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.     

滑桃树内生链霉菌5B发酵产物中的一个新吡唑生物碱

从表面消毒的滑桃树(Trewia nudiflora Linn.)根部分离得到一株内生链霉菌5B,经10升固体YMG培养3周后,从发酵产物中分离得到一个新吡唑类生物碱.该生物碱通过理化性质、NMR及HRMS等波谱数据鉴定为5,6-dihydro-2-isopropyl-4H-pyrrolo[1,2-b]pyrazole.     

Kalafungin, a New Antibiotic Produced by Streptomyces tanashiensis Strain Kala

Kalafungin is a new antimicrobial agent obtained from the culture broth of a soil isolate of Streptomyces tanashiensis, designated Streptomyces tanashiensis strain Kala UC-5063. Kalafungin is a chemically stable, nonpolyene agent which is ex-extremely inhibitory in vitro against a variety of pathogenic fungi, yeasts, protozoa, gram-positive bacteria, and, to a lesser extent, gram-negative bacteria.     

Methods for Estimating the Parameters of Nonlinear Adsorption Isotherms of Langmuir and Freundlich Types from a Response Curve of Pulse Input of an Adsorbate

Methods for estimating the parameters of nonlinear adsorption isotherms of Langmuir and Freundlich types from a pulse response curve are proposed here based on the migration rate of an adsorbate at a constant concentration and the mean residence time of the adsorbate in a bed. The methods were used to estimate the parameters in isotherms for various combinations of adsorbent and adsorbate. The isotherms estimated by the proposed methods were compared with those estimated by conventional methods. It was demonstrated that the proposed methods could evaluate the parameters with fairly good precision when the type of isotherm was known. The criteria for discriminating the type of isotherm from the pulse response curve are also described.     

Phyllospadine,a New Flavonoidal Alkaloid from the Sea-Grass Phyllosphadix iwatensis

Attempts to solubilize active ubiquinol: cytochrome c reductase, cytochrome b-c₁ complex, from the submitochondrial particles from sweet potato root tissue ended in failure because all detergents tested caused inactivation of this enzyme complex. Consequently, the complex was isolated with the content of cytochrome b as the marker for purification after solubilization with deoxycholate though it was inactive. Deoxycholate had no effect on two ±-bands at 555 and 558 nm but caused a blue shift of an ±-band at 563 nm in the reduced-minus-oxidized difference spectrum of the submitochondrial particles at low temperature. The purified complex exhibited the same difference spectra at low and room temperatures as the submitochondrial particles in the presence of deoxycholate, which suggests that the complex has three (at least two) cytochrome b components with different spectroscopic properties and that the apparent molar ratio of cytochrome b to c₁ is 1.5. The purified complex consisted of eight subunits: I, 51 kDa; II, 49kDa; III, 33kDa; IV, 32 kDa; V, 27 kDa; VI, 17 kDa; and VII and VIII, 10 kDa. Subunits III and IV were cytochrome c₁ and b, respectively.     

A New Hybrid Strain of an Oxytetracycline-producing Organism, Streptomyces rimosus

A new strain, Streptomyces rimosus LS-T hybrid, characterized by a lower level of foaming and higher antibiotic activity as compared to the other active strains of S. rimosus, is obtained as a result of selection among prototrophic recombinant forms of strains LS-T293 and BS-21. The studies on strain LS-T hybrid show the possibilities of combining properties of different strains of S. rimosus in the hybrid forms. The occurrence of new properties in the hybrid forms is detected.     

Okaramine A,a Novel Indole Alkaloid with Insecticidal Activity,from Penicillium simplicissimum AK-40

We evaluated the neurotrophic activity of dietary polyphenols by using primary cultures of fetal rat hippocampal neurons in a serum-free medium. Among the tested compounds, chlorogenic acid and its metabolite, m-coumaric acid, together with catechins and flavanone, were found to promote neuronal differentiation comparable to the phytochemical, honokiol, which has been reported to show potent neurotrophic activity. The present findings may contribute to the development of further neurotrophic studies on dietary polyphenols and their metabolites.     

