Objective:To examine the acaricidal effects of the essential oil of Cymbopogon citratits leaf extract(lemongrass)and ethanolic Azadirachta indica leaf extract(neem)against house dust mites Dermatophagoides farinae(D.f...Objective:To examine the acaricidal effects of the essential oil of Cymbopogon citratits leaf extract(lemongrass)and ethanolic Azadirachta indica leaf extract(neem)against house dust mites Dermatophagoides farinae(D.farinae)and Dermalophagoides pteronyssinus(D.pteronyssinus).Methods:Twenty-five adults mites were placed onto treated filter paper that is soaked with plant extract and been tested at different concentrations(50.00%,25.00%,12.50%,6.25%and 3.13%)and exposure times(24hrs,48hrs,72hrs and 96 hrs).All treatments were replicated 7 times,and the experiment repeated once.The topical and contact activities of the two herbs were investigated.Results:Mortalities from lemongrass extract were higher than neem for both topical and contact activities.At 50%concentration,both 24 hrs topical and contact exposures to lemongrass resulted in more than 91%mortalities for both species of inites.At the same concentration and exposure time,neem resulted in topical mortalities of 40.3%and 15.7%against D.pteronyssinus and D.farinae respectively;contact mortalities were 8.0%and 8.9%against the 2 mites,respectively.There was no difference in topical mortalities of D.pteronyssinus from exposure to concentrations oflemongrass and neem up to 12.50%;lemongrass was more effective than neem at the higher concentrations.Conclusions:Generally,topical mortalities of D.farinae due to lemongrass are higher than that due to neem.Contact mortalities of lemongrass are always higher that neem against both species of mites.展开更多
The increasing demand for natural food antioxidants has hastened research to extract the biologically active substances from a variety of raw materials. The consumption of anthocyanin-rich food promotes health by con...The increasing demand for natural food antioxidants has hastened research to extract the biologically active substances from a variety of raw materials. The consumption of anthocyanin-rich food promotes health by contributing to cardio protection, lowering high blood pressure and by helping to protect against cancer. In this study, centrifugal partition chromatography （CPC） was studied for anthocyanin separation from Hibiscus sabdariffa L. （HS）. A simple elution and two displacement protocols were implemented. The displacement modes were strong ion-exchange （SIX） and pH-zone refining （pHZR） method. Among the three protocols, SIX CPC using trioctylmethylammonium chloride （Aliquat 336 ？） as a strong exchanger was the most successful in purifying four anthocyanins from an ethanolic extract of HS, identified as delphinidin-3-O-sambubioside （DS）, cyanidin-3-O-sambubioside （CS）, delphinidin-3-O-glucoside （DG） and cyanidin-3-O-glucoside （CG）. The purification process was carried out on a gram scale using the ternary biphasic system ethyl acetate：n-butanol：water （mobile organic phase： 4.0/4.6/1.4; aqueous stationary phase： 0.5/0.5/9.0） in the ascending mode. Aliquat 336？ was used as the anion extractant in the aqueous stationary phase and sodium iodide （NaI） as the cation displacer in the organic mobile phase. From 1 g of crude HS extract, 80 mg of DS, 40 mg of CS, 15 mg of DG, and 4 mg of CG were obtained after 75 minutes. High performance liquid chromatography （HPLC-UV and LC-MS） analysis revealed the identity and the purity of the isolated compounds： 88% for DS, 92% for CS, 93% for DG and 70% for CG. This new methodology for the isolation of anthocyanin mixtures successfully increased the purity and ef？ciency especially for DG and CG, while maintaining excellent recovery rate and being relatively low cost. The availability of high purity anthocyanin mixtures will facilitate anthocyanin testing studies and will widen the use of anthocyanins in the food, supplements and pharmaceutical industries.展开更多
文摘Objective:To examine the acaricidal effects of the essential oil of Cymbopogon citratits leaf extract(lemongrass)and ethanolic Azadirachta indica leaf extract(neem)against house dust mites Dermatophagoides farinae(D.farinae)and Dermalophagoides pteronyssinus(D.pteronyssinus).Methods:Twenty-five adults mites were placed onto treated filter paper that is soaked with plant extract and been tested at different concentrations(50.00%,25.00%,12.50%,6.25%and 3.13%)and exposure times(24hrs,48hrs,72hrs and 96 hrs).All treatments were replicated 7 times,and the experiment repeated once.The topical and contact activities of the two herbs were investigated.Results:Mortalities from lemongrass extract were higher than neem for both topical and contact activities.At 50%concentration,both 24 hrs topical and contact exposures to lemongrass resulted in more than 91%mortalities for both species of inites.At the same concentration and exposure time,neem resulted in topical mortalities of 40.3%and 15.7%against D.pteronyssinus and D.farinae respectively;contact mortalities were 8.0%and 8.9%against the 2 mites,respectively.There was no difference in topical mortalities of D.pteronyssinus from exposure to concentrations oflemongrass and neem up to 12.50%;lemongrass was more effective than neem at the higher concentrations.Conclusions:Generally,topical mortalities of D.farinae due to lemongrass are higher than that due to neem.Contact mortalities of lemongrass are always higher that neem against both species of mites.
文摘The increasing demand for natural food antioxidants has hastened research to extract the biologically active substances from a variety of raw materials. The consumption of anthocyanin-rich food promotes health by contributing to cardio protection, lowering high blood pressure and by helping to protect against cancer. In this study, centrifugal partition chromatography （CPC） was studied for anthocyanin separation from Hibiscus sabdariffa L. （HS）. A simple elution and two displacement protocols were implemented. The displacement modes were strong ion-exchange （SIX） and pH-zone refining （pHZR） method. Among the three protocols, SIX CPC using trioctylmethylammonium chloride （Aliquat 336 ？） as a strong exchanger was the most successful in purifying four anthocyanins from an ethanolic extract of HS, identified as delphinidin-3-O-sambubioside （DS）, cyanidin-3-O-sambubioside （CS）, delphinidin-3-O-glucoside （DG） and cyanidin-3-O-glucoside （CG）. The purification process was carried out on a gram scale using the ternary biphasic system ethyl acetate：n-butanol：water （mobile organic phase： 4.0/4.6/1.4; aqueous stationary phase： 0.5/0.5/9.0） in the ascending mode. Aliquat 336？ was used as the anion extractant in the aqueous stationary phase and sodium iodide （NaI） as the cation displacer in the organic mobile phase. From 1 g of crude HS extract, 80 mg of DS, 40 mg of CS, 15 mg of DG, and 4 mg of CG were obtained after 75 minutes. High performance liquid chromatography （HPLC-UV and LC-MS） analysis revealed the identity and the purity of the isolated compounds： 88% for DS, 92% for CS, 93% for DG and 70% for CG. This new methodology for the isolation of anthocyanin mixtures successfully increased the purity and ef？ciency especially for DG and CG, while maintaining excellent recovery rate and being relatively low cost. The availability of high purity anthocyanin mixtures will facilitate anthocyanin testing studies and will widen the use of anthocyanins in the food, supplements and pharmaceutical industries.
