scholarly journals Terrosamycins A and B, Bioactive Polyether Ionophores from Streptomyces sp. RKND004 from Prince Edward Island Sediment

Marine Drugs ◽  
2019 ◽  
Vol 17 (6) ◽  
pp. 347 ◽  
Author(s):  
Amanda Sproule ◽  
Hebelin Correa ◽  
Andreas Decken ◽  
Bradley Haltli ◽  
Fabrice Berrué ◽  
...  
Keyword(s):  
Prince Edward Island ◽  
Fermentation Broth ◽  
Antibiotic Activity ◽  
Breast Cancer Cell Lines ◽  
X Ray Diffraction ◽  
Streptomyces Sp ◽  
X Ray ◽  
Methoxy Groups ◽  
The One ◽  
Hydroxy Groups

Terrosamycins A (1) and B (2), two polycyclic polyether natural products, were purified from the fermentation broth of Streptomyces sp. RKND004 isolated from Prince Edward Island sediment. The one strain-many compounds (OSMAC) approach coupled with UPLC-HRMS-based metabolomics screening led to the identification of these compounds. The structure of 1 was determined from analysis of NMR, HRMS, and X-ray diffraction data. NMR experiments performed on 2 revealed the presence of two methoxy groups replacing two hydroxy groups in 1. Like other polyether ionophores, 1 and 2 exhibited excellent antibiotic activity against Gram-positive pathogens. Interestingly, the terrosamycins also exhibited activity against two breast cancer cell lines.

scholarly journals Novel Macrolactams from a Deep-Sea-Derived Streptomyces Species

Marine Drugs ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 13
Author(s):  
Pei Wang ◽  
Dongyang Wang ◽  
Rongxin Zhang ◽  
Yi Wang ◽  
Fandong Kong ◽  
...  
Keyword(s):  
Deep Sea ◽  
Spectroscopic Analysis ◽  
Fermentation Broth ◽  
Light Conditions ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
Streptomyces Species ◽  
Deep Sea Sediment ◽  
Streptomyces Sp ◽  
X Ray

Four polyene macrolactams including the previously reported niizalactam C (4), and three new ones, streptolactams A–C (1–3) with a 26-membered monocyclic, [4,6,20]-fused tricyclic and 11,23-oxygen bridged [14,16]-bicyclic skeletons, respectively, were isolated from the fermentation broth of the deep-sea sediment-derived Streptomyces sp. OUCMDZ-3159. Their structures were determined based on spectroscopic analysis, X-ray diffraction analysis, and chemical methods. The abiotic formation of compounds 2 and 4 from compound 1 were confirmed by a series of chemical reactions under heat and light conditions. Compounds 1 and 3 showed a selective antifungal activity against Candida albicans ATCC 10231.

scholarly journals ZnOTe Compounds Grown by DC-Magnetron Co-Sputtering

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 570
Author(s):  
Olga Sánchez ◽  
Manuel Hernández-Vélez
Keyword(s):  
Molar Fraction ◽  
Variable Parameter ◽  
Point Of View ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sample Series ◽  
Solid Phases ◽  
The One ◽  
High Bulk ◽  
Substrate Sample

ZnOTe compounds were grown by DC magnetron cosputtering from pure Tellurium (Te) and Zinc (Zn) cathodes in O2/Ar atmosphere. The applied power on the Zn target was constant equal to 100 W, while the one applied on the Te target took two values, i.e., 5 W and 10 W. Thus, two sample series were obtained in which the variable parameter was the distance from the Te targets to the substrate. Sample compositions were determined by Rutherford Backscattering Spectroscopy (RBS) experiments. Structural analysis was done using X-Ray diffraction (XRD) spectrometry and the growth of the hexagonal w-ZnO phase was identified in the XRD spectra. RBS results showed high bulk homogeneity of the samples forming ZnOTe alloys, with variable Te molar fraction (MF) ranging from 0.48–0.6% and from 1.9–3.1% for the sample series obtained at 5 W and 10 W, respectively. The results reflect great differences between the two sample series, particularly from the structural and optical point of view. These experiments point to the possibility of Te doping ZnO with the permanence of intrinsic defects, as well as the possibility of the formation of other Te solid phases when its content increases. The results and appreciable variations in the band gap transitions were detected from Photoluminescence (PL) measurements.

