秦艽环烯醚萜苷类成分分离纯化工艺及抑菌活性研究

研究优化XDA-1大孔吸附树脂分离纯化秦艽环烯醚萜苷的最佳工艺,并测试其纯化产物的抑菌活性。以龙胆苦苷的含量为指标,利用动态吸附分离方法,确定秦艽环烯醚萜苷的最佳分离纯化工艺。结果表明XDA-1大孔吸附树脂分离纯化秦艽环烯醚萜苷类化学成分的最佳工艺条件为:上样液浓度0.07 g原药材/mL,pH值为5.0,吸附流速4 BV/h,上样液体积32 BV,洗脱剂浓度50%乙醇溶液,pH值7.0,解吸附流速3 BV/h,洗脱剂用量为8 BV,纯化后环烯醚萜苷含量可达62.97%,并证明了所选的大孔树脂纯化工艺稳定、可靠,值得在生产中推广应用。通过对3种细菌抑菌圈和最小抑菌浓度测定,初步评判该纯化产物的抑菌活性,结果表明,该纯化后产物具有一定的抑菌活性。     

巴戟天抗疲劳功效成分的研究

为探究巴戟天抗疲劳功效及活性成分。实验采用乙醇回流提取,经大孔树脂、MCI、ODS柱层析分离,核磁共振鉴定结构。结果表明,巴戟天醇提物大孔树脂分离得10%乙醇洗脱物对小鼠运动抗疲劳作用效果最明显,再经MCI、ODS柱分离,得到四个化合物单体,分别是耐斯糖(1)、4-羧基-7-羟基-8-羟甲基-3,6-环烯醚萜苷(2)、4-乙酰基-8-羟甲基-3,7-环烯醚萜苷(3)和4-羧基-7-羟基-8-羟甲基-10-乙酰基-3,6-环烯醚萜苷(4)。化合物2、3、4为首次从巴戟天中分离得到的环烯醚萜苷类化合物。     

栀子苷及其衍生物药理活性的研究进展

栀子苷是一种环烯醚萜苷类化舍物,是栀子的主要药效成分。概述了栀子苷及其衍生物对降血糖、抗炎、抗肿瘤、神经退行性疾病的药理活性等作用机制的新近研究进展。     

葛花不同工艺提取物的异黄酮成分含量比较研究

目的:以不同浓度乙醇和大孔吸附树脂法提取和纯化葛花的提取物,并用HPLC和UV进行异黄酮成分含量比较分析。方法:以不同浓度的乙醇回流提取葛花药材制备提取物,并采用大孔吸附树脂对其进行纯化;然后以HPLC法对提取物中的3种主要黄酮类成分进行定量分析,并以UV法测定其总黄酮含量。结果:葛花不同提取物的黄酮类成分含量差别较大;所建立的HPLC方法可以同时测定葛花提取物中鸢尾苷、6"-O-木糖鸢尾苷和染料木素的含量;UV法与HPLC法联合应用,可对不同葛花提取物中的异黄酮类成分进行评价。结论:不同工艺提取的葛花提取物中异黄酮类成分有较大区别,大孔吸附树脂纯化后可显著提高总黄酮的纯度;HPLC联合UV法可共同用于葛花的质量评价及提取工艺的研究。     

牡丹籽饼粕中芍药苷类成分及其大孔吸附树脂纯化研究

采用乙醇提取,树脂纯化,HPLC制备以及LC-MS和1H NMR鉴定,从牡丹籽粕的醇提物中分离纯化了4种主要成分,分别为6'-O-β-D-葡萄糖芍药内酯苷、芍药内酯苷、β-gentiobiosylpaeoniflorin和芍药苷。对大孔吸附树脂法纯化芍药苷类成分的条件进行了试验,从4类11种树脂中筛选出HPD-200A型大孔吸附树脂,其较优的吸附分离条件为:上样液浓度(芍药苷)8.0 mg/mL,上样体积为4.5倍床体积(BV),流速为1/16 BV/min,洗脱剂乙醇溶液浓度为50%(v/v),洗脱体积为4 BV,流速为1/16 BV/min。此条件下所得提取物中含芍药苷32.3%、芍药内酯苷16.5%、6'-O-β-D-葡萄糖芍药内酯苷8.02%、β-gentiobiosylpaeoniflorin 6.63%。     

