大孔吸附树脂对杜仲叶中绿原酸、总黄酮的分离研究

通过对静态吸附容量和洗脱效果的选择，从10种大孔吸附树脂中确定出最适于杜仲叶中绿原酸、总黄酮分离的XDA-5树脂。研究了用该树脂吸附分离杜仲叶中绿原酸和总黄酮的方法，得出以下结论：1)杜仲叶绿原酸和总黄酮的最佳分离工艺为：上柱液pH值为2-3，静态吸附时间8h，绿原酸最佳洗脱剂为10％～15％乙醇溶液，黄酮洗脱剂为50％-70％乙醇溶液，流速为每分钟流出液体积相当于吸附剂体积的8％；2)10％～15％乙醇洗脱液经真空浓缩后，其固形物得率为4．85％，绿原酸含量为36．65％；3)50％～70％乙醇洗脱液经真空浓缩后，其固形物得率为4．98％，总黄酮含量为28．34％。     

大孔树脂提纯竹叶黄酮的吸附解吸动力学研究

通过对4种大孔吸附树脂吸附率及解吸率的测定,确定最佳型号树脂;通过静态和动态吸附解吸动力学研究,确定大孔树脂吸附法分离竹叶黄酮的最佳工艺条件。结果表明,AB-8型大孔树脂吸附量大,易于洗脱,纯化分离效果好。获得最佳分离纯化工艺参数为：上柱溶液pH为5．0,以1．0mL/min的吸附流速上样,用4倍床体积的60％乙醇以1．5mL／min洗脱速率洗脱。该工艺生产的竹叶黄酮纯度达到54．16％。     

大孔吸附树脂提取甜茶苷的研究

从6种大孔树脂中筛选了适宜的提取分离甜茶苷的吸附剂,研究了大孔吸附树脂提取甜茶苷的工艺,包括甜茶苷溶液的质量浓度、pH值和流速对吸附过程的影响,解吸荆及解吸温度对解吸过程的影响。结果表明：AB-8树脂是理想的甜茶苷吸附剂,其吸附甜茶苷较理想的工艺条件是：原料液质量浓度约为7．7ms／L,pH值约为8,流速为3BV／h（BV为层析柱中树脂床的体积）;理想的洗脱条件为：流速为3BV／h,室温下以70％乙醇溶液为洗脱剂,用量为5BV,或40℃下,以60％乙醇溶液为洗脱剂,用量为4BV。实验室利用该工艺成功地分离出甜茶苷。     

滑菇子实体多糖纯化工艺的初步研究

试验比较了3种大孔树脂对滑菇多糖的纯化效果,并研究了纯化效果最好的大孔树脂的纯化工艺。试验结果表明,AB-8大孔树脂对滑菇子实体多糖分离纯化的效果最好,而且AB-8型树脂对滑菇多糖纯化工艺为,吸附时间3h,pH值5．0,样品浓度1．5mg／mL,洗脱剂为70％乙醇溶液,解吸时间4h,洗脱速率2mL／min,在此工艺条件下纯化效果最好,即：吸附率为86．67％,解吸率为71．38％,纯化的滑菇多糖产品中多糖含量为78．64％,是滑菇多糖粗品的1．3倍。     

LSA-10大孔吸附树脂分离纯化栀子黄色素研究

通过静态吸附试验选择对栀子黄色素吸附效果较佳的大孔吸附树脂,然后通过动态吸附试验考察上样流速、上样浓度、洗脱剂对大孔吸附树脂分离纯化栀子黄色素的影响。结果表明,LSA-10大孔吸附树脂能高效分离纯化栀子黄色素。分离纯化条件为:上样液体积与树脂质量的比值为5∶1(mL∶g),上样流速为6mL/min,上样浓度为7mg/mL,先用水洗脱杂质和部分的栀子苷,再用浓度为20%乙醇洗脱栀子苷,最后用浓度为80%的乙醇洗脱栀子黄色素。在此条件下,得到色价为337.5,OD值为0.37的栀子黄色素产品。LSA-10大孔吸附树脂适合于高效分离纯化栀子黄色素。     