A Novel Hydroxyapatite Carrier for Enrichment of Hydrocarbon Degradation Bacteria

2007 ◽  
Vol 336-338 ◽  
pp. 1914-1917
Author(s):  
Lei Yang ◽  
Zhen Yi Zhang ◽  
Xiao Shan Ning ◽  
Guang He Li
Keyword(s):  
Activated Carbon ◽  
Sol Gel ◽  
Hydrocarbon Degradation ◽  
Potential Candidate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bacterial Enrichment ◽  
Bet Method ◽  
The One ◽  
Scanning Electron

In this paper, a novel and highly efficient hydroxyapatite (HA) carrier for cultivating hydrocarbon degradation bacteria (HDB) is introduced. The HA particles synthesized through a sol-gel method and different heat treatments were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and BET method. The microbial amount and activities of HDB cultivated on HA carriers were quantitatively investigated in order to assess their enriching capabilities. The results showed that HA synthesized at 550°C and the one without calcination could enrich HDB 3 and 2 magnitude orders more than the activated carbon, respectively. Mechanisms of bacterial enrichment on HA and activated carbon were also studied, and it is believed that the high bioactivity and the surface morphology of HA were responsible for the efficient reproduction of HDB. It is concluded that HA is a potential candidate to replace the conventionally used activated carbon as a novel carrier applied in the filed of bioremediation for oil contaminated soil.

A Simple High-Yield Synthesis of Gallium(I) Tetrachlorogallate(III) and the Reaction of Digallium Tetrachloride Tetrahydrofuran Solvate with 1,2-Diols

2001 ◽  
Vol 56 (4-5) ◽  
pp. 337-341 ◽  
Author(s):  
Eva S. Schmidt ◽  
Annette Schier ◽  
Norbert W. Mitzel ◽  
Hubert Schmidbaur
Keyword(s):  
Crystalline Phase ◽  
Hydrogen Gas ◽  
High Yield ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Atoms ◽  
Gallium Hydride ◽  
Hydroxy Groups ◽  
Tetrahydrofuran Solution ◽  
Analogous Product

Abstract Gallium(I) tetrachlorogallate(III) Ga[GaCU] was prepared in quantitative yield by thermal de­composition of dichlorogallane [HGaCl2]2, which is readily available from Et3SiH and [GaCl3]2. The reaction of catechol with solutions of this gallium(I) tetrachlorogallate(III) in tetrahydrofuran leads to the evolution of hydrogen gas and affords a dinuclear gallium(III) complex with penta-coordinate metal atoms chelated and bridged by mono-deprotonated catechol ligands. In the crystalline phase tetrahydrofuran molecules are hydrogen-bonded to the hydroxy groups: [Ga(1,2 -OC6H4OH)Cl2(C4H8O)]2. The reaction with pinacol also gives hydrogen and the analogous product [Ga(OCMe2CMe2OH)Cl2(C4H8O)]2. The structures of the two compounds have been determined by X-ray diffraction. A mechanism of the new reaction has been proposed which involves oxidative addition of the diol to the solvate (THF)Cl2Ga-GaCl2(THF) present in the tetrahydrofuran solution to give a gallium hydride intermediate.

Polysulfonylamine, CXXV [1]. Neue Komplexe von Disulfonylaminen mit Kronenethern - im voraus entworfen oder zufällig entdeckt / Polysulfonylamines, CXXV [1]. New Complexes of Disulfonylam ines with Crown Ethers - Preconceived or Discovered by Serendipity

2000 ◽  
Vol 55 (3-4) ◽  
pp. 299-316 ◽  
Author(s):  
Dagmar Henschel ◽  
Karna Wijaya ◽  
Oliver Moers ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Hydrogen Bonds ◽  
X Ray Diffraction ◽  
Ladder Structure ◽  
Triclinic Space Group ◽  
One Dimensional ◽  
X Ray ◽  
Bonding System ◽  
Supramolecular Aggregate ◽  
Guest Species ◽  
The One

