastewater treatments need to be monitored continuously to ensure efficient operation. This manuscript presents an application of 1H nuclear magnetic resonance (NMR) associated with chemometric and quantitative analyses to study the wastewater before and after the sewage treatment plant (STP). The concentration of compounds related to organic matter degradation ranged with treatment and seasonality. Anomalous discharges and the influence of stormwater on the sewage composition were further identified. All the variations indicated that the employed procedure might be useful to enhance the effectiveness of STPs, plan prevention actions for equipment protection and preserve the environment.

A bactéria Xanthomonas axonopodis (Xac) causa uma das mais temidas e incuráveis doenças da citricultura: o cancro cítrico. Para compreender o mecanismo de resposta das laranjeiras quando atacadas pela Xac, folhas e frutos de Citrus sinensis foram diretamente avaliados por espectroscopia de RMN HRMAS (ressonância magnética nuclear de alta resolução com giro no ângulo mágico). Esta técnica permite a análise de amostras sem as laboriosas etapas de pré-tratamento, acessando as informações importantes sobre a sua composição química. As folhas de laranjeira e cascas do fruto investigadas neste estudo demonstraram as alterações bioquímicas causadas pela Xac. Auxiliado pelas análises quimiométricas, os resultados de RMN HRMAS apresentaram alterações relevantes no conteúdo de aminoácidos, carboidratos, ácidos orgânicos e terpenóides.

Xanthomonas axonopodis (Xac) bacterium causes one of the most feared and untreatable diseases in citriculture: citrus canker. To understand the response mechanisms of orange trees when attacked by Xac, leaves and fruits of Citrus sinensis were directly evaluated by HRMAS NMR (high resolution magic angle spinning nuclear magnetic resonance) spectroscopy. This technique allows the analysis of samples without laborious pre-treatments and also allows access to important information about chemical composition of samples. The orange tree leaves and fruit peels investigated in this study demonstrated the biochemical changes caused by Xac. Aided by chemometric analysis, the HRMAS NMR results show relevant changes in amino acids, carbohydrates, organic acids and terpenoids content.

Várias tecnologias para o desenvolvimento de novas cultivares de cana-de-açúcar têm focado, principalmente, no aumento da produtividade e maior resistência à doença. Cultivares de cana-de-açúcar são, geralmente, identificadas pela organografia das folhas e caule, análise de peroxidase e atividade da isoenzima esterase, proteínas solúveis totais e teor de sólidos solúveis. A ressonância magnética nuclear (RMN) associada às análises quimiométricas provou ser uma técnica valiosa para avaliação de plantas. Assim, este trabalho descreve o potencial das análises quimiométricas aplicadas a RMN de ¹H de alta resolução com giro no ângulo mágico (HRMAS) e em solução para investigação de cultivares de cana-de-açúcar. Para esta proposta, folhas de oito diferentes cultivares de cana-de-açúcar foram analisadas por espectroscopia de RMN de ¹H aliada à quimiometria. As técnicas empregadas apresentaram-se como ferramentas úteis para a distinção e classificação das diferentes cultivares, bem como para acessar as diferenças na composição química das cultivares.

Several technologies for the development of new sugarcane cultivars have mainly focused on the increase in productivity and greater disease resistance. Sugarcane cultivars are usually identified by the organography of the leaves and stems, the analysis of peroxidase and esterase isoenzyme activities and the total soluble protein as well as soluble solid content. Nuclear magnetic resonance (NMR) associated with chemometric analysis has proven to be a valuable tool for cultivar assessment. Thus, this article describes the potential of chemometric analysis applied to ¹H high resolution magic angle spinning (HRMAS) and NMR in solution for the investigation of sugarcane cultivars. For this purpose, leaves from eight different cultivars of sugarcane were investigated by ¹H NMR spectroscopy in combination with chemometric analysis. The approach shows to be a useful tool for the distinction and classification of different sugarcane cultivars as well as to access the differences on its chemical composition.

A análise multivariada da composição química dos óleos essenciais das folhas de Eugenia uniflora com diferentes cores de fruto indicou a presença de três grupos de óleos em relação ao biótipo do fruto das amostras. O primeiro grupo incluiu amostras de frutos amarelos, vermelhos escuros e roxos contendo altas percentagens de germacreno B (11,1-30,7%), germacrona (9,8-54%) e atractilona (0-19,9%). No grupo II, com amostras de frutos vermelhos claro, os constituintes majoritários foram o curzereno (42,0-43,2%), germacreno D (8,7-9,0%) e germacreno A (5,9-8,9%), enquanto que o grupo III incluiu amostras com frutos vermelho-alaranjado, caracterizadas por um alto conteúdo de selina-1,3,7(11)-trien-8-ona (40,3-55,4%) e epóxido de selina-1,3,7(11)-trien-8-ona (12,7-24,4%). Os óleos essenciais foram investigados frente ao fungo Paracoccidioides brasiliensis pela técnica de macrodiluição em caldo. O resultado mais significativo foi obtido com o óleo do grupo II, com a forma leveduriforme de P. brasiliensis sendo inibida completamente na concentração de 62,5 µg mL-1.

The multivariate chemical analysis of essential oils of Eugenia uniflora leaves with different fruit colours indicated the presence of three oil clusters regarding sample biotypes. The first cluster included yellowish, dark red and purple fruits with high percentages of germacrene B (11.1-30.7%), germacrone (9.8-54%) and atractylone (0-19.9%). In cluster II, with bright red fruit samples, the major constituents were curzerene (42.0-43.2%), germacrene D (8.7-9.0%) and germacrene A (5.9-8.9%), whereas cluster III included red-orange fruit samples containing high contents of selina-1,3,7(11)-trien-8-one (40.3-55.4%) and selina-1,3,7(11)-trien-8-one epoxide (12.7-24.4%). The clustered oils were investigated against the systemic fungus Paracoccidioides brasiliensis via the broth macrodilution method. The oil from cluster II revealed the most significant result. The yeast form of P. brasiliensis was completely inhibited at a concentration of 62.5 µg mL-1.