南极土壤真菌C3368菌株产生的抗生素——Ⅰ.C3368菌株的分类学、发酵及抗生素的生物活性

从南极乔治王岛土壤分离到一株丝状真菌C3368,经分类鉴定为疣状金孢霉chrysosporium verrucosum Tubaki.C3368。经低温发酵、提纯分离得到两个活性成分:C3368-A为R-(一)-Bisdechlorogeodin;C3368-B为Questin。这两个活性成分具有很强的抑制肿瘤细胞核苷转运的作用和小鼠脾淋巴细胞摄取核苷的作用。从南极土壤真菌的代谢产物中找到具有上述作用的抗生素,还是首例。     

南极微生物的分离及抗肿瘤活性筛选

对南极地区(南极大陆、潮间带、南大洋)的海水、海泥、土壤、植物样品进行了微生物分离,并采用海虾生物致死法和流式细胞术对极地微生物发酵产物进行了抗肿瘤活性筛选。从南极样品中共分离极地微生物259株,筛选结果显示,11%的微生物具有显著的抗肿瘤活性,显示出极地微生物在活性物质研究方面具有良好的应用潜力。     

南极海洋丝状真菌多样性及其次级代谢产物的研究进展

海洋真菌由于能够产生结构新颖,活性独特的次级代谢产物,现已成为药物先导化合物的重要来源。南极海洋独特而严酷的自然环境使得真菌在生物物种、活性代谢产物等方面表现出明显的多样性和新颖性,正在成为微生物药物研究新的重要资源。本文对近年来国内外南极海洋丝状真菌多样性及其次级代谢产物的研究进展进行综述。     

南极乔治王岛陆地土壤和潮间带放线菌多样性及其抑菌活性研究

目的 系统研究南极乔治王岛陆地土壤和潮间带中放线菌的多样性,并对分离菌株拮抗临床多重耐药菌活性进行筛选。方法 利用放线菌门特异引物扩增16S rDNA序列, 构建放线菌16S rDNA基因克隆文库, 对文库进行多样性指数分析和系统发育分析。采用琼脂块扩散法以3株临床多重耐药菌为指示菌,筛选具有高抑菌活性的潜在药用放线菌。结果 土壤放线菌文库和潮间带放线菌文库的覆盖率分别为54.55%和87.2%,陆地土壤中放线菌群落以放线菌纲为优势菌,潮间带样品中酸微菌纲占据明显优势。陆地土壤中的放线菌分布于10个目16个科中,潮间带底泥中放线菌则分布于7个目13个科中。纯培养得到141株放线菌,其中从陆地样品中分离得到93株菌,分布于放线菌纲的7个属17个种中,从潮间带样品中分离得到41株菌,分布于5个属10个种中。有17株具有显著抑菌效果的菌株,其中4株菌抑菌活性最强,可强烈抑制3株多重耐药菌。结论 南极乔治王岛陆地土壤和潮间带底泥环境中蕴涵着丰富且多样的放线菌资源,陆地土壤中放线菌的多样性要高于潮间带底泥中放线菌的多样性。南极链霉菌和诺卡氏菌具有较强的拮抗多重耐药菌的活性,具有深一步研究的价值。     

南极嗜冷真菌Pseudogymnoascus sp. OUCMDZ-3578次级代谢产物研究

摘要：目的 对来源于南极苔藓的嗜冷真菌Pseudogymnoascus sp. OUCMDZ-3578进行菌种鉴定及次级代谢产物的研究。方法 通过分子生物学方法鉴定菌株种属;综合运用硅胶柱层析、薄层色谱和半制备高效液相色谱等色谱学方法对次级代谢产物进行分离纯化,通过核磁共振（NMR）、质谱（MS）等现代波谱学方法并结合文献对所得化合物进行结构鉴定。结果 分离鉴定6个单体化合物,包含3个二苯甲酮类化合物sulochrin (1)、hydroxysulochrin (2)、desmethylsulochrin (3),3个蒽醌类化合物questin (4)、questinol (5)、endocrocin (6)。测试了化合物的抗老年痴呆活性。结论 从南极苔藓样品,分离获得嗜冷真菌,通过分子生物学和形态学鉴定为Pseudogymnoascus sp. OUCMDZ-3578,从中分离鉴定了化合物1~6,对研究嗜冷真菌及其代谢产物做出了探索。     