配位吸附树脂对沙棘中黄酮类成分的吸附分离

【目的】研究配位吸附树脂在非水体系中对沙棘中黄酮类成分的吸附情况。【方法】通过静态吸附与解吸实验考察树脂的吸附性能,选择对黄酮类成分吸附效果最佳的配位吸附树脂,对沙棘提取液中黄酮类成分进行分离纯化;采用HPLC法测定沙棘黄酮的含量。【结果】配位吸附树脂在环己烷体系中吸附作用较好,动态吸附饱和吸附量为33．16-g／g;以5％HAc乙醇溶液为洗脱剂,消耗10BV溶剂洗脱率为93％;经过3次重复实验树脂吸附量及洗脱率基本没有变化。【结论】经配位吸附树脂吸附分离后沙棘提取物中黄酮纯度由14．93％提高到55．74％,起到纯化精制的目的。树脂不需要再生,连续使用吸附性能稳定。     

大孔吸附树脂对蓝莓花色苷的分离工艺

以蓝莓果提取液为原料,研究了12种大孔树脂对花色苷的静态吸附与解吸效果,对比了5种对花色苷分离效果较优树脂的静态等温吸附曲线,优化了最优树脂分离纯化蓝莓花色苷的工艺技术参数。研究结果表明XDA-7最适用于蓝莓花色苷的分离纯化,最佳吸附工艺是:室温条件下,蓝莓提取液pH值3.0、质量浓度0.94 g/L、流速30 mL/h,最大吸附量15.41 g/L(湿树脂);最佳洗脱工艺是:室温条件下,80%甲醇、pH值3.0、流速60 mL/h、洗脱剂量75 mL,解吸率达92.65%。在该工艺参数下,经XDA-7树脂纯化冷冻干燥所得产品为紫黑色粉末,花色苷纯度由2.20%提高到24.54%,花色苷得率为70.2%,产品色价为121。     

树脂静态吸附法生产茶多酚初步试验

以食用酒精为提取溶剂,AB-8树脂为吸附剂,用溶剂提取萃取法工业化生产茶多酚的装置对树脂静态吸附法工业化生产茶多酚进行初步试验。结果表明:用60%酒精提取干茶叶,回收酒精后的物料用硫酸调至pH为1.5,过滤,滤液用水稀释9倍并调pH为1.5,再用AB-8树脂静态吸附,吸附饱和的AB-8树脂用pH为3的5%酒精淋洗,再用70%的酒精解吸,解吸液回收酒精后,喷雾干燥得到茶多酚成品;成品中儿茶素总量达88.6%,产品得率达10.5%。     

茶多酚、茶氨酸联合分离提取的研究

以绿茶为原料,先采用ZJL大孔离子交换树脂从茶叶的浸提液中提取茶氨酸和脱除咖啡因,再用ZJX大孔吸附树脂提取茶多酚.通过对树脂的静态、动态吸附性能的实验研究,确定了茶多酚、茶氨酸联合分离提取的工艺.研究结果表明:该工艺能很好地脱除咖啡因,提取的茶氨酸纯度达85.43%,提取率为0.94%;提取的茶多酚纯度达95.62%,提取率为12.35%,且茶多酚中的咖啡因含量低于0.8%.     

大孔吸附树脂提甜茶苷的研究

从6种大孔树脂中筛选了适宜的提取分离甜茶苷的吸附剂,研究了大孔吸附树脂提取甜茶苷的工艺,包括甜茶苷溶液的质量浓度、pH值和流速对吸附过程的影响,解吸剂及解吸温度对解吸过程的影响.结果表明:AB-8树脂是理想的甜茶苷吸附剂,其吸附甜茶苷较理想的工艺条件是:原料液质量浓度约为7.7mg/L,pH值约为8,流速为3BV/h(BV为层析柱中树脂床的体积);理想的洗脱条件为:流速为3BV/h,室温下以70%乙醇溶液为洗脱剂,用量为5BV,或40℃下,以60%乙醇溶液为洗脱剂,用量为4BV.实验室利用该工艺成功地分离出甜茶苷.     

