来源于深海链霉菌Streptomyces sp. OUCMDZ-4112的吡咯生物碱

目的: 分离鉴定深海来源放线菌Streptomyces sp. OUCMDZ-4112的活性天然产物。方法：采用硅胶色谱,凝胶色谱及高效液相色谱(HPLC)等常规分离纯化手段对菌株的天然产物进行分离、纯化;运用核磁共振、CD、紫外、红外和旋光等方法鉴定所得化合物的结构;采用MTT法和CCK-8法评价化合物的细胞毒活性、对硝基苯基-α-吡喃葡萄糖苷(PNPG)法评价化合物的α-糖苷酶抑制活性。结果：从深海沉积物来源的链霉菌OUCMDZ-4112的发酵产物中分离鉴定了2个新的吡咯生物碱：S(+)-2-甲氧基-4-氧亚基-4-(2-吡咯基)丁酰胺(1)和R(–)-2-甲氧基-4-氧亚基-4-(2-吡咯基)丁酰胺(2)、以及2个已知的灵菌红素(PGs)：streptoriubin B (3) 和undecylprodigiosin (4)。化合物3和4对K562肿瘤细胞株具有强细胞毒活性,IC₅₀分别为0.60 μmol/L和0.01 μmol/L(阿霉素的 IC₅₀ 为0.43 μmol/L);同时外消旋1/2和化合物3、4具有α-糖苷酶抑制活性,IC₅₀值分别为2.61、0.082和0.92 mmol/L(阿卡波糖的IC₅₀为1.12 mmol/L)。结论：本文首次报道了PGs类化合物 3和 4的α-糖苷酶抑制活性;作为中间产物,新化合物1和 2的分离鉴定,证明了文献中PGs的生合成途径。     

耐碱放线菌Streptomyces sindenensis OUCMDZ-1368的次生代谢产物研究

目的研究碱胁迫对放线菌次生代谢产物的影响,寻找结构新颖并具有抗菌和肿瘤细胞毒活性的化合物。方法采用化学和生物活性相结合的集成筛选方法,从耐碱放线菌中筛选获得代谢产物丰富并具有生物活性的目标菌株;通过碱胁迫目标菌株,利用硅胶柱色谱、凝胶柱色谱和高效液相色谱等方法对发酵产物进行分离和纯化,运用波谱学和钼靶X-射线单晶衍射分析方法鉴定化合物的结构。结果筛选到一株高产吩嗪生物碱的耐碱放线菌OUCMDZ-1368,鉴定为链霉菌Streptomyces sindenensis;该菌株在p H9的培养基中的次生代谢产物的产量最大,从其发酵产物中分离鉴定了11个化合物,其结构分别为phenazine-1-carboxamide(1,主产物)、phenazine-1-carboxylic acid(2,主产物)、(E)-2-non-1-en-1-yl-4(1H)quinolone(3)、2-methyl-4(1H)quinolone(4)、2-heptyl-4(1H)quinolone(5)、2-nonyl-4(1H)quinolone(6)、2-undecyl-4(1H)quinolone(7)、2-heptyl-3-hydroxy-4(1H)quinolone(8)、2-nonyl-3-hydroxyl-4(1H)quinolone(9)、S-methyl-2,4-dihydroxy-3,5-dimethyl-6-isopropylbenzothioate(10)和N-[2-(4-hydroxyphenyl)ethyl]acetamide(11);化合物1和2对A549细胞有中等程度抑制活性,IC50分别为4.9和5.0μmol/L,化合物1-10分别对金黄色葡萄球菌、枯草杆菌、铜绿假单孢菌、产气杆菌以及白念珠菌表现出不同程度的抑制作用(MIC 17~45μmol/L)。结论培养基的p H值影响放线菌的次生代谢产物,通过碱调节可以诱导微生物产生不同的活性代谢产物。     

