海洋放线菌Streptomyces sp.（No.30701）次生代谢产物研究

目的 研究一株海洋放线菌Streptomyces sp.（No.30701）的化学成分。方法 采用硅胶开放柱色谱、Sephadex LH-20凝胶柱色谱以及高效液相色谱等分离手段进行化合物的分离、纯化;利用理化性质和波谱学分析对单体化合物进行结构鉴定。结果 从海洋放线菌Streptomyces sp.（No.30701）发酵物中分离得到9个环二肽类化合物,分别鉴定为环(L-脯-L-缬)二肽（1）、环(D-脯-L-缬)二肽（2）、环(L-脯-L-亮)二肽（3）、环(4-羟基-脯-亮)二肽（4）、环(L-脯-L-异亮)二肽（5）、环(L-脯-L-酪)二肽（6）、环(L-亮-L-缬)二肽（7）、环(D-苯丙-甘)二肽（8）、环(L-苯丙-L-缬)二肽（9）。结论 以上化合物均为海洋放线菌常见的次生代谢产物,但化合物2、8含有天然界中不多见的D型氨基酸,并且化合物2是从链霉菌属放线菌中首次分离得到。     

仿刺参共附生放线菌Kytococcus sp.中的环二肽成分

目的对仿刺参共附生放线菌Kytococcus sp.化学成分进行研究。方法用硅胶柱色谱,Sephadex LH-20凝胶柱色谱,反向高效液相柱层析(RP-HPLC)等分离手段对放线菌(Kytococcus sp.)乙酸乙酯提取物进行分离纯化,并利用1 H NMR、13 C NMR、质谱(MS)等手段并与文献对照相结合,鉴定化合物的结构。结果分离得到9个已知的环二肽类化合物,其结构分别为:环(L-脯-L-缬)二肽(1),环(L-脯-L-丙)二肽(2),环(L-脯-L-酪)二肽(3),环(L-脯-L-异亮)二肽(4),环(L-脯-L-亮)二肽(5),环(L-脯-L-苯丙)二肽(6),环(L-缬-L-亮)二肽(7),(L-亮-L-异亮)二肽(8),环(L-亮-L-亮)二肽(9)。结论这是首次从仿刺参中分离得到放线菌Kytococ-cus sp.,9个化合物均为首次从该属放线菌中分离得到。     

海洋放线菌Micromonospora sp.(No.69)抗MRSA活性成分研究

目的对一株小单孢菌属放线菌Micromonospora sp.(No.69)的抗耐甲氧西林金黄色葡萄球菌(MRSA)活性成分进行研究。方法采用活性追踪分离的方法,通过硅胶开放柱色谱、Sephadex LH 20柱色谱、ODS开放柱色谱、反相高效液相色谱等手段对Micromonospora sp.(No.69)发酵液的甲醇提取物进行分离和纯化,利用ESI-MS、~1H-NMR、~(13)C-NMR等波谱技术对单体化合物进行结构鉴定。结果从Micromonosporasp.(No.69)发酵液的甲醇提取物中分离得到8个化合物,分别鉴定为:环(L-缬-L-脯)二肽(1)、环(L-异亮-L-脯)二肽(2)、环(L-亮-L-脯)二肽(3)、环(甘-L-脯)二肽(4)、环(苏-L-脯)二肽(5)、环(L-丙-L-脯)二肽(6)、环(L-酪-L-脯)二肽(7)、环(L-苯丙-L-脯)二肽(8)。抗MRSA活性测试结果表明化合物1和2对MRSA具有抑制作用,IC_(50)分别为3.2 mmol·L~(-1)和6.5 mmol·L~(-1)。结论以上化合物均为首次从该属菌株中分离得到,其中化合物1和2显示出抗MRSA活性。     

海洋放线菌Micromonospora sp.(M2DG17)细胞毒活性成分研究

目的对海洋放线菌Micromonospora sp.(M2DG17)中的活性次生代谢产物进行研究。方法在活性追踪分离思路的指导下,综合利用硅胶开放柱色谱、ODS中低压柱色谱、Sephadex LH-20凝胶柱色谱以及高效液相色谱等分离技术进行化合物的分离、纯化;利用化合物理化性质和波谱学分析对单体化合物进行结构鉴定,并对其进行活性评价。结果从海洋放线菌Micromonospora sp.(M2DG17)发酵物中分离得到了7个化合物,分别鉴定为3-羟甲基-β-卡巴林(3-hydroxymethyl-β-carboline,1)、3-甲基-β-卡巴林(3-methyl-β-carbo-line,2)、β-卡巴林(β-carboline,3)、环(L-脯-L-苯丙)二肽[Cyclo-(L-Pro-L-Phe),4]、环(L-脯-L-缬)二肽[Cyclo-(L-Pro-L-Val),5]、环(L-脯-L-亮)二肽[Cyclo-(L-Pro-L-Leu),6]以及环(L-脯-L-异亮)二肽[Cyclo-(L-Pro-L-Ile),7],并对单体化合物进行了HCT116细胞生长抑制活性测试。结论化合物1~4、6为首次从该菌中分离得到,化合物2显示出弱的HCT116细胞生长抑制活性(IC50为65.0μmol.L-1)。     