南极海洋真菌Penicillium chrysogenum PR4-1-3的活性次级代谢产物研究

目的对一株具有明显细胞毒活性的南极海洋真菌Penicillium chrysogenum PR4-1-3的活性成分进行研究。方法采用溶剂萃取、柱色谱层析及制备HPLC等方法对菌株发酵产物进行活性追踪分离,通过理化性质及波谱学手段进行化学结构鉴定,以SRB法评价化合物的抗肿瘤活性,采用CPE方法对化合物1和2进行抗H1N1甲型流感病毒活性测试。结果从中分离得到5个芳香酚醌类化合物,其结构分别鉴定为secalonic acid D(1)s、ecalonic acid F(2)、chrysophanol(3)、emodin(4)和citreorosein(5)。这几个化合物均具有不同程度的细胞毒活性。化合物1在50μg.mL-1时,对H1N1病毒的抑制率为50%,具有一定的抗病毒活性。结论以上化合物均为首次从南极海洋微生物中分离得到,并初步发现secalonic acid D具有一定的抗H1N1病毒活性。     

南极来源嗜/耐冷真菌的多样性及生物活性研究

目的 研究南极来源真菌的多样性及其生物活性。方法 通过形态观察,化学筛选和序列比较,对南极来源的真菌进行排重,依据真菌ITS rDNA基因序列分析比对结果,使用MEGA 5.0软件对排重后的真菌进行鉴定和系统发育分析。采用纸片法进行抑菌活性筛选,采用MTT法进行抗肿瘤活性筛选。结果 南极来源的147株真菌经形态分析,化学排重和序列分析后获得48株代表菌株,ITS基因序列亲缘关系分析结果显示,属于子囊菌门（Ascomycota）的4个目和6个属：Penicillium、Malbranchea、Aspergillus、Cladosporium、Pseudogymnoascus、Emericellopsis。其中,所鉴定的真菌以Penicillium属为优势菌属,占58.9％,12株嗜/耐冷菌在系统发育树中的亲缘关系相近且以Pseudogymnoascus属为优势菌属。通过活性测试筛选显示耐冷真菌具有良好的抑菌和抗肿瘤活性。结论 南极来源菌株具有丰富的种群和生物活性的多样性,是天然产物活性先导化合物的重要生物资源。     

南极普里兹湾海绵共附生放线菌的分离及其次级代谢潜力评估

【目的】通过研究了解南极海域海绵共附生放线菌的多样性以及活性次级代谢产物的合成潜力。【方法】采用11种分离培养基对南极海绵进行放线菌的分离培养,对分离到的菌株进行抗菌及微藻克生活性的筛选,对活性菌株的进行基于聚酮合酶、非核糖体肽合成酶和卤化酶的基因筛选。【结果】共分离得到59株海绵共附生放线菌,分布于9个属中,以链霉菌最多。21株具有较好的抗菌活性;6株菌表现出明显的赤潮微藻克生活性;有7株活性菌株至少含2种关键的功能基因,菌株OAct311和408同时含有4种功能基因。【结论】研究结果揭示了南极海绵共附生放线菌物蕴含丰富的放线菌资源并且有较高的合成活性次级代谢物的潜力,具有深一步研究的价值。     

