薯蓣皂苷元衍生物的合成及其抗血栓形成活性

目的设计合成薯蓣皂苷元衍生物,并评价其体内抗血栓形成活性.方法以薯蓣皂苷元为先导物,经过酯化等反应得到薯蓣皂苷元酯类衍生物,选择动静脉旁路血栓形成模型,评价体内抗血栓形成活性.结果合成了6个目标化合物,结构经过1H-NMR、13C-NMR、MS确证.抗血栓形成活性筛选结果显示,目标化合物3β-薯蓣皂苷元丁二酸单酯具有较...     

薯蓣皂苷元衍生物的制备及其抗肿瘤活性

目的 设计、合成薯蓣皂苷元衍生物并研究其体外抗肿瘤活性.方法 以薯蓣皂苷元为原料,与不同的L-氨基酸缩合,合成了6个化合物(Ⅰ～Ⅵ);与1,2,3-三氮唑和1,2,4-三氮唑偶联合成了2个中间体(Ⅶ,Ⅷ);再分别与不同的苄溴化合物反应得到一系列的盐(Ⅸ～Ⅻ).结果 合成的化合物中,除化合物Ⅴ外,其余11个是新化合物.结论 所合成的化合物结构经1HNMR、13CNMR确证.采用噻唑蓝(MTT)法测定了部分化合物的体外抗肿瘤活性.所测化合物都有良好的抗肿瘤活性,其中,化合物Ⅵ的抗肿瘤活性与阳性对照1-(3β-薯蓣皂苷元)-3-苄基咪唑溴盐相当.     

薯蓣皂苷元抗肿瘤衍生物的设计和合成(Ⅱ)

目的 合成薯蓣皂苷元衍生物并进行其体外抗肿瘤活性的研究.方法运用Autodock进行目标分子辅助设计.薯蓣皂苷元通过Mitsunobu反应合成1-(3α-薯蓣皂苷元)-1,2,3-三氮唑和1-(3α-薯蓣皂苷元)-1,2,4-三氮唑两个中间体,再分别与不司的溴代物反应得到一系列的盐.采用MTT法对人恶性黑色素瘤细胞A3...     

薯蓣皂苷元A环和F环的结构改造及其抗肿瘤活性初探

目的提高薯蓣皂苷元类衍生物的抗肿瘤活性以及进一步研究其构效关系。方法基于薯蓣皂苷元结构,运用Autodock 4.2进行对接设计,合成了一系列全新A环、F环结构改造的氨基酸酰胺,内酰胺杂环薯蓣皂苷元类衍生物。采用MTT法对人肝癌细胞HepG-2、人恶性黑色素瘤细胞A375和人肺癌细胞A549进行体外抗肿瘤活性实验。结果合成13个新化合物,结构经1HNMR、13CNMR确定,体外抗肿瘤活性结果表明化合物8～13具有一定活性。结论化合物8～13都具有一定的体外抗肿瘤活性,化合物13的药理学活性与阳性对照品紫杉醇活性相近。     

盾叶薯蓣难溶性甾体皂苷的提取及其抑制人肝癌细胞HepG2增殖的研究

目的 研究盾叶薯蓣水难溶性提取物的化学成分及对人肝癌细胞HepG2生长的抑制作用.方法 采用正、反相硅胶柱色谱方法分离纯化水难溶性提取物的单体化合物,并通过波谱学方法鉴定其结构;采用MTT法评价其体外抑制人肝癌细胞的增殖作用.结果 采用化学方法分离并鉴定了5个化合物,分别是薯蓣皂苷元(Ⅰ)、延令草皂苷(Ⅱ)、薯蓣皂苷元纤维二糖苷(Ⅲ)、三角叶皂苷(Ⅳ)和盾叶皂苷Ⅰ(Ⅴ);5个化合物对人肝癌细胞的增值具有明显的抑制作用,其中化合物V对人肝癌细胞HepG2的生长抑制作用最强.结论 盾叶皂苷Ⅰ具有明显的抗癌活性.     