红榄李内生真菌Aspergillus terreus HT-1二酮哌嗪类次级代谢产物研究

目的 研究红榄李Lumnitzera littorea内生真菌Aspergillus terreus HT-1的次级代谢产物。方法 对从红榄李中分离得到的内生真菌A. terreus HT-1进行大规模发酵,并采用多种色谱技术对其发酵产物进行分离纯化。通过多种波谱方法鉴定单体化合物结构。结果 从A. terreus HT-1发酵产物的乙酸乙酯萃取物中分离得到了15个二酮哌嗪类化合物,分别鉴定为bis(dethio)bis(methylsulfanyl) gliotoxin（1）,环(D-4-羟基-脯氨酸-L-苯丙氨酸)二肽（2）,环(L-4-羟基-脯氨酸-L-苯丙氨酸)二肽（3）,环(L-4-羟基-脯氨酸-L-酪氨酸)二肽（4）,环(L-4-羟基-脯氨酸-L-亮氨酸)二肽（5）,环(L-丙氨酸-L-4-羟基-脯氨酸)二肽（6）,环(D-4-羟基-脯氨酸-D-异亮氨酸)二肽（7）,环(D-脯氨酸-L-酪氨酸)二肽（8）,环(L-亮氨酸-L-脯氨酸)二肽（9）,环(L-脯氨酸-L-苏氨酸)二肽（10）,环(L-脯氨酸-L-丙氨酸)二肽（11）,环(L-脯氨酸-甘氨酸)二肽（12）,环(L-苯丙氨酸-甘氨酸)二肽（13）,环(谷氨酸-L-酪氨酸)二肽（14）,terezine D（15）,并采用MTT法检测全部化合物的神经保护活性。结论 在200 μmol/L浓度下,化合物1和5显示出较好的神经保护活性,使H2O2诱导氧化损伤的神经细胞（HT22）的细胞存活率从44.06%分别提高到69.51%和76.75%。本研究为红榄李及其内生真菌的开发利用研究提供了理论基础。     

海洋来源放线菌Demequina litorisediminis SCSIO 53428的化学成分研究

目的对南海深海沉积物来源的放线菌Demequina litorisediminis SCSIO 53428的发酵物化学成分进行研究。方法利用各种色谱技术,包括硅胶柱色谱、ODS反相柱色谱、Sephadex LH-20凝胶色谱、高效液相色谱等分离手段对放线菌Demequina litorisediminis发酵物的乙酸乙酯提取物进行分离纯化,通过波谱学数据分析并结合文献比较鉴定了化合物的结构。结果分离得到13个化合物,其结构分别为:环(L-酪-L-脯)二肽(1)、环(L-苯丙-L-脯)二肽(2)、环(L-缬-L-脯)二肽(3)、环(L-亮-L-脯)二肽(4)、环(反式-4-羟基-L-脯-L-亮)二肽(5)、环(甘-L-脯)二肽(6)、环(L-丙-L-脯)二肽(7)、环(缬-酪)二肽(8)、环(异亮-脯)二肽(9)、对羟基苯甲醛(10)、苯甲酸(11)、N-(2-羟基苯基)-乙酰胺(12)、2-乙酰氨基苯甲酸(13)。结论对海洋来源放线菌Demequina litorisediminis SCSIO53428的化学成分做了初步研究,化合物1～13均为首次从该属放线菌中分离得到。     

一株南海红树林底泥来源抗真菌放线菌No. 41-51发酵物的化学成分研究

目的 对一株来源于南海红树林底泥的抗真菌放线菌No. H 41-51发酵物中的化学成分进行研究。方法 对该菌株进行发酵培养,将发酵物进行离心分离成菌丝和菌液,菌液用乙酸乙酯萃取,并对具有活性的该乙酸乙酯部位进行成分分离和鉴定;发酵物菌丝体用95-80%乙醇提取,再用不同极性的溶剂萃取,对具有活性的石油醚部位进行成分分离和鉴定。整个提取和分离过程用纸碟片法进行活性追踪分离。通过硅胶柱、Sephadex LH-20柱色谱及HPLC制备方法分离纯化化合物样品,用NMR、MS等光谱方法,并结合文献数据比对鉴定化合物结构。 结果 分离得到14个化合物,并分别将其鉴定为邻苯二甲酸二丁酯(1)、二(2-乙基己基)苯-1,2-二甲酸酯(2)、3,3-二吲哚-2-羟基-丙醇(3)、环(苯丙-丙)二肽(4)、环(R-脯-S-苯丙)二肽(5)、环(S-脯-S-苯丙)二肽(6)、环(D-苯丙-L-异亮)二肽(7)、dankasterone(8)、4-hydroxy-17R-methylincisterol(9)、Calvasterol B(10)、Calvasterol A(11)、抗霉素 A_1a(12)、抗霉素 A_1b(13)和甘油醇-1-单油酸酯(14)。体外活性实验表明：化合物8~11对MCF-7、SF-268和NCI-H460细胞株表现出程度不等的细胞毒活性,化合物12和13表现出抗白色念珠菌活性。结论 菌株H 41-51发酵可产生多种不同结构类型和生物活性的次生代谢产物。化合物8~11对MCF-7、NCI-H460和SF-268细胞株具有细胞毒活性,化合物12、13具有抗白色念珠菌活性。     

