微生物酶法从虎杖中提取白藜芦醇的研究

用微生物发酵法酶解虎杖,可以提高从虎杖中获取白藜芦醇的得率.通过对多种含糖甙键水解酶菌株的筛选,获得四株可以直接作用于虎杖的优良菌株.其中用 Aspergillus niger 1分解虎杖,提取白藜芦醇,与传统醇提工艺和自酶解法相比,提取率明显提高.     

超声辅助离子液体/阴离子表面活性剂双水相萃取虎杖中的虎杖苷和白藜芦醇

将超声辅助离子液体/阴离子表面活性剂双水相萃取和高效液相色谱法相结合,建立一种简单、绿色、高效的分析方法用于检测虎杖中的虎杖苷和白藜芦醇。本研究以水溶性离子液体为萃取剂,以阴离子表面活性剂为成相盐,在超声的辅助作用下,目标分析物被萃取于离子液体中。实验结果表明,最佳提取条件为:以400μL 1-丁基-3-甲基咪唑四氟硼酸盐为萃取剂,0.16 g十二烷基苯磺酸钠为成相盐,样品溶液pH 7.0,超声时间20 min,超声功率160 W。各化合物在线性范围内都具有良好的线性关系(r0.9995),日内和日间精密度分别低于3.27%和6.31%,检出限和定量限分别为2.8~12.3和9.4~41.1 ng/mL,样品加标回收率在86.88~94.13%之间。本研究采用离子液体代替传统的有机溶剂作为萃取剂,集提取、分离和纯化于一体,具有操作简单、溶剂用量少、提取时间短等优点,可广泛应用于中药活性成分的提取与分析。     

虎杖苷对镉致小鼠睾丸氧化应激损伤的保护作用

目的：探讨虎杖苷对镉致小鼠睾丸氧化应激损伤的保护作用。方法：40 只小鼠随机分成5 组：正常对照组,镉组,25、50、100 mg/（kg•d）虎杖苷保护组,于实验第1天,镉组及虎杖苷保护组小鼠一次性腹腔注射2 mg/kg氯化镉（氯化镉质量浓度为0.2 mg/mL）,制造小鼠睾丸氧化应激损伤,虎杖苷保护组小鼠同时经口灌胃给予25、50、100 mg/（kg•d）虎杖苷,连续灌胃1 周后处死小鼠,统计小鼠睾丸脏器系数;苏木精-伊红（hematoxylin-eosin,HE）染色,观察小鼠睾丸组织病理学变化;检测虎杖苷对小鼠睾丸超氧化物歧化酶（superoxide dismutase,SOD）、谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）活性,以及丙二醛（malonaldehyde,MDA）和8-羟基脱氧鸟苷（8-hydroxy-2-deoxyguanosine,8-OHdG）含量的影响。结果：与正常对照组比较,镉组小鼠睾丸脏器系数显著降低,睾丸组织细胞变性、坏死,生精细胞明显减少,而虎杖苷保护组小鼠睾丸组织细胞损伤均明显减轻;与正常对照组比较,镉组小鼠睾丸组织SOD及GSH-Px活性均极显著降低,MDA及8-OHdG含量均极显著升高（P＜0.01）。与镉组比较,50、100 mg/（kg•d）虎杖苷保护组小鼠的睾丸脏器系数显著或极显著升高（P＜0.05或P＜0.01）,睾丸组织的SOD活性明显升高,差异达到显著或极显著水平（P＜0.05或P＜0.01）;25、50、100 mg/（kg•d）虎杖苷保护组小鼠睾丸组织的GSH-Px活性明显升高,差异达到显著或极显著水平（P＜0.05或P＜0.01）,而MDA及8-OHdG含量均明显降低,差异同样达到显著或极显著水平（P＜0.05或P＜0.01）。结论：虎杖苷能减轻镉致小鼠睾丸组织细胞脂质过氧化损伤,抑制氧化应激对睾丸细胞DNA的损伤。     

Characterization of the Supermolecular Structure of Polydatin/6‐O‐α‐Maltosyl‐β‐cyclodextrin Inclusion Complex

Polydatin is the main bioactive ingredient in many medicinal plants, such as Hu‐zhang (Polygonum cuspidatum), with many bioactivities. However, its poor aqueous solubility restricts its application in functional food. In this work, 6‐O‐α‐Maltosyl‐β‐cyclodextrin (Malt‐β‐CD), a new kind of β‐CD derivative was used to enhance the aqueous solubility and stability of polydatin by forming the inclusion complex. The phase solubility study showed that polydatin and Malt‐β‐CD could form the complex with the stoichiometric ratio of 1:1. The supermolecular structure of the polydatin/Malt‐β‐CD complex was characterized by ultraviolet–visible spectroscopy (UV), Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffractometry (XRD), thermogravimetric/differential scanning calorimetry (TG/DSC), and proton nuclear magnetic resonance (¹H‐NMR) spectroscopy. The changes of the characteristic spectral and thermal properties of polydatin suggested that polydatin could entrap inside the cavity of Malt‐β‐CD. Furthermore, to reasonably understand the complexation mode, the supermolecular structure of polydatin/Malt‐β‐CD inclusion complex was postulated by a molecular docking method based on Autodock 4.2.3. It was clearly observed that the ring B of polydatin oriented toward the narrow rim of Malt‐β‐CD with ring A and glucosyl group practically exposed to the wide rim by hydrogen bonding, which was in a good agreement with the spectral data.     