不同生长季节下藏药麻花秦艽活性成分含量研究

采用高效液相色谱法测定了野生与栽培藏药麻花秦艽（Gentiana straminea）根中龙胆苦苷、落干酸、獐牙菜苦苷和獐牙菜苷四种环烯醚萜苷类化学成分的含量及其在不同生长季节的变化趋势。结果表明,4种环烯醚萜苷类成分的含量随植物的生长季节而波动,其活性成分含量在野生种与栽培种之间发生了一定的差异。但是,栽培根中的龙胆苦甙已达到药典的标准,可供药用。     

栀子环烯醚萜苷四种载药系统体外透膜吸收的比较研究

本研究制备栀子环烯醚萜苷四种载药系统(溶液剂、凝胶剂、脂质体、纳米粒),采用Franz扩散池,选用新鲜猪鼻黏膜为渗透屏障,以栀子苷为测定指标,HPLC方法测定其含量,进行栀子环烯醚萜苷四种载药系统的体外透膜吸收特性考察。结果表明,四种载药体系的累计渗透量对时间呈良好的线性关系,符合一级动力学方程。四种载药系统中,以溶液剂的渗透速率及表观渗透系数最大,其次为凝胶剂,脂质体和纳米粒相当。     

大孔树脂——溶剂萃取法精制高色价栀子黄色素的集成技术研究

以栀子为原料提取栀子黄色素,采用大孔吸附树脂--有机溶剂萃取相结合的集成技术,从栀子中分离纯化得到高色价的栀子黄色素.先采用大孔吸附树脂对栀子黄色素进行初步精制,以306型大孔吸附树脂为研究对象,探讨了大孔树脂对栀子黄色素的静态吸附率、吸附流速和洗脱剂浓度对吸附的影响,从而得到较为合适的工艺:吸附流速2.O mT/mi...     

广西甜茶苷柱纯化工艺研究

以含70%的广西甜茶粗提取物为原料,通过柱纯化与重结晶对甜茶苷进行提纯,从而制备高纯度的甜茶苷单体。以聚酰胺和LSA-10大孔吸附树脂树脂为吸附剂乙醇为洗脱剂进行柱纯化。实验表明,比较聚酰胺与大孔吸附树脂的吸附与脱附能力,皆为后者强;比较不同吸附材料处理所得甜茶苷单体的纯度,则是聚酰胺所吸附的样纯度高,特别是25%乙醇的处理样。     

欧亚旋覆花总黄酮提取与富集工艺研究

为研究欧亚旋覆花总黄酮的最佳提取与大孔吸附树脂富集工艺,采用不同溶剂、多种提取方法、L9(34)正交实验优化及AB-8大孔吸附树脂富集,结果表明其最佳提取工艺为用10倍量水为溶剂回流提取3次,每次1h,再结合AB-8大孔吸附树脂富集,以70%乙醇洗脱效果最佳,总黄酮回收率达90%,总黄酮含量达50%以上。此工艺简便可行,符合工业化生产要求。     

Selective sequestration of iridoid glycosides from their host plants in Longitarsus flea beetles

We investigated in eight species of the flea beetles genus Longitarsus (Coleoptera, Chrysomelidae) whether the beetles take up iridoid glycosides from their host plants of the Lamiaceae, Plantaginaceae, and Scrophulariaceae. Five of the beetle species, L. australis, L. lewisii, L. melanocephalus, L. nigrofasciatus, and L. tabidus, could be shown to sequester iridoid glycosides in concentrations between 0.40 and 1.55% of their dry weight. Eight different iridoid glycosides, acetylharpagide, ajugol, aucubin, catalpol, 8-epi-loganic acid, gardoside, geniposidic acid, and harpagide could be identified in the host plants, yet only aucubin and catalpol are sequestered by the beetles. No iridoid glycosides could be detected in the beetles if neither aucubin nor catalpol were present in the host plant, as in L. minusculus on Stachys recta (acetylharpagide only) and in L. salviae on Salvia pratensis (no iridoid glycosides). In one beetle species, L. luridus, we could not detect any iridoid glycosides although its field host, Plantago lanceolata, had considerable amounts of aucubin and catalpol plus two further iridoids. The five sequestering Longitarsus species differ in their capacity to store the compounds and in their affinity for catalpol relative to aucubin.     

Variable chemical defence in the checkerspot butterfly Euphydryas gillettii (Lepidoptera: NymphaIidae)

Abstract.

