A new alkaloid was isolated from the bulbs of Lycoris aurea （L＇Herit.） Herb. Its structure was established as 3-o-ethyltazettinol through chemical and spectroscopic studies including 2D NMR.
Acetylcholinesterase （ACHE） plays an important role in enzyme-based detection of pesticides in the environment. In this paper, ACHE from the Triton X-100 extract of brain tissues of Oreochromis aurea was purified by...Acetylcholinesterase （ACHE） plays an important role in enzyme-based detection of pesticides in the environment. In this paper, ACHE from the Triton X-100 extract of brain tissues of Oreochromis aurea was purified by （NH4）2SO4 fractional precipitation, Sephadex G-100 gel filtration, and DEAE-cellulose ion exchange chromatography. Certain biochemical characterizations of the purified enzyme and inhibition of pesticides on the enzyme were also studied. The specific activity of this purified enzyme was 20.628 U/mg protein, fold of purification was 139, and recovery was 22.1%. The optimal temperature of this enzyme was between 35-40 ℃, and optimal pH was between 7.5-8.0. The Michaelis constant （Kin） for acetylthiocholine iodide was 0.183 mmol/L. The enzyme activity was inhibited by excess substrate, and optimal substrate concentration was 6 mmol/L. Four pesticides （dichlorvos, phoxim, triazophos, and methomyl） exhibited strong inhibitions on this enzyme with IC50 less than 5 μg/mL. This study suggests that Oreochromis aurea （tilapia） could be a good enzyme source for pesticide monitoring in water environments.展开更多
[Objectives]To explore the antimicrobial and antioxidant activities of flavonoid and polysaccharide extracts from bulbs of Lycoris aurea.[Methods]The disc diffusion method was used to evaluate the antimicrobial activi...[Objectives]To explore the antimicrobial and antioxidant activities of flavonoid and polysaccharide extracts from bulbs of Lycoris aurea.[Methods]The disc diffusion method was used to evaluate the antimicrobial activity of flavonoid and polysaccharide extracts from the bulbs of L.aurea.The antioxidant activity was determined by scavenging of hydroxyl and 1,1-diphenyl-2-picrylhydrazine(DPPH)free radicals,and reducing ability.[Results]Flavonoids were effective on 7 microorganisms,but polysaccharides had no effect.Flavonoids had better hydroxyl free radical scavenging activity and reducing capacity than polysaccharides,but weaker than ascorbic acid.However,flavonoids had similar DPPH free radical activity to ascorbic acid.The strong antibacterial and antioxidant activities of flavonoids were mainly attributed to the high content of total phenols in the extract,which was(76.71±4.42)mg/g.[Conclusions]The study shows that flavonoids from bulbs of L.aurea could be regarded as a new potential source of natural bacterial inhibitors and antioxidants.展开更多
Mature eggs of Oreochromis aurea were obtained with artificial reproduction technology, and the hybrids were acquired with Siniperca chuatsi (♂) using artificial insemination . Genomic DNA of O. aurea (♀), S. chuats...Mature eggs of Oreochromis aurea were obtained with artificial reproduction technology, and the hybrids were acquired with Siniperca chuatsi (♂) using artificial insemination . Genomic DNA of O. aurea (♀), S. chuatsi (♂) and their progeny were examined using RAPD method. Only 2 primers (S336, OPZ06) of screened 11 random primers could be amplified into two specifically RAPD bands on progeny which were the same as those of S. chuatsi (♂) and did not exist in O. aurea (♀), and other amplified bands on progeny were all from O. aurea (♀). Genetic similarity index was 0.858 between the progeny and O. aurea (♀), while that was (0.049) between the progeny and S. chuatsi (♂). This indicated that the genetic substance of progeny was mostly from O. aurea (♀). The primary function of sperm from S. chuatsi (♂) was stimulating development of eggs from O. aurea (♀), at the same time little genetic substance of S.chuatsi(♂) appeared in the progeny, which laid the foundation for breeding of fine varieties having characters of O. aurea (♀) and S. chuatsi (♂).展开更多
基金support from National Natural Science Foundation of China(No.30572312)
文摘A new alkaloid was isolated from the bulbs of Lycoris aurea （L＇Herit.） Herb. Its structure was established as 3-o-ethyltazettinol through chemical and spectroscopic studies including 2D NMR.
基金supported by Huizhou Science and Technology Planning Project Foundation (Grant No.2008P60)
文摘Acetylcholinesterase （ACHE） plays an important role in enzyme-based detection of pesticides in the environment. In this paper, ACHE from the Triton X-100 extract of brain tissues of Oreochromis aurea was purified by （NH4）2SO4 fractional precipitation, Sephadex G-100 gel filtration, and DEAE-cellulose ion exchange chromatography. Certain biochemical characterizations of the purified enzyme and inhibition of pesticides on the enzyme were also studied. The specific activity of this purified enzyme was 20.628 U/mg protein, fold of purification was 139, and recovery was 22.1%. The optimal temperature of this enzyme was between 35-40 ℃, and optimal pH was between 7.5-8.0. The Michaelis constant （Kin） for acetylthiocholine iodide was 0.183 mmol/L. The enzyme activity was inhibited by excess substrate, and optimal substrate concentration was 6 mmol/L. Four pesticides （dichlorvos, phoxim, triazophos, and methomyl） exhibited strong inhibitions on this enzyme with IC50 less than 5 μg/mL. This study suggests that Oreochromis aurea （tilapia） could be a good enzyme source for pesticide monitoring in water environments.
基金Independent Application Project of Agricultural and Social Development Scientific Research in Hangzhou(20191203B31).
文摘[Objectives]To explore the antimicrobial and antioxidant activities of flavonoid and polysaccharide extracts from bulbs of Lycoris aurea.[Methods]The disc diffusion method was used to evaluate the antimicrobial activity of flavonoid and polysaccharide extracts from the bulbs of L.aurea.The antioxidant activity was determined by scavenging of hydroxyl and 1,1-diphenyl-2-picrylhydrazine(DPPH)free radicals,and reducing ability.[Results]Flavonoids were effective on 7 microorganisms,but polysaccharides had no effect.Flavonoids had better hydroxyl free radical scavenging activity and reducing capacity than polysaccharides,but weaker than ascorbic acid.However,flavonoids had similar DPPH free radical activity to ascorbic acid.The strong antibacterial and antioxidant activities of flavonoids were mainly attributed to the high content of total phenols in the extract,which was(76.71±4.42)mg/g.[Conclusions]The study shows that flavonoids from bulbs of L.aurea could be regarded as a new potential source of natural bacterial inhibitors and antioxidants.
文摘Mature eggs of Oreochromis aurea were obtained with artificial reproduction technology, and the hybrids were acquired with Siniperca chuatsi (♂) using artificial insemination . Genomic DNA of O. aurea (♀), S. chuatsi (♂) and their progeny were examined using RAPD method. Only 2 primers (S336, OPZ06) of screened 11 random primers could be amplified into two specifically RAPD bands on progeny which were the same as those of S. chuatsi (♂) and did not exist in O. aurea (♀), and other amplified bands on progeny were all from O. aurea (♀). Genetic similarity index was 0.858 between the progeny and O. aurea (♀), while that was (0.049) between the progeny and S. chuatsi (♂). This indicated that the genetic substance of progeny was mostly from O. aurea (♀). The primary function of sperm from S. chuatsi (♂) was stimulating development of eggs from O. aurea (♀), at the same time little genetic substance of S.chuatsi(♂) appeared in the progeny, which laid the foundation for breeding of fine varieties having characters of O. aurea (♀) and S. chuatsi (♂).
