HPLC法同时测定不同产地大花红景天中6种活性成分

目的对青藏高原不同产地大花红景天Rhodiola crenulata中没食子酸、红景天苷、酪醇、儿茶素、没食子酸乙酯、对香豆酸进行分析研究,建立定量分析方法,为其进一步利用提供依据。方法采用30%乙醇提取样品;Diamonsil C18色谱柱(250 mm×4.6 mm,5μm);以乙腈-0.3%磷酸溶液为流动相进行梯度洗脱;检测波长275 nm,柱温25℃。结果没食子酸、红景天苷、酪醇、儿茶素、没食子酸乙酯、对香豆酸分别在38.2~382.0 ng/m L(r=0.999 8)、301.0~3 010.0μg/m L(r=0.999 9)、19.8~198.0 ng/m L(r=0.999 6)、17.1~171.0 ng/m L(r=0.999 6)、4.5~45.0 ng/m L(r=0.999 8)、6.38~63.80 ng/m L(r=0.999 4)呈良好的线性关系,加样回收率均符合定量测定要求。结论该方法简便,快速,准确,可用于同时对青藏高原大花红景天中6种活性成分的测定。     

同时制备克级高纯度酪醇、大花红天素及红景天苷的工艺研究

酪醇、大花红天素及红景天苷3种化合物均是红景天的主要活性成分,具有广泛的药理活性.该实验首次从大花红景天中同时分离出克级高纯度的酪醇、大花红天素及红景天苷,红景天经70％乙醇提取后,以3种化合物的收率为指标,对树脂工艺进行优化筛选,再利用硅胶柱分离纯化,最终同时得到克级高纯度的酪醇、大花红天素及红景天苷,经HPLC测定,3种化合物的纯度均超过98％.该方法工艺简洁、操作简单、有机溶剂用量少、收率及重复率都很高,适合3种化合物的同时制备.     

HPLC-小粒径色谱柱法测定红景天提取物中红景天苷、酪醇和络赛维

目的 建立应用小粒径色谱柱快速测定红景天（蔷薇红景天）提取物中红景天苷、酪醇和络赛维的HPLC方法。方法 色谱柱为HALO C₁₈（150 mm×4.6 mm,2.7 μm）;流动相为乙腈（A）-0.1%甲酸水溶液（B）,梯度洗脱：0～5 min,7%～15% A;5～8 min,15%～18% A;8～20 min,18%～30% A;20～25 min,30%～40% A;25～30 min,40%～55% A;体积流量0.6 mL/min;柱温30 ℃;检测波长280 nm;进样量5 μL。结果 红景天苷、酪醇、络赛维15 min内达到分离,峰形尖锐对称,线性范围分别为0.41～106.00、0.42～108.00、0.38～98.00 μg/mL,平均加样回收率分别为99.29%、98.82%、98.33%。采用所建立的方法测定不同来源红景天提取物的多种成分,结果表明单一采用红景天苷作为质量控制指标,9批样品的差异度较小（RSD＝7.95%）,如果将酪醇或络赛维引入质量评价体系,则红景天提取物各批次间就存在较大的差异（酪醇,RSD＝24.42%;络赛维,RSD＝50.55%）;但是,同一单位提供的样品间的差异度较小。结论 建立的HPLC-小粒径色谱柱法高效、准确,经济,精密度好,灵敏度高,可用于红景天提取物中的红景天苷、酪醇和络赛维的同时快速测定;引入多成分的测定方法,可以评价不同厂家提取物质量的差异,并筛选出导致质量差异的成分,为提取物的工艺优化提供参考。     

Metabolic disposition and biological significance of simple phenols of dietary origin: hydroxytyrosol and tyrosol

Hydroxytyrosol and tyrosol are dietary phenolic compounds present in virgin olive oil and wine. Both compounds are also endogenously synthesized in our body as byproducts of dopamine and tyramine metabolisms, respectively. Over the last decades, research into hydroxytyrosol and tyrosol has experienced an increasing interest due to the role that these compounds may play in the prevention of certain pathologies (e.g. cardiovascular, metabolic, neurodegenerative diseases and cancer). The translation of promising in vitro and in vivo biological effects from preclinical studies to the context of human disease prevention initially depends on whether the dose ingested becomes available at the site of action. In this regard, information regarding the bioavailability and metabolic disposition of hydroxytyrosol and tyrosol is of most importance to evaluate the impact they may have on human health. In this review, we discuss and summarize the state of the art of the scientific evidence regarding the processes of absorption, distribution, metabolism and excretion of both hydroxytyrosol and tyrosol. We also examine the impact of these compounds and their metabolites on biological activity in terms of beneficial health effects. Finally, we evaluate the different analytical approaches that have been developed to measure the plasma and urinary levels of hydroxytyrosol, tyrosol and their metabolites.     