Abstract In a study aim ed at the „deconstruction“ of the supramolecular aggregate 3(18C6) · 2HN( SO2Me)2 (1,18C6 = 18-crown-6), which is known to display a ladder structure with two isotactic [18C6 - Me SO2N(H)SO2Me···)∞ polymers forming the uprights and symmetrically N - H···O bonded 18C6 rings providing the rungs, the following crystalline complexes were isolated and (except for 2b) characterized by low-temperature X-ray diffraction: 18C6-ClN (SO2Me)2 (2a, triclinic, space group P1̅, Z = 2), 18C6-PhN (SO2Me)2 (2b), 18C6 -MeN(SO2Me)2 (3, monoclinic, P21/c, Z = 8), Bz18C6-HN(SO2Me)2 (4, Bz18C6 = benzo-18-crown-6, monoclinic, P21/n, Z = 4), 18C6-2 MeN (SO2Me)2 (5, triclinic, P1̅, Z = 1), 18C6-Me2SO- HN( SO2Me) (SO2Ph) (13, triclinic, P1̅, Z = 2), and 18C6-H2OMe2SO·2HN(SO2Me)2 (14, triclinic, P1̅, Z = 2). Each of the one-dimensional polymers 2a (syndiotactic), 3 (disyndiotactic) and 4 (isotactic) mimics a single upright of 1; in contrast to 1 and 2a, where the intra-catemer connectivity solely relies on S - Me ··· crow n and crown ··· O = S hydrogen bonds, this bonding system is reinforced in 3 by N -Me ··· crown and in 4 by N - H ··· crown hydrogen bonds. Complex 5 is monomeric and matches a fragment formally extruded from the catemer 3; moreover, 3 and 5 represent a rare case of two structurally characterized 18C6 complexes containing the same uncharged guest species in distinct molecular ratios. The surprising structure of the quaternary adduct 14 exhibits an [18C6 ··· MeSO2N(H)SO2Me ··· ]∞ chain, which can be regarded both as an isolated, though unmodified upright from the ladder 1 and, being syndiotactic, as a stereochemical analogue of 2a; the potentially rung-forming *NH functions in the chain are blocked by hydrogenbonded side chains of the type * N - H ··· water ··· sulfoxide ··· H - N (SO2Me)2. The ternary complex 13 consists of chains [18C6 ··· Me2SO ··· H - N (SO2Ph)SO2Me···]∞ and is not closely related to the other structures

scholarly journals Формирование и трансформация моноклинной и орторомбической фаз в реакторных порошках сверхвысокомолекулярного полиэтилена

2018 ◽  
Vol 60 (9) ◽  
pp. 1847
Author(s):  
М.В. Байдакова ◽  
П.В. Дороватовский ◽  
Я.В. Зубавичус ◽  
Е.М. Иванькова ◽  
С.С. Иванчев ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Room Temperature ◽  
Monoclinic Phase ◽  
Orthorhombic Phase ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Polymer Synthesis ◽  
X Ray Diffraction ◽  
Reactor Powder ◽  
X Ray ◽  
The One

AbstractUsing powerful synchrotron X-ray radiation of the beamline “Belok” operated by the National Research Center “Kurchatov Institute,” we perform X-ray diffraction (XRD) study of an intact, virgin (not subjected to any external mechanical loads) particle isolated from reactor powder of ultrahigh molecular weight polyethylene. Along with the peaks originating from the orthorhombic phase, we detect the peaks characteristic of the monoclinic phase that is stable only under mechanical stress, suggesting that the mechanical stress that leads to the formation of the monoclinic phase and persists at room temperature develops during the polymer synthesis. The monoclinic phase gradually disappears when the particle is heated stepwise in increments of 5 K, and its peaks become undetectable when the temperature reaches 340 K. We contrast the results obtained for the phase composition of the virgin particle to those for a tablet prepared by compaction of the same reactor powder at room temperature. XRD analyses of the tablet were performed on D2 Phaser (Bruker) instrument. The monoclinic phase that originates during the polymer synthesis and the one that forms in the tablet during compaction have different parameters. We discuss the mechanisms by which these two different monoclinic phases originate during the processes involved.

scholarly journals Time-resolved XRD experiments for a fine description of mechanisms induced during reactive sintering

2005 ◽  
Vol 37 (1) ◽  
pp. 27-34 ◽  
Author(s):  
S. Paris ◽  
E. Gaffet ◽  
D. Vrel ◽  
D. Thiaudiere ◽  
M. Gailhanou ◽  
...  
Keyword(s):  
Reactive Sintering ◽  
X Ray Diffraction ◽  
Reaction Parameters ◽  
Time Resolved ◽  
X Ray ◽  
Synthesis Conditions ◽  
Nanostructure Materials ◽  
Synchrotron Beam ◽  
The One

The control of Mechanically Activated Field Activated Pressure Assisted Synthesis hereafter called the MAFAPAS process is the main objective to be achieved for producing nanostructure materials with a controlled consolidation level. Consequently, it was essential to develop characterization tools "in situ" such as the Time Resolved X-ray Diffraction (TRXRD), with an X-ray synchrotron beam (H10, LURE Orsay) coupled to an infrared thermography to study simultaneously structural transformations and thermal evolutions. From the 2003 experiments, we took the opportunity to modify the sample-holder in order to reproduce the better synthesis conditions of the MAFAPAS process, but without the consolidation step. The versatility of the setup has been proved and could even be enhanced by the design of new sample holders. In addition, this work clearly shows that this equipment will allow, on the one hand, to make progress of the understanding of MAFAPAS mechanisms and, on the other hand, to adjust reaction parameters (mechanical activation and combustion synthesis) for producing many materials with an expected microstructure.

