超声波法提取荷叶多酚工艺研究

研究利用超声波辅助提取荷叶中多酚类化合物的最佳条件,考察了超声作用时间、提取次数、料液比和乙醇体积分数等因素对荷叶多酚提取率的影响,并在单因素实验的基础上进行正交实验,确定其优化工艺条件为:乙醇体积分数60%,作用时间15 m in,料液比为1:14,提取次数为4次。     

响应面法优化超声辅助提取贯众多酚工艺

利用响应面法优化贯众多酚的提取工艺。在单因素试验的基础上,选择超声时间、超声温度、料液比、乙醇浓度为自变量,贯众中多酚的提取率为响应值,进行Box-Benhnken中心组合实验设计,运用响应面法优化提取条件,得到最优提取条件如下:超声时间20 min,超声温度46℃,料液比1∶40,乙醇浓度35%,经验证,贯众中多酚的提取率为8.11660%,理论值为8.12986%,RSD为0.15%。该工艺高效、稳定,有一定的应用价值。     

刺葡萄籽中多酚的超声波提取及提取物中齐墩果酸的含量分析

本文研究了超声波法提取刺葡萄籽中多酚类物质的方法,考察了提取剂、提取时间、料液比等因素对提取率的影响。结果表明,用超声波法进行多酚类物质提取的最佳工艺条件为：以70％的丙酮水溶液为提取剂,料液比为1：10,室温下超声波提取两次,每次30min。采用Folin—Ciocaheau方法测定粗提物中多酚的含量,得出刺葡萄籽多酚粗提物得率为4．95％,纯度为49．89％。本文还对多酚粗提物中活性成分齐墩果酸进行了进一步的分离、鉴定与检测。     

响应面设计法优化仙鹤草总多酚的超声提取工艺

在单因素实验的基础上,采用响应面分析法对影响超声辅助提取仙鹤草总多酚得率的主要因素(超声温度、料液比和乙醇浓度)进行优化,建立了影响因素与总多酚之间的函数关系。获得最佳工艺条件为:71%乙醇,料液比1∶24,超声提取温度60℃,提取时间20 min。在此最佳条件下,总多酚得率为3.56%,试验结果与模型预测值相符。     

诃子中总多酚含量的测定及其超声提取工艺的研究

目的：利用超声波辅助法提取诃子中总多酚。方法：考察了超声波的提取时间、乙醇浓度、料液比三个单因素对多酚提取率的影响,并在单因素实验基础上进行正交实验。结果：确立了诃子中总多酚的最佳工艺条件为：60%乙醇;料液比为1：20;超声提取60min。总多酚得率为13.27%。结论：此提取方法能够避免多酚在高温下的分解,极大地缩短了提取时间。     

二次旋转正交法优化提取板栗壳斗中多酚类物质的工艺及其抗氧化性研究

为实现二次旋转正交法优化提取板栗壳斗中多酚类抗氧化剂,本文用板栗壳为原材料,采用传统水液溶解和加热提取的工艺,以单因素的结果设计二次旋转正交实验,以总多酚提取率为评定对象,得出板栗壳中多酚提取的最佳工艺条件,并对产品进行了抗氧化测试和光谱分析。实验结果表明,板栗壳多酚的最佳工艺条件为:乙醇浓度57%,提取温度85℃,提取时间45 min。在该条件下,板栗壳多酚的最佳提取率为5.44%。当多酚浓度为1 mg/m L时,产品对羟基自由基清除率为8.15%。产品的红外光谱和紫外光谱均符合多酚类物质的光谱特征。     

响应面优化-超声提取黄姜中总黄酮工艺研究

目的:利用响应面法对黄姜总黄酮的提取工艺进行优化.方法:在单因素的基础上以超声功率、超声时间、料液比、乙醇浓度为响应因素,黄姜总黄酮的提取率为响应值,根据中心组合实验原理,采用四因素三水平的响应面分析法.结果:确定提取最佳工艺参数为超声时间29.53 min、超声功率为400.76w、料液比为1:42.19、乙醇浓度为79.60％,在此条件下总黄酮提取率的预测值为11.15 (mg/g).结论:考虑到实际操作的问题,将提取最佳工艺参数修正为超声时间30 min、超声功率400w、料液比1:40、乙醇浓度80％,进行3次平行试验,结果总黄酮提取率为11.09 mg/g,绝对误差为0.057％,说明实验结果与模型吻合很好.     

