scholarly journals New Metabolites From the Endophytic Fungus Cercophora samala Associated With Mitragyna inermis

2021 ◽  
Vol 16 (5) ◽  
pp. 1934578X2110132
Author(s):  
Erik Donfack Vouffo ◽  
Clovis Douanla-Meli ◽  
Angelbert Fusi Awantu ◽  
Bruno Ndjakou Lenta ◽  
Sylvère Ngouela ◽  
...  
Keyword(s):  
Natural Products ◽  
Dft Calculations ◽  
Absolute Configuration ◽  
Endophytic Fungus ◽  
Spectroscopic Data ◽  
Spectroscopic Analysis ◽  
The Absolute ◽  
New Metabolites ◽  
Mitragyna Inermis

Two new natural products, mitrafungidione (1) elucidated as prototrop-isomers of ( R-3-acetyl-5-ethyl-4-hydroxy-5 H-furan-2-one, and maristachone F (2a), elucidated as 5-(1-hydroxyethyl)-4-(hydroxymethyl)-3-methoxy-2-methylphenol, together with 5 known compounds have been isolated from the solid cultures of an endophytic fungus associated with Mitragyna inermis (Rubiaceae) and identified as Cercophora samala. The structures of these compounds were elucidated by detailed spectroscopic analysis and by comparison of their spectroscopic data with those reported in the literature. The absolute configuration of 1 and 2a were determined by extensive DFT calculations.

scholarly journals Structure and Absolute Configuration of Phenanthro-perylene Quinone Pigments from the Deep-Sea Crinoid Hypalocrinus naresianus

Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 445
Author(s):  
Sahithya Phani Babu Vemulapalli ◽  
Juan Carlos Fuentes-Monteverde ◽  
Niels Karschin ◽  
Tatsuo Oji ◽  
Christian Griesinger ◽  
...  
Keyword(s):  
Natural Products ◽  
Dft Calculations ◽  
Absolute Configuration ◽  
13C Nmr ◽  
Deep Sea ◽  
Spectroscopic Analysis ◽  
2D Nmr ◽  
Water Soluble ◽  
Spectroscopy Analysis ◽  
1H And 13C Nmr

Two new water-soluble phenanthroperylene quinones, gymnochrome H (2) and monosulfated gymnochrome A (3), as well as the known compounds gymnochrome A (4) and monosulfated gymnochrome D (5) were isolated from the deep-sea crinoid Hypalocrinus naresianus, which had been collected in the deep sea of Japan. The structures of the compounds were elucidated by spectroscopic analysis including HRMS, 1D 1H and 13C NMR, and 2D NMR. The absolute configuration was determined by ECD spectroscopy, analysis of J-couplings and ROE contacts, and DFT calculations. The configuration of the axial chirality of all isolated phenanthroperylene quinones (2–5) was determined to be (P). For gymnochrome H (2) and monosulfated gymnochrome A (3), a (2′S,2″R) configuration was determined, whereas for monosulfated gymnochrome D (5) a (2′R,2″R), configuration was determined. Acetylated quinones are unusual among natural products from an echinoderm and gymnochrome H (2) together with the recently reported gymnochrome G (1) represent the first isolated acetylated phenanthroperylene quinones.

Determination of the absolute configuration of natural products

2014 ◽  
Vol 11 (3) ◽  
pp. 193-198 ◽  
Author(s):  
Ling-Yi KONG ◽  
Peng WANG
Keyword(s):  
Natural Products ◽  
Absolute Configuration ◽  
The Absolute

scholarly journals Massiliamide, a cyclic tetrapeptide with potent tyrosinase inhibitory properties from the Gram-negative bacterium Massilia albidiflava DSM 17472T

2020 ◽  
Author(s):  
Andri Frediansyah ◽  
Jan Straetener ◽  
Heike Brötz-Oesterhelt ◽  
Harald Gross
Keyword(s):  
Absolute Configuration ◽  
Inhibitory Activity ◽  
Liquid Culture ◽  
Spectroscopic Analysis ◽  
2D Nmr ◽  
Negative Bacterium ◽  
Gram Negative ◽  
The Absolute ◽  
Potent Inhibitory Activity ◽  
Cyclic Tetrapeptide

AbstractA cyclic tetrapeptide, designated massiliamide, was isolated from the liquid culture of the Gram-negative bacterium Massilia albidiflava DSM 17472T. The structure was elucidated through extensive spectroscopic analysis, including HR-MS and 1D and 2D NMR experiments. The absolute configuration was determined using the Marfey´s method. Massiliamide showed potent inhibitory activity towards tyrosinase with an IC50 value of 1.15 µM and no cytotoxicity.

