海洋抗癌活性物质的研究进展

海洋抗癌活性物质在海洋天然产物研究中起着主导作用，新的结构和新的作用机制不断出现，并已有许多化合物进入临床及临床前试验阶段。本文就近年来对海洋抗癌活性物质的研究进展作一简要综述。     

海洋天然活性物质心血管药理作用的研究进展

从30多年来国内外学者在海洋生物天然活性物质的研究中，对具心血管药理作用的活性产物作系统、概括的报道。从1968年以来获得的55种海洋生物活性物质，对每一种天然产物分别概括其来源、化学成分，并重点阐述其心血管方面的药理作用。系统报道这些海洋天然活性物质的研究成果及进展，对进一步开展海洋心血管药物的研发提供参考。     

海洋天然抗肿瘤活性产物的临床研究现状

海洋特殊的生态系统是天然抗肿瘤活性物质的重要来源之一,许多源于海洋生物的抗肿瘤活性化合物已经进入临床研究阶段。简要介绍海洋天然抗肿瘤活性产物的作用机制,综述新近发现的海洋天然抗肿瘤活性化合物的最新临床研究进展。     

陆地抗癌动物及相关产物的研究近况

癌淀已成为威胁人类生命的第二大杀手。100多年来,各国科学家们在对植物中天然抗癌产物进行研究的基础上,也致力于从动物资源中寻找天然抗癌产物,并且获得了很大成功。迄今为止,人们已从动物中发现许多具有应用价值的生理活性物质。本文即对近几年10余种陆地抗癌动物资源的适用范围、活性物质、作用机制作一综述。     

海洋抗癌活性物质最新研究概况

分类简要概述近年来源自海洋生物抗肿瘤药物的最新研究与开发,其中包括肽类、大环内酯类、生物碱类、萜类、多聚乙酰类、多烯醚类等。海洋抗癌活性物质在海洋天然产物研究中占据重要地位,大多具有新结构和新作用机制,其中许多化合物作为抗癌药物已进入临床前及临床研究阶段。     

海洋天然产物来源的生物碱及其药理活性研究进展

生物碱是一类重要的天然物质,多具有结构新颖、活性显著等特点,一直是新药研发的热点。本文针对2015-2020年期间新发现的来源于海洋天然产物的生物碱进行了综述,主要从抑菌、抗癌、抗氧化、抗炎、抗病毒等药理活性方面进行阐述,以期为开发新的海洋生物碱药物提供理论依据。     

天然药物中抗氧化剂的研究进展

目的:探讨氧化损伤在癌变中的作用及抗氧化剂清除体内过多的活性氧的作用机制。方法:在介绍抗氧化剂清除体内过多的活性氧的作用机制的基础上,寻找天然药物中可能存在的抗氧化剂,按单体成分分类,进行文献的分类整理。结果:黄酮类、苯酚类、萜类、多糖类及维生素和微量元素硒等都具有较强的抗氧化活性。结论:许多天然来源的抗氧化物质都具有较强的抗癌活性。     

具有抗真菌活性的海洋天然产物研究进展

海洋是世界上最大的生物资源宝库。由于海洋生态系统的特殊性(高压、高盐、低氧)给海洋生物之间的生存带来了非常激烈的竞争，导致很多海洋生物在其生命活动中产生了具有大量特殊结构和生物活性的次生代谢产物。本文总结了2016—2021年从海洋来源的微生物、动物、植物中提取的93个天然的抗真菌活性物质，并对它们的应用前景进行了展望。同时，还总结了这些海洋天然产物的抗真菌作用。     

海洋放线菌多样性及其代谢产物研究进展

海洋放线菌由于能够产生结构新颖、功能多样的活性物质,成为天然活性产物和新药开发的重要来源,日益受到人们的关注。本文综述可培养海洋放线菌的多样性及近几年海洋放线菌活性代谢产物的研究进展,重点描述了一些活性代谢产物的结构及其相关生物活性。     

具有抗菌活性的海洋真菌天然产物研究新进展

近年来,病原微生物的耐药性已严重威胁到人类健康,从海洋微生物中寻找对耐药菌敏感的化合物成为研究的热点,其中海洋真菌因其能够产生大量结构新颖、活性显著的代谢产物而受到广泛关注。本文按照海洋真菌的来源进行分类,从海洋动物来源真菌、红树林来源真菌、海藻来源真菌、海水来源真菌等4个方面,综述了2014年来发表的具有抗菌活性的海洋真菌来源的新的天然产物,主要介绍天然产物的化学结构和生物活性,化合物结构式曾有文献报道的未包括在内,为具有抗菌活性的海洋真菌天然产物的进一步研究开发提供了参考。     

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.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

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.     

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.