海绵共附生菌Streptomyces olivaceus LHW2444的分离鉴定及其抗青枯菌活性代谢产物研究

目的 从海绵中分离培养放线菌,筛选具有抗青枯菌活性的菌株,分离鉴定活性代谢产物。方法 以来源于南海西沙永兴岛附近海域的海绵Leucetta chagosensis为实验材料,采用三种选择性分离培养基分离海绵的共附生放线菌,利用16S rRNA序列分析对各菌株进行种属鉴定。对各菌株的发酵提取物进行抗青枯菌活性筛选,采用硅胶柱层析、Sephadex LH-20凝胶柱层析和高效液相色谱法对筛选到的活性菌株的发酵产物进行分离、纯化,运用核磁共振(NMR)、质谱(MS)等手段,鉴定化合物的结构。采用微量稀释法测定化合物的最小抑菌浓度(MIC)。结果 分离培养海绵共附生放线菌16株,筛选得到一株具有较好抗青枯菌活性的菌株Streptomyces olivaceus LHW2444,并从该菌株的发酵产物中分离鉴定2个吡咯类化合物、1个苯并二恶茂类化合物、2个吡喃酮类化合物,分别为pyrrole-2-carboxamide(1)、pyrrole-2-carboxylic acid(2)、1,3-benzodioxole-2-one-4-carboxylamide(3)、germicidin B(4)、germicidin C(5),化合物1-5为首次从该种属放线菌分离得到。首次发现pyrrole-2-carboxylic acid对青枯菌具有较强抑制作用,MIC值为8 μg/mL。结论 海绵共附生菌Streptomyces olivaceus LHW2444是潜在的植物青枯病生防菌,pyrrole-2-carboxylic acid是抗青枯菌的活性代谢产物。     

黄河三角洲植物真菌的分离、活性菌株的筛选及活性产物的鉴定

目的 从黄河三角洲植物中分离真菌,筛选具有抗菌或抗肿瘤活性菌株,分离鉴定活性成分。方法 蔗糖密度梯度法分离菌株,对其发酵物进行抗菌活性和细胞毒活性筛选,采用硅胶柱色谱、凝胶柱色谱对发酵产物进行分离、纯化,运用核磁共振、质谱等手段鉴定化合物的结构。结果 从黄河三角洲的9种植物样品中分离纯化真菌136株,筛选得到具有抑菌活性菌株25株、具有细胞毒活性菌株17株,并从1株枝孢属真菌Cladosporium sp. OUCMDZ-2046的发酵产物中分离鉴定了1个对白色念珠菌和人乳腺癌细胞株MCF-7具有抑制作用的化合物：桔青霉素。结论 黄河三角洲的植物真菌具有开发为药用活性菌株的潜力。     

湖泊放线菌SIIA-A16124的分类鉴定及基因组挖掘

目的 对湖泊放线菌SIIA-A16124进行分类鉴定和基因组挖掘。方法 采用多相分类法对菌株的形态学、生理生化、细胞壁化学组分、16S rRNA基因序列进行测定和分类鉴定,采用基因组挖掘分析生物合成基因簇,经发酵培养、抗菌活性检测及活性产物质谱分析,推测其活性产物的化合物结构类别。结果 菌株SIIA-A16124的16S rRNA基因与菌株Actinokineospora inagensis NRRL B-24050T同源性最高为99%;菌株SIIA-A16124在ISP3培养基上中等产孢和水解淀粉的特性与模式菌株存在明显差异;鉴定菌株SIIA-A16124为动孢菌Actinokineospora sp.,具有羊毛硫肽生物合成基因簇,其活性次级代谢产物属于羊毛硫肽类抗生素。结论 首次发现动孢菌属放线菌具有生物合成羊毛硫肽类抗生素的能力。     

海洋放线菌分离及菌株Streptomyces sp.LXF-80的次级代谢产物的研究

目的对黄海和渤海的海泥样品进行海洋放线菌分离,并选出1株次级代谢产物较丰富的菌株Streptomyces sp.LXF-80进行研究。方法采用稀释涂布平板法进行海洋放线菌的分离,应用溶剂萃取,TLC分析,柱色谱层析及制备HPLC等方法对菌株LXF-80的发酵产物进行研究,通过理化性质及波谱学手段并参阅文献进行化学结构鉴定,采用SRB法及MTT法评价化合物的抗肿瘤活性。结果从海泥样品中分离到海洋放线菌142株,从菌株LXF-80发酵提取物中分离到化合物5个,其中聚酮类化合物1个,环二肽类化合物4个,经结构鉴定分别为Enterocin(1)、Cyclo(L-Trp-L-Lue)(2)、Cyclo-...     