• 1 Like other checkerspots, Euphydryas gillettii butterflies may contain the defensive chemicals, iridoid glycosides, which are sequestered from their hostplants during larval feeding.
• 2 We analysed the iridoid glycoside content of E.gillettii adults from two different populations, Warm Lake, Idaho, and Granite Creek, Wyoming, that have different patterns of hostplant use.
• 3 Gas chromatographic analysis of thirty butterflies from the Wyoming population showed that they contained a mean of 1.27 (±0.19 SE) % dry weight iridoid glycosides. Notably, 20% of these butterflies contained no detectable iridoid glycosides.
• 4 In contrast, nineteen butterflies from the Idaho population contained a mean of 3.89 (±0.38 SE) % dry weight iridoid glycosides, and all butterflies contained iridoid glycosides.
• 5 These results illustrate how the chemical defence of herbivorous insects varies according to differential use of potential hostplants.

     

Low rates of iridoid glycoside hydrolysis in two Longitarsus leaf beetles with different feeding specialization confer tolerance to iridoid glycoside containing host plants

Iridoid glycosides are plant defence compounds that are deterrent and/or toxic for unadapted herbivores but are readily sequestered by dietary specialists of different insect orders. Hydrolysis of iridoid glycosides by β‐glucosidase leads to protein denaturation. Insect digestive β‐glucosidases thus have the potential to mediate plant–insect interactions. In the present study, mechanisms associated with iridoid glycoside tolerance are investigated in two closely‐related leaf beetle species (Coleoptera: Chrysomelidae) that feed on iridoid glycoside containing host plants. The polyphagous Longitarsus luridus Scopoli does not sequester iridoid glycosides, whereas the specialist Longitarsus tabidus Fabricius sequesters these compounds from its host plants. To study whether the biochemical properties of their β‐glucosidases correspond to the differences in feeding specialization, the number of β‐glucosidase isoforms and their kinetic properties are compared between the two beetle species. To examine the impact of iridoid glycosides on the β‐glucosidase activity of the generalist, L. luridus beetles are kept on host plants with or without iridoid glycosides. Furthermore, β‐glucosidase activities of both species are examined using an artificial β‐glucosidase substrate and the iridoid glycoside aucubin present in their host plants. Both species have one or two β‐glucosidases with different substrate affinities. Interestingly, host plant use does not influence the specific β‐glucosidase activities of the generalist. Both species hydrolyse aucubin with a much lower affinity than the standard substrate. The neutral pH reduces the β‐glucosidase activity of the specialist beetles by approximately 60% relative to its pH optimum. These low rates of aucubin hydrolysis suggest that the ability to sequester iridoid glycosides has evolved as a key to potentially preventing iridoid glycoside hydrolysis by plant‐derived β‐glucosidases.     

Potential benefits of iridoid glycoside sequestration in Longitarsus melanocephalus (Coleoptera,Chrysomelidae)

Whenever potentially noxious plant compounds are taken up and recycled by herbivorous insects, a protective function of these sequestered compounds is assumed. The flea beetle Longitarsus melanocephalus sequesters iridoid glycosides from its host plant up to a concentration of 2% DW, yet so far it remained unknown whether the insects gain protection from natural enemies by sequestering plant compounds at these comparatively low concentrations. Here we tested whether iridoid glycosides might deter or inhibit various soil and litter-dwelling potential enemies and pathogens. In choice experiments presenting L. melanocephalus pupae together with Tribolium castaneum pupae, the predator Lithobius forficatus was deterred by the iridoid glycoside containing pupae, while Forficula auricularia as well as the nematode Heterorhabditis bacteriophora were not deterred. L. forficatus also avoided artificial baits doted with 2% iridoid glycosides while F. auricularia showed no aversion to iridoid glycosides at these concentrations and H. bacteriophora did not suffer any toxic effect. Of the pathogens tested, the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae were not inhibited in their growth by iridoid glycosides ranging up to 2%. However, an inhibitory effect could be observed against the entomopathogenic bacterium Bacillus thuringiensis, even at the relatively small concentrations that are common in L. melanocephalus. The antibacterial effect might thus be another important selective value of iridoid glycoside sequestration in this species.     

