Objective:To evaluate the antioxidant potential of different extract/fractions of Anthocephalus cadamba（A.cadamba）（Roxb.） Miq.（Rubiaceae） and study the tentative identification of their active constituents.Metho...Objective:To evaluate the antioxidant potential of different extract/fractions of Anthocephalus cadamba（A.cadamba）（Roxb.） Miq.（Rubiaceae） and study the tentative identification of their active constituents.Methods:The extract/fractions were screened for antioxidant activity using various in vitro assays viz.DPPH assay,ABTS assay,superoxide anion radical scavenging assay, reducing power assay and plasmid DNA nicking assay.Total phenolic content of extract/fractions was determined by colorimetric method.An ultra-performance LC-electrospray-quadrupoletime of flight mass spectrometry method was used to analyse the active constituents of extract/ fractions of A.cadamba.Results:The ethyl acetate fraction was found to be most active fraction in all the assays as compared to other extract/fractions.The IC<sub>50</sub> value of ethyl acetate fraction （ETAC fraction） was 21.24μg/mL,1.12μg/mL,9.68μg/mL and S7.81μg/mL in DPPH assay, ABTS assay,reducing power assay and superoxide scavenging assay respectively.All the extract/ fractions also showed the potential to protect the plasmid DNA（pBR322） against the attack of hydroxyl radicals generated by Fenton’s reagent.The bioactive compounds were identified by UPLC-ESI-QTOF-MS,by comparing the mass andλ<sub>max</sub> with literature values.Conclusions:The potential of the extract/fractions to scavenge different free radicals in different systems indicated that they may be useful therapeutic agents for treating radical-related pathologic damage.展开更多
The present study explored the Spilanthes acmella Murr. for insecticidal principle, a plant of high value. The seed extract showed insecticidal activity against Plutella xylostella. Further, bioassay guided isolation ...The present study explored the Spilanthes acmella Murr. for insecticidal principle, a plant of high value. The seed extract showed insecticidal activity against Plutella xylostella. Further, bioassay guided isolation of bioactive compounds resulted in insecticidal active molecule, which was identified with the help of ESI-MS and NMR. Highest activity of 95 - 100 percent was observed at low dose of 2 g/l with spilanthol, while 60 - 70 and 80 - 90 percent mortality at 5 g/l in crude seed extracts prepared in methanol and hexane after 48 hours exposure, respectively. LC50 of 1.49, 5.14, 5.04, 11.75 g/l was observed with spilanthol, crude seed extract of methanol, hexane, deltamethrin, respectively. The findings indicate the potential of S. acmella with potent insecticidal toxicity for the management of P. xylostella and other insects of agricultural importance.展开更多
Brassinosteroids (BRs) are a large group of polyhydroxy steroids, which regulate numerous aspects of plant growth and development, including stem elongation, leaf bending, tracheary element differentiation, stress pro...Brassinosteroids (BRs) are a large group of polyhydroxy steroids, which regulate numerous aspects of plant growth and development, including stem elongation, leaf bending, tracheary element differentiation, stress protection and photomorphogenesis. Recent studies indicate antigenotoxic and anticancerous activities of these compounds. The role of natural BRs in H2O2 (hydrogen peroxide) -induced DNA damage in human lymphocytes is still unknown. The present study reports the presence of Castasterone from leaves of Centella asiatica, an important medicinal herb commonly used as a memory enhancer and immunomodulator. CA50 fraction isolated from Centella asiatica was characterized as Castasterone by electrospray ionization mass spectral data with standard Castasterone. An attempt has been made to study antigenotoxic activity of the isolated Castasterone against H2O2 -induced DNA damage in human blood lymphocytes using Single cell gel electrophoresis assay (Comet Assay). Castasterone at 10–9 M concentration proved to be effective in diminishing the DNA damage by 89.42 %.展开更多
A study was undertaken to assess the distribution behaviour of Dimethoate in tea leaf. Tea bushes were subjected to Dimethoate spray at recommended dose and double the recommended doses. The extraction of pesticide wa...A study was undertaken to assess the distribution behaviour of Dimethoate in tea leaf. Tea bushes were subjected to Dimethoate spray at recommended dose and double the recommended doses. The extraction of pesticide was done using chloroform and the analysis was done using a Hewlett-Packard 5890 series II gas chromatograph with Nitrogen Phosphorus Detector (NPD). The penetration behaviour of Dimethoate was studied in dry and wet seasons. Variations in penetration were observed in dry and wet seasons which was attributed to climatic factors like temperature, humidity, rainfall, sunlight and physicochemical properties of the residue like water solubility, partition coefficient and formulation type. Residues observed in the cell wall and tissues confirm its good penetrating ability inspite of its hydrophilic nature. Higher penetration in wet season as indicated can be attributed to the route through the stomatal pores.展开更多
