Two New Butenolides Produced by an Actinomycete Streptomyces sp.

Two new butenolides, (4S)‐4,10‐dihydroxydodec‐2‐en‐1,4‐olide ( 1 ) and (4S)‐4,8,10‐trihydroxy‐10‐methyldodec‐2‐en‐1,4‐olide ( 2 ), together with three known compounds, MKN‐003B ( 3 ), MKN‐003C ( 4 ), and cyclo(Ala‐Leu) ( 5 ), were isolated from the culture broth of a bacterium of the genus Streptomyces derived from soil environment. The structures of these compounds were elucidated on the basis of spectroscopic analysis. The inhibitory activities of the butenolides against eight pathogenic fungi were evaluated. All of the butenolides showed moderate‐or‐weak antifungal activities in a broth microdilution assay.     

链霉菌FIM-080014产生的核苷类代谢产物研究

本文采用大孔吸附树脂、硅胶柱色谱、反相柱色谱、凝胶sephadex LH-20及HPLC等方法对链霉菌FIM-080014发酵液及菌丝体中的代谢产物进行分离,得到7个核苷类化合物。通过NMR及MS等方法鉴定了上述化合物的结构,分别为尿嘧啶(1)、尿嘧啶核苷(2)、2'-脱氧尿嘧啶核苷(3)、5'-C-甲基尿嘧啶核苷(4)、2'-脱氧胸腺嘧啶核苷(5)、2'-脱氧鸟嘌呤核苷(6)和次黄嘌呤(7),其中化合物4首次从微生物代谢产物中分离得到。活性分析表明化合物1～7对神经氨酸酶具有一定的抑制活性,其IC50值分别为3.7、2.1、4.4、1.4、3.6、2.5和2.4 mM。     

New Avermectin Analogues from a Mutant Streptomyces avermectinius Strain

Two new avemectin analogues 1 and 2 belonging to ‘b’ series of components were isolated from a ?aveCDE mutant Streptomyces avermectinius strain. Their structures were elucidated by detailed analysis of NMR and MS spectroscopic data. Compounds 1 and 2 displayed moderate cytotoxicities against B16, MG ‐63, and Saos‐2 cell lines in an in vitro assay.     

Chemical Structures of New Piericidins Produced by Streptomyces pactum

Chemical structures of new piericidins produced by Streptomyces pactum are elucidated on the basis of mass, PMR and CMR spectral analyses. Consequently, these piericidins were shown to be constructed by a combination of variations in each four functionalities and carbon skeletons.     

4种地衣提取物抗氧化和抗肿瘤活性研究

本研究初步评估了4种药用地衣(太白茶、金刷把、黑石耳、红石耳)不同溶剂提取物的抗氧化活性及其粗多糖的抗肿瘤活性。通过测定清除DPPH自由基、羟基自由基和还原能力,对4种地衣不同溶剂提取物进行体外抗氧化活性评价,结果表明,金刷把和黑石耳的甲醇提取相清除DPPH自由基能力高于其它溶剂提取相,其IC50值(半抑制浓度)分别为0.7847 mg/mL和0.5595 mg/mL;黑石耳甲醇提取相(IC50=0.5747 mg/mL)清除羟基自由基能力优于阳性对照物Vc(IC50=0.6126 mg/mL);黑石耳氯仿提取相、金刷把乙酸乙酯提取相和太白茶甲醇提取相清除羟基自由基能力与Vc相当;4种地衣甲醇提取相还原能力均较强,且与其浓度呈较好的量效关系。利用MTT法分析4种地衣多糖对HeLa、A375和Hep G2细胞体外生长增殖的抑制作用,结果显示黑石耳粗多糖对Hep G2细胞的抑制作用较为突出(IC50=0.2567 mg/mL),而金刷把抑制HeLa细胞的生长增殖作用最强,其IC50值为0.4332 mg/mL。     

Four new doramectin congeners with acaricidal and insecticidal activity from Streptomyces avermitilis NEAU1069

Four new doramectin congeners, 1-4, were isolated from Streptomyces avermitilis NEAU1069. The structures of 1-4 were elucidated on the basis of spectroscopic analysis, including 1D- and 2D-NMR as well as HR-ESI-MS, ESI-MS, UV, and IR, and comparison with literature data. All compounds exhibited noticeable acaricidal and insecticidal activities. Especially compound 2 was found to be the most potent pesticide of the compounds evaluated with the IC(50) values of 10.2, 65.1 and 124.4 μg/ml against adult two-spotted spider mites (Tetranychus urticae Koch), two-spotted spider mite eggs, and Mythimna separata, respectively, which are comparable to those of commercial pesticide milbemycin A(3)/A(4) as positive reference.     