深海链霉菌Streptomyces sp.SCSIO 04777中肠道菌素的分离鉴定

目的对从印度洋深海沉积物中分离的1株深海放线菌Streptomyces sp.SCSIO 04777进行鉴定并对其抗菌活性次级代谢产物进行研究。方法通过16SrDNA序列分析并构建系统发育进化树来鉴定菌株,利用有机溶剂萃取、正相和反相硅胶层析等分离手段对海洋放线菌SCSIO 04777的发酵产物进行分离纯化,通过波谱数据分析并参阅文献对化合物进行结构鉴定。结果该放线菌被鉴定为Streptomyces sp.SCSIO04777,并从其发酵产物中分离鉴定了芳香聚酮类化合物-肠道菌素。结论首次筛选得到了1株产生肠道菌素的深海链霉菌,为肠道菌素的开发利用提供了新的菌株资源。     

海洋放线菌SCSIO 07745中红霉素衍生物的分离、鉴定和生物合成基因簇的分析

目的：对从中国南海沉积物样品中分离的放线菌SCSIO 07745中抑菌活性次级代谢产物进行研究,并对相应产物的生物合成基因簇进行分析。方法：提取菌株SCSIO 07745基因组DNA,利用Illumina Hiseq和PacBio SMRT技术进行基因组测序;通过对16S rDNA序列进行分析构建系统发育进化树以鉴定菌种;以有机溶剂萃取得到发酵产物并利用正相反相柱层析等色谱手段进行分离纯化;通过波谱数据分析对化合物进行结构鉴定。利用生物信息学技术对基因组进行注释并对合成该化合物的基因簇进行定位分析,推导其生物合成途径。结果：该放线菌被鉴定为糖多孢红霉菌Saccharopolyspora erythraea,从其发酵产物中分离鉴定了2个大环内酯类化合物sporeamicin A(1)和erythromycin A enol ether(2)。全基因组序列测序发现该菌株基因组DNA为线状,含有31个次级代谢产物生物合成基因簇,其中基因簇3可能负责红霉素衍生物的生物合成,并对其生物合成途径进行了推导。结论：筛选得到了1株产生红霉素类化合物的海洋糖多孢红霉菌S. erythraea SCSIO 07745,为红霉素类抗生素的开发提供了新的菌株资源。同时,该菌株的全基因组序列为其蕴藏的次级代谢产物的挖掘奠定了基础。     

海洋放线菌NRPS基因的筛选

目的 建立快速、高效的NRPS基因筛选体系,从海洋微生物中筛选具有潜在合成多肽类次级代谢产物的活性菌株,为定向获得新的含氨基酸抗生素奠定基础.方法 采用选择性培养分离获得海洋放线菌,通过快速抗菌活性初筛,设计特异性引物利用PCR技术对初筛活性菌株进行NRPS基因筛选,进一步对阳性菌株进行16S rDNA排重.结果 利用建立的NRPS基因筛选体系对初筛具有抗菌活性的295株放线菌进行筛选,得到12株阳性菌株,分别属于小单孢菌属、链霉菌属和疣孢菌属.结论 利用PCR技术建立了快速、高效的NRPS基因筛选体系,为多肽类活性化合物的获得提供了基因学的依据.     

