(1S,2R,4S,5S)-angelicoidenol-2-o-β-d-glucopyranoside—A moose deterrent compound in Scots pine (Pinus sylvestris L.)

Hydrophilic extracts of Scots pine (Pinus sylvestris L.) twigs have been investigated for palatability to moose in feeding experiments. The predominant repellent effect was observed from the 2-O--d-glucopyranoside of the monoterpene (1S,2R,4S,5S)-angelicoidenol. Of other isolated and tested substances, only taxifolin-3-O--d-glucopyranoside had a deterring effect. One fraction-containing mainly aliphatic compounds-also had a strong effect, but the effect was lost after further fractionation. Tannin-containing fractions had no effect. Angelicoidenol glucoside has not previously been reported fromP. sylvestris. The results are discussed in view of phenols as defense compounds.     

Determination of polyphenolic constituents and biological activities of bark extracts from different Pinus species

BACKGROUND: The most common commercially available pine bark extract is Pycnogenol^®, a standardised extract of Pinus maritima, which has been reported to have cardiovascular benefits and enhance microcirculation. The present study was conducted to determine the chemical composition of four pine bark extracts, assess their biological activities and to compare the results with Pycnogenol^®. RESULTS: The Pinus species were analysed by LC and LC‐MS; extracts of P. brutia and P. nigra showed higher levels of phenolic constituents compared to P. sylvestris and P. pinea. In particular, P. brutia contained extremely high concentrations of taxifolin (18.5%). The highest radical scavenging activities were attained with P. pinea (88.6%), P. nigra (87.2%) and P. brutia (86.4%) bark extracts. Additionally, anticarcinogenic effects of the extracts and their kinetics were determined in four cell lines including human prostate (PC‐3, DU 145, LNCaP) and breast adenocarcinoma (MCF7) by the MTT assay. Cell viability was reduced to 40% by extracts of P. pinea, and P. sylvestris in PC‐3 cells showing a similar effect like the positive control, CPT‐11. CONCLUSION: Pinus species other than P. maritima definitively possess high biological activities, and therefore present a huge potential to be utilised in the food and the pharmaceutical industries. Copyright © 2009 Society of Chemical Industry     

葡萄皮渣中花旗松素提取工艺优化及其抗氧化能力测定

采用乙醇加热法提取葡萄花旗松素,利用响应面分析法优化葡萄花旗松素的提取工艺并测定其最优组的抗氧化性能。结果表明:葡萄花旗松素的最佳提取工艺为静置处理时间为30 min、乙醇含量58%、提取温度56℃、液料比23:1 mL/g、提取时间2.0 h,最佳提取量为3.936 mg/g。以V_C为参照测定提取液对ABTS自由基、DPPH自由基和铁离子还原力,其中葡萄花旗松素提取液对自由基清除能力及铁离子还原力均高于V_C溶液,对DPPH自由基的清除效果最好,浓度为50 μg/mL的提取液对DPPH自由基的清除率可达到90%。此外,研究还表明花旗松素提取液对ABTS自由基、DPPH自由基的IC₅₀值分别为28.15、22.65 μg/mL。本结果对于葡萄皮渣的开发利用具有一定的意义。     

中国野生刺葡萄（Vitis davidii Foex）及其单品种葡萄酒中花旗松素含量分析

利用高效液相色谱-串联质谱联用技术对原产中国的野生刺葡萄果实的果皮、果肉、种子及单品种葡萄酒中的花旗松素含量（以鲜质量计算）进行测定与分析。结果表明：刺葡萄果实果皮中花旗松素含量最高,其含量在刺葡萄黑、白果实中分别为（2.44±0.18）、（2.03±0.14） mg/kg,在种子中分别为（1.66±0.13）、（1.38±0.12） mg/kg,果肉中含量最低,分别为（0.36±0.02）、（0.25±0.02） mg/kg。刺葡萄黑、白果实中各个部位花旗松素含量均无明显差异,但对照品种黑色果实果皮中的花旗松素含量显著高于白色果实,这说明花旗松素含量的高低与葡萄果皮颜色并无直接关系。在单品种酒中,白葡萄酒由于酿造工艺不同,果皮和种子中的花旗松素无法进入酒中,花旗松素含量仅为红葡萄酒的20%;葡萄酒中的花旗松素含量略低于果实是因为提取果实中花旗松素的溶剂是甲醇,而葡萄酒中只是水和乙醇的自然浸渍。     

