scholarly journals Isolation and X-ray Structure of Deoxycholic Acid from the Sponge Ircinia sp

2011 ◽  
Vol 6 (9) ◽  
pp. 1934578X1100600
Author(s):  
Keisham Sarjit Singh ◽  
Werner Kaminsky
Keyword(s):  
Antimicrobial Activity ◽  
Carboxylic Acid ◽  
Spectroscopic Data ◽  
Deoxycholic Acid ◽  
Ethyl Acetate Extract ◽  
Optical Rotation ◽  
Side Chain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scuba Divers

Ethyl acetate extract of the sponge Ircinia sp., collected by SCUBA divers off the coast of southern India, contained a cholest-based sterol of insignificant antimicrobial activity, with one carboxylic acid side chain (3α, 7β-dihydroxy-5β-cholan-24-oic acid, DCA). The structure of the compound was determined by spectroscopic data and single crystal X-ray diffraction studies. DCA crystallizes in the tetragonal space group P41212, chirality documented by solution optical rotation [α]D = +67.4° ( c 0.16, CHCl3).

scholarly journals Discovery of Stealthin Derivatives and Implication of the Amidotransferase FlsN3 in the Biosynthesis of Nitrogen-Containing Fluostatins

Marine Drugs ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 150 ◽  
Author(s):  
Chunshuai Huang ◽  
Chunfang Yang ◽  
Zhuangjie Fang ◽  
Liping Zhang ◽  
Wenjun Zhang ◽  
...  
Keyword(s):  
Spectroscopic Data ◽  
Bioinformatics Analysis ◽  
Biological Activities ◽  
Side Chain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aromatic Polyketides ◽  
Plausible Mechanism ◽  
Encoding Gene

Diazobenzofluorene-containing atypical angucyclines exhibit promising biological activities. Here we report the inactivation of an amidotransferase-encoding gene flsN3 in Micromonospora rosaria SCSIO N160, a producer of fluostatins. Bioinformatics analysis indicated that FlsN3 was involved in the diazo formation. Chemical investigation of the flsN3-inactivation mutant resulted in the isolation of a variety of angucycline aromatic polyketides, including four racemic aminobenzo[b]fluorenes stealthins D–G (9–12) harboring a stealthin C-like core skeleton with an acetone or butanone-like side chain. Their structures were elucidated on the basis of nuclear magnetic resonance (NMR) spectroscopic data and X-ray diffraction analysis. A plausible mechanism for the formation of stealthins D–G (9–12) was proposed. These results suggested a functional role of FlsN3 in the formation/modification of N–N bond-containing fluostatins.

scholarly journals Two New Isocoumarin Derivatives from an Endophytic Fungi Pestalotiopsis coffeae Isolated from a Mangrove Fishtail Palm

2018 ◽  
Vol 13 (1) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Zhong Wang ◽  
Peng Fan ◽  
Tong-Dan Xue ◽  
Lin-Lin Meng ◽  
Wen-Bin Gao ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Endophytic Fungi ◽  
Endophytic Fungus ◽  
Spectroscopic Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chinese Plant

Two new isocoumarin derivatives, 6,8-dihydroxy-7-methyl-1-oxo-1H-isochromene-3-carboxylic acid (1) and 6,8-dihydroxy-3-methoxy-3,7- dimethyl-isochroman-1-one (2), together with five known compounds (3-7), were isolated from the endophytic fungus Pestalotiopsis coffeae derived from the Chinese plant fishtail palm. The structures of these compounds were determined mainly by analysis of their NMR spectroscopic data. The structure of compound 2 was further confirmed by X-ray diffraction.

scholarly journals Seven New Drimane-Type Sesquiterpenoids from a Marine-Derived Fungus Paraconiothyrium sporulosum YK-03

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1817 ◽  
Author(s):  
Li-Hua Zhang ◽  
Gang Chen ◽  
Yi Sun ◽  
Hai-Feng Wang ◽  
Jiao Bai ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Diffraction Analysis ◽  
Aromatic Ring ◽  
Spectroscopic Data ◽  
Ethyl Acetate Extract ◽  
Fermentation Broth ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Absolute ◽  
Circular Dichroism Data

Seven new drimane-type sesquiterpenoids, namely the sporulositols A–D (1–4), 6-hydroxydiaporol (5), seco-sporulositol (6) and sporuloside (7) were isolated from the ethyl acetate extract of fermentation broth for a marine-derived fungus Paraconiothyrium sporulosum YK-03. Their structures were elucidated by analysis of extensive spectroscopic data, and the absolute configurations were established by crystal X-ray diffraction analysis and comparisons of circular dichroism data. Among them, sporulositols A–E (1–4) and seco-sporulositol (6) represent the first five examples of a unique class of drimanic mannitol derivatives, while compounds 6 and 7 may represent two new series of natural drimanes, possessing an aromatic ring with a rare 4,5-secodrimanic skeleton and an unusual CH3-15 rearranged drimanic α-D-glucopyranside, respectively. Furthermore, the origin of mannitol moiety was investigated by reliable HPLC and NMR analyses.

