GC/MS Analyses of the Essential Oils Obtained from Different Jatropha Species, Their Discrimination Using Chemometric Analysis and Assessment of Their Antibacterial and Anti-Biofilm Activities.

The essential oils of Jatropha intigrimma, J. roseae and J. gossypifolia (Euphorbiaceae) were analyzed employing GC/MS (Gas Chromatography coupled with Mass Spectrometry) analyses. A total of 95 volatile constituents were identified from J. intigrimma, J. gossypifolia and J. roseae essential oils, accounting for 91.61, 90.12, and 86.24%, respectively. Chemometric analysis using principal component analysis (PCA) based on the obtained GC data revealed the formation of three discriminant clusters due to the placement of the three Jatropha species in three different quadrants, highlighting the dissimilarity between them. Heneicosane, phytol, nonacosane, silphiperfol-6-ene, copaborneol, hexatriacontane, octadecamethyl-cyclononasiloxane, 9,12,15-Octadecatrienoic acid, methyl ester and methyl linoleate constitute the key markers for their differentiation. In vitro antibacterial activities of the essential oils were investigated at doses of 10 mg/mL against the Gram-negative anaerobe Escherichia coli using the agar well diffusion method and broth microdilution test. J. gossypifolia essential oil showed the most potent antimicrobial activity, demonstrating the largest inhibition zone (11.90 mm) and the least minimum inhibitory concentration (2.50 mg/mL), followed by the essential oil of J. intigrimma. The essential oils were evaluated for their anti-adhesion properties against the Gram-negative E. coli biofilm using a modified method of biofilm inhibition spectrophotometric assay. J. intigrimma essential oil showed the most potent biofilm inhibitory activity, demonstrating the least minimum biofilm inhibitory concentration (MBIC) of 31.25 µg/mL. In silico molecular docking performed within the active center of E. coli adhesion protein FimH showed that heneicosane, followed by cubebol and methyl linoleate, displayed the best fitting score. Thus, it can be concluded that the essential oils of J. gossypifolia and J. intigrimma leaves represent promising sources for antibacterial drugs with antibiofilm potential.

New γ-pyrone glycoside from Pachira glabra and assessment of its gastroprotective activity using an alcohol-induced gastric ulcer model in rats.

Pachira glabra is a medium sized tree that is famous for its delicious edible seeds and leaves. Phytochemical investigation of Pachira glabra leaf alcohol extract led to the isolation of a new γ-pyrone glycoside, 7-hydroxy maltol-3-O-ß-d-glucoside (HMGlu). In vivo assessment of the gastro-protective activity of HMGlu demonstrated superior gastro-protection at a dose of 100 mg kg-1, close to the value triggered by the standard reference omeprazole drug (evidenced by morphological and histopathological examinations). This was further confirmed by immunohistochemical staining where pretreatment with HMGlu (100 mg kg-1) markedly reduced NFκB, COX-2 and BAX positively-stained cells. Thus, it can be concluded that 7-hydroxy maltol-3-O-ß-d-glucoside can be a new pharmaceutically active agent with promising gastro-protective activity of natural origin.