Gas chromatography-mass spectrometry analysis and antimicrobial, antioxidant and anti-cancer activities of essential oils and extracts of Stachys schtschegleevii plant as biological macromolecules.

This work reports the chemical composition and antimicrobial activity of the essential oil as well as antioxidant and anti-cancer activities of ethyl acetate and aqueous extracts from leaf and stem of Stachys schtschegleevii. The structure of volatile parts and effective phenolic compounds as biological macromolecules as well as biological activity of the Stachys schtschegleevii plant were studied using various methods. Essential oils of stem and leaf were identified by steam distillation method and characterization was performed using a gas chromatography-mass spectrometry (GC-MS) analysis. Anti-microbial activity of extracted macromolecules from essential oils of two ethyl acetate and aqueous parts of stem and leaf were analyzed by minimal inhibition concentration (MIC) method. The crude extracts exhibited no appreciable antioxidant activities, in 2,2-diphenyl-1-picrylhydrazyl (DPPH) test by IC50 317.98 and 328.09 µg/mL for aqueous and ethyl acetate fractions, respectively. But, antioxidant activities for butylated hydroxytoluene (BHT) as a standard antioxidant showed significant results (18.16 µg/mL). Also, it was confirmed that antioxidant activities with the phenolic and flavonoid content of the plant for the aqueous and ethyl acetate elements were obtained 57.73, 59.81 and 21.95, 26.124 µg/mg, respectively. Furthermore, in ß-carotene/linoleic acid assay, inhibition percentages were recorded 71.17 and 96.24 for the aqueous and ethyl acetate elements, respectively. Therefore, ethyl acetate section of the plant showed antioxidant activity more than aqueous part. Hydrogen peroxide scavenging assay evaluated antioxidant activity for aqueous and the ethyl acetate extracts sections as 565 and 560 µg/mL, respectively. Also, power determinations of iron (III) oxide antioxidants from aqueous and ethyl acetate fractions were 6113 and 2.69, respectively. Furthermore, Anti-cancer activity of aqueous and ethyl acetate components evaluated in brine shrimp lethality test with LC50 about 100 and 700 µg/mL for aqueous and ethyl acetate fractions, respectively. The results showed that aqueous section species has a much lower effect than the calculated standard, but ethyl acetate section of the plant sample shows a more favorable effect than the standard. Therefore, the plant screened good antimicrobial, antioxidant and anti-cancer activities for its essential oil and ethyl acetate extract.

Combination of GC/FID/Mass spectrometry fingerprints and multivariate calibration techniques for recognition of antimicrobial constituents of Myrtus communis L. essential oil.

Myrtus communis L. is an aromatic evergreen shrub and its essential oil possesses known powerful antimicrobial activity. However, the contribution of each component of the plant essential oil in observed antimicrobial ability is unclear. In this study, chemical components of the essential oil samples of the plant were identified qualitatively and quantitatively using GC/FID/Mass spectrometry system, antimicrobial activity of these samples against three microbial strains were evaluated and, these two set of data were correlated using chemometrics methods. Three chemometric methods including principal component regression (PCR), partial least squares (PLS) and orthogonal projections to latent structures (OPLS) were applied for the study. These methods showed similar results, but, OPLS was selected as preferred method due to its predictive and interpretational ability, facility, repeatability and low time-consuming. The results showed that α-pinene, 1,8 cineole, ß-pinene and limonene are the highest contributors in antimicrobial properties of M. communis essential oil. Other researches have reported high antimicrobial activities for the plant essential oils rich in these compounds confirming our findings.

Essential oil composition and antioxidant and antimicrobial properties of the aerial parts of Salvia eremophila Boiss. from Iran.

The essential oil composition and in vitro antioxidant and antimicrobial activity of the essential oil and methanol extract of Salvia eremophila were evaluated in this research. GC and GC/MS analysis of the plant essential oil resulted in the identification of 28 compounds representing 99.24% of the oil. Borneol (21.83%), alpha-pinene (18.80%), bornyl acetate (18.68%) and camphene (6.54%) were detected as the major components consisting 65.85% of the oil. The plant essential oil and methanol extract were also subjected to screenings for the evaluation of their antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and beta-carotene-linoleic acid tests. While the plant essential oil showed only weak antioxidant activities, its methanol extract was considerably active in both DPPH (IC(50)=35.19 microg/ml) and beta-carotene-linoleic acid (inhibition percentage: 72.42%) tests. Appreciable total phenolic content (101.25 microg/mg) was also detected for the plant methanol extract as gallic acid equivalent in the Folin-Ciocalteu test. The plant was also screened for its antimicrobial activity and good to moderate inhibitions were recorded for its essential oil and methanol extract against most of the tested microorganisms.

