Identification and structural elucidation of bioactive compounds from Scirpoides holoschoenus.

Phytochemical investigations of dichloromethane and methanol extracts of roots and rhizomes of Scirpoides holoschoenus afforded 21 stilbenes, six flavonoids, six ferulic acid derivatives and four diterpenes. Among these constituents, six stilbenes, one flavonoid, one diterpene and two ferulic acid derivatives, represent previously unreported natural products. Structure elucidation was performed by HRESI-MS, NMR, GC-MS, and ECD data evaluation. The monoprenylated flavonoid (sophoraflavanone B) and all isolated stilbene oligomers (trans-scirpusin B, scirpusin A, cassigarol E, cyperusphenol B, cyperusphenol D, passiflorinol A, cyperusphenol A and mesocyperusphenol A) showed strong inhibitory activities on spore germination of two Botrytis cinerea strains isolated from field-infected grape berries and apple fruits compared to the reference controls resveratrol, piceid, and fenhexamid at a test concentration of 2.0 mM. For sophoraflavanone B and cyperusphenol A, the EC50 values were determined by concentration response curves and resulted in values of 0.35 mM and 0.53 mM, respectively. The data suggest that stilbene oligomers but also prenylated flavonoids should be examined further to gain more information on their antimicrobial activity and might be a suitable addition to chemical fungicides on the market to combat gray mold.

Recent advances in tackling microbial multidrug resistance with essential oils: combinatorial and nano-based strategies.

The emergence of multidrug resistant pathogens is a great challenge to the medical field and a major global health threat requiring novel therapeutic strategies. Among plant products, essential oils have significant antimicrobial properties that make them promising agents in the fight against drug resistant human pathogens. The aim of the present review was to highlight the most important essential oil-based antimicrobial strategies as revealed by recent studies. Synergistic interactions between essential oils or their bioactive compounds in combination with known antibiotics are presented. Also, nanoformulation approaches to boost the antimicrobial activity of essential oils are reviewed in terms of bioefficiency, stability and design of the nanostructured delivery systems. The focus was mainly put on the antimicrobial activity against multi-drug resistant pathogens, also called "ESKAPE" organisms (Enterococcus spp., Staphylococcus aureus, Klebsiella spp., Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.). Thus, essential oils in combinatorial and nano-based strategies may cope with infections caused by drug-resistant bacteria and may offer possibilities for reducing antibiotic use. Research on the in vivo efficacy and safety of such strategies is required for further clinical antimicrobial chemotherapy. In this regard, the understanding of the interactions between essential oil-based strategies and biological interface is essential.

Essential Oils and Their Components as Modulators of Antibiotic Activity against Gram-Negative Bacteria.

Gram-negative bacteria cause infections that are difficult to treat due to the emergence of multidrug resistance. This review summarizes the current status of the studies investigating the capacity of essential oils and their components to modulate antibiotic activity against Gram-negative bacteria. Synergistic interactions are particularly discussed with reference to possible mechanisms by which essential oil constituents interact with antibiotics. Special emphasis is given to essential oils and volatile compounds that inhibit efflux pumps, thus reversing drug resistance in Gram-negative bacteria. In addition, indifference and antagonism between essential oils/volatile compounds and conventional antibiotics have also been reported. Overall, this literature review reveals that essential oils and their purified components enhance the efficacy of antibiotics against Gram-negative bacteria, being promising candidates for the development of new effective formulations against Gram-negative bacteria.

Antioxidant Activity of Essential Oil From Carum Carvi L. Cultivated in North-Eastern Romania.

