本文阐述一种高效,环保制备高价值天然抗氧化剂根皮素的方法。以天然的柑橘提取物柚皮苷为原料,经一锅法加氢反应制得柚苷二氢查尔酮,再以α-鼠李糖苷酶(α-rhamnosidase)和纤维素酶(cellulase)高效催化水解而制得根皮素。采用单因素和...本文阐述一种高效,环保制备高价值天然抗氧化剂根皮素的方法。以天然的柑橘提取物柚皮苷为原料,经一锅法加氢反应制得柚苷二氢查尔酮,再以α-鼠李糖苷酶(α-rhamnosidase)和纤维素酶(cellulase)高效催化水解而制得根皮素。采用单因素和正交实验对α-鼠李糖苷酶和纤维素酶酶解反应的p H、温度、酶与底物比进行优化,同时对根皮素、三叶苷、柚苷二氢查尔酮、柚苷的抗氧化性进行了研究,结果表明:α-鼠李糖苷酶(α-rhamnosidase)酶解最佳工艺为温度60℃、p H 4、酶与底物比为0.6:1;纤维素酶(cellulase)最佳工艺为温度45℃、p H 5.5、酶与底物比为0.3:1。在此工艺下根皮素的转化率为96.10%,比原工艺提高了10.53%。抗氧化性研究结果为:清除DPPH自由基能力根皮素(0.18±1.45)>三叶苷(0.3±1.63)>柚苷二氢查尔酮(0.95±1.24)>柚苷(8±1.97),还原铁离子能力为根皮素(7.1±0.68)>三叶苷(2.51±0.75)>柚苷二氢查尔酮(2.05±0.58)>柚苷(0.11±0.92)。本方法条件温和,周期短且转化率高,易于放大生产。抗氧化性结果表明根皮素具有较高的抗氧化性。这对根皮素的放大生产及应用具有重大意义。展开更多
Identification of differentially expressed salivary gland proteins between the fed and unfed female Rhipicephalus haemaphysaloides may obtain valuable functional molecules. In this study, comparative two-dimensional g...Identification of differentially expressed salivary gland proteins between the fed and unfed female Rhipicephalus haemaphysaloides may obtain valuable functional molecules. In this study, comparative two-dimensional gel electrophoresis (2-DE) and mass spectrometry were used to separate and identify differentially expressed salivary gland proteins between the fed and unfed female R. haemaphysaloides. The soluble proteins from the salivary glands of fed and unfed female R. haemaphysaloides were separated by a sequential extraction method followed by 2-DE and 2-DE images. Image analysis of the gels revealed 1 096 ± 87 protein spots from the fed female ticks and 991 ±64 protein spots from the unfed female ticks. Among those protein spots, about 724 ±34 were present both in the fed and unfed female ticks. Fourteen spots from the fed ticks and six spots from the unfed ticks were selected for peptide mass fingerprinting (PMF) and sequencing assay by mass spectrometry (MS). Bioinformatic analysis showed that a majority of the differentially expressed proteins were involved in signal transduction, metabolism, and transcriptional regulation. These differentially expressed proteins might be antigen candidates for the development of vaccines against the tick.展开更多
Ixodid ticks play an important role in the transmission of a variety of zoonoses of viral, bacterial and protozoan origin, and they also harbor a wealth of microorganisms. To gain more detailed insights into the poten...Ixodid ticks play an important role in the transmission of a variety of zoonoses of viral, bacterial and protozoan origin, and they also harbor a wealth of microorganisms. To gain more detailed insights into the potential interactions between bacterial flora and tick-borne pathogens, we investigated the midgut bacterial flora of laboratory-reared Haemaphysalis longicornis, Hyalomma asiaticum and Rhipicephalus haemaphysaloides. Based on morphological, biochemical, and 16 S rDNA sequencing results, we identified 15 species belonging to 12 genera in the midgut of the three ticks. The bacterial communities were similar to those found in other studies of hematophagous arthropods. Kocuria sp. was the most frequently isolated species and its 16 S rDNA gene sequence was very similar to Kocuria koreensis P31 T. To our knowledge, this is the first report of the bacterial flora of tick midguts and the results show that there were many different bacterial species in each tick species. Among the most common genera, there may have been a novel species in the genus Kocuria. The results might be the first step for looking for different aspects of the pathogen and tick interaction.展开更多
