Two new triterpenoid glucosides ecliptasaponin A(3)and ecliptasaponin B(4)were isolated together with echinocystic acid(1)and oleanolic acid(2)from Eclipta alba(L.) Hassk.Their structures were deduced as 3β,16a-dihyd...Two new triterpenoid glucosides ecliptasaponin A(3)and ecliptasaponin B(4)were isolated together with echinocystic acid(1)and oleanolic acid(2)from Eclipta alba(L.) Hassk.Their structures were deduced as 3β,16a-dihydroxy olean-12-ene-28-oic acid-3β-O-β-D-glu-copyranoside(3)and 3β-O-[β-D-glucopyranosyl(1-4)]-β-D-glucopyranosyl-16a-hydroxy olean-12-ene-28-oic acid 28-O-β-D-glucopyranoside(4),based on spectral analysis and chemical evidences as well as results ofhydrolysis.展开更多
Due to ease of application, cost effectiveness and environmentally safe, in this study, the corrosion inhibition effect of aqueous extract of Eclipta alba in 1N hydrochloric acid has been investigated by weight loss, ...Due to ease of application, cost effectiveness and environmentally safe, in this study, the corrosion inhibition effect of aqueous extract of Eclipta alba in 1N hydrochloric acid has been investigated by weight loss, potentiodynamic polarization and impedance methods and the extracts of Eclipta alba were found to be effective corrosion pickling inhibitor. The effect of immersion time and temperature revealed that the extracts of Eclipta alba with an optimum concentration of 8.0% v/v showed maximum inhibition efficiency of 99.6% at 3 h immersion time and 30℃. Arrhenius plots for mild steel immersed in 1N HCl solution in the absence and presence of optimum concentration （8.0% in v/v） of Eclipta alba extract showed the effect of temperature. Polarization studies indicate that this plant extract acts as a mixed type inhibitor. The adsorption of Eclipta alba follows Langmuir adsorption isotherm. The inhibition action may be due to the presence of the Wedelactone and also the alkaloid Ecliptine present in the leaves of Eclipta alba.展开更多
Objective:The present study deals with the investigation of larvicidal and ovicidal activities of benzene,hexane,ethyl acetate,methanol and chloroform leaf extract of Eclipta alba（E.alba） against dengue vector,Aedes...Objective:The present study deals with the investigation of larvicidal and ovicidal activities of benzene,hexane,ethyl acetate,methanol and chloroform leaf extract of Eclipta alba（E.alba） against dengue vector,Aedes aegypti（Ae.Aegypti）.Methods:Twenty five earlyⅢinstar larvae of Ae.aegypti was exposed to various concentrations（50-300 ppm） and was assayed in the laboratory by using the protocol of WHO 2005;the 24 h LC<sub>50</sub> values of the E.alba leaf extract was determined by Probit analysis.For ovicidal activity,slightly modified method of Su and Mulla was performed.The ovicidal activity was determined against Ae.aegypti to various concentrations ranging from 100-350 ppm under the laboratory conditions.The egg hatch rates were assessed 48 h post treatment.Results:The LC<sub>50</sub> values of benzene,hexane,ethyl acetate,methanol and chloroform extract of E.alba against early third instar larvae of Ae.aegypti were 151.38,165.10, 154.88,127.64 and 146.28 ppm,respectively.Maximum larvicidal activity was observed in the methanol extract followed by chloroform,benzene,ethyl acetate and hexane extract.No mortality was observed in control.Among five solvent tested the methanol extract was found to be most effective for ovicidal activity against Ae.aegypti.The methanol extracts exerted 100%mortality （zero hatchability） at 300 ppm.Conclusions:From the results it can be concluded the crude extract of E.alba was an excellent potential for controlling Ae.aegypti mosquito.展开更多
文摘Two new triterpenoid glucosides ecliptasaponin A(3)and ecliptasaponin B(4)were isolated together with echinocystic acid(1)and oleanolic acid(2)from Eclipta alba(L.) Hassk.Their structures were deduced as 3β,16a-dihydroxy olean-12-ene-28-oic acid-3β-O-β-D-glu-copyranoside(3)and 3β-O-[β-D-glucopyranosyl(1-4)]-β-D-glucopyranosyl-16a-hydroxy olean-12-ene-28-oic acid 28-O-β-D-glucopyranoside(4),based on spectral analysis and chemical evidences as well as results ofhydrolysis.
文摘Due to ease of application, cost effectiveness and environmentally safe, in this study, the corrosion inhibition effect of aqueous extract of Eclipta alba in 1N hydrochloric acid has been investigated by weight loss, potentiodynamic polarization and impedance methods and the extracts of Eclipta alba were found to be effective corrosion pickling inhibitor. The effect of immersion time and temperature revealed that the extracts of Eclipta alba with an optimum concentration of 8.0% v/v showed maximum inhibition efficiency of 99.6% at 3 h immersion time and 30℃. Arrhenius plots for mild steel immersed in 1N HCl solution in the absence and presence of optimum concentration （8.0% in v/v） of Eclipta alba extract showed the effect of temperature. Polarization studies indicate that this plant extract acts as a mixed type inhibitor. The adsorption of Eclipta alba follows Langmuir adsorption isotherm. The inhibition action may be due to the presence of the Wedelactone and also the alkaloid Ecliptine present in the leaves of Eclipta alba.
基金the Department of Science and Technology(DST),New Delhi,India for providing financial assistance for the present investigation
文摘Objective:The present study deals with the investigation of larvicidal and ovicidal activities of benzene,hexane,ethyl acetate,methanol and chloroform leaf extract of Eclipta alba（E.alba） against dengue vector,Aedes aegypti（Ae.Aegypti）.Methods:Twenty five earlyⅢinstar larvae of Ae.aegypti was exposed to various concentrations（50-300 ppm） and was assayed in the laboratory by using the protocol of WHO 2005;the 24 h LC<sub>50</sub> values of the E.alba leaf extract was determined by Probit analysis.For ovicidal activity,slightly modified method of Su and Mulla was performed.The ovicidal activity was determined against Ae.aegypti to various concentrations ranging from 100-350 ppm under the laboratory conditions.The egg hatch rates were assessed 48 h post treatment.Results:The LC<sub>50</sub> values of benzene,hexane,ethyl acetate,methanol and chloroform extract of E.alba against early third instar larvae of Ae.aegypti were 151.38,165.10, 154.88,127.64 and 146.28 ppm,respectively.Maximum larvicidal activity was observed in the methanol extract followed by chloroform,benzene,ethyl acetate and hexane extract.No mortality was observed in control.Among five solvent tested the methanol extract was found to be most effective for ovicidal activity against Ae.aegypti.The methanol extracts exerted 100%mortality （zero hatchability） at 300 ppm.Conclusions:From the results it can be concluded the crude extract of E.alba was an excellent potential for controlling Ae.aegypti mosquito.