Ferrocenes with simple chiral substituents: an in-depth theoretical and experimental VCD and ECD study

2019 ◽  
Vol 21 (18) ◽  
pp. 9419-9432 ◽  
Author(s):  
Angela Patti ◽  
Sonia Pedotti ◽  
Giuseppe Mazzeo ◽  
Giovanna Longhi ◽  
Sergio Abbate ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Absolute Configuration ◽  
The Absolute

Ferrocenes bearing chiral pendants are investigated through VCD and ECD. The VCD spectra are best interpreted by GVPT2-anharmonic DFT calculations. Diagnostic bands related to the absolute configuration of the title compounds are found in both kinds of spectra.

scholarly journals Antibacterial Polyketides from Antarctica Sponge-Derived Fungus Penicillium sp. HDN151272

Marine Drugs ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 71 ◽  
Author(s):  
Mudassir Shah ◽  
Chunxiao Sun ◽  
Zichao Sun ◽  
Guojian Zhang ◽  
Qian Che ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Absolute Configuration ◽  
Spectroscopic Data ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant ◽  
Penicillium Sp ◽  
Mycobacterium Phlei ◽  
The Absolute

Three new polyketides, ketidocillinones A–C (1–3), were discovered from the extract of an Antarctica sponge-derived fungus Penicillium sp. HDN151272. All the structures were deduced by spectroscopic data, including NMR and HRESIMS. The absolute configuration of compound 3 was established by using ECD calculation. Compounds 1−3 can be slowly oxidized to quinone form when exposed to air. Ketidocillinones B and C (2 and 3) exhibited potent antibacterial activity against Pseudomonas aeurigenosa, Mycobacterium phlei, and MRCNS (methicillin-resistant coagulase-negative staphylococci) with MIC values ranging from 1.56 to 25.00 µg/mL.

scholarly journals Chaetolactone, A Skeletally New Cyclopentenone from Chaetomium sp. C521

2018 ◽  
Vol 13 (7) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Wen-Bo Han ◽  
He Li ◽  
Hui-Yi Zhou ◽  
Jia Meng ◽  
Jin-Ming Gao ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Absolute Configuration ◽  
Magnaporthe Oryzae ◽  
Spectroscopic Analysis ◽  
Alternaria Solani ◽  
Carbon Skeleton ◽  
The Absolute

Chaetolactone, a new polyketide with an unprecedented carbon skeleton, was constructed by Chaetomium sp. C521. Its structure was characterized by a combination of detailed spectroscopic analysis and ECD method, which facilitated the establishment of the absolute configuration for chaetolactone. The new compound was tested for anti-phytopathogenic activity against Botrytis cinerea, Alternaria solani, Gibberella saubinettii, and Magnaporthe oryzae, but exhibited negligible inhibition at a concentration of 20 μM.

ChemInform Abstract: SYNTHESIS OF THE ENANTIOMERS OF SCLEROSPORIN AND SCLEROSPORAL TO DETERMINE THE ABSOLUTE CONFIGURATION OF THE NATURAL PRODUCTS

1985 ◽  
Vol 16 (7) ◽  
Author(s):  
T. KITAHARA ◽  
T. MATSUOKA ◽  
M. KATAYAMA ◽  
S. MARUMO ◽  
K. MORI
Keyword(s):  
Natural Products ◽  
Absolute Configuration ◽  
The Absolute

Determination of the Absolute Configuration of Peptide Natural Products by Using Stable Isotope Labeling and Mass Spectrometry

2012 ◽  
Vol 18 (8) ◽  
pp. 2342-2348 ◽  
Author(s):  
Helge B. Bode ◽  
Daniela Reimer ◽  
Sebastian W. Fuchs ◽  
Ferdinand Kirchner ◽  
Christina Dauth ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Natural Products ◽  
Stable Isotope ◽  
Absolute Configuration ◽  
Isotope Labeling ◽  
Stable Isotope Labeling ◽  
The Absolute

ChemInform Abstract: The Online Assignment of the Absolute Configuration of Natural Products: HPLC-CD in Combination with Quantum Chemical CD Calculations

ChemInform ◽  
2008 ◽  
Vol 39 (39) ◽  
Author(s):  
Gerhard Bringmann ◽  
Tobias A. M. Gulder ◽  
Matthias Reichert ◽  
Tanja Gulder
Keyword(s):  
Natural Products ◽  
Absolute Configuration ◽  
Quantum Chemical ◽  
The Absolute
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