Passiflora edulis Sims F. flavicarpa along with several other plants belonging to the genus Passiflora have been reported as sedatives and for treatment or prevention of central disorders. This study evaluated the anxiolytic effect of P. edulis ethanol extract and its fractions (viz. chloroform, ethyl acetate and butanol) using the elevated plus-maze model of anxiety and assessment of γ-aminobutyric acid levels. The results revealed that butanol and chloroform extracts exhibit the strongest effect followed by ethyl acetate suggesting that a combination of different classes of metabolites is likely to mediate for P. edulis anxiolytic effect in these fractions. To further pinpoint bioactive agents in fractions, ultra-performance liquid chromatography (UPLC) coupled to high resolution qTOF-MS was used for secondary metabolite profiling. A total of 65 metabolites were characterized including O-flavonoids, C-flavonoids, cyanogenic glycosides and fatty acids. Harman type alkaloids found in P. incarnata were not detected in P. edulis ethanol extract or any of its fractions suggesting that they do not mediate for its CNS modulating effects. Multivariate data analysis (PCA) was further applied to identify metabolite markers for fractions and revealed that enrichment of C-glycoside type flavonoids in chloroform/ethyl acetate fractions versus the exclusive presence of cyanogenic glycosides in its butanol fraction.

Plant extracts have recently received increased attention as alternative sources of antimicrobial agents in the fight against multidrug-resistant bacteria. Non-targeted metabolomics liquid chromatography-quadrupole time-of-flight tandem mass spectrometry, molecular networking, and chemometrics were used to evaluate the metabolic profiles of red and green leaves of two Brassica juncea (L.) varieties, var. integrifolia (IR and IG) and var. rugosa (RR and RG), as well as to establish a relationship between the elucidated chemical profiles and antivirulence activity. In total, 171 metabolites from different classes were annotated and principal component analysis revealed higher levels of phenolics and glucosinolates in var. integrifolia leaves and color discrimination, whereas fatty acids were enriched in var. rugosa, particularly trihydroxy octadecadienoic acid. All extracts demonstrated significant antibacterial activity against Staphylococcus aureus and Enterococcus faecalis, presenting the IR leaves the highest antihemolytic activity against S. aureus (99 % inhibition), followed by RR (84 %), IG (82 %), and RG (37 %) leaves. Antivirulence of IR leaves was further validated by reduction in alpha-hemolysin gene transcription (∼4-fold). Using various multivariate data analyses, compounds positively correlated to bioactivity, primarily phenolic compounds, glucosinolates, and isothiocyanates, were also identified.

This study comprehensively characterized the metabolite profiles of six lettuce varieties and established the correlation between the elucidated profiles and their antivirulence effects. A total of 195 metabolites were annotated using LC-QTOF-MS/MS metabolomics assisted by molecular networking and integrated with chemometrics. Red varieties (red longifolia and lolla rosa) demonstrated higher chlorogenic and chicoric acids suggesting their antioxidant properties. In parallel, amino acids and disaccharides were enriched in romaine longifolia rationalizing its palatable taste and nutritional potential, while crispa, capitata, and lolla bionda presented a high β-carboline alkaloid content. The antibacterial and antihemolytic potential of all varieties against methicillin-sensitive and methicillin-resistant Staphylococcus aureus was assessed and validated by prominent downregulation of α-hemolysin transcriptional levels in both strains. Moreover, correlation analysis revealed sesquiterpenes, β-carboline alkaloids, amino acids, and oxy-fatty acids as the main bioactives. Results emphasize lettuce significance as a functional food and nutraceutical source, and highlight varieties naturally rich in antibacterial agents to adapt breeding programs.