Antibacterial and Antibiofilm Activity of Flavonoid and Saponin Derivatives from Atriplex tatarica against Pseudomonas aeruginosa.

A new flavonoid glucoside derivative, patuletin 3 -O-(2- O-feruloyl)-ß-d-glucuronopyranosyl-(1→2)-ß-d-glucopyranoside, named atriplexin IV (1), and three new triterpenoid saponin derivatives, two sulfonylated, ß-d-glucopyranosyl-3 -O-(2- O-sulfo-ß-d-galactopyranosyl)-(1→2)-α-l-arabinopyranoside-30-alolean-12-en-28-oate (2), named atriplexogenin I, ß-d-glucopyranosyl-3- O-(2- O-sulfo-ß-d-galactopyranosyl)-(1→2)-α-l-arabinopyranoside)-30-hydroxyolean-12-en-28-oate (3), named atriplexogenin II, and ß-d-glucopyranosyl-3 -O-(ß-d-glucopyranosyl-(1→2)-ß-d-galactopyranosyl-(1→2)-α-l-arabinopyranoside)-30-alolean-12-en-28-oate (4), named atriplexogenin III, were isolated by silica gel column and semipreparative HPLC chromatography from the n-butanol extract of the salt marsh plant Atriplex tatarica. In addition, two known secondary metabolites, patuletin3 -O-ß-d-apiofuranosyl-(1‴→2″)-ß-d-glucopyranoside (5) and patuletin 3 -O-5‴- O-feruloyl-ß-d-apiofuranosyl-(1‴→2″)-ß-d-glucopyranoside (6), were isolated for the first time from A. tatarica. The structures of the isolated compounds were elucidated by 1D and 2D NMR, HRESIMS, IR, and UV data. Antibacterial activity by the microdilution method and antibiofilm activity against P. aeruginosa were assessed. Compound 5 possesses significant antibacterial activity, while the most potent antibiofilm agent is compound 2.

Chemical Composition and Antibacterial Activity of Angelica archangelica Root Essential Oil.

Roots of wild growing Angelica archangelica L. from Mt. Ozren (Serbia) were subjected to hydrodistillation and GC-MS analysis. The roots contained 0.10% of essential oil with a-pinene (29.7%), 8-3-carene (14.2%), and a mixture of P-phellandrene and limonene (13.2%) as main compounds. The modified resazurin microtiter-plate assay was used to evaluate the antibacterial activity of the essential oil against Staphylococcus aureus and Escherichia coli. The minimum inhibitory concentration (MIC) values were 14.2 µL/mL for S. aureus and 28.4 µL/mL for E. coli, while the minimum bactericidal concentrations (MBC) were 56.8 µL/mL and 113.6 µL/mL, respectively. According to the obtained results, the angelica root essential oil can be applied as a natural preservative in food and as a natural antibiotic for the treatment of several infectious diseases caused by these two bacteria.

Phenolic Compounds from Atriplex littoralis and Their Radiation-Mitigating Activity.

From the aerial parts of Atriplex littoralis, three new flavonoid glycosides named atriplexins I-III (1-3), a known flavonoid glycoside, spinacetin 3-O-ß-d-glucopyranoside (4), arbutin (5), and 4-hydroxybenzyl-ß-d-glucopyranoside (6) were isolated. Their structures were elucidated on the basis of detailed spectroscopic analysis, including 1D and 2D NMR (COSY, NOESY, TOCSY, HSQC, HMBC) and HRESITOF MS data. The compounds were tested for in vitro protective effects on chromosome aberrations in peripheral human lymphocytes using a cytochalasin-B-blocked micronucleus (MN) assay in a concentration range of 0.8-7.4 µM of final culture solution. Chromosomal damage was induced by 2 Gy of γ-radiation on binucleated human lymphocytes, and the effects of the compounds were tested 2 to 19 h after irradiation. The frequency of micronuclei (MNi) was scored in binucleated cells, and the nuclear proliferation index was calculated. The highest prevention of in vitro biochemical and cytogenetic damage of human lymphocytes induced by γ-radiation was exhibited by 3 (reduction of MN frequency by 31%), followed by 4 and 6.