山豆根化学成分研究

利用多种柱层析方法,从山豆根中分得5个化合物。经过理化及波谱分析,分别鉴定为L-广高丽槐素(1)、红车轴草苷(2)、槲皮素(3)、芦丁(4)和异鼠李素-3-芸香糖甙(5)。其中化合物3,5为首次从该植物中分离得到。关键词：山豆根;L-高丽槐素;红车轴草苷;槲皮素;芦丁;异鼠李素-3-芸香糖甙     

RP-HPLC同时测定喙果绞股蓝中芦丁和槲皮素的含量

目的:建立RP-HPLC同时测定喙果绞股蓝中芦丁和槲皮素含量的方法,并揭示其含量动态变化规律。方法:采用大连依利特SinoChromODS-APC18色谱柱(250 mm×4.6 mm,5μm),流动相:甲醇-0.4%磷酸水溶液梯度洗脱,流速:1 mL/min,检测波长:364 nm,柱温:30℃。结果:芦丁在0.1525～3.8120μg范围内线性关系良好,r=0.9998,平均回收率为98.2%(RSD=2.0%);槲皮素在0.0589～1.4720μg范围内线性关系良好,r=0.9999,平均回收率为97.7%(RSD=2.3%)。含量测定结果表明芦丁和槲皮素的含量具季节性动态变化,芦丁8月份含量高,平均质量分数达6.31 mg/g,槲皮素9月份含量最高,平均质量分数达0.86 mg/g。结论:该方法简单,准确度高,为喙果绞股蓝的质量控制提供实验依据,芦丁和槲皮素含量动态变化规律为其开发利用提供参考。     

Does enhanced expression of the Na+-CA2+ exchanger increase myocardial vulnerability to ischemia/reperfusion injury in rabbit hearts?

The present study focused on examining the efficacy of feeding a rutin-glucose derivative (G-rutin) to inhibit glycation reactions that can occur in muscle, kidney and plasma proteins of diabetic rats. Both thiobarbituric acid-reactive substance levels and protein carbonyl contents in muscle and kidney were significantly (p < 0.05) reduced in streptozotocin-induced diabetic rats fed G-rutin supplemented diet, compared to diabetic rats fed control diet. The N -fructoselysine content in muscle and kidney, a biomarker of early glycation reaction, was markedly (p < 0.05) increased by diabetes, but significantly (p < 0.05) reduced in diabetic rats fed G-rutin. Advanced glycation end-products (AGEs) in serum and kidney protein were measured by immunoblot using anti-AGE antibody, and were also reduced in diabetic rats fed dietary G-rutin. Feeding G-rutin also slightly inhibited aldose reductase activity in these animals. These results demonstrate for the first time that dietary G-rutin consumption can provide potential health benefits that are related to the inhibition of tissue glycation reactions common to diabetes.     

蔓茎堇菜总黄酮提取工艺初探

分别采用热水浸提法、甲醇浸提法和乙醇浸提法来提取蔓茎堇菜样品的总黄酮,并以芦丁为标准品,用紫外分光光度法在265nm处测定各提取液的总黄酮含量。结果表明,甲醇浸提法和乙醇浸提法显著优于热水浸提法,而用70％乙醇为提取溶剂时效果最佳。研究结果可为利用蔓茎堇菜工业化生产黄酮类药用成分提供科学依据。     

Inhibitors of amyloid β-protein aggregation mediated by GM1-containing raft-like membranes

The aggregation (fibril formation) of amyloid β-protein (Aβ) is considered to be a crucial step in the etiology of Alzheimer's disease (AD). The inhibition of Aβ aggregation and/or decomposition of fibrils formed in aqueous solution by small compounds have been studied extensively for the prevention and treatment of AD. However, recent studies suggest that Aβ aggregation also occurs in lipid rafts mediated by a cluster of monosialoganglioside GM1. This study examined the effects of representative compounds on Aβ aggregation and fibril destabilization in the presence of GM1-containing raft-like liposomes. Among the compounds tested, nordihydroguaiaretic acid (NDGA), rifampicin (RIF), tannic acid (TA), and quercetin (QUE) showed strong fibrillization inhibitory activity. NDGA and RIF inhibited the binding of Aβ to GM1 liposomes by competitively binding to the membranes and/or direct interaction with Aβ in solution, thus at least partly preventing fibrils from forming. Coincubation of Aβ with NDGA, RIF, and QUE in the presence of GM1 liposomes resulted in elongate particles, whereas the presence of TA yielded protofibrillar structures. TA and RIF also destabilized fibrils. The most potent NDGA prevented Aβ-induced toxicity in PC12 cells by inhibiting Aβ accumulation. Furthermore, a comparison of the inhibitory effects of various compounds between aqueous-phase and GM1-mediated aggregation of Aβ suggested that the two aggregation processes are not identical.     

凤尾蕨内生真菌的研究Ⅱ——1株产芦丁内生真菌初步研究

报道了从凤尾蕨属井栏边草(Pteris multifida)根状茎中分离出一内生真菌——菌株JJF006,对其形态特征进行了初步研究,并用TLC对该菌株培养物进行了分析。初步结果表明:该真菌液体培养基中含有芦丁成分。     

Rutin as promising drug for the treatment of Parkinson’s disease: an assessment of MAO-B inhibitory potential by docking,molecular dynamics and DFT studies

ABSTRACT

Inhibitors of monoamine oxidase (MAO)-B have been used for many years in the therapy of Parkinson’s disease (PD). Owing to the safety concerns of the currently used agents, the discovery of novel scaffolds is of considerable interest. MAO-B inhibitory potential of rutin, a flavonoid derived from natural sources, has been established in experimental findings. Hence, the current study seeks to examine the interactions between rutin and crystal structure of human MAO-B enzyme. Molecular docking calculations, as well as molecular dynamics simulations, were employed to investigate the binding mode and the stability of the rutin/MAO-B complex. Energies of highest occupied/lowest unoccupied molecular orbitals were computed through DFT studies and used to calculate electron affinity, hardness, chemical potential, electronegativity, and electrophilicity index in order to investigate the capability of these parameters to influence the ligand–receptor interactions. It was found that rutin traverses both the entrance cavity and the substrate cavity, forcing the Ile-199 ‘gate’ to rotate into its open conformation. It results in the fusion of the two cavities of the MAO-B binding site and directly leads to better binding interactions. Results of the current study can be used for lead modification and development of novel drugs for the treatment of PD.     

Interactive effects of rutin and constant versus alternating temperatures on performance ofManduca sexta caterpillars

The effects of different concentrations of rutin and constant temperature (20 °C) versus alternating temperatures (23∶15 °C) on growth, molting and food utilization efficiencies of third instar tobacco hornworms (Manduca sexta) were determined. Relative consumption rate (RCR) and relative growth rate (RGR) were significantly higher for larvae at the alternating thermal regime compared to those at the constant (representing the average) temperature. With increasing concentrations of rutin, the negative effect of rutin on RCR and RGR increased for the larvae in the alternating thermal regime; however, at the constant temperature, rutin had little effect. The alternating thermal regime promoted synchrony in the timing of spiracle apolysis (the earliest morphological marker of molt). Rutin disrupted that synchrony. I discuss how patterns of host plant resistance may be altered with a decrease, in amplitude of diurnal temperatures (as has been documented recently for temperate regions) through the uncoupling of herbivore performance and allelochemical concentration. I conclude that simultaneous consideration of fluctuating temperatures and allelochemicals is advisable when assessing the effects of temperature and allelochemicals on performance of insect herbivores because interactive effects between temperature and dietary components occur and perhaps are common.