Investigating specialized plant metabolites, traditionally referred to as ‘secondary metabolites’ present in leaf extracts of cashew trees (Anacardium occidentale) resistant and susceptible to anthracnose disease was carried out using metabolomics combined with chemometric tools. We used clones of dwarf-cashew with the following variations of characteristics: resistant and healthy (CCP 76, BRS 226, BRS 189), susceptible and healthy (BRS 265), and another clone also susceptible but affected by the disease (BRS 265). The UPLC-QTOF-MSE (ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry) analysis of the leaves of Anacardium clones allowed us to annotate a total of 39 metabolites. The multiple orthogonal partial discriminant analysis of the least-squares (OPLS-DA) allowed twelve metabolites to be potential biomarkers of differentiation among the clones studied. Namely, the triene-(17:3)-anacardic acid found on CCP 76 and BRS 189 clones, respectively, is the main candidate for biomarker of resistance. While catechin, B-type procyanidin isomers, and procyanidin dimer monogallate identified in BRS 265 are significant potential biomarkers of susceptibility.

Crotalaria ochroleuca (Fabaceae) is rich in bioactive compounds used for nematode control. Transformed root culture allows the production of a large amount of hairy root biomass, conditioned by auxin biosynthesis-related genes integrated via the process of Agrobacterium rhizogenes infection, which is known to cause a hairy root phenotype. We transformed A. rhizogenes to increase the biomass of hairy roots and optimized the process of production of bioactive compounds. The transformed nature of hairy roots was confirmed by polymerase chain reaction, which confers kanamycin resistance. The transformed roots were cultured in full-strength in liquid media to realize the growth of hairy roots and the production of bioactive compounds. The transformed roots were grown in a culture medium supplemented with elicitors to produce total phenols, and flavonoids. Chromatographic analysis of transformed roots revealed the presence of flavonoids apigenin-6,8-C-diglucoside and luteolin-6-C-glucoside. The results were obtained by conducting physiological and biochemical studies with the Flavonoids and studying the pathways that led to the production of large amounts of bioactive compounds from the hairy roots of C. ochroleuca. It was observed that the extraction of the compounds significantly affected nematodes and insect larvae, resulting in significantly high levels of economic damage to crops.

Black mold, a disease caused by the fungus Pilgeriella anacardii Arx & Müller, affects cashews (Anacardium occidentale). Some cashew clones are more resistant to the pathogen; however, little is known about the chemical profile responsible for this trait. The investigation of volatile organic compounds (VOCs) from leaves of dwarf cashew clones resistant (BRS 226 and BRS 265) and susceptible (CCP 76 and BRS 189) to the pathogen was carried out. Leaves were collected during the months of disease incidence and decline (March to July 2019, Brazil), and VOCs were analyzed by gas chromatography-mass spectrometry (GC-MS) combined with chemometric tools. The GC-MS analysis tentatively identified 96 compounds. Partial least squares discriminant analysis (PLS-DA), orthogonal partial least squares discriminant analysis (OPLS DA), hierarchical cluster analysis (HCA), and ROC curves analysis were useful in dividing VOCs into distinct resistance and associated chemical susceptibility groups for different clones. The VOCs in the leaves of the resistant clones were identified as alcohols and aldehydes containing six carbons: (E)-hex-2-enal, hex-3-en-1-ol, (Z)-hex-2-en-1-ol, (E)-hex-2-en-1-ol, and hexan-1-ol. Moreover, α-pinene, pseudolimonene, α-phellandrene, β-myrcene, sylvestrene, β-cis-ocimene, methyl salicylate, myrtenol, α-copaene, γ-muurolene, germacrene D, valencene, and germacrene B were also detected in these samples and may be candidate chemical biomarkers for cashew resistance to P. anacardii.

Plant phenolic extracts are widely recognized as an important source of natural antioxidant substances and potential compounds for cosmetic formulations. This study aimed to evaluate the chemical profile, photoprotective and antioxidant activities of stem bark extract of Spondias purpurea L. (ciriguela) and its application in photoprotective formulations. Thirty phenolic constituents were annotated by ultra-performance liquid chromatography coupled with an electrospray ionization quadrupole time-of-flight mass spectrometry in mode negative (UPLC-QTOF-MS2). The stem bark extract antioxidant and chelation potential, expressed in half maximal inhibitory concentration (IC50), showed 6.25 and 352.22 µg mL−1, respectively. The phenolic extract was used as an active ingredient in six sunscreen formulations, with concentrations ranging from 0.2 to 10%. The ultraviolet (UV) protection properties of the formulations were evaluated by sun protection factor (SPF) values obtained in 0.2 mg mL−1 (0.495 to 2.27) and 2.0 mg mL−1 (2.29 to 15.87). The SPF value for the extract (14.37 and 26.16) was high, but there was a reduction in the base formulation. However, these results suggested that the bioactive extracted of stem bark of Spondias purpurea L. has interesting potential to reduce the damage caused by UV radiation and may be utilized as an active ingredient in a sunscreen formulation.

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.

Myracrodruon urundeuva (“aroeira-do-sertão”) is a species threatened with extinction due to anthropogenic exploitation. Phytochemical analysis of bark, branch and leaf extracts revealed the presence of several compounds such as flavonoids, phenols, tannins, quercetin derivatives and anacardic acids. Dereplication methodology was performed to tentatively identify 50 compounds analyzed by ultra-performance liquid chromatography coupled with an electrospray ionization quadrupole time-of-flight mass spectrometry operating in MSE mode (UPLC-QTOF-MSE). The extracts exhibited anti-tumor effect in cancer cells HCT-116 (colorectal), SF-295 (glioblastoma), HL-60 (leukemia), and RAJI (leukemia). Also, these results correlate with the principal component analysis (PCA) data that identified three distinct groups indicating, efficiently, metabolic differences between organs of M. urundeuva. Through discriminatory analysis of the orthogonal partial least squares (OPLS-DA), the variable of importance in the projection (VIP) and S-Plot, we were able to determine 30 potential biomarkers. The fingerprint of hydroethanolic extracts was correlated with the cytotoxicity assay and demonstrated a significant difference in the composition of plant extract.

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.