Chemical composition and antioxidant activities of the essential oil and methanol extracts of Psammogeton canescens.

This study is outlined to probe the chemical composition of essential oil and in vitro antioxidant activity of the essential oil and methanol extracts of Psammogeton canescens. The chemical composition of the hydrodistilled essential oil of the aerial parts of P. canescens was analyzed by GC and GC/MS. The main constituents of the oil were found to be beta-bisabolene (33.35%), apiole (28.34%), alpha-pinene (11.86%) and dill apiole (8.17%). Antioxidant activities of the samples were determined by three various testing systems namely DPPH, beta-carotene/linoleic acid, and reducing power assay. In DPPH system, the highest radical-scavenging activity was seen by the polar subfraction of methanol extract (49.5+/-1.21mug/ml). Furthermore, in the second case the inhibition capacity (%) of the polar subfraction (92.40%+/-0.72) found to be the stronger one. However, in the reducing power assay, a reverse activity pattern more than in the first two systems was observed, and the essential oil was stronger radical reducer than was the methanol extract in all of the concentration tested. Our findings demonstrate that the essential oil and methanol extracts of P. canescens possess significant antioxidant activities and may be suggested as a new potential source of natural antioxidant.

Synthesis and antibacterial activity of N-[5-(chlorobenzylthio)-1,3,4-thiadiazol-2-yl] piperazinyl quinolone derivatives.

A series of N-[5-(chlorobenzylthio)-1,3,4-thiadiazol-2-yl] piperazinyl quinolone derivatives (4a-I) have been synthesized by reaction of piperazinyl quinolones with 5-chloro-2-(chlorobenzylthio)-1,3,4-thiadiazoles. Their structures were confirmed by elemental analysis, IR and NMR spectra. The antibacterial activities of 4a-I against a variety of Gram-positive and Gram-negative bacteria were determined. Several compounds showed a good antibacterial activity against Gram-positive bacteria among which, compound 4e with a 2-chlorobenzylthio moiety in ciprofloxacin derivative, exhibited high activities against Staphylococcus aureus and Staphylococcus epidermidis (MIC = 0.06 microg/mL). The structure-activity relationship (SAR) study revealed that the position of chlorine atom on benzyl moiety would dramatically affect the antibacterial activities of the synthesized compounds.

DNA sequence recognition by an imidazole-containing isopropyl-substituted thiazole polyamide (thiazotropsin B).

We have used DNA footprinting and fluorescence melting experiments to study the sequence specific binding of an imidazole-containing isopropyl-substituted thiazole polyamide (thiazotropsin B) to DNA. While the parent compound (thiazotropsin A) binds to the hexanucleotide sequence ACTAGT, changing one of the N-methylpyrrole groups to N-methylimidazole changes the preferred binding sequence to (A/T)CGCG(T/A). Experiments with DNA fragments that contain variants of this sequence suggest that the ligand can also bind, with lower affinity, to sequences which differ from this by 1bp in any position.

Synthesis and antimicrobial activity of some netropsin analogues.

Nine novel lexitropsins were synthesized by linking two netropsin-like moieties through three different dicarboxylic acids; 9,10-dihydro-2,7-phenanthrenedicarboxylic acid; [(3-[[(carboxymethyl)amino]carbonyl]benzoyl)amino]acetic acid and indole-2,5-dicarboxylic acid. The netropsin residues were modified by the use of N-isopentylpyrrole, 5-methylthiophene or 5-isopropylthiazole heterocyclic building blocks in place of the usual N-methylpyrrole. The compounds were tested against five gram-positive bacteria: Staphylococcus aureus, Streptomyces faecalis, methicillin resistant Staphylococcus aureus, Enterobacter cloacae, Mycobacterium fortuitum, three gram-negative bacteria: Klebsiella aerogenes, Proteus vulgaris, Escherichia coli and three fungi: Aspergillus niger, Candida albicans and Aspergillus nidulans. Some of the compounds showed significant inhibitory effects on the growth of the microorganisms.