2株南极来源放线菌所产的二酮哌嗪类化合物研究

目的 对从南极潮间带沉积物样品中分离得到的两株具有抗菌活性的放线菌进行分类鉴定并进行次生代谢产物研究。方法 通过形态学分析及构建系统发育进化树鉴定菌株并对其发酵产物进行生物活性评价;利用硅胶、凝胶柱层析、semi-HPLC等色谱分离手段对两株菌的发酵产物进行分离纯化;采集所得化合物的质谱、NMR等数据并分析后鉴定其结构。结果 两株菌分别鉴定为Streptomyces sp. SCSIO 40061和Nocardiopsis sp. SCSIO KS107;从相应的发酵产物中分离得到两个二酮哌嗪类化合物,结构分别鉴定为：(3Z,6E)-1-N-甲基-3-苯亚甲基-6-(2-甲基-3-羟基丙烷)-2,5-二酮哌嗪 (1) 以及(3Z,6Z)-3-(4-对甲氧苯亚甲基)-6-(2-甲基丙烷)-2,5-二酮哌嗪 (2) 。结论 发现了两株能产二酮哌嗪类化合物的南极来源放线菌。     

海洋放线菌Streptomyces sp.(No.172221)次生代谢产物研究

目的研究一株海洋放线菌Streptomyces sp.(No.172221)的次生代谢产物。方法采用各种色谱方法进行成分分离,综合运用多种波谱学手段确定单体化合物的结构。结果分离到8个化合物,鉴定其结构分别为麦角甾-3β,5α,6β-三醇(1);麦角甾-3β,5α,6β-三醇-3-Ο-β-D葡萄糖苷(2);N-苯甲基氨基甲酸(3);1,3-丙二醇苯乙酸酯(4);环(脯-亮)二肽(5);环(脯-缬)二肽(6);脯氨酸(7)和腺嘌呤核苷(8)。结论化合物1和2为甾体类化合物,其中化合物2为首次从放线菌中分离得到,化合物3、4为新天然产物,化合物5和6为常见的细菌代谢产物环二肽类。     

红树林真菌草酸青霉(092007)的环二肽类成分

目的研究海南文昌红树林真菌草酸青霉(Penicillium oxalicum)的代谢产物,寻找新的抗肿瘤活性化合物。方法利用硅胶、Sephadex LH-20、ODS柱色谱及制备型高效液相色谱等方法进行分离,通过化合物的理化性质及各种波谱技术鉴定它们的结构,采用MTT法评价化合物体外细胞毒活性。结果从真菌菌丝体的丙酮提取物中分离得到6个环二肽类化合物,鉴定其结构分别为:环(苯丙-异亮)二肽[cyclo-(Phe-Ile)](1)、环(苯丙-缬)二肽[cyclo-(Phe-Val)](2)、环(异亮-亮)二肽[cyclo-(Ile-Leu)](3)、环(缬-缬)二肽[cyclo-(Val-Val)](4)、环(脯-缬)二肽[cyclo-(Pro-Val)](5)、环(脯-甘)二肽[cyclo-(Pro-Gly)](6)。体外活性表明:化合物1、3和5在50μg.mL-1下对肝癌细胞HepG-Ⅱ的抑制率分别为31%、32%、17%,对前列腺癌细胞LNCaP抑制率分别为50%、43%、53%。结论这些化合物均为首次从该属真菌的代谢产物中分离得到,其中化合物2、3和5具有一定的细胞毒活性。     

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.

     

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.     

2-(Acetoxyphenyl)-(Z)-styryl sulfides as cyclooxygenase inhibitors

2-(Acetoxyphenyl)-(Z)-styryl sulfides are described as selective cyclooxygenase-2 (COX-2) inhibitors, useful for treating inflammation and COX-2-mediated disorders including neoplasia. 2-(Acetoxyphenyl)-(Z)-styryl sulfide is claimed to be the most potent COX inhibitor in the series with a COX-2 selectivity ratio of 33. This compound is also claimed to be superior to celecoxib (Celebrex^®, Pfizer) in inhibiting cell growth of colorectal carcinoma cells. In this evaluation, the COX inhibitory activity of this compound is compared to that previously disclosed for diarylheterocycles and 2-(acetoxyphenyl)alkyl sulfides. The validity of the DLD-1 cell line in the growth inhibition studies is questioned based on recent literature reports indicating the lack of COX-2 expression in this cell line.