Antibacterial/Antifungal Activity and Synergistic Interactions between Polyprenols and Other Lipids Isolated from Ginkgo Biloba L. Leaves

Abstract

Polyprenols separated from lipids are promising new components from Ginkgo biloba L. leaves (GBL). In this paper, ginkgo lipids were isolated by extraction with petroleum ether, saponification, and molecular distillation. Eight known compounds: isophytol (1), nerolidol (2), linalool (3), β-sitosterol acetate (4), β-sitosterol (5), stigmasterol (6), ergosterol (7), β-sitosterol-3-O-β-D-glucopyranoside (8) and Ginkgo biloba polyprenols (GBP) were separated from GBL by chromatography and identified mainly by NMR. The separated and identified compounds 1, 2 and 3 are reported here for the first time in GBL. The 3D-DAD-HPLC-chromatogram (190–232 nm) of GBP was recorded. This study provides new evidence as there are no previous reports on antibacterial/antifungal activities and synergistic interactions between GBP and the compounds separated from GBL lipids against Salmonella enterica, Staphylocococus aureus and Aspergillus niger. Nerolidol (2) showed the highest activity among all the tested samples and of all mixture groups tested the GBP with isophytol (1) mixture had the strongest synergistic effect against Salmonella enterica among the three tested strains. A proportion of isophytol and GBP of 38.19%:61.81% (wt/wt) was determined by mixture design as the optimal proportion for the synergistic effect of GBP with isophytol against Salmonella enterica.

Potential of Herbal Drug and Antibiotic Combination Therapy: A New Approach to Treat Multidrug Resistant Bacteria

“…The combinations between various components have been tested for synergy. The FIC of 0.25 showed that GBP with isophytol mixture had the strongest synergistic effect against Salmonella enterica among all the three tested strains [56].…”

Polyprenols ofGinkgo bilobaEnhance Antibacterial Activity of Five Classes of Antibiotics

“…And the fluorescence was collected at 30-second intervals and measured at λ ex = 405 nm and λ em = 418 nm with a Varioskan Flash multimode plate reader (Thermo Fisher Scientific, Finland). The fluorescence is expressed as mean values with standard error of the means (SEM) and analysis of variance (single-factor ANOVA, Tukey's test at 5% probability) [6]. …”

Chemical Composition and Activity of Essential Oils of Carissa macrocarpa (Eckl.) A.DC. Cultivated in Tunisia and Its Anatomical Features

“…Here we reported some of them with the aims of justifying and confirming the antimicrobial activity of the major compounds found in our EOs. Tao et al [34] reported that nerolidol, followed by linalool, separated from Ginkgo biloba L. leaf EO showed the highest activity and inhibited the growth of Salmonella enterica, Staphylocococus aureus and Aspergillus niger. Lang and Buchbauer [31] reviewed that nerolidol could inhibit the Gram-positive bacteria, but did not sufficiently harm the Gram-negative bacteria.…”