冷泉来源诺卡氏菌OUCLQ19-35-1次级代谢产物的研究

目的 探究深海冷泉来源微生物的次级代谢产物产生能力,从中挖掘具有抗多重耐药(multi-drug resistant, MDR)菌活性的次级代谢产物,为新药研发提供化合物实体。方法 采用稀释涂布法分离纯化深海冷泉海泥样品中的放线菌,通过琼脂扩散法筛选具有抗MDR菌活性的放线菌;基于16S rRNA基因片段序列分析和系统进化树构建初步确定目标放线菌种属;对目标放线菌进行大规模发酵,采用有机溶剂萃取、反相硅胶柱层析、半制备高效液相等分离手段对发酵产物进行分离纯化,利用NMR、MS等波谱学技术并结合文献对化合物进行结构鉴定,然后对化合物进行抗MDR菌活性测试。结果 从深海冷泉中筛选到一株具有抗MDR菌Micrococcus luteus ML01和Staphylococcus aureus CCARM3090活性的放线菌OUCLQ19-35-1,16S rRNA序列及系统进化树分析初步确定其为Nocardiopsis synnemataformans;从其发酵产物中分离得到3个化合物,分别为questiomycin A(1)、1,6-dihydroxyphenazine(2)和5a,6,11a,12-tetrahydro-5a,11a-dimethyl[1,4]benzoxazino[3,2-b][1,4]benzoxazine(3);活性结果显示,化合物1-3均无抗MDR菌活性,但其所在的组分有抑菌活性。结论 从深海冷泉筛选得到一株诺卡氏菌OUCLQ19-35-1,其能够产生抗MDR菌的活性次级代谢产物,具有潜在的应用价值,但其活性成分待进一步的确定。     

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.     

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.     

Sleep-disordered breathing with chronic opioid use

Chronic opioid use for pain relief or as substitution therapy for illicit drug abuse is prevalent in our societies. In the US, retail distribution of methadone and oxycodone has increased by 824 and 660%, respectively, between 1997 and 2003. μ-Opioids depress respiration and deaths related to illicit and non illicit chronic opioid use are not uncommon. Since 2001 there has been an emerging literature that suggests that chronic opioid use is related to central sleep apnoea of both periodic and non-periodic breathing types, and occurs in ～ 30% of these subjects. The clinical significance of these sleep-related abnormalities are unknown. This review addresses the present knowledge of control of ventilation mechanisms during wakefulness and sleep, the effects of opioids on ventilatory control mechanisms, the sleep-disordered breathing found with chronic opioid use and a discussion regarding the future research directions in this area.     

Drug targets for cognitive enhancement in neuropsychiatric disorders

The investigation of novel drug targets for treating cognitive impairments associated with neurological and psychiatric disorders remains a primary focus of study in central nervous system (CNS) research. Many promising new therapies are progressing through preclinical and clinical development, and offer the potential of improved treatment options for neurodegenerative diseases such as Alzheimer's disease (AD) as well as other disorders that have not been particularly well treated to date like the cognitive impairments associated with schizophrenia (CIAS). Among targets under investigation, cholinergic receptors have received much attention with several nicotinic agonists (α7 and α4β2) actively in clinical trials for the treatment of AD, CIAS and attention deficit hyperactivity disorder (ADHD). Both glutamatergic and serotonergic (5-HT) agonists and antagonists have profound effects on neurotransmission and improve cognitive function in preclinical experiments with animals; some of these compounds are now in proof-of-concept studies in humans. Several histamine H3 receptor antagonists are in clinical development not only for cognitive enhancement, but also for the treatment of narcolepsy and cognitive deficits due to sleep deprivation because of their expression in brain sleep centers. Compounds that dampen inhibitory tone (e.g., GABA_A α5 inverse agonists) or elevate excitatory tone (e.g., glycine transporter inhibitors) offer novel approaches for treating diseases such as schizophrenia, AD and Down syndrome. In addition to cell surface receptors, intracellular drug targets such as the phosphodiesterases (PDEs) are known to impact signaling pathways that affect long-term memory formation and working memory. Overall, there is a genuine need to treat cognitive deficits associated with many neuropsychiatric conditions as well as an increasingly aging population.