抗肿瘤薯蓣皂苷元衍生物的设计与合成(Ⅰ)

目的 针对抗肿瘤活性,设计、合成薯蓣皂苷元衍生物并研究其体外抗肿瘤活性.方法 基于作用机制并运用Autodock进行目标分子辅助设计.以薯蓣皂苷元为原料,与氯乙酸缩合,得中间体(Ⅰ)后,再与杂环(哌啶、吗啉、哌嗪)或取代杂环(哌嗪)反应制得化合物Ⅱ～Ⅵ;以薯蓣皂苷元为原料,将其F环开环得到中间体(Ⅶ)后,再与不同的疏水性脂肪酸、芳香酸或酚缩合,制备了化合物Ⅷ～Ⅺ.采用MTT法对人恶性黑色素瘤细胞A375、人肺腺癌细胞A549、人肝癌细胞HepG-2进行体外抗肿瘤活性试验.结果 制备的化合物中,除化合物Ⅶ外,其余10个是新化合物,其结构经1HNMR、13CNMR确证.结论 薯蓣皂苷元衍生物的初步体外活性测试均表现出良好的抗肿瘤活性,其中,化合物Ⅳ、Ⅵ的抗肿瘤活性与阳性对照1-(3β-薯蓣皂苷元)-3-苄基咪唑溴盐相当.     

新型三唑-薯蓣皂苷元衍生物的设计合成及其抗阿尔茨海默病活性初步评估

摘要：目的:基于薯蓣皂苷元的结构骨架,设计合成具有抗阿尔茨海默病（AD）的活性分子。方法:以薯蓣皂苷元为原料,通过缩合反应,在3-OH上引入抗AD的活性片段苯基1,2,3-三唑。利用MTT法评估薯蓣皂苷元衍生物对Aβ1-42诱导PC12细胞损伤的保护作用。通过ELISA法测定化合物G4在PC12细胞中对Aβ1-42聚集的影响,并通过蛋白质免疫印迹进行初步机制探究。结果:共设计合成6个新型三唑-薯蓣皂苷元衍生物。体外活性筛选发现化合物G4表现出明显优于先导物薯蓣皂苷元的神经细胞保护活性,且在5～40μmol·L-1浓度下未显示出细胞毒。此外,化合物G4还能有效抑制Aβ1-42的聚集,效果优于多奈哌齐;其抗AD机制可能通过抑制NLRP3炎症小体的信号通路,减少IL-1β、Caspase-1 P20蛋白,从而抑制Aβ产生而发挥神经细胞保护作用。结论:所设计合成的新型三唑-薯蓣皂苷元衍生物G4表现出强劲的抗AD活性,值得进一步深入研究。     

薯蓣皂苷元抗肿瘤衍生物的设计、合成与抗肿瘤活性

薯蓣皂苷元对A375、K562等细胞株具有抑制生长并诱导其凋亡的作用。其作用靶点之一是线粒体中的Bcl-2亚家族蛋白。本文以Bcl-2为靶点,运用Autodock设计并合成了一系列全新的薯蓣皂苷元衍生物,希望完善相关化合物的构效关系及提高其抗肿瘤活性。MTT法体外抗肿瘤活性研究结果表明,所设计的化合物大多对K562、A375、A549等3种肿瘤细胞株有较好的抑制作用,而对H293、L02等2种正常细胞株无明显作用。其中,化合物1、6～8对K562表现出了较好的活性(IC50值为1.96～4.35μmol.L-1)。     

薯蓣皂苷元衍生物的制备及对豚鼠离体气管平滑肌的作用

目的 研究薯蓣皂苷元及其衍生物的制备及对豚鼠离体气管平滑肌的作用.方法 采用酰化和还原的方法合成衍生物;药理学实验在豚鼠离体气管模型上进行.结果 合成了11个薯蓣皂苷元衍生物(化合物Ⅰ～Ⅺ);薯蓣皂苷元及其衍生物对豚鼠离体气管平滑肌都有不同程度的舒张作用.结论 经1HNMR、13CNMR鉴定了所合成衍生物的结构;首次发现薯蓣皂苷元对离体豚鼠气管条有舒张作用,其3位的结构修饰可以提高其活性.     

薯蓣皂苷元衍生物的抗肿瘤活性研究

目的研究薯蓣皂苷元衍生物在体外的抗肿瘤活性。方法采用MTT法对人恶性黑色素瘤细胞A375、人肺腺癌细胞A549、人肝癌细胞HepG-2及人慢性髓原白血病细胞株K562进行体外抗肿瘤活性试验。结果薯蓣皂苷元衍生物对4个肿瘤细胞株A375、A549、K562、HepG-2具有不同程度的抗肿瘤活性。结论绝大部分薯蓣皂苷元衍生物对4个肿瘤细胞株有较好的抗肿瘤活性,IC50值都低于30μmol.L-1。化合物22对细胞株A375的IC50=4.48μmol.L-1,化合物9、10对细胞株K562的IC50分别为2.51、2.38μmol.L-1;显示其抗肿瘤活性与对照化合物1-(3β-薯蓣皂苷元)-3-苄基咪唑溴盐相当。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.