Characterization of chitinase from Streptomyces luridiscabiei U05 and its antagonist potential against fungal plant pathogens

Streptomyces luridiscabiei U05 was isolated from wheat rhizosphere. It produced chitinase, which showed in vitro antifungal properties. The crude enzyme inhibited the growth of Alternaria alternata, Fusarium oxysporum, F. solani, Botrytis cinerea, F. culmorum and Penicillium verrucosum. The chitinase enzyme of the molecular weight of 45 kDa was purified using affinity chromatography of chitin. Streptomyces luridiscabiei U05 produced different chitinolytic enzymes. The highest enzyme activity was observed with the use of 4‐MU‐(GlcNAc)_, which points to the presence of an β‐N‐acetylhexosaminidase. The optimum activity was obtained at 35–40°C and pH 7–8. The enzyme showed thermostability at 35–40°C during 240 min of preincubation and lost its activity at 50°C and 60°C in 60 min. The chitinase activity from S. luridiscabei U05 was strongly inhibited by Hg²⁺ and Pb²⁺ ions, and sodium dodecyl sulphate (SDS). The Ca²⁺, Cu²⁺ and Mg²⁺ ions stimulated the activity of the enzyme.     

星海链霉菌抑菌活性物质的分离纯化

星海链霉菌(Streptomyces xinghaiensis)是从大连星海湾海泥样品中分离的海洋链霉菌新种,其发酵液具有广谱抗菌活性。研究该菌株的发酵液对临床分离的耐药菌的抑制活性,发现星海链霉菌发酵液对鲍曼不动杆菌和耐甲氧西林金黄色葡萄球菌菌株具有抑制活性。采用SPE、大孔吸附树脂HP-20、葡聚糖凝胶Sephadex LH-20、HPLC、TLC等对抗耐甲氧西林金黄色葡萄球菌的物质进行了活性追踪,发现活性物质为弱碱性水溶性成分,无特征紫外吸收,可被茚三酮显色,推断活性物质可能为氨基糖苷类化合物。对星海链霉菌基因组序列进行初步分析,发现一个与核糖霉素生物合成基因簇相似性较高的基因簇,但TLC分析结果表明,活性化合物与核糖霉素不同。     

Two New Pyrrolosesquiterpenes Produced by a Streptomyces Species

Two new pyrrolosesquiterpenes, 1 and 2 , were isolated from cultures of the soil actinomycete Streptomyces sp. Hd7–21. The structures of these compounds were established as (2Z,4E,9E)‐6,7,11‐trihydroxy‐3,7,11‐trimethyl‐1‐(1H‐pyrrol‐2‐yl)dodeca‐2,4,9‐trien‐1‐one ( 1 ) and (2Z,4E)‐5‐{3‐[(2E)‐4‐hydroxy‐4‐methylpent‐2‐en‐1‐yl]‐3‐methyloxiran‐2‐yl}‐3‐methyl‐1‐(1H‐pyrrol‐2‐yl)penta‐2,4‐dien‐1‐one ( 2 ) by extensive spectroscopic analyses including MS, and 1D‐ and 2D‐NMR data. Their cytotoxic activities against a panel of human cancer cell lines were evaluated.     

The antimicrobial activity of substances derived from the lichens Physcia aipolia, Umbilicaria polyphylla, Parmelia caperata and Hypogymnia physodes

In this study, in vitro antimicrobial activity of the physodic acid, usnic acid, atranorin and gyrophoric acid isolated from the lichens Hypogymnia physodes, Parmelia caperata, Physcia aipolia and Umbilicaria polyphylla, has been investigated. An antibiotic assessment was done against six bacteria (three Gram-positive and three Gram-negative) and eight fungi by determining the minimal inhibitory concentration (MIC) by the broth tube dilution method. The tested lichen substances inhibited growth of all the tested microorganisms. The bacteria showed a higher sensitivity against the tested fungi. The highest antimicrobial activity was found in the usnic acid of the Parmelia caperata lichen, where the lowest MIC was 0.0037 mg/ml against the Klebsiella pneumoniae (even lower than the one given by the streptomycin standard). The weakest antimicrobial activity was found in the physodic acid, which inhibited most of the microorganisms in the concentration of 1 mg/ml. Generally, all the components had relatively strong antimicrobial activity against the tested microorganisms, among which were human and animal pathogens. This could be of significance for their use for pharmaceutical purposes.     

Neuraminidase Inhibitors from marine‐derived actinomycete Streptomyces seoulensis

Aims

This work was performed to characterize new secondary metabolites with neuraminidase (NA) inhibitory activity from marine actinomycete strains.

Methods and Results

An actinomycete strain IFB‐A01, capable of producing new NA inhibitors, was isolated from the gut of shrimp Penasus orientalis and identified as Streptomyces seoulensis according to its 16S rRNA sequence (over 99% homology with that of the standard strain). Repeated chromatography of the methanol extract of the solid‐substrate culture of S. seoulensis IFB‐A01 led to the isolation of streptoseolactone ( 1 ), and limazepines G ( 2 ) and H ( 3 ). The structures of 1 – 3 were determined by a combination of IR, ESI‐MS, 1D (¹H and ¹³C NMR, and DEPT) and 2D NMR experiments (HMQC, HMBC, ¹H‐¹H COSY and NOESY). Compounds 1 – 3 showed significant inhibition on NA in a dose‐dependent manner with IC₅₀ values of 3·92, 7·50 and 7·37 μmol l^?1, respectively.