大孔树脂ADS-7分离纯化多穗柯黄酮工艺研究

采用大孔树脂ADS-7分离纯化多穗柯黄酮粗提物(CE),对主要工艺条件进行了研究。得出最佳工艺条件为:将CE先配成10%(体积分数)CE溶液,10?溶液体积与树脂质量比值(mL∶g)略大于3、在中性pH值下静态吸附2 h,再以3倍装柱体积(1 500 mL)的80%(体积分数)乙醇、每小时1倍装柱体积流速进行动态洗脱。该工艺条件得到的纯化产物中黄酮的质量分数由粗提物中的40%提高到纯化产物的88%,得率为91%。     

茶皂素提取与精制方法的改进研究

以无水乙醇为提取剂并采取改进的胆甾醇纯化法，得到了精制茶皂素，40．0g油茶籽粉经脱油处理后用300mL无水乙醇提取。所得粗品经素氏抽提除杂并制得皂素－胆甾醇复合物（投料质量为比为胆甾醇：皂素＝0．75：1）。以甲苯为溶剂再次索氏抽提分离该复合物，同时得到纯度为98．5％以上的茶皂素精品。     

黄连木叶的多酚提取和抗氧化研究

以黄连木叶为原料,比较了不同溶剂以及超声和微波辅助对多酚提取率的影响,在单因素实验的基础上采用正交实验对多酚提取工艺参数进行了优化。结果显示最佳提取条件为乙醇50%、超声时间20 min、提取温度70℃、料液比1∶20,多酚得率15.39%。滤液经乙酸乙酯萃取,减压蒸馏,低温干燥成粉末,多酚纯度达到78.96%。用DPPH清除法对提取物的自由基清除作用进行测定,其体外抗氧化活性高于维生素C(Vc),与纯度为98%的茶多酚相当。     

Isolation and characterization of a germination inhibitor from leaves of Empetrum hermaphroditum hagerup

An extract of Empetrum hermaphroditum Hagerup leaves was examined for germination inhibitors using an assay based on germination of Populus tremula L. seeds. The substances were extracted in water and purified by solvent partitioning. The acidic ethyl acetate fraction, containing the major part of the inhibitory activity was purified by reversed‐phase high‐performance liquid chromatography. Two zones of inhibitory activity were detected, combined and further purified by normal‐phase HPLC. One major zone of inhibitory activity was thereafter detected and the substance in this fraction was crystallized and identified by nuclear magnetic resonance and gas chromatography‐mass spectrometry as 5‐methoxy‐3,3´‐dihydroxy‐dihydrostilbene or batatasin III. Ca. 100 mg of the substance was then, by sequential HPLC, isolated in crystalline form from E. hermaphroditum leaves. The inhibitory activity of the pure substance was compared with a crude water extract of E. hermaphroditum leaves. It was concluded that the pure substance exhibited ca. 28 % of the inhibitory activity of the crude extract. The difference in inhibitory activity might be explained by the presence of a glucosidic conjugate of 5‐methoxy‐3,3´‐dihydroxy‐dihydrostilbene in the crude extract.     

The aromatic and polyphenolic composition of lemon verbena tea

The chemical composition of the largely used tea from lemon verbena, Aloysia triphylla, was investigated. The qualitative and quantitative composition of the main aromatic and polyphenolic constituents of tea made by infusion from leaves were examined. The results showed that the relative proportions of the active constituents differ from those of the original leaves. The tea contained a large amount of polyphenolic compounds (mean value 675 mg/l; extraction yield 65%) including verbascoside (400 mg/l) and luteolin 7-diglucuronide (100 mg/l). It contained also 42 mg/l of essential oil (extraction yield 51%) with much more citral (77% of the essential oil) than the original leaves (41%).     

