The aqueous extract of Phellodendron amurense Rupr. （Amur Cork Tree） provides a rich source of antioxidants and chemical compounds, and can be used for food and wood preservative materials. In this study, we charact...The aqueous extract of Phellodendron amurense Rupr. （Amur Cork Tree） provides a rich source of antioxidants and chemical compounds, and can be used for food and wood preservative materials. In this study, we characterized the chemical composition of this extract by GC and GC/MS. The antioxidant capacity was evaluated using a variety of antioxidant assays （superoxide radical, hydroxyl radical, nitric oxide radical, and DPPH radical scavenging activity）. Additionally, total polyphenolic content was determined. Phenolic acids and acetone derivatives were major compounds of the extract capable of scavenging the DPPH free radical and reducing ferric ions. DPPH and ferric ion reduction results were strongly correlated with total phenolic content of the extract which also exhibited strong nitric oxide, hydroxyl radical scavenging and superoxide anion radical scavenging activities.展开更多
A heavy metal contaminated soil sample collected from a mine in Chonnam Province of South Korea was found to be a source of heavy metal adsorbing biosorbents. Chemical analyses showed high contents of lead （Pb） at 3...A heavy metal contaminated soil sample collected from a mine in Chonnam Province of South Korea was found to be a source of heavy metal adsorbing biosorbents. Chemical analyses showed high contents of lead （Pb） at 357 mg/kg and cyanide （CN） at 14.6 mg/kg in the soil. The experimental results showed that Penicillium sp. MRF-1 was the best lead resistant fungus among the four individual metal tolerant fungal species isolated from the soil. Molecular characterization of Penicillium sp. MRF-1 was determined using ITS regions sequences. Effects of pH, temperature and contact time on adsorption of Pb（Ⅱ） by Penicillium sp. MRF-1 were studied. Favorable conditions for maximum biosportion were found at pH 4 with 3 hr contact time. Biosorption of Pb（Ⅱ） gradually increased with increasing temperature. Efficient performance of the biosorbent was described using Langmuir and Freundlich isotherms. Adsorption kinetics was studied using pseudo first-order and pseudo second-order models. Biosorbent Penicillium sp. MRF-1 showed the maximum desorption in alkali conditions. Consistent adsorption/desorption potential of the biosorbent in repetitive cycles validated the efficacy of it in large scale. SEM studies given notes on surface modification of fungal biomass under metal stress and FT-IR results showed the presence of amino groups in the surface structure of the biosorbent. In conclusion, the new biosorbent Penicillium sp. MRF- 1 may potentially be used as an inexpensive, easily cultivatable material for the removal of lead from aqueous solution.展开更多
文摘The aqueous extract of Phellodendron amurense Rupr. （Amur Cork Tree） provides a rich source of antioxidants and chemical compounds, and can be used for food and wood preservative materials. In this study, we characterized the chemical composition of this extract by GC and GC/MS. The antioxidant capacity was evaluated using a variety of antioxidant assays （superoxide radical, hydroxyl radical, nitric oxide radical, and DPPH radical scavenging activity）. Additionally, total polyphenolic content was determined. Phenolic acids and acetone derivatives were major compounds of the extract capable of scavenging the DPPH free radical and reducing ferric ions. DPPH and ferric ion reduction results were strongly correlated with total phenolic content of the extract which also exhibited strong nitric oxide, hydroxyl radical scavenging and superoxide anion radical scavenging activities.
基金supported by Agricultural R&D Promotion Center,South Korea (No. 060101001)
文摘A heavy metal contaminated soil sample collected from a mine in Chonnam Province of South Korea was found to be a source of heavy metal adsorbing biosorbents. Chemical analyses showed high contents of lead （Pb） at 357 mg/kg and cyanide （CN） at 14.6 mg/kg in the soil. The experimental results showed that Penicillium sp. MRF-1 was the best lead resistant fungus among the four individual metal tolerant fungal species isolated from the soil. Molecular characterization of Penicillium sp. MRF-1 was determined using ITS regions sequences. Effects of pH, temperature and contact time on adsorption of Pb（Ⅱ） by Penicillium sp. MRF-1 were studied. Favorable conditions for maximum biosportion were found at pH 4 with 3 hr contact time. Biosorption of Pb（Ⅱ） gradually increased with increasing temperature. Efficient performance of the biosorbent was described using Langmuir and Freundlich isotherms. Adsorption kinetics was studied using pseudo first-order and pseudo second-order models. Biosorbent Penicillium sp. MRF-1 showed the maximum desorption in alkali conditions. Consistent adsorption/desorption potential of the biosorbent in repetitive cycles validated the efficacy of it in large scale. SEM studies given notes on surface modification of fungal biomass under metal stress and FT-IR results showed the presence of amino groups in the surface structure of the biosorbent. In conclusion, the new biosorbent Penicillium sp. MRF- 1 may potentially be used as an inexpensive, easily cultivatable material for the removal of lead from aqueous solution.