文摘本文阐述一种高效,环保制备高价值天然抗氧化剂根皮素的方法。以天然的柑橘提取物柚皮苷为原料,经一锅法加氢反应制得柚苷二氢查尔酮,再以α-鼠李糖苷酶(α-rhamnosidase)和纤维素酶(cellulase)高效催化水解而制得根皮素。采用单因素和正交实验对α-鼠李糖苷酶和纤维素酶酶解反应的p H、温度、酶与底物比进行优化,同时对根皮素、三叶苷、柚苷二氢查尔酮、柚苷的抗氧化性进行了研究,结果表明:α-鼠李糖苷酶(α-rhamnosidase)酶解最佳工艺为温度60℃、p H 4、酶与底物比为0.6:1;纤维素酶(cellulase)最佳工艺为温度45℃、p H 5.5、酶与底物比为0.3:1。在此工艺下根皮素的转化率为96.10%,比原工艺提高了10.53%。抗氧化性研究结果为:清除DPPH自由基能力根皮素(0.18±1.45)>三叶苷(0.3±1.63)>柚苷二氢查尔酮(0.95±1.24)>柚苷(8±1.97),还原铁离子能力为根皮素(7.1±0.68)>三叶苷(2.51±0.75)>柚苷二氢查尔酮(2.05±0.58)>柚苷(0.11±0.92)。本方法条件温和,周期短且转化率高,易于放大生产。抗氧化性结果表明根皮素具有较高的抗氧化性。这对根皮素的放大生产及应用具有重大意义。
基金supported by the National High Technology Research and Development Program of China(2006AA 10A207)the Basic Research Foundationfor National Commonweal Institute of China(2006JB02)
文摘Identification of differentially expressed salivary gland proteins between the fed and unfed female Rhipicephalus haemaphysaloides may obtain valuable functional molecules. In this study, comparative two-dimensional gel electrophoresis (2-DE) and mass spectrometry were used to separate and identify differentially expressed salivary gland proteins between the fed and unfed female R. haemaphysaloides. The soluble proteins from the salivary glands of fed and unfed female R. haemaphysaloides were separated by a sequential extraction method followed by 2-DE and 2-DE images. Image analysis of the gels revealed 1 096 ± 87 protein spots from the fed female ticks and 991 ±64 protein spots from the unfed female ticks. Among those protein spots, about 724 ±34 were present both in the fed and unfed female ticks. Fourteen spots from the fed ticks and six spots from the unfed ticks were selected for peptide mass fingerprinting (PMF) and sequencing assay by mass spectrometry (MS). Bioinformatic analysis showed that a majority of the differentially expressed proteins were involved in signal transduction, metabolism, and transcriptional regulation. These differentially expressed proteins might be antigen candidates for the development of vaccines against the tick.
基金supported by grants from the Special Fund for National Commonweal Institute of China (2012JB12)
文摘Ixodid ticks play an important role in the transmission of a variety of zoonoses of viral, bacterial and protozoan origin, and they also harbor a wealth of microorganisms. To gain more detailed insights into the potential interactions between bacterial flora and tick-borne pathogens, we investigated the midgut bacterial flora of laboratory-reared Haemaphysalis longicornis, Hyalomma asiaticum and Rhipicephalus haemaphysaloides. Based on morphological, biochemical, and 16 S rDNA sequencing results, we identified 15 species belonging to 12 genera in the midgut of the three ticks. The bacterial communities were similar to those found in other studies of hematophagous arthropods. Kocuria sp. was the most frequently isolated species and its 16 S rDNA gene sequence was very similar to Kocuria koreensis P31 T. To our knowledge, this is the first report of the bacterial flora of tick midguts and the results show that there were many different bacterial species in each tick species. Among the most common genera, there may have been a novel species in the genus Kocuria. The results might be the first step for looking for different aspects of the pathogen and tick interaction.