密度感应分子对白色念珠菌生物被膜形成作用的研究

目的:白色念珠菌生物被膜形成受密度感应分子调控,法尼醇和酪醇是白色念珠菌产生的两种密度感应分子?本研究探讨不同生物被膜时相,密度感应分子对白色念珠菌形态及生物被膜形成的作用?方法:体外构建白色念珠菌生物被膜?研究分为法尼醇处理组?酪醇处理组?法尼醇和酪醇联合处理组?对照组?首先采用XTT检测不同生物被膜时相酪醇和法尼醇对白色念珠菌细胞活力的作用?扫描电子显微镜(scanning electron microscopy,SEM)观察酪醇和法尼醇对白色念珠菌生物被膜的作用?同时采用气相色谱-质谱联用(gas chromatography-mass spectrometry,GC/MS)检测白色念珠菌生物被膜法尼醇的产生,高效液相色谱(high press liquid chromograph,HPLC)检测白色念珠菌生物被膜酪醇的产生?结果:XTT结果显示,与对照组比较,酪醇可促进6 h白色念珠菌生物膜活力(P < 0.05),法尼醇抑制早期(3 h和6 h)生物被膜活力(P < 0.05),联合作用组抑制6 h生物被膜活力(P < 0.001)?扫描电镜观察发现,酪醇促进3 h和6 h白色念珠菌细胞的出芽,法尼醇抑制3 h和6 h菌丝形成,两者联合作用以后者对菌丝形成的抑制作用为主?GC/MS及 HPLC结果表明在早期(3 h和6 h)生物被膜,2种密度感应分子产生少且无明显升高趋势(P > 0.05);随着生物被膜成熟(24 h及36 h),酪醇产生明显增多(P < 0.05),法尼醇产生也明显增多(P < 0.05)?24 h生物被膜产生酪醇最多,36 h 生物被膜产生法尼醇最多?结论:酪醇可以促进白色念珠菌出芽和菌丝伸长,促进早期生物被膜形成?法尼醇抑制出芽和菌丝形成,抑制早期生物被膜形成?两者联合作用以法尼醇对菌丝形成的抑制作用为主?     

女贞子中红景天甙元的分析与测定

对女贞子的成分进行薄层层析和紫外薄层扫描含量测定，结果表明．女贞子含有齐墩果酸和红景天甙元──酪醇，后者含量高达０．８３％，接近于四裂红景天中的含量，可为红景天的资源寻找和女贞子的开发利用提供参考。     

Effects of differing phenolic content in dietary olive oils on lipids and LDL oxidation

Summary.Background: Evidence from in vitro studies suggests that antioxidant olive oil phenolic compounds can prevent LDL oxidation. However, in vivo evidence in support of this hypothesis is sparse.Aim of the study: to establish the antioxidant effect of olive oils with differences in their phenolic compounds content in humansMethods: A controlled, double blind, cross-over, randomized, clinical trial using three similar olive oils with increasing phenolic concentration (from 0 to 150 mg/Kg) was conducted in 30 healthy volunteers. Olive oils were administered over three periods of 3 weeks preceded by two-week washout periods.Results: Urinary tyrosol and hydroxytyrosol increased (p < 0.020), in vivo plasma oxidized LDL decreased (p = 0.006), and ex vivo resistance of LDL to oxidation increased (p = 0.012) with the phenolic content of the olive oil administered. After virgin olive oil administration, an increase (p = 0.029) was observed in HDL cholesterol levels.Conclusions: Sustained consumption of virgin olive oil with the high phenolic content was more effective in protecting LDL from oxidation and in rising HDL cholesterol levels than that of other type of olive oils. Dose-dependent changes in oxidative stress markers, and phenolic compounds in urine, were observed with the phenolic content of the olive oil administered. Our results support the hypothesis that virgin olive oil consumption could provide benefits in the prevention of oxidative processes.* Participants of the SOLOS-Investigation are listed in the Appendix.     