Conclusions

This is the first report of two new ( 1 and 2 ) and known ( 3 , recovered as a natural product for the first time in the work) NA inhibitors from the marine‐derived actinomycete S. seoulensis IFB‐A01.

Significance and Impact of the Study

The three natural NA inhibitors maybe of value for the development of drug(s) necessitated for the treatment of viral infections.     

灰色变异链霉菌2507抑菌活性成分的研究

以枯草芽孢杆菌为指示生物进行活性跟踪,通过对灰色变异链霉菌2507发酵液的初步分离纯化,得到两个化合物,由波谱数据解析鉴定其结构分别为香草酸和丁香酸。这两个化合物为首次从这种微生物代谢产物中分离得到。     

嗜热链球菌CGMCC 1.1864所产的一种新型细菌素ST9

本文利用琼脂扩散法测定嗜热链球菌(Streptocccus thermophilus) CGMCC 1.1864发酵上清液的抑菌效果, 结果表明此菌能够产生抑菌物质, 且在排除有机酸和过氧化氢的影响后上清液不但能抑制革兰氏阳性菌, 对革兰氏阴性菌也有抑制能力。此抑菌物质具有热稳定性, 于100°C处理 2 h及121°C处理20 min仍保留抑菌活性, 但若将其在100°C处理2 h的上清液立即置于?20°C保存, 其抑菌活性有较大损失。常温下(37°C), 该抑菌物质在pH 2.0?9.0范围内有很好的稳定性。发酵上清液经各种蛋白酶及?-淀粉酶处理后抑菌活性完全消失, 而对过氧化氢酶不敏感, 表明此抑菌物质为多肽, 属于细菌素, 本文初步将其命名为嗜热链球菌素ST9。由于ST9对其产生菌具有吸附作用, 选择pH吸附释放法对该嗜热链球菌素进行粗提, 然后经SephadexG-25凝胶层析柱除去杂蛋白, 最后冷冻干燥得纯品。通过Tricine-SDS-PAGE分析得到其分子量约为5.0 kD。     

Hexokinase II Inhibitory Effect of Secondary Metabolites Derived from a Streptomyces sp. Associated with Mud Dauber Wasp

Insect‐microbial symbioses have vast biochemical diversity, which is beneficial to produce bioactive secondary metabolites. In this study, chemical examination of a Streptomyces sp. associated with a mud dauber wasp led to the isolation of fourteen compounds. Their structures were determined by spectroscopic methods and comparison with literature data. Among the isolates, compounds 1,2,3‐benzotriazin‐4(1H)‐one and 4‐(2‐aminoethyl)phenyl acetate were first reported from this species. Bioactivities of the isolated compounds were assayed for the first time against hexokinase II. 4‐(2‐Aminoethyl)phenyl acetate, germicidin B, phenylacetic acid, isogermicidin A and germicidin C displayed significant inhibitory activity against hexokinase II, with the IC₅₀ values of 5.11, 7.11, 7.15, 8.45 and 8.78 μM, respectively.     

Jiangchuanmycin,a New Pyrrolizidine Analog from Streptomyces sp. YIM S01863

Jiangchuanmycin ( 1 ), a new indole containing pyrrolizidine, and six known peptides ( 2–7 ) were obtained from the fermentation broth of a Streptomyces isolate collected from a sediment sample of Xingyun Lake, Jiangchuan, China. Their structures were elucidated on the detailed analysis of the HR-ESI-MS, 1D and 2D NMR, ECD, and X-ray crystallographic data. Jiangchuanmycin ( 1 ) presented weak inhibitory effects on cell lines of H1299, MHCC97H, HCT116 with the IC₅₀ values of 97.6 μM, 98.6 μM and 40.6 μM, respectively.     

抗菌豆豉发酵菌株的筛选及其脂肽组分鉴定和特性研究

目的:从豆豉中分离广谱抗菌活性菌株,并鉴定其发酵产物中的抗菌成分.方法:采用生理生化实验结合16SrRNA序列测定法鉴定目标分离株,通过LC-MS和ESI/CID技术对其抗菌组分进行鉴定.结果:从8个豆豉样品中分离出7株具有抗菌活性菌株,其中抗菌活性较强的分离株NT-6为枯草芽孢杆菌(Bacillus subtilis),其发酵液抗菌提取物的主要成分是抗菌脂肽类物质iturin、fengycin、surfactin同系物的混合物.该提取物对供试革兰氏阳性、阴性细菌、霉菌等指示菌具有广谱的抗菌活性,在pH 2～ 12、121℃条件下加热30min活性不丧失,说明具有广泛的pH适应范围和良好的耐热性.结论:该菌株产生多组分抗菌脂肽,其抑菌谱宽,适应性好,显示了在食品、农业、医药等领域具有良好的应用前景.