基金UGC(DRS-SAP),New Delhi for providing financial assistance
文摘Objective:To evaluate the antioxidant potential of different extract/fractions of Anthocephalus cadamba（A.cadamba）（Roxb.） Miq.（Rubiaceae） and study the tentative identification of their active constituents.Methods:The extract/fractions were screened for antioxidant activity using various in vitro assays viz.DPPH assay,ABTS assay,superoxide anion radical scavenging assay, reducing power assay and plasmid DNA nicking assay.Total phenolic content of extract/fractions was determined by colorimetric method.An ultra-performance LC-electrospray-quadrupoletime of flight mass spectrometry method was used to analyse the active constituents of extract/ fractions of A.cadamba.Results:The ethyl acetate fraction was found to be most active fraction in all the assays as compared to other extract/fractions.The IC<sub>50</sub> value of ethyl acetate fraction （ETAC fraction） was 21.24μg/mL,1.12μg/mL,9.68μg/mL and S7.81μg/mL in DPPH assay, ABTS assay,reducing power assay and superoxide scavenging assay respectively.All the extract/ fractions also showed the potential to protect the plasmid DNA（pBR322） against the attack of hydroxyl radicals generated by Fenton’s reagent.The bioactive compounds were identified by UPLC-ESI-QTOF-MS,by comparing the mass andλ<sub>max</sub> with literature values.Conclusions:The potential of the extract/fractions to scavenge different free radicals in different systems indicated that they may be useful therapeutic agents for treating radical-related pathologic damage.
文摘The present study explored the Spilanthes acmella Murr. for insecticidal principle, a plant of high value. The seed extract showed insecticidal activity against Plutella xylostella. Further, bioassay guided isolation of bioactive compounds resulted in insecticidal active molecule, which was identified with the help of ESI-MS and NMR. Highest activity of 95 - 100 percent was observed at low dose of 2 g/l with spilanthol, while 60 - 70 and 80 - 90 percent mortality at 5 g/l in crude seed extracts prepared in methanol and hexane after 48 hours exposure, respectively. LC50 of 1.49, 5.14, 5.04, 11.75 g/l was observed with spilanthol, crude seed extract of methanol, hexane, deltamethrin, respectively. The findings indicate the potential of S. acmella with potent insecticidal toxicity for the management of P. xylostella and other insects of agricultural importance.
文摘Brassinosteroids (BRs) are a large group of polyhydroxy steroids, which regulate numerous aspects of plant growth and development, including stem elongation, leaf bending, tracheary element differentiation, stress protection and photomorphogenesis. Recent studies indicate antigenotoxic and anticancerous activities of these compounds. The role of natural BRs in H2O2 (hydrogen peroxide) -induced DNA damage in human lymphocytes is still unknown. The present study reports the presence of Castasterone from leaves of Centella asiatica, an important medicinal herb commonly used as a memory enhancer and immunomodulator. CA50 fraction isolated from Centella asiatica was characterized as Castasterone by electrospray ionization mass spectral data with standard Castasterone. An attempt has been made to study antigenotoxic activity of the isolated Castasterone against H2O2 -induced DNA damage in human blood lymphocytes using Single cell gel electrophoresis assay (Comet Assay). Castasterone at 10–9 M concentration proved to be effective in diminishing the DNA damage by 89.42 %.
文摘A study was undertaken to assess the distribution behaviour of Dimethoate in tea leaf. Tea bushes were subjected to Dimethoate spray at recommended dose and double the recommended doses. The extraction of pesticide was done using chloroform and the analysis was done using a Hewlett-Packard 5890 series II gas chromatograph with Nitrogen Phosphorus Detector (NPD). The penetration behaviour of Dimethoate was studied in dry and wet seasons. Variations in penetration were observed in dry and wet seasons which was attributed to climatic factors like temperature, humidity, rainfall, sunlight and physicochemical properties of the residue like water solubility, partition coefficient and formulation type. Residues observed in the cell wall and tissues confirm its good penetrating ability inspite of its hydrophilic nature. Higher penetration in wet season as indicated can be attributed to the route through the stomatal pores.