A MOF based on a lead(II) 2-oxido-6-methylpyridine-4-carboxylate network

2020 ◽  
Vol 75 (4) ◽  
pp. 365-369
Author(s):  
Long Tang ◽  
Yu Pei Fu ◽  
Na Cui ◽  
Ji Jiang Wang ◽  
Xiang Yang Hou ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Carboxylic Acid ◽  
Thermogravimetric Analysis ◽  
Metal Organic Framework ◽  
X Ray Diffraction ◽  
X Ray ◽  
Connected Node ◽  
Metal Organic ◽  
Solid State Fluorescence

AbstractA new metal-organic framework, [Pb(hmpcaH)2]n (1), has been hydrothermally synthesized from Pb(OAc)2 · 3H2O and 2-hydroxy-6-methylpyridine-4-carboxylic acid (hmpcaH2; 2), and characterized by IR spectroscopy, elemental and thermogravimetric analysis, and single-crystal X-ray diffraction. In complex 1, each hmpcaH− ligand represents a three-connected node to combine with the hexacoordinated Pb(II) ions, generating a 3D binodal (3,6)-connected ant network. The crystal structure of 2 was determined. The solid-state fluorescence properties of 1 and 2 were investigated.

New iboga-type alkaloids from Ervatamia hainanensis

RSC Advances ◽  
2016 ◽  
Vol 6 (36) ◽  
pp. 30277-30284 ◽  
Author(s):  
Zhi-Wen Liu ◽  
Xiao-Jun Huang ◽  
Han-Lin Xiao ◽  
Guo Liu ◽  
Jian Zhang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Spectroscopic Data ◽  
X Ray Diffraction ◽  
X Ray

The structures and absolute configurations of seven new iboga-type alkaloids 1–7 were determined by spectroscopic data, Mosher's method, single crystal X-ray diffraction and ECD analyses.

Synthesis of Nanocomposites of V2OO5©Selenium Nanoparticles and Multiwalled Carbon Nanotubes for Antimicrobial Activity

2021 ◽  
Vol 21 (11) ◽  
pp. 5673-5680
Author(s):  
Muthukrishnan Francklin Philips ◽  
Jothirathinam Thangarathinam ◽  
Jayakumar Princy ◽  
Cyril Arockiaraj Crispin Tina ◽  
Cyril Arockiaraj Crispin Tina ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Antimicrobial Activity ◽  
Multiwalled Carbon Nanotubes ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Functionalized Multiwalled Carbon Nanotubes ◽  
Uv Visible ◽  
Micro Organisms

The authors report the preparation of the nanocomposite comprising of vanadium pentoxide (V2O5) and selenium (Se) nanoparticles and functionalized multiwalled carbon nanotubes (MWCNTs) (V2O5@Se NPs/MWCNTs). Since Se NPs possesses extraordinary physicochemical properties including larger surface area with higher adsorption capacity, V2O5 NPs were adsorbed onto Se NPs surface through physisorption process (designated as V2O5@Se NPs). The nanocomposite synthesized hydrothermally was evaluated for its antimicrobial activity. The morphology and microstructure of the nanocomposite were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, respectively. Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectroscopy (UV-Vis) were employed to analyze the spectral properties of nanocomposite. The microbicidal efficacy of nanocomposite was tested against Gram-negative (G-)ZGram-positive (G+) bacteria and fungus. This is the first report on the synthesis of V2O5@Se NPs/MWCNTs nanocomposites by chemical method that showed microbicidal effect on micro-organisms. The thiol (-SH) units facilitates the enrichment of V2O5@Se NPs onto MWCNTs surface. Ultimately, it reflects on the significant antimicrobial activity of V2O5@Se NPs/MWCNTs.

scholarly journals Aspergiloid I, an unprecedented spirolactone norditerpenoid from the plant-derived endophytic fungus Aspergillus sp. YXf3