Influence of Polydatin on the Tumor Microenvironment In Vitro: Studies with a Colon Cancer Cell Model

The tumor microenvironment of colon carcinoma, the site at which tumor cells and the host immune system interact, is influenced by signals from tumor cells, immunocompetent cells, and bacterial components, including LPS. A large amount of LPS is available in the colon, and this could promote inflammation and metastasis by enhancing tumor cell adhesion to the endothelium. Polydatin (PD), the 3-β-D-glucoside of trans-resveratrol, is a polyphenol with anti-cancer, anti-inflammatory, and immunoregulatory effects. This study was designed to explore whether PD is able to produce antiproliferative effects on three colon cancer lines, to reduce the expression of adhesion molecules that are upregulated by LPS on endothelial cells, and to decrease the proinflammatory cytokines released in culture supernatants. Actually, we investigated the effects of PD on tumor growth in a coculture model with human mononuclear cells (MNCs) that mimics, at least in part, an in vitro tumor microenvironment. The results showed that PD alone or in combination with MNC exerts antiproliferative and proapoptotic effects on cancer cells, inhibits the production of the immunosuppressive cytokine IL-10 and of the proinflammatory cytokines upregulated by LPS, and reduces E-selectin and VCAM-1 on endothelial cells. These data provide preclinical support to the hypothesis that PD could be of potential benefit as a therapeutic adjuvant in colon cancer treatment and prevention.     

Determination of polydatin by gold nanoparticle-enhanced chemiluminescence of silver nitrate and luminol

A novel flow injection method for the determination of polydatin is reported based on the inhibition of silver nitrate, luminol, and gold nanoparticles chemiluminescence. Under the optimum condition, the decrease in chemiluminescence was proportional to the concentration of polydatin from 1.0 × 10^?8 to 1.0 × 10^?5 mol/L. The detection limit was 2.1 × 10^?9 mo1/L and the relative standard deviation was 2.1% for the determination of 1.0 × 10^?6 mol/L polydatin. This method was successfully employed for the determination of polydatin in Polygonum cuspidatum roots and human urine.     

虎杖内生菌转化虎杖苷和转化产物抗氧化活性研究

研究虎杖内生真菌对虎杖苷转化及转化产物抗氧化活性。采用薄层层析法筛选转化虎杖苷的内生真菌;通过形态学特征和ITS-5.8S r DNA基因序列分析对内生真菌进行鉴定;利用大孔吸附树脂、制备薄层色谱和高效液相色谱分离纯化生物转化产物;以VC、BHT、虎杖苷及5种虎杖苷衍生物为对照,对转化产物清除DPPH·自由基和OH·自由基的生物活性进行比较研究。经筛选发现其中l株内生真菌J3能转化虎杖苷形成转化产物。内生真菌J3 ITS-5.8S r DNA序列全长573bp,Gen Bank登录号KM 434883,确定为烟曲霉Aspergillus fumigatus。转化产物A-2在体外具有清除DPPH·自由基和OH·自由基的能力,且清除OH·自由基的能力高于底物虎杖苷,A-1在体外无清除DPPH·自由基和OH·自由基的能力。虎杖内生真菌Aspergillus fumigatus能对虎杖苷进行生物转化,形成具抗氧化活性的物质。     

Polydatin Attenuates Hypoxic Pulmonary Hypertension and Reverses Remodeling through Protein Kinase C Mechanisms

Hypoxic pulmonary hypertension is a life-threatening emergency if untreated. Consistent pulmonary hypertension also leads to arteries and ventricular remodeling. The clinical therapeutic strategy for pulmonary hypertension and the corresponding remodeling mainly interacts with NO, angiotensin II (Ang II) and elevated endothelin (ET) targets. In the present study, we evaluated the effects of polydatin on hypoxia-induced pulmonary hypertension. It was observed that polydatin attenuated hypoxic pulmonary hypertension, reversed remodeling, and regulated NO, Ang II, ET contents in the serum and lung samples. However, forced activation of PKC signaling by its selective activator thymeleatoxin (THX) could abate the effects of polydatain. These results suggest that polydatin might be a promising candidate for hypoxic pulmonary treatment through interaction with PKC mechanisms.     

Detection of Novel Carbohydrate-Related Compounds in Aqueous Samples Using a Capillary Electrophoretic Profiling Method

The aim of this research was to extend an existing capillary electrophoresis (CE) method, originally developed for the determination of mono- and disaccharides, to the determination of alternative carbohydrate compounds, namely furfural and polydatin. Empirical validation confirms that this novel method can be applied for the determination of analyte concentrations from complex matrices, and the evaluation of their carbohydrate composition. It is concluded that the approach has validity as an analytical procedure and has the ability to determine industrially important analytes from a heterogeneous biological sample matrix, and thus, the method adds value to the development of large scale separation processes. However, some additional optimization is required before online applications.