南极放线菌XE发酵条件的优化及抑菌物质性质的初步研究

目的 优化南极放线菌XE发酵工艺,提高抑菌活性物质的产量并对菌株产生的活性代谢产物性质进行了初步研究。方法 以发酵液抑菌活性为指标,采用单因素实验和正交实验对放线菌XE发酵培养基和发酵条件进行优化;观察pH值、温度、储藏温度对抑菌物质稳定性的影响;了解抑菌物质的极性及疏水特性。结果 获得了南极放线菌XE的最佳发酵培养基：可溶性淀粉30g/L,黄豆10g/L,海水晶35g/L,KON₃ 1.5g/L;最佳发酵条件：温度28℃,起始pH8,接种量2%,摇床转速110rpm,发酵时间3天;抑菌物质热稳定性好,-20℃储藏活性基本不变,在强碱环境中失活,不耐强碱,活性物质极性较小。结论 通过优化工艺实验,确定了菌株XE最佳发酵培养基和发酵条件,抑菌物质热稳定性好,在-20℃储藏活性基本不变,极性较小,不耐强碱。     

甘草次酸C3、C11、C30衍生物的合成及其体外抗肿瘤活性研究

目的对甘草次酸C3、C11、C30进行结构改造及其体外抗肿瘤活性研究。方法甘草次酸经锌汞齐还原为11-脱氧甘草次酸,然后C30-羧基与卤代烃发生酯化反应,C3-羟基与甲基磺酰氯在0℃冰浴条件下发生甲基磺酰化反应,最后在104℃回流条件下与叠氮钠发生消除反应,从而得到目标产物;通过SRB法对上述合成的甘草次酸衍生物进行体外抗肿瘤活性研究。结果设计并合成了7个目标产物5a~5g,利用IR、MS和1H-NMR确证了结构;抗肿瘤活性筛选结果表明5a对MCF-7的抑制率比母体显著提高,5a、5c、5e对A549的抑制率均比母体有所提高。结论结构改造合理,对进一步开展甘草次酸衍生物的结构改造和抗肿瘤活性研究具有一定的参考价值。     

Uricosuric and diuretic activities of DR-3438 in dogs and rabbits

The purpose of this study was to evaluate the uricosuric and diuretic properties of the new diuretic agent DR-3438. In the conventional clearance studies in urate-loaded dogs, intravenous injection of DR-3438 (3-30 mg/kg) resulted in dose-related increases in fractional excretion of urate (FEua), urine flow and sodium excretion. At doses causing similar natriuresis, tienilic acid (50 mg/kg, i.v.) markedly increased the FEua value, whereas indacrinone (1 mg/kg, i.v.) had no significant effect on it. Trichloromethiazide (1 mg/kg, i.v.) and furosemide (0.3 mg/kg, i.v.) tended to decrease the FEua. Thus, the uricosuric activity of DR-3438 (30 mg/kg) was 0.6-fold that of tienilic acid and 3.4-fold that of indacrinone. In contrast, in urate-loaded rabbits that exhibit net tubular secretion of urate, intravenous DR-3438 (30 mg/kg) produced a significant decrease in FEua. Stop-flow studies in dogs revealed that DR-3438 (30 mg/kg) blocks both urate reabsorption and p-aminohippurate secretion in the proximal segment of the nephron and strongly inhibits reabsorption of water, sodium and potassium in the distal segments. These results suggest that DR-3438 exerts uricosuric activity through blocking urate transport in the proximal tubules and diuretic and saluretic activities by inhibiting water and sodium reabsorption in the distal segment of the nephron.     

Hepatotoxicity of DR-3438, tienilic acid, indacrinone and furosemide studied in vitro

A new diuretic antihypertensive, DR-3438, and marketed diuretic drugs were evaluated for their toxicity in vitro. Hepatocytes were isolated from male rats by the collagenase perfusion method and incubated in Dulbecco's modified Eagle medium containing various doses of DR-3438, tienilic acid, indacrinone or furosemide. Tienilic acid decreased cell viability and glutathione content in hepatocytes and increased lipid peroxidation in the cells. Indacrinone also decreased cell viability, but neither cell viability nor glutathione content was affected by furosemide or DR-3438.     

