In this study, laurel essential oils were obtained by using solvent-free microwave extraction (SFME) and hydrodistillation (HD) methods from Laurus nobilis leaves and determined their antioxidant and antimicrobial act...In this study, laurel essential oils were obtained by using solvent-free microwave extraction (SFME) and hydrodistillation (HD) methods from Laurus nobilis leaves and determined their antioxidant and antimicrobial activity. Extraction time was reduced by about 43% in SFME at 622 W and 67% in SFME at 249 W compared to hydrodistillation. Essential oil of laurel was extracted by SFME at 622 W (100%) and 249 W (40%) power levels and HD inhibited oxidation generated by ABTS radical by 93.88%, 94.13% and 92.06%, respectively. Trolox equivalent antioxidant capacities (TEAC) of essential oils were 0.18 mM/mL oil for SFME at 622 W, 1.36 mM/mL oil for SFME at 249 W and 2.40 mM/mL oil for HD (p < 0.05). Essential oils of L. nobilis were extracted by SFME at 100% and 40% power levels and HD inhibited linoleic acid peroxidation by 70.57%, 63.53% and 89.18% respectively. Inhibition effects of laurel essential oils obtained by SFME at different power levels and HD on DPPH radical cation oxidation were not significantly different. The strongest antioxidant activity against DPPH radical was found in the essential oil obtained by SFME at 100% power level. Essential oils displayed antimicrobial activity against Staphylococcus aureus 6538P, Escherichia coli O157:H7 and Salmonella typhimurium NRRL E 4463 except for Listeria monocytogenes. The inhibitory effect on Staphylococcus aureus 6538P survival of laurel oil obtained from SFME by using lower power level was found to be lower than that obtained from SFME at 100% power level and HD展开更多
The recent studies unveil more and more therapeutic properties of the essential oil of Bay leaf （Laurus nobilis L.）. The aim of this study is to determine the chromatographic profile of the essential oil of Bay leaf...The recent studies unveil more and more therapeutic properties of the essential oil of Bay leaf （Laurus nobilis L.）. The aim of this study is to determine the chromatographic profile of the essential oil of Bay leaf cultivated under the climatic conditions of the Algerian East and to test its antibiotic activity, against 8 bacterial strains （Escherichia coil, Serratia sp., Proteus sp., Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus D, Pseudomonas aeruginosa and Acinetobacter baumanii）, by using different concentrations. The GC/MS analysis showed that the essential oil is rich in eucalyptol （35.31%）, [3 linalool （22.52%）, eugenol methyl ether （9.17%）, camphene （7.37%） and 3 carene （5.39%）. The antibiotic activity of the essential oil was determined by the diffusion on agar method. Measuring diameters of inhibition method of Vincent [1] indicated that bacterial strains which are very sensitive to even very diluted essential oil are Pseudomonas aeruginosa, Streptococcus D, Serratia sp. and Klebsiella pneumoniae. Staphylococcus aureus, E. coli and Acinetobacter baumanii exhibit less sensitivity and Proteus sp. is especially sensitive to the pure oil. Laurus nobilis L. is a Mediterranean endemic that presents an interesting antibacterial activity and its culture should be encouraged and expanded in Algeria.展开更多
The leaves ofLaurus nobilis were collected in the middle of four seasons （spring, summer, autumn, and winter） to determine the best harvesting time for obtaining the highest oil yield, 1,8-cineole and polyphenol con...The leaves ofLaurus nobilis were collected in the middle of four seasons （spring, summer, autumn, and winter） to determine the best harvesting time for obtaining the highest oil yield, 1,8-cineole and polyphenol content and antioxidant activity. After drying the plant materials in shade, their EOs （essential oils） were obtained by hydro-distillation method. Analysis of variance showed harvesting time had significant effect on the oil yields of L. nobilis. Seventy one components were identified in the oils of L. nobilis with 1, 8-cineole （5.7%-42.6%）, ot-terpinyl acetate （3.2%-13.1%）, sabinene （2.3%-12.0%）, beta-elemene （0.2%-17.7%） and （E）-caryophyllene （0.2%-16.9%） as the main constituents in different seasons. The predominant phenolic constituents in L. nobilis were cinnamic acid, carvacrol, quercetin and coumarin, respectively. Gallic acid, catechin, caffeic acid, chloregenic acid, p-Comaric acid and rutin were not detected in any seasons. The best antioxidant activity was in spring （268.6μg/mL） and the lowest one was in winter （702.1μg/mL）.展开更多