茶树不同器官氨同化关键酶活性测定及比较

为取得茶树氨同化关键酶活性的最优测定方法,以4个茶树品种的不同器官为材料,比较和讨论了不同器官间和品种间氨同化关键酶活性,对Tris-HCl缓冲液不同pH值的条件下提取的氨同化关键酶活性分析比较,得出缓冲液对酶活性的影响以及4个茶树品种的最适宜pH值。结果表明缓冲液的pH值对茶树顶芽、当年生叶、2年生叶以及根系的酶活性影响极显著,并且均以缓冲液pH值为7.0时得到的酶活性较高。4个器官的GS活性基本上是随缓冲液pH值的升高而增强,并且在pH7.0和7.5时处于较高水平;4种器官的GOGAT活性则是随pH的升高呈现"下降-上升-下降"的变化,当年生叶和2年生叶片的GOGAT活性在pH6.0时最低,之后开始上升,根系和顶芽则是在pH6.5时最低。主成分分析结果表明,缓冲液pH7.0是研究4个茶树品种4个器官氨同化酶活性的最优pH值。品种间GS活性差异显著,GOGAT活性差异极显著;器官间GS和GOGAT活性差异均极显著。     

锰对苦丁茶化学品质的影响

为探讨锰对苦丁茶化学品质的影响,采用国际通用的营养液配方对苦丁茶进行砂培盆栽试验。结果表明：MnCl2·4H2O对苦丁茶叶片中游离氨基酸、可溶性蛋白、维生素C等含量的提高非常有利。锰处理苦丁茶30 d后,上述各物质含量均随着锰质量浓度的增加呈先增加后降低的变化,而锰和皂苷则随着质量浓度的增加而增加。MnCl2·4H2O质量浓度为6.0 mg/L时,苦丁茶叶片中可溶性蛋白、维生素C、黄酮及茶多酚含量最高,此质量浓度对提高这几种化学物质含量较好;MnCl2·4H2O质量浓度为8.0 mg/L时,苦丁茶叶片中锰和皂苷含量最高,分别为0.555μg/g和0.828 mg/g。酚氨比随着锰质量浓度的增加先增加后降低。以MnCl2·4H2O质量浓度为6.0mg/L时茶多酚、黄酮、游离氨基酸和可溶性蛋白含量最高,品质良好,开发利用价值相对较好。     

Do tannins in leaves of trees and shrubs from African and Himalayan regions differ in level and activity?

Mature leaves of trees and shrubs from sub-humid tropical regions of Benin (Acioa barteri, Cassia sieberiana, Dialium guineense, Dichrostachys cinerea, Guiera senegalensis, Milletia thonningii, Piliostigma reticulatum) and arid and semiarid regions of Zimbabwe and Niger (Acacia holosericea, A. nilotica, Dichrostachys cinerea, Securidaca longepedunculata, Parinari cuvetelio, Ziziphus mucronata) in Africa, and from sub-tropical region in foot-hills of North-West Humid Himalayan range (Albizia stipulata, Bauhenia variegata, Cedrela toona, Celtis australis, Dendrocalamus hamiltonii, Grewia optiva, Leucocephala leucocephala, Morus alba, Papulus ciliata, Quercus incana, Q. semecarpifolia, Q. glauca, Q. serrata, Q. ilex, Robinia pseudoacacia, Salix tetrasperma) were analysed for crude protein, total phenols (TP), protein precipitation capacity (PPC) and operational activity of tannins (values are as mean ± SE). There was no significant difference in the crude protein values of forages obtained from the Himalayan and African region (15.2 ± 1.16 and 14.1 ± 1.19%, respectively), however the levels of TP and biological value of tannins as PPC were significantly higher for the African forages (TP 15.7 ± 4.27 vs 6.0 ± 1.0%; PPC 327.2 ± 113.6 vs 56 ± 15.9 mg bovine serum albumin precipitated/g). The operational activity of tannins expressed as mg protein precipitated per unit of phenols was also significantly higher in forages from the African regions (1.97 ± 0.47 vs 0.66 ± 0.17). For a small set of leaves from arid and semiarid zones of Middle East (Syria, A. cyanophylla; Israel, A. saligna) and India (Eugenia jambolana, Eucalyptus punctata, Prosopis cineraria and Shorea robusta) TP, PPC and tannin activity were closer to those for the African forages.This revised version was published online in November 2005 with corrections to the Cover Date.