龙脑樟去油枝叶中总多酚的酶解-超声辅助提取及抗氧化活性

为探讨龙脑樟去油枝叶中总多酚的酶解-超声辅助提取工艺,在单因素实验的基础上,通过Box-Behnken设计-响应面法研究纤维素酶用量(X_1)、乙醇浓度(X_2)、液料比(X_3)对龙脑樟去油枝叶中总多酚提取率的影响;同时,以清除DPPH自由基和羟基自由基的能力为评价指标,对总多酚提取物的抗氧化活性进行测定。结果表明,各因素对总多酚提取率的影响顺序为液料比(X_3)乙醇浓度(X_2)酶用量(X_1);酶解-超声辅助提取龙脑樟去油枝叶中总多酚的最优工艺条件为:酶用量1.9%,乙醇浓度54%,液料比34 m L/g,酶解温度50℃,酶解时间1.5 h,超声时间30 min,超声频率45 k Hz,超声功率360 W,超声温度70℃;在此条件下,总多酚提取率的平均值为22.08 mg/g,与预测值相近,二次回归模型预测性良好。总多酚提取物对DPPH自由基和羟基自由基的清除作用均呈现量效关系,半数抑制浓度(IC_(50))值分别为0.36和0.15 mg/m L,表明总多酚提取物具有较强的抗氧化能力。     

枇杷叶中黄酮类化合物提取工艺研究

以枇杷叶为原料,对黄酮类化合物的提取工艺进行研究,考察乙醇浓度、提取温度、提取时间、料液比对枇杷叶中黄酮类化合物提取率的影响,并采用正交实验进行优化。结果表明四种因素对枇杷叶中黄酮类化合物提取率影响的大小顺序为:乙醇浓度>提取时间>提取温度>料液比,枇杷叶中黄酮类化合物提取的最佳工艺条件为提取时间30min、提取温度80℃、乙醇浓度40%、料液比1:20(g/mL),最佳条件下黄酮类化合物提取率为6.92%。     

葡萄皮多酚的提取、纯化及组成研究

以巨峰葡萄皮为原料,采用超声波辅助提取法,研究葡萄皮多酚的提取工艺,并用响应面法进行优化,进一步通过HPLC法确定多酚的组成和含量。得出最佳的提取工艺参数为：料液比1∶40、超声时间1.6h、超声功率430W、乙醇浓度33%,提取率为29.16 mg/g;AB-8型大孔吸附树脂对葡萄多酚分离效果良好;在葡萄皮酚类物质中确定了10种单体酚,其中主要酚类物质为儿茶素,含量为15.74±0.21μg/mg。     

On the origin of the Hirudinea and the demise of the Oligochaeta

The phylogenetic relationships of the Clitellata were investigated with a data set of published and new complete 18S rRNA gene sequences of 51 species representing 41 families. Sequences were aligned on the basis of a secondary structure model and analysed with maximum parsimony and maximum likelihood. In contrast to the latter method, parsimony did not recover the monophyly of Clitellata. However, a close scrutiny of the data suggested a spurious attraction between some polychaetes and clitellates. As a rule, molecular trees are closely aligned with morphology-based phylogenies. Acanthobdellida and Euhirudinea were reconciled in their traditional Hirudinea clade and were included in the Oligochaeta with the Branchiobdellida via the Lumbriculidae as a possible link between the two assemblages. While the 18S gene yielded a meaningful historical signal for determining relationships within clitellates, the exact position of Hirudinea and Branchiobdellida within oligochaetes remained unresolved. The lack of phylogenetic signal is interpreted as evidence for a rapid radiation of these taxa. The placement of Clitellata within the Polychaeta remained unresolved. The biological reality of polytomies within annelids is suggested and supports the hypothesis of an extremely ancient radiation of polychaetes and emergence of clitellates.     