Essential oils have significant antioxidant activity, being used frequently as preservatives in the food and cosmetic industries. Aim: To assess the in vitro antioxidant activity of essential oil from Carum carvi L. (caraway) cultivated in northeastern Romania. Materials and Methods: The essential oil was isolated by hydrodistillation from dried caraway fruits. The chemical composition was investigated by gas chromatography and gas chromatography­mass spectrometry analyses. Antioxidant activity was evaluated by three different in vitro antioxidant assays (DPPH∙ and ABTS•+ scavenging and reducing power assays). Butylhydroxyanisole was used as reference standard. Results and Discussion: Carvone was the major compound of essential oil of caraway fruits (48.53%), followed by limonene (44.42%). Evaluation of the antioxidant activity (DPPH∙and ABTS•+ scavenging activity and reducing power) revealed significant effects, with IC50 values of 46.51 ± 1.61 µg/mL, 5.34 ± 0.07 µg/mL and 7.64 ± 0.22 µg/mL, respectively, as compared to those of the reference standard, butylhydroxyanisole (6.09 ± 0.27 µg/mL, 1.49 ± 0.00 µg/mL and 3.39 ± 0.07 µg/mL, respectively). Conclusions: Essential oil of Carum carvi cultivated in northeastern Romania belongs to carvone chemotype. Due to its high antioxidant activity it might be a potential alternative to conventional preservatives in the food, cosmetic and pharmaceutical industries.

ANTIOXIDANT AND PHYTOBIOLOGICAL STUDIES ON TWO ALLIUM CEPA L. EXTRACTS.

AIM: To investigate the antioxidant potential of two Allium cepa L. extracts. MATERIAL AND METHODS: The antioxidant activity of the two extracts (encoded EC1 and EC2) was assessed using two methods: DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging capacity and determination of their reducing power; phytobiological, studies were performed using grains of Triticum aestivum L., Falmura variety. RESULTS AND DISCUSSIONS: EC1 and EC2 extracts had a particular affinity for binding DPPH radicals. At equivalent concentrations, the reducing power of EClextract was about 2 times higher compared to EC2, increasing with the concentration of the analyzed sample. The phytobiological study demonstrated that the investigated extracts had no cytotoxic and genotoxic potential.

Phytotoxicity assessment of methanolic extracts from Coriadrum sativum L. fruits.

UNLABELLED: The fruits of Coriandrum sativum L. (Apiaceae) are used as a spicing and flavoring agent in food products and are also recommended as a drug in the treatment of digestive tract disorders. The safety of botanicals and botanical preparations used as food supplements is of great interest, as the market of such products is expanding worldwide. AIM: In this study, aimed at assessing the safety of coriander as food ingredient, we investigated the phytotoxicity of fruit extracts on Triticum aestivum L. MATERIAL AND METHODS: We studied the effects of methanolic coriander fruit extracts, Omagiu cultivar (VI-V3; three dilutions: 1%, 2.5% and 5% in distilled water), upon germination, elongation, and accumulation of fresh and dry biomass in the plants; also it was investigated the influence of the extracts on mythosis in root tissues. RESULTS AND DISCUSSIONS: The extracts did not influence the germination and growth of test plants and did not inhibit root and shoot elongation of wheat plants (a 20% increase in root length over the control being registered for V2 1%). Frequency of aberrant anaphases and telophases in Triticum aestivum L. varied slightly around the percentage of the control, the highest percent of aberrant chromosomes (5.07 %) being observed in V3 2.5%. CONCLUSIONS: The investigated coriander fruit extracts did not have phytotoxic effects but had a slight stimulating effect on germination and growth of Triticum aestivum L.

[Contributions to the study of the chemical variability of some Galium album Mill. Populations harvested from wild flora in northern Moldavia]. / Contributii la studiul variabilitatii chimice a unor populatii de Galium album Mill. Recoltate din flora spontana din nordul Moldovei.

UNLABELLED: Within a complex research regarding the chemical intra- and inter-specific variability of some medicinal plants, we compared two species of Galium: Galium verum L. and Galium album Mill. AIM: In the present study, we quantified some secondary metabolites from 7 natural populations of Galium album Mill., harvested from Suceava and Neamt districts, during July 2008. MATERIAL AND METHODS: The chemical investigations used TLC, UV-VIS spectrophotometry and HPLC, in order to analyze the composition in iridoids, flavones and polyphenolic acids. RESULTS: Our study revealed the existence of important chemical variations between the different populations (Râsca, Crucea/ Borca, Runc, Târzial). Meanwhile the harvesting moment within the vegetative cycle plays a major role for the further quality of the product.