Lytic Enzyme from Streptomyces globisporus 1829 Strain

The maximum yield of lytic enzyme was obtained from shake flask cultures of Streptomyces globisporus 1829 which were grown at 30°DC for 48 hr in a medium containing 2% dextrin, 0.5% soybean meal, 0.2% polypeptone, 0.5% Na₂HP0₄. 12H₂0, 0.1% KH₂P0₄, 0.1% MgS0₄·7H₂0, 1.0% NaCI and 0.02% CaCl₂, pH 7.5. The activity of successively transferred substrains of St. globisporus 1829 gradually decreased. However, a mutant strain obtained by ultra-violet irradiation has been shown not to have lost any lytic activity for 2 years. The enzyme exhibited maximum activity at 60°C in the pH range of 6 to 6.5 and was lytic against the intact cells of Streptococci, Lactobacilli and Bacilli but inert against the intact cells of Staphylococcus aureus and Micrococcus lysodeikticus.     

Ansaetherone,a New Radical Scavenger from Streptomyces sp.

We identified a new radical scavenger, ansaetherone (C₂₆H₃₃NO₇), from a culture of the Streptomyces sp. USF-4727 strain. In our previous study, it was shown that this strain produced four lipoxygenase inhibitors, tetrapetalones A, B, C and D. The chemical structure of ansaetherone was elucidated by the spectroscopic method, indicating that this compound was constructed with an aglycon and a sugar moiety. This chemical structure suggested that ansaetherone was related to the tetrapetalones. This finding provided information regarding tetrapetalone biosynthesis. Ansaetherone showed radical scavenging activity with an ED₅₀ value of 300 μM in our assay.     

Diphaladine A，扁枝石松中一个新的石松生物碱

从扁枝石松（Diphasiastrum complanatum）的95％乙醇提取物中分离得到1个新的石松生物碱,经波谱技术鉴定其结构,命名为diphaladine A（1）。同时还分离得到其它9个已知石松生物碱类化合物,其中obsctmmaine A（2）,L20,lycoposerramine—K,des—N—methyl—β—obscurine,des-N—methyl-α—obscurine,lycoflexion,和phlegmariurine B等7个化合物均为首次从该植物中分离得到。     

New Olimycins from a Cold-Seep-Derived Streptomyces olivaceus

Cold-seeps are areas of the ocean floor in which hydrogen sulfide and methane are released into the open water. The cold-seep microbes are an emerging source of novel bioactive natural products. Four new ansa-ring opened linear ansamycin analogues, named olimycins E−H ( 1 – 4 ) were isolated from the cold-seep-derived Streptomyces olivaceus OUCLQ19-3. The planar and stereochemical structures of the isolated compounds were elucidated based on extensive MS and NMR spectroscopic analyses together with ECD calculations.     

SAF,a New Cell Aggregation Factor Produced by Streptomyces murinus Strain No. A-2805

We searched for a new cell aggregation factor, and found one we called SAF in the mycelia of a strain of Streptomyces murinus. SAF was purified by active carbon and ion exchange column chromatographies and gel filtration of Sepharose 2B from the homogenized mycelia by sonication. SAF was stable from pH 7 to 9 at 37°C and up to 40°C at pH 8.0. The aggregation activity of SAF was maximum around pH 8.0 at 30°C, and the factor required for its activity metallic ions such as calcium and manganese. The aggregation activity of SAF was inhibited by laminarin, but it was not influenced by various other saccharides. SAF aggregated E. coli, S. aureus, M. luteus, sarcoma 180, and HeLa cells as well as S. marcescens, above all, its highest activity was toward B. subtilis, but P. vulgaris, P. aeruginosa, C. albicans, each type of human erythrocytes, and hepatoma 109A cells were quite resistant to SAF. These properties has proved that SAF is completely different from the other aggregation factors so far reported.     

Stemospironine,a New Insecticidal Alkaloid of Stemona japonica Miq. Isolation,Structural Determination and Activity

A new alkaloid named stemospironine (I) was isolated together with stemofoline (II) as the main insecticidal constituents of leaves and stems of Stemona japonica Miq. The absolute stereostructure of I has been determined by X-ray crystallographic analysis. Stemofoline (II) showed a much stronger activity than I against silkworm larvae (Bombyx mori L.) by oral administration.     