Formulation and Characterization of Taxifolin‐Loaded Lipid Nanovesicles (Liposomes,Niosomes, and Transfersomes) for Beverage Fortification

In this study, nanovesicles such as transfersomes, niosomes, and liposomes prepared by an ethanol injection method (EIM) (EIM) and formulated with soybean lecithin, Tween 80, Span 60, and cholesterol, are used to improve the bioavailability of taxifolin, a natural antioxidant with beneficial properties for health and food preservation. Morphology, stability, and the in‐vitro release of the optimal formulations are fully examined. The obtained results indicate that taxifolin‐loaded nanovesicles present sizes ranging between 98 and 215 nm along with a narrow size distribution (polydispersity index less than 0.250). The zeta potential of nanovesicles is negative and in the range of ?20.40 to ?32.20 mV. The optimal formulations with the maximum encapsulation efficiency (72–75%) are the transfersomes formulated with lecithin and Tween 80 in the presence and absence of cholesterol. Additionally, in vitro release behavior of nanovesicles shows low taxifolin released (3.68–10.13%) at intestinal conditions, whereas more than 90% of taxifolin is released in gastrointestinal conditions. The compatibility between taxifolin and nanovesicles components is confirmed by FTIR. Transmission electron microscopy demonstrates spherical shaped particles around 200 nm. Backscattering profiles variations show the potential application of taxifolin nanovesicles for producing fortified apple juice with excellent physical stability. Practical Applications: Taxifolin is a flavanonol, which fulfills a particular task in preserving stable functions of the circulatory system owing to its special antioxidant ability and biological activity. Nevertheless, its low bioavailability is a salient drawback for biomedical and food applications. Thus, the current study is conducted to encapsulate taxifolin in nanovesicles (such as liposome, niosome, transfersome) by EIM to improve its bioavailability. Nanocarriers with relatively decent physical stability and high encapsulation efficiency can be brought about through Tween 80, soybean lecithin, and in the presence and absence of cholesterol as stabilizer which ensures the successful delivery of taxifolin to food formats such as beverages.     

Micronization of taxifolin by supercritical antisolvent process and evaluation of radical scavenging activity

The aim of this study was to prepare micronized taxifolin powder using the supercritical antisolvent precipitation process to improve the dissolution rate of taxifolin. Ethanol was used as solvent and carbon dioxide was used as an antisolvent. The effects of process parameters, such as temperature (35-65 °C), pressure (10-25 MPa), solution flow rate (3-6 mL/min) and concentration of the liquid solution (5-20 mg/mL) on the precipitate crystals were investigated. With a lower temperature, a stronger pressure and a lower concentration of the liquid solution, the size of crystals decreased. The precipitation temperature, pressure and concentration of taxifolin solution had a significant effect. However, the solution flow rate had a negligible effect. It was concluded that the physicochemical properties and dissolution rate of crystalline taxifolin could be improved by physical modification such as particle size reduction using the supercritical antisolvent (SAS) process. Further, the SAS process was a powerful methodology for improving the physicochemical properties and radical scavenging activity of taxifolin.     

黄杉素分子印迹聚合物的合成与性能研究

采用本体聚合法以黄杉素(Taxifolin,TAX)为模板分子,2-乙烯基吡啶(2-Vpy)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,制备了黄杉素分子印迹聚合物(TAX-MIP)。通过紫外光谱考察了TAX与2-Vpy的非共价作用,并采用静态和动态结合实验评价了TAX-MIP对底物分子的结合特性。结果表明,TAX与2-Vpy通过静电作用形成主客体配合物,其结合常数和化学配位比分别为K=6.06×10 10(mol/L)-4和n=4;TAX-MIP对TAX存在不同亲和力的两类结合位点,并对TAX显示出很高的选择吸附特性和良好的分子识别性能;TAX-MIP对TAX的吸附符合准二级反应动力学方程。     

RP-HPLC法测定落叶松中二氢槲皮素的含量

采用反相高效液相色谱法测定落叶松中二氢槲皮素的含量。确定色谱条件为：色谱柱Hypersil ODS—C18（4．6mm×200mm,5μm）;流动相为V（甲酵）：V（水）：V（冰醋酸）=40：59：1;流速为1．0mL·min^-1;检测波长为288nm;柱温为28℃。在此条件下,二氢槲皮素与其它组分得到良好的分离。线性范围为0．02～0．2μg·μL^-1（r=0．9998）,精密度RSD为0．96％（n=5）,平均回收率为100．4％。