Traditionally,Laurus nobilis is used for the treatment of earaches and skin rashes as well as rheuma-tism.The most common technique to isolate the oil is hydro-distillation and steam-distillation.The investigation pre...Traditionally,Laurus nobilis is used for the treatment of earaches and skin rashes as well as rheuma-tism.The most common technique to isolate the oil is hydro-distillation and steam-distillation.The investigation presented in this paper was aimed to unravel the antimicrobial activity and chemical composition of essential oil in the leaves of L.nobilis grown in Oman.The essential oil was extracted from the leave of the selected plant species by hydro distillation using Clevenger type apparatus.The antimicrobial assay was done by disc diffusion methods against three bac-terial strains,Staphylococcus aureus,Pseudomonas aeruginosa and Escherichia coli,and one fungal strain:Candida albicans.The isolated essential oil was analyzed by gas chromatography-mass spectrometry(GC-MS).The percentage yield of the essential oil was 0.064%(w/w).The essen-tial oil was found actively against the applied bacterial and fungal strains.The highest activity was found against S.aureus and the lowest was against E.coli,and the order was S.aureus>P.aeruginosa>E.coli.The essential oil was also active against the fungus C.albicans.The range of inhibition zones was 6-14 mm.The results of GC-MS analysis showed(E)-𝛽-caryophyllene to be the major component about 59.62%.Other major components included𝛼-selinene(14.03%),𝛼-humulene(8.65%),𝛽-selinene(4.99%),and𝛼-pinene(4.98%).In addition,several minor com-ponents were found in the essential oil of L.nobilis.Based on the experimental results,it showed that the plant species that grown in Oman were a potential source of therapeutic agents.In con-clusion,the essential oil and the plant could be used as natural and potential therapeutic agents to treat earaches,skin rashes,and rheumatism.展开更多
Carbapenem-resistant Acinetobacter baumannii infections are becoming increasingly difficult to treat.Thus,this paper focused on identification of carbapenemase genes in carbapenem-resistant A.baumanii isolates,determi...Carbapenem-resistant Acinetobacter baumannii infections are becoming increasingly difficult to treat.Thus,this paper focused on identification of carbapenemase genes in carbapenem-resistant A.baumanii isolates,determining the antibacterial activities of Laurus nobilis L.leaves extracts in both carbapenem-sensitive and resistant strains,and comparing MIC values in strains with various carbapenemase genotypes.Besides,the components of Laurus nobilis extracts and the theoretical calculation of the antibacterial effect mechanisms of Laurus nobilis extracts on A.baumanii isolates were investigated.The MIC value of Laurus nobilis extracts was found to be 250μg/ml in A.baumanii isolates carrying one or two carbepenemase genes,while the MIC value was found to be 500μg/ml in strains carrying three or more carbapenemase genes.The extracts of Laurus nobilis had the highest concentration of rutin,followed by ferulic acid.The interaction of the major component of the extract,rutin,with OXA-51 was explored by molecular docking to demonstrate its binding potential.Its interaction was then compared to the interaction of a standard drug(doripenem).The binding potential of rutin was found to be slightly higher than that of doripenem that reflected the limited activity of the extract on the carbapenem-resistant strains.Consequently,new treatment drugs have needed to limit the spread of carbapenem-resistant A.baumannii.展开更多
The authors regret that the above-mentioned article lacked descrip-tive text in the legend of Fig.2.The correct and complete legend for Fig.2 should read as follows:Fig.2.Graphics depicting the particle size distribut...The authors regret that the above-mentioned article lacked descrip-tive text in the legend of Fig.2.The correct and complete legend for Fig.2 should read as follows:Fig.2.Graphics depicting the particle size distribution of essential oils utilized in the present study.展开更多
This study investigated the effect of chitosan(CHT)incorporated with essential oils(EOs)from three plants:Laurus nobilis L.(bay leaf),Piper nigrum L.(black pepper),and Cinnamomum verum J.Presl(cinnamon)on fresh foods....This study investigated the effect of chitosan(CHT)incorporated with essential oils(EOs)from three plants:Laurus nobilis L.(bay leaf),Piper nigrum L.(black pepper),and Cinnamomum verum J.Presl(cinnamon)on fresh foods.A panel of expert sensory analysts selected the best EO olfactory profile to be used with cheese and cured meat.The components of EOs were studied by gas chromatography coupled with mass spectrometry(GC-MS).Bay leaf EO was mainly rich in 1,8-cineole(28.1%),while black pepper was mainly characterized byβ-caryophyllene(45.7%)and cinnamon was dominated by(E)-cinnamaldehyde(85.5%).The food samples were divided into four groups and subjected to the following treatments:control,chitosan(CHT),EO,and CHT+EO at different concentrations to determine their influence on the oviposition behavior of Piophila casei over time.Under those conditions,the best concentration of EO to be used to control the P.casei oviposition was assessed.The samples coated with CHT+EOs showed the highest efficacy in controlling the oviposition behavior of P.casei as the treatment was able to decrease the oviposition percentage from 40 to 80%(control)to 5-10%.The EOs of bay leaf(1%)and black pepper(0.5%)were pinpointed as the best choices because they totally controlled the oviposition.Besides,the panelists accepted their sensory profile,overall pleasantness,and hedonic index with the highest scores.Therefore,the use of a CHT mixed with EOs was the most effective solution to repel P.casei without negatively affecting the organoleptic qualities of the treated foods.展开更多
基金The TUBİTAK,The Scientific and Technologic Research Council of Turkey(Grant No.TOVAG 104 O 265)financially supported this study.
