Chemical Constituents of the Methanolic Extract of Leaves of Leiothrix spiralis Ruhland and Their Antimicrobial Activity

Abstract

Chemical fractionation of the methanolic extract of leaves of Leiothrix spiralis Ruhland afforded the flavonoids luteolin-6-C-β-D-glucopyranoside (1), 7-methoxyluteolin-6-C-β-D-glucopyranoside (2), 7-methoxyluteolin-8-C-β-D-glucopyranoside (3), 4′-methoxyluteolin-6-C-β-D-glucopyranoside (4), and 6-hydroxy-7-methoxyluteolin (5), and the xanthones 8-carboxymethyl-1,5,6-trihydroxy-3-methoxyxanthone (6), 8-carboxy-methyl-1,3,5,6-tetrahydroxyxanthone (7). Methanolic extract, fractions, and isolated compounds of the leaves of L. spiralis were assayed against Gram-positive (Staphylococcus aureus, Bacillus subtilis and Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Salmonella setubal and Helicobacter pylori) and fungi (the yeasts Candida albicans, C. tropicalis, C. krusei and C. parapsilosis). We observed the best minimum inhibitory concentration values for the methanolic extract against Candida parapsilosis, for the fraction 5 + 6 against Gram-negative bacteria E. coli and P. aeruginosa, and compound 7 against all tested Candida strains. The methanolic extract contents suggest that this species may be a promising source of compounds to produce natural phytomedicines.

Bioprospecting of Ocotea minarum (Laurales: Lauraceae) by ethanolic extract in control of strains of gender Candida

“…Based on the criteria of Araújo [5], the evaluation of the antifungal activity of ethanol extract of Ocotea minarum , observed effective antifungal activity against the strains of Candida tropicalis in a concentration of 64 mg / mL and Candida krusei concentration of 1024 mg / ml. Strains of Candida albicans and Candida glabrata were not growth inhibited by the extract.…”

Antimicrobial Activity of Paepalanthus planifolius and its Major Components against Selected Human Pathogens

“…For the determination of minimal bactericidal concentration (MBC), a portion from each well that showed antibacterial activity was plated on Muller-Hinton agar and incubated at 37 °C for 24 h. The lowest concentration that showed no bacteria growth in the subcultures was used as the MBC. 6 Antifungal activity and minimum fungicidal concentration (MFC)…”

“…4,5 Although Eriocaulaceae are used in the manufacture of ornamental products, literature reports studies with Eriocaulaceae species that have promising antimicrobial activity. 6,7 Other studies have previously demonstrated the importance of extract and isolated substances in the Eriocaulaceae family, mainly because they present a great biological potential, such as the already identified antioxidant activities, 8,9 cytotoxic, 10,11 antiulcerogenic, 12 antibacterial and vulvovaginal candidiasis treatment. 13,14 Thus, in search of new biological compounds we described the antimicrobial activity of ethyl acetate (EtOAc) extract of capitula from Paepalanthus planifolius and its phytochemical characterization.…”

Antimicrobial Screening of Endophytic Fungi Isolated from the Aerial Parts of Paepalanthus chiquitensis (Eriocaulaceae) Led to the Isolation of Secondary Metabolites Produced by Fusarium fujikuroi

“…Supplementary information ( 1 H and 13 C NMR and MS spectra for the isolated compounds 1-4) is available free of charge at http://jbcs.sbq.org.br as PDF file. …”

“…For the determination of minimum bactericidal concentration (MBC), a portion from each well that showed antibacterial activity was plated on Muller-Hinton agar and incubated at 37 °C for 24 h. The lowest concentration that showed no bacteria growth in the subcultures was used as the MBC. 13 Antifungal activity and minimum fungicidal concentration (MFC)…”