红景天主要成分对小鼠免疫细胞的促增殖转化作用

目的 观察红景天中主要成分红景天苷、苷元酪醇、络塞维对小鼠免疫系统的保护作用。方法 以Giemsa染色法、MTT法及NO检测法等为研究手段,分析不同浓度红景天苷、酪醇、络塞维对小鼠外周血T、B淋巴细胞、小鼠外周血白细胞及小鼠腹腔巨噬细胞等具有代表意义的免疫细胞活性及功能的影响。结果 红景天苷能够促进T/B淋巴细胞的转化及增殖,对外周血白细胞及腹腔巨噬细胞的吞噬能力有显著的提升作用。苷元酪醇(62.5~250 μg·mL-1)能够特异性的刺激B淋巴细胞的增殖和转化(P<0.05),且作用效果高于阳性药物组。络塞维则对静止型T细胞向母细胞转化具有显著的促进作用(P<0.05)。结论 不同红景天主要成分在体外会对不同的免疫靶细胞起作用,具有细胞免疫和体液免疫功能,同时能提高单核细胞的吞噬能力,免疫活性广泛。     

Tyrosol prevents AlCl3 induced male reproductive damage by suppressing apoptosis and activating the Nrf-2/HO-1 pathway

Aluminium is a ubiquitous element that occurs naturally in the soil making human exposure to it is unavoidable. Tyrosol is present in olive oil and is known to have antioxidant effects. Therefore, the present study explores the toxic effects of aluminium chloride (AlCl₃) and evaluates the possible protection by tyrosol in male rats. Testicular injury was induced by the administration of AlCl₃ (34 mg kg⁻¹ day⁻¹). Rats were treated with either tyrosol (20 mg kg⁻¹ day⁻¹) or AlCl3 (34 mg kg⁻¹ day⁻¹). The experiment lasted for 10 weeks. Biochemical, histopathological and protein expression profiles were determined to decipher the role of tyrosol in protecting the cellular damage. Further, histomorphometric analyses of testes showed deranged architecture along with other noted abnormalities. AlCl₃ group rats' testes showed decreased GSH levels, CAT activities, Nrf-2, HO-1, bcl-2 expressions and sperm motility whereas increased caspase-3 expressions, MDA levels, abnormal and dead/live sperm ratio. However, tyrosol treatment attenuated these changes. The present results demonstrate the beneficial role of tyrosol treatment in AlCl₃ induced testicular toxicity alterations of rat.     

Rhodiola‐induced inhibition of adipogenesis involves antioxidant enzyme response associated with pentose phosphate pathway

The aim of this study was to investigate whether Rhodiola crenulata extract and tyrosol, a major bioactive phenolic compound present in Rhodiola, change the activities of endogenous antioxidant enzyme response (AER) and energy pathways linked to proline‐mediated pentose phosphate pathway (PPP) during adipogenesis. Treatment with Rhodiola extracts inhibited the activities of proline dehydrogenase (PDH) and glucose‐6‐phosphate dehydrogenase (G6PDH) as well as lipid accumulation and reactive oxygen species (ROS) production. The inhibition of PDH and G6PDH activities by Rhodiola likely prevented proline oxidation required for critical ATP generation that is coupled to AER via the PPP, leading to inhibition of adipogenesis. Rhodiola extracts dose‐dependently increased superoxide dismutase (SOD) activity, resulting in a reduced ROS level during adipogenesis. Moreover, the effects of tyrosol, a major bioactive compound in Rhodiola species, were directly correlated with all observed effects by Rhodiola extracts. These results indicate that the antiadipogenic effects of Rhodiola extracts can be attributed to a phenolic tyrosol that may potentially disrupt proline‐mediated energy generation and AER via PPP, resulting in the suppression of adipogenesis and lipid accumulation. This further provides a biochemical rationale to identify the roles of phenolics that modulate the cellular redox environment and therefore have relevance for obesity management. Copyright © 2010 John Wiley & Sons, Ltd.