In vitro antimicrobial activity and chemical composition of the essential oil of Foeniculum vulgare Mill.

UNLABELLED: In our study, four samples of volatile oil from Foeniculum vulgare, cultivated in different pedoclimatic conditions, were investigated for their antimicrobial activity and chemical composition. MATERIAL AND METHODS: Organisms. Staphylococcus aureus ATCC 25923, Bacillus cereus, Pseudomonas aeruginosa, Escherichia coli ATCC 25922, Candida albicans were included in the report. Antimicrobial susceptibility tests. The comparative inhibitory activity of volatile oil samples with other antimicrobial agents was quantitative determined by minimum inhibitory concentration (MIC). Oil samples are the volatile oils extracted by steam distillation, from two ecological vegetative populations of Foeniculum vulgare. Gas chromatography coupled to mass spectrometry (GC-MS) was used to determine the chemical composition of the essential oils. RESULTS: All oil samples have a good activity against E. coli and S. aureus at low concentrations. Against B. cereus and P. aeruginosa these oil samples are less active. The oil samples were generally bactericidal at a concentration up to twofold or fourfold higher than the MIC value. Significantly synergic activity with amoxicillin or tetracycline showed all fennel samples against E. coli, Sarcina lutea and B. subtilis strains. Fennel oil samples have shown high activity against Candida albicans. CONCLUSION: No significant antimicrobial activity variations were observed for Foeniculum vulgare volatile oil samples obtained after two or three years cultivation period. The most important identified compounds in all samples of fennel volatile oils were trans-anethole, estragole, fenchone, limonene, alpha-pinene and gamma-terpinene.

Chemical composition and in vitro antimicrobial activity of essential oil of Melissa officinalis L. from Romania.

UNLABELLED: Melissa officinalis L. (lemon balm) is used in traditional medicine to treat insomnia, anxiety, gastric conditions, psychiatric conditions, migraines, hypertension and bronchial conditions. Natural essential oils (mixtures of fragrant chemical) obtained from various parts of plants are efficient active antimicrobial agents. The widespread use of antimicrobial agents selects resistant bacterial strains, which seriously compromise the effectiveness of antibiotic treatment. The use of herbal medicines might be a precautionary measure to prevent the development of lack of susceptibility to synthetic antibiotics that is associated with therapeutic failures. MATERIAL AND METHODS: In this work, the chemical composition and the antimicrobial properties of essential oil from romanian Melissa officinalis were determined. Therefore, the purpose of this study was to evaluate in vitro antimicrobial activity of lemon balm oil by comparison with lavender essential oil, which is also utilised for its antimicrobial properties in folk medicine. RESULTS: The most important identified compounds, well known for their antimicrobial effects were citral (neral and geranial) (16.10%), citronellal (3.76%) and trans-caryophyllene (3.57%).The lemon balm oil sample exhibited a higher degree antibacterial activity than did Lavandula oil against Gram-positive strains. The both oil samples tested has shown a high activity against Candida albicans. The gram-negative bacteria were not affected by the lemon balm oil.

Biochemical differences in Cannabis sativa L. depending on sexual phenotype.

Hemp (Cannabis sativa L.) is a species considered as having one of the most complicated mechanisms of sex determination. Peroxidase and esterase isoenzymes in leaves of the two sexual phenotypes of hemp were studied. Significant differences in isoperoxidase and isoesterase patterns were found between male and female plants, both in the number and stain intensity of bands. For both esterase and peroxidase, the isoenzymatic spectrum is richer for staminate plants. Also, some differences are obvious between the two sexes concerning catalase and peroxidase activities, as well as the level of soluble protein. The quantitative analysis of flavones, polyholozides and polyphenols emphasized differences depending not only on sex, but also on tested organ.