On the ontogeny of the haptor and the evolution of the Monogenea

Data on the ontogeny of the posterior haptor of monogeneans were obtained from more than 150 publications and summarised. These data were plotted into diagrams showing evolutionary capacity levels based on the theory of a progressive evolution of marginal hooks, anchors and other attachment components of the posterior haptor in the Monogenea (Malmberg, 1986). 5 + 5 unhinged marginal hooks are assumed to be the most primitive monogenean haptoral condition. Thus the diagrams were founded on a 5 + 5 unhinged marginal hook evolutionary capacity level, and the evolutionary capacity levels of anchors and other haptoral attachement components were arranged according to haptoral ontogenetical sequences. In the final plotting diagram data on hosts, type of spermatozoa, oncomiracidial ciliation, sensilla pattern and protonephridial systems were also included. In this way a number of correlations were revealed. Thus, for example, the number of 5 + 5 marginal hooks correlates with the most primitive monogenean type of spermatozoon and with few sensillae, many ciliated cells and a simple protonephridial system in the oncomiracidium. On the basis of the reviewed data it is concluded that the ancient monogeneans with 5 + 5 unhinged marginal hooks were divided into two main lines, one retaining unhinged marginal hooks and the other evolving hinged marginal hooks. Both main lines have recent representatives at different marginal hook evolutionary capacity levels, i.e. monogeneans retaining a haptor with only marginal hooks. For the main line with hinged marginal hooks the name Articulon-choinea n. subclass is proposed. Members with 8 + 8 hinged marginal hooks only are here called Proanchorea n. superord. Monogeneans with unhinged marginal hooks only are here called Ananchorea n. superord. and three new families are erected for its recent members: Anonchohapteridae n. fam., Acolpentronidae n. fam. and Anacanthoridae n. fam. (with 7 + 7, 8 + 8 and 9 + 9 unhinged marginal hooks, respectively). Except for the families of Articulonchoinea (e.g. Acanthocotylidae, Gyrodactylidae, Tetraonchoididae) Bychowsky's (1957) division of the Monogenea into the Oligonchoinea and Polyonchoinea fits the proposed scheme, i.e. monogeneans with unhinged marginal hooks form one old group, the Oligonchoinea, which have 5 + 5 unhinged marginal hooks, and the other group form the Polyonchoinea, which (with the exception of the Hexabothriidae) has a greater number (7 + 7, 8 + 8 or 9 + 9) of unhinged marginal hooks. It is proposed that both these names, Oligonchoinea (sensu mihi) and Polyonchoinea (sensu mihi), will be retained on one side and Articulonchoinea placed on the other side, which reflects the early monogenean evolution. Except for the members of Ananchorea [Polyonchoinea], all members of the Oligonchoinea and Polyonchoinea have anchors, which imply that they are further evolved, i.e. have passed the 5 + 5 marginal hook evolutionary capacity level (Malmberg, 1986). There are two main types of anchors in the Monogenea: haptoral anchors, with anlages appearing in the haptor, and peduncular anchors, with anlages in the peduncle. There are two types of haptoral anchors: peripheral haptoral anchors, ontogenetically the oldest, and central haptoral anchors. Peduncular anchors, in turn, are ontogenetically younger than peripheral haptoral anchors. There may be two pairs of peduncular anchors: medial peduncular anchors, ontogentically the oldest, and lateral peduncular anchors. Only peduncular (not haptoral) anchors have anchor bars. Monogeneans with haptoral anchors are here called Mediohaptanchorea n. superord. and Laterohaptanchorea n. superord. or haptanchoreans. All oligonchoineans and the oldest polyonchoineans are haptanchoreans. Certain members of Calceostomatidae [Polyonchoinea] are the only monogeneans with both (peripheral) haptoral and peduncular anchors (one pair). These monogeneans are here called Mixanchorea n. superord. Polyonchoineans with peduncular anchors and unhinged marginal hooks are here called the Pedunculanchorea n. superord. The most primitive pedunculanchoreans have only one pair of peduncular anchors with an anchor bar, while the most advanced have both medial and lateral peduncular anchors; each pair having an anchor bar. Certain families of the Articulonchoinea, the Anchorea n. superord., also have peduncular anchors (parallel evolution): only one family, the Sundanonchidae n. fam., has both medial and lateral peduncular anchors, each anchor pair with an anchor bar. Evolutionary lines from different monogenean evolutionary capacity levels are discussed and a new system of classification for the Monogenea is proposed.In agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. EditorIn agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. Editor