文摘In this study, laurel essential oils were obtained by using solvent-free microwave extraction (SFME) and hydrodistillation (HD) methods from Laurus nobilis leaves and determined their antioxidant and antimicrobial activity. Extraction time was reduced by about 43% in SFME at 622 W and 67% in SFME at 249 W compared to hydrodistillation. Essential oil of laurel was extracted by SFME at 622 W (100%) and 249 W (40%) power levels and HD inhibited oxidation generated by ABTS radical by 93.88%, 94.13% and 92.06%, respectively. Trolox equivalent antioxidant capacities (TEAC) of essential oils were 0.18 mM/mL oil for SFME at 622 W, 1.36 mM/mL oil for SFME at 249 W and 2.40 mM/mL oil for HD (p < 0.05). Essential oils of L. nobilis were extracted by SFME at 100% and 40% power levels and HD inhibited linoleic acid peroxidation by 70.57%, 63.53% and 89.18% respectively. Inhibition effects of laurel essential oils obtained by SFME at different power levels and HD on DPPH radical cation oxidation were not significantly different. The strongest antioxidant activity against DPPH radical was found in the essential oil obtained by SFME at 100% power level. Essential oils displayed antimicrobial activity against Staphylococcus aureus 6538P, Escherichia coli O157:H7 and Salmonella typhimurium NRRL E 4463 except for Listeria monocytogenes. The inhibitory effect on Staphylococcus aureus 6538P survival of laurel oil obtained from SFME by using lower power level was found to be lower than that obtained from SFME at 100% power level and HD
文摘The recent studies unveil more and more therapeutic properties of the essential oil of Bay leaf （Laurus nobilis L.）. The aim of this study is to determine the chromatographic profile of the essential oil of Bay leaf cultivated under the climatic conditions of the Algerian East and to test its antibiotic activity, against 8 bacterial strains （Escherichia coil, Serratia sp., Proteus sp., Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus D, Pseudomonas aeruginosa and Acinetobacter baumanii）, by using different concentrations. The GC/MS analysis showed that the essential oil is rich in eucalyptol （35.31%）, [3 linalool （22.52%）, eugenol methyl ether （9.17%）, camphene （7.37%） and 3 carene （5.39%）. The antibiotic activity of the essential oil was determined by the diffusion on agar method. Measuring diameters of inhibition method of Vincent [1] indicated that bacterial strains which are very sensitive to even very diluted essential oil are Pseudomonas aeruginosa, Streptococcus D, Serratia sp. and Klebsiella pneumoniae. Staphylococcus aureus, E. coli and Acinetobacter baumanii exhibit less sensitivity and Proteus sp. is especially sensitive to the pure oil. Laurus nobilis L. is a Mediterranean endemic that presents an interesting antibacterial activity and its culture should be encouraged and expanded in Algeria.
文摘The leaves ofLaurus nobilis were collected in the middle of four seasons （spring, summer, autumn, and winter） to determine the best harvesting time for obtaining the highest oil yield, 1,8-cineole and polyphenol content and antioxidant activity. After drying the plant materials in shade, their EOs （essential oils） were obtained by hydro-distillation method. Analysis of variance showed harvesting time had significant effect on the oil yields of L. nobilis. Seventy one components were identified in the oils of L. nobilis with 1, 8-cineole （5.7%-42.6%）, ot-terpinyl acetate （3.2%-13.1%）, sabinene （2.3%-12.0%）, beta-elemene （0.2%-17.7%） and （E）-caryophyllene （0.2%-16.9%） as the main constituents in different seasons. The predominant phenolic constituents in L. nobilis were cinnamic acid, carvacrol, quercetin and coumarin, respectively. Gallic acid, catechin, caffeic acid, chloregenic acid, p-Comaric acid and rutin were not detected in any seasons. The best antioxidant activity was in spring （268.6μg/mL） and the lowest one was in winter （702.1μg/mL）.