大孔树脂分离纯化“黑金刚”紫马铃薯花青苷工艺研究

以紫色马铃薯"黑金刚"花青苷为原料,采用D101、HDP100A、HDP450A、NK-9、AB-8五种大孔吸附树脂对花青苷的吸附与解析特性进行了比较研究,并在此基础上,采用最佳大孔树脂对花青苷纯化过程中的静态、动态吸附和解析附条件进行了优化研究。结果表明AB-8大孔树脂具有较好的吸附和解析能力,是纯化紫色马铃薯花青苷的最佳树脂,较优纯化条件为:上样液花青苷浓度为0.028mg.g-1,上样液pH=2,洗脱液乙醇浓度为50%,洗脱液pH=1,吸附流速为1mL.min-1,洗脱流速为1mL.min-1。经大孔树脂纯化后,色价值比纯化前提高了7.55倍。     

4'-deoxy iridoid glycosides from Centranthus longiflorus

The new iridoid glycosides, 4'-deoxykanokoside A and 4'-deoxykanokoside C, were isolated from the methanolic root extract of Centranthus longiflorus ssp. longiflorus. They were accompanied by the three known iridoid glycosides, kanokoside A, kanokoside C and valerosidatum, and two known phenylpropanoid glycosides, coniferin and isoconiferinoside. The structures were elucidated mainly by spectroscopic methods. The presence of 4-deoxy glucose as a part of plant glycosides is rather unusual. Cytotoxic effects of the isolated compounds were also investigated.     

Biosynthesis and therapeutic implications of iridoid glycosides from <Emphasis Type="Italic">Picrorhiza</Emphasis> genus: the road ahead

Picrorhiza genus is emerging as an important paradigm for herbal drug formulations due to its versatile iridoid glycosides exhibition and robustness in the treatment of diverse infections including hepatic amoebiasis, cancer, malaria, ulcerative colitis and cerebral ischemia reperfusion injury. Owing to the superiority of these bioactivities, iridoid glycosides from Picrorhiza have become a hot research area over the years. A metabolic pathway for the formation of iridoid glycosides has been proposed. However, some enzymes and genes of this route are still unidentified and demand the enumeration of facilitating pathways contributing to the biosynthesis of iridoid glycosides. This review summarizes the current knowledge of all naturally occurring iridoid glycosides from Picrorhiza, their biosynthesis and pharmacological capabilities which could provide the insight into metabolic regulation and the basis for the development of new drugs.     

The interplay between toxin-releasing β-glucosidase and plant iridoid glycosides impairs larval development in a generalist caterpillar, Grammia incorrupta (Arctiidae)

Herbivores with polyphagous feeding habits must cope with a diet that varies in quality. One of the most important sources of this variation in host plant suitability is plant secondary chemistry. We examined how feeding on plants containing one such group of compounds, the iridoid glycosides, might affect the growth and enzymatic activity in a polyphagous caterpillar that feeds on over 80 plant species in 50 different families. Larvae of the polyphagous arctiid, Grammia incorrupta, were reared exclusively on one of two plant species, one of which contains iridoid glycosides (Plantago lanceolata, Plantaginaceae) while the other does not (Taraxacum officinale, Asteraceae). Larval weight was measured on the two host plants, and midgut homogenates of last instar larvae were then assayed for activity and kinetic properties of β-glucosidases, using both a standard substrate, 4-nitrophenyl-β-D-glucose (NPβGlc), and the iridoid glycoside aucubin, one of the two main iridoid glycosides in P. lanceolata. Larvae feeding on P. lanceolata weighed significantly less and developed more slowly compared to larvae on T. officinale. While the larval midgut β-glucosidase activity determined with NPβGlc was significantly decreased when fed on P. lanceolata, aucubin was substantially hydrolyzed and the larval β-glucosidase activity towards both substrates correlated negatively with larval weight. Our results demonstrate that host plants containing high concentrations of iridoid glycosides have a negative impact on larval development of this generalist insect herbivore. This is most likely due to the hydrolysis of plant glycosides in the larval midgut which results in the release of toxic aglycones. Linking the reduced larval weight to the toxin-releasing action of an iridoid glycoside cleaving β-glucosidase, our results thus support the detoxification limitation hypothesis, suggesting fitness costs for the larvae feeding solely on P. lanceolata. Thus, in addition to the adaptive regulation of midgut β-glucosidase activity, host plant switching as a behavioral adaptation might be a prerequisite for generalist herbivores that allows them to circumvent the negative effects of plant secondary compounds.     

Iridoids from Scutellaria albida ssp. albida

Three iridoid glycosides, 6'-O-E-p-coumaroylgardoside (1), 6'-O-p-E-coumaroyl-8-epi-loganic acid (2) and scutelloside (3) were isolated from the aerial parts of Scutellaria albida subsp. albida, in addition to an anomeric mixture in equilibrium of one iridoid aglycone (4, 4a), nine iridoid glycosides (5-13), four known phenylethanoid glycosides (14-17), and six known phenolic derivatives (18-23).