Phosphate adsorption kinetics of resuspended sediments in a shallow lake,Neusiedlersee, Austria

The phosphate adsorption capacity of Neusiedlersee suspended sediments was evaluated using a silicone oil-filter-centrifugation technique with³²P and³H-H₂O labelling. This technique is quick, convenient and allows uptake processes to be followed during the first few seconds. The time dependent phosphate uptake was tested for concentration and pH dependency; the highest uptake was recorded at pH 9.00. The high calcite proportion in the sestonic material seems to influence the adsorption process. The kinetics of adsorption (at lake orthophosphate level and pH) could be explained by a biphasic Langmuir isotherm.     

Trans-3-Methylthioacrylamide,a New Metabolic Product from Streptomyces sioyaensis

Rhodosporidium toruloides is a lipid-producing yeast, the growth of which is severely suppressed when hydrolysates of lignocellulosic biomass are used as carbon source. This is probably due to the toxic substances, such as organic acids, furans, and phenolic compounds produced during the preparation of the hydrolysates. In order to solve this problem, R. toruloides cultures were subjected to atmospheric room-temperature plasma mutagenesis, resulting in the isolation of mutants showing tolerance to sugarcane bagasse hydrolysate (SBH). Three mutant strains, M11, M13, and M18, were found to grow with producing lipids with SBH as carbon source. M11 in particular appeared to accumulate higher levels (up to 60% of dry cell weight) of intracellular lipids. Further, all three mutant strains showed tolerance of vanillin, furfural, and acetic acid, with different spectra, suggesting that different genetic determinants are involved in SBH tolerance.     

New bioactive derivatives of nonactic acid from the marine Streptomyces griseus derived from the plant Salicornia sp.

Three new compounds, butyl homononactate (5), butyl nonactate (6), 8-actyl homononactic acid (7), along with four known compounds homononactic acids (1), nonactic acid (2), homononactyl nonactate (3), homononactyl homononactate (4) were isolated from the marine Streptomyces griseus RSH0407, derived from the plant Salicornia sp., Chenopodiaceae. Their structures were elucidated by extensive spectroscopic techniques and by comparison with data reported in the literature. The absolute configuration of 3 was first reported by using X-ray copper radiation. Compound 5 exhibited cytotoxic activities against the HCT-8, A2780, BGC-823, BEL-7402, and A549 cell lines in vitro, with IC₅₀ values of 2.87 ± 0.20, 4.90 ± 0.30, 2.19 ± 0.32, 5.07 ± 0.23 and 1.78 ± 0.18 μM, respectively, and compounds 4–7 showed weak antibacterial activities against four bacterials respectively.     

东川乌头中一个新的去甲二萜生物碱( 英文)

从东川乌头 (AconitumgeniculatumFletcheretLauener)块根的乙醇提取物中分离得到 3个去甲二萜生物碱 ,经 1D、 2D -NMR技术鉴定 ,分别为 2 0 -乙基 - 8-乙酰氧基 - 14- (对 -羟基苯甲酰氧基 ) - 1α ,6α ,16 β ,18-四甲氧基乌头烷 - 3α ,13β二醇 (1)、 2 0 -乙基 - 8-乙酰氧基 - 14-苯酯基乌头烷 - 3α ,13β二醇 (2 )和 2 0 -乙基 - 8-乙酰氧基 - 14- (对 -甲氧基苯酯基 )乌头烷 - 3α ,13β二醇 (3) ,其中 1为新化合物 ,命名为滇羟碱 (geniculine)。     

A New Diterpenoid Alkaloid from Aconitum leucostomum

Four diterpenoid alkaloids were isolated by means of column chromatography and preparative HPLC from the roots of Aconitum leucostomum Worosch. Their structures were determined from the spectral data. One of them was found to be a new compound named leucostine ( Ⅱ ). The other three are known alkaloids, leuconine ( Ⅰ ), dehydroacosanine ( Ⅲ ) and sepaconitine (IV).     

不等弯孢菌HS-FG-257中一个新的苯甲酸类化合物(英文)

从土壤不等弯孢菌HS-FG-257中分离得到4个化合物,通过波谱学鉴定为4-hydroxy-3-(3-methyoxy-3-methylbutyl)-benzoic acid(1),4-hydroxy-3-(3-hydroxy-3-methylbutyl)-benzoic acid(2),4-hydroxy-3-prenylbenzoicacid(3)and radicinin(4),其中化合物1为新化合物。