文摘Traditionally,Laurus nobilis is used for the treatment of earaches and skin rashes as well as rheuma-tism.The most common technique to isolate the oil is hydro-distillation and steam-distillation.The investigation presented in this paper was aimed to unravel the antimicrobial activity and chemical composition of essential oil in the leaves of L.nobilis grown in Oman.The essential oil was extracted from the leave of the selected plant species by hydro distillation using Clevenger type apparatus.The antimicrobial assay was done by disc diffusion methods against three bac-terial strains,Staphylococcus aureus,Pseudomonas aeruginosa and Escherichia coli,and one fungal strain:Candida albicans.The isolated essential oil was analyzed by gas chromatography-mass spectrometry(GC-MS).The percentage yield of the essential oil was 0.064%(w/w).The essen-tial oil was found actively against the applied bacterial and fungal strains.The highest activity was found against S.aureus and the lowest was against E.coli,and the order was S.aureus>P.aeruginosa>E.coli.The essential oil was also active against the fungus C.albicans.The range of inhibition zones was 6-14 mm.The results of GC-MS analysis showed(E)-𝛽-caryophyllene to be the major component about 59.62%.Other major components included𝛼-selinene(14.03%),𝛼-humulene(8.65%),𝛽-selinene(4.99%),and𝛼-pinene(4.98%).In addition,several minor com-ponents were found in the essential oil of L.nobilis.Based on the experimental results,it showed that the plant species that grown in Oman were a potential source of therapeutic agents.In con-clusion,the essential oil and the plant could be used as natural and potential therapeutic agents to treat earaches,skin rashes,and rheumatism.
文摘Carbapenem-resistant Acinetobacter baumannii infections are becoming increasingly difficult to treat.Thus,this paper focused on identification of carbapenemase genes in carbapenem-resistant A.baumanii isolates,determining the antibacterial activities of Laurus nobilis L.leaves extracts in both carbapenem-sensitive and resistant strains,and comparing MIC values in strains with various carbapenemase genotypes.Besides,the components of Laurus nobilis extracts and the theoretical calculation of the antibacterial effect mechanisms of Laurus nobilis extracts on A.baumanii isolates were investigated.The MIC value of Laurus nobilis extracts was found to be 250μg/ml in A.baumanii isolates carrying one or two carbepenemase genes,while the MIC value was found to be 500μg/ml in strains carrying three or more carbapenemase genes.The extracts of Laurus nobilis had the highest concentration of rutin,followed by ferulic acid.The interaction of the major component of the extract,rutin,with OXA-51 was explored by molecular docking to demonstrate its binding potential.Its interaction was then compared to the interaction of a standard drug(doripenem).The binding potential of rutin was found to be slightly higher than that of doripenem that reflected the limited activity of the extract on the carbapenem-resistant strains.Consequently,new treatment drugs have needed to limit the spread of carbapenem-resistant A.baumannii.
文摘The authors regret that the above-mentioned article lacked descrip-tive text in the legend of Fig.2.The correct and complete legend for Fig.2 should read as follows:Fig.2.Graphics depicting the particle size distribution of essential oils utilized in the present study.
基金the PRIMA program,project FEDKITOsupported by the European Union and by the Italian Ministero dell’Universitàe della Ricerca.
文摘This study investigated the effect of chitosan(CHT)incorporated with essential oils(EOs)from three plants:Laurus nobilis L.(bay leaf),Piper nigrum L.(black pepper),and Cinnamomum verum J.Presl(cinnamon)on fresh foods.A panel of expert sensory analysts selected the best EO olfactory profile to be used with cheese and cured meat.The components of EOs were studied by gas chromatography coupled with mass spectrometry(GC-MS).Bay leaf EO was mainly rich in 1,8-cineole(28.1%),while black pepper was mainly characterized byβ-caryophyllene(45.7%)and cinnamon was dominated by(E)-cinnamaldehyde(85.5%).The food samples were divided into four groups and subjected to the following treatments:control,chitosan(CHT),EO,and CHT+EO at different concentrations to determine their influence on the oviposition behavior of Piophila casei over time.Under those conditions,the best concentration of EO to be used to control the P.casei oviposition was assessed.The samples coated with CHT+EOs showed the highest efficacy in controlling the oviposition behavior of P.casei as the treatment was able to decrease the oviposition percentage from 40 to 80%(control)to 5-10%.The EOs of bay leaf(1%)and black pepper(0.5%)were pinpointed as the best choices because they totally controlled the oviposition.Besides,the panelists accepted their sensory profile,overall pleasantness,and hedonic index with the highest scores.Therefore,the use of a CHT mixed with EOs was the most effective solution to repel P.casei without negatively affecting the organoleptic qualities of the treated foods.