2014 ◽  
Vol 10 ◽  
pp. 2677-2682 ◽  
Author(s):  
Zhi Kai Guo ◽  
Rong Wang ◽  
Wei Huang ◽  
Xiao Nian Li ◽  
Rong Jiang ◽  
...  
Keyword(s):  
Endophytic Fungus ◽  
Spectroscopic Data ◽  
Biosynthetic Pathway ◽  
Culture Broth ◽  
Ring System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Anti Oxidant ◽  
Inhibitory Activities ◽  
Aspergillus Sp

An unusual C18 norditerpenoid, aspergiloid I (1), was isolated from the culture broth of Aspergillus sp. YXf3, an endophytic fungus derived from Ginkgo biloba. Its structure was unambiguously established by analysis of HRMS–ESI and spectroscopic data, and the absolute configuration was determined by low-temperature (100 K) single crystal X-ray diffraction with Cu Kα radiation. This compound is structurally characterized by a new carbon skeleton with an unprecedented 6/5/6 tricyclic ring system bearing an α,β-unsaturated spirolactone moiety in ring B, and represents a new subclass of norditerpenoid, the skeleton of which is named aspergilane. The hypothetical biosynthetic pathway for 1 was also proposed. The cytotoxic, antimicrobial, anti-oxidant and enzyme inhibitory activities of 1 were evaluated.

Are mesoionic compounds aromatic?

1998 ◽  
Vol 76 (6) ◽  
pp. 869-872 ◽  
Author(s):  
Alfredo Mayall Simas ◽  
Joseph Miller ◽  
Petrônio Filgueiras de Athayade Filho
Keyword(s):  
Experimental Evidence ◽  
Key Words ◽  
Dipole Moments ◽  
The Other ◽  
Side Chain ◽  
Theoretical Studies ◽  
X Ray Diffraction ◽  
Ring Plane ◽  
X Ray ◽  
Single Bonds

We have evaluated the experimental evidence relevant to the structure and character of mesoionic compounds, accumulated for more than 100 years and including X-ray diffraction studies. We have also evaluated relevant theoretical studies. All these, including our own extensive work, lead us to conclude that mesoionic compounds are not aromatic. According to our recent definition “mesoionic compounds are planar five-membered heterocyclic betaines with at least one side chain whose α-atom is also in the ring plane and with dipole moments of the order of 5 D. Electrons are delocalized over two regions separated by what are essentially single bonds. One region, which includes the a-atom of the side chain is associated with the HOMO and negative π-charge whereas the other is associated with the LUMO and positive π-charge.” Key words: mesoionic compounds, betaines, aromaticity.

Synthese und Kristallstrukturen einiger Tetramethylstibonium-Hydrogendicarboxylate / Synthesis and Crystal Structures of Some Tetramethylstibonium Hydrogendicarboxylates

1982 ◽  
Vol 37 (11) ◽  
pp. 1393-1401 ◽  
Author(s):  
Beatrix Milewski-Mahrla ◽  
Hubert Schmidbaur
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Spectroscopic Data ◽  
Molar Ratio ◽  
Ionic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylate Oxygen ◽  
Donor Acceptor ◽  
New Compounds

Reactions of pentamethylantimony (CH3)5Sb with carboxylic acids in the molar ratio 1:2 afford one equivalent of methane and essentially quantitative yields of crystalline tetramothylstibonium hydrogendicarboxylates. Six new compounds of this series have been synthesized using benzoic, o-phthalic, salicylic, 4-ethoxy-salicylic, oxalic, and malic acid, and characterized by analytical and spectroscopic data. An ionic structure with strong hydrogen bonds in the anionic components is proposed.The crystal structures of the hydrogen-dibenzoato (1), hydrogen-ortho-plithalato (2) and 4-ethoxy-hydrogen-salicylate (3) were determined by single crystal X-ray diffraction. The compounds can be described as having ionic lattices with some donor-acceptor inter­actions between the stibonium centers and the carboxylate oxygen atoms. The anions are characterized by strong hydrogen bonds O...H...O. Thus, the (CH3)4Sb-tetrahedron in 1 is distorted by two benzoate oxygon atoms (at 304(2) and 340(2) pin). The cation in 2 is largely undistorted and the anion has a hydrogenphthalate hydrogen bond of d(O...H...O) = 232 pm. The cation-anion contact in 3 is as short as d(Sb-O) = 289 pm rendering the Sb atom pentacoordinate.

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