Preparation of nanocellulose by hydrolysis with ionic liquids and two-step hydrolysis with ionic liquids and enzymes

2021 ◽  
Vol 116 ◽  
pp. 5-14
Author(s):  
Marta Babicka ◽  
Magdalena Woźniak ◽  
Kinga Szentner ◽  
Sławomir Borysiak ◽  
Krzysztof Dwiecki ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Degree Of Crystallinity ◽  
Cellulolytic Enzyme ◽  
X Ray Diffraction ◽  
Production Methods ◽  
Step Process ◽  
X Ray ◽  
One Step ◽  
Xrd Patterns ◽  
The One

The aim of this study was to compare parameters of nanocellulose obtained by two different procedures: hydrolysis with ionic liquids (1-allyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium acetate) and hydrolysis with ionic liquids in combination with hydrolysis using a cellulolytic enzyme from Trichoderma reesei. Avicel cellulose was treated with two ionic liquids: 1-allyl-3-methylimidazolium chloride (AmimCl) and 1-ethyl 3-methylimidazolium acetate (EmimOAc). In the two-step hydrolysis cellulose after treatment with ionic liquids was additionally hydrolyzed with a solution of enzymes. In order to characterize the obtained material, the following analyses were used: infrared spectroscopy, X-ray diffraction and dynamic light scattering. The results indicated that cellulose obtained by two-step nanocellulose production methods (first hydrolysis with ionic liquids and then with enzymes) showed similar parameters (particle size, XRD patterns and degree of crystallinity) as the material after the one-step process, i.e. hydrolysis with ionic liquids.

5,6,7,8-Tetrahydronaphthalen-1-amine as Precursor for Thiazolidi­nones and Benzothiazepinones: Synthesis and Atropisomeric Relationship

Synthesis ◽  
2017 ◽  
Vol 49 (23) ◽  
pp. 5167-5175 ◽  
Author(s):  
Bruna Drawanz ◽  
Georgia Zimmer ◽  
Leticia Rodrigues ◽  
Andressa Nörnberg ◽  
Manfredo Hörner ◽  
...  
Keyword(s):  
Small Difference ◽  
Mercaptoacetic Acid ◽  
X Ray Diffraction ◽  
Ring Plane ◽  
One Pot ◽  
X Ray ◽  
Nmr Techniques ◽  
The One ◽  
Electron Donating Groups ◽  
Weak Electron

The one-pot reaction of 5,6,7,8-tetrahydronaphthalen-1-amine, mercaptoacetic acid, and arenealdehydes having strong and weak electron-withdrawing groups gave the corresponding 1,3-thiazolidin-4-ones (47–70%). When arenealdehydes bearing strong and weak electron-donating groups were used as precursors, the 1,4-benzothiazepin-2-ones were obtained (30–72%) by p-TsOH catalysis. All compounds are unknown and were characterized by GC-MS and NMR techniques, and available crystals by X-ray diffraction studies. The atropisomerism phenomenon was observed in several 1,3-thiazolidin-4-ones as confirmed by VTNMR method. The Tc was established as 332 K and the energy required for the interconversion of one atrop­isomer into another is around 16.8 kcal·mol–1. Chemical quantum calculation and NOESY displayed that more stable isomer has the tetrahydro­naphthalene portion below the five-ring plane. Only a small difference between isomers (–0.21 to –0.84 kcal·mol–1) was observed by calculated energy.

Sonochemical Co-Precipitation Synthesis of Gallic Acid-Modified Magnetite

2015 ◽  
Vol 1101 ◽  
pp. 286-289 ◽  
Author(s):  
Maya Rahmayanti ◽  
Sri Juari Santosa ◽  
Sutarno
Keyword(s):  
Magnetic Properties ◽  
Gallic Acid ◽  
Precipitation Method ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
One Step ◽  
The Fourier Transform ◽  
The One ◽  
Co Precipitation

Gallic acid-modified magnetites were synthesized by one and two-step reactions via the newly developed sonochemical co-precipitation method. The two-step reaction included the formation of magnetite powder and mixing the magnetite powder with gallic acid solution, while the one-step reaction did not go through the formation magnetite powder. The obtained gallic acid-modified magnetites were characterized by the Fourier Transform Infrared (FTIR) spectroscopy, the X-Ray Diffraction (XRD) and the Scanning Electron Microscopy (SEM). More over, the magnetic properties were studied by using a Vibrating Sample Magnetometer (VSM). The characterization results showed that there were differences in crystalinity, surface morphology and magnetic properties of products that were formed by one and two-step reactions.

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