BBR 3438, a novel 9-aza-anthrapyrazole, in patients with advanced gastric cancer: A phase II study group trial of the central European Society of Anticancer-Drug Research (CESAR)

BBR 3438, a member of the 9-aza-anthrapyrazole family designed to decrease anthracycline dependent cardiotoxicity and to improve efficacy provided high in vivo activity in gastric carcinoma xenograft models. The present study was carried out to assess the efficacy and safety of BBR 3438 applied at a dose of 50 mg/m² four-weekly as an 1-hour infusion to pretreated patients with gastric cancer. Twenty-seven patients received at least one administration of BBR 3438. Lymph nodes and liver were the most common sites of metastases. A total of 94 cycles were administered (median 2, range 1–6). The main toxicity consisted of (worst per patient [%]; NCIC CTC grades 1/2/3/4) neutropenia 7/7/19/52 (one case of febrile neutropenia), stomatitis 15/19/4/-, nausea 22/26/7/-, vomiting 19/7/7/-, alopecia 15/33/-/-. Neutrophil nadir (520/μl) was reached after a median 15 days. The median time to recovery to ≤grade 1 neutropenia was 13.5 days. The median average cumulative dose of BBR 3438 was 166.8 mg, and the median dose intensity was 48.8 mg/m². Left ventricular ejection function (LVEF) was monitored with multiple-gated angiography (MUGA). Median LVEF values at baseline and at the end of cycle 2 were 67.5% and 65%, respectively, and no patient showed a relevant decrease of LVEF. In 25 patients evaluable for response no remission was observed. Four patients (16%) had stable disease. Median time to progression was 51 days, median overall survival was 64 days. In all, the feasibility and tolerability of BBR 3438 applied 4-weekly at a dose of 50 mg/m² was confirmed and neither relevant LVEF decreases nor hints of cardiac toxicity were observed. In terms of antitumor activity, BBR 3438 was found to be ineffective in the treatment of gastric cancer.     

SP-sephadex C25离子交换层析纯化细胞色素C的工艺研究

目的 :研究SP sephadexC2 5离子交换层析纯化细胞色素C的工艺。 方法 :用SP sephadexC2 5树脂取代AmberliteIRC 5 0树脂对细胞色素C进行纯化。结果 :SP sephadexC2 5离子交换纯化细胞色素C一次层析收率达 85 %以上 ,纯度达 98%左右。结论 :SP sephadexC2 5树脂用于细胞色素C的纯化 ,与用AmberliteIRC 5 0树脂相比 ,大大提高了层析得率和产品的纯度 ,提高了产品合格率。     

Comparison of gentamicin C1 and (C1a,C2)-levels in patients

Summary A high performance liquid chromatographic (HPLC) assay method has been used to measure gentamicin serum concentrations in patients receiving gentamicin complex. The HPLC method resolves gentamicin C₁ from the other two components, C_1a and C₂; gentamicin C_1a and C₂ cochromatograph. In the analysis of 46 serum samples collected from 16 patients it was found that the mean ratio (PHR) of the peak height of gentamicin C₁ to the height of the peak due to components C_1a and C₂ was 0.53±0.05; this value agreed well with the PHR's usually found from the HPLC analysis of aqueous solutions of gentamicin complex or of gentamicin dosage forms. In an additional two patients, the HPLC analysis of a sample of the gentamicin dosage form administered, a urine sample, and serum samples, resulted in almost identical PHR's for the respective patients. Finally, similar results were obtained from an experiment in a rabbit. It was concluded that the disposition of all three components of gentamicin complex are the same or very similar.     

丝裂霉素C的心肌毒性作用

丝裂霉素C对心肌细胞有明显毒性作用,电子显微镜观察显示小鼠在体心肌细胞肌丝集合体断裂、溶解,细胞核染色质集聚、核膜皱缩等;对体外培养心肌细胞可引起搏动频率减慢、节律失常,乳酸脱氢酶释放增加,严重者细胞停搏甚至固缩或脱落,对心肌细胞的DNA合成也有明显抑制作用。