scholarly journals Mansouramycins E–G, Cytotoxic Isoquinolinequinones from Marine Streptomycetes

Marine Drugs ◽  
2021 ◽  
Vol 19 (12) ◽  
pp. 715
Author(s):  
Mohamed Shaaban ◽  
Khaled A. Shaaban ◽  
Gerhard Kelter ◽  
Heinz Herbert Fiebig ◽  
Hartmut Laatsch
Keyword(s):  
Nmr Spectra ◽  
High Resolution Mass Spectrometry ◽  
Ethyl Acetate Extract ◽  
2D Nmr ◽  
Computer Assisted ◽  
Tumor Cell Lines ◽  
Activity Profile ◽  
2D Nmr Spectra ◽  
Tumor Selectivity ◽  
Related Compounds

Chemical investigation of the ethyl acetate extract from the marine-derived Streptomyces sp. isolate B1848 resulted in three new isoquinolinequinone derivatives, the mansouramycins E–G (1a–3a), in addition to the previously reported mansouramycins A (5) and D (6). Their structures were elucidated by computer-assisted interpretation of 1D and 2D NMR spectra, high-resolution mass spectrometry, and by comparison with related compounds. Cytotoxicity profiling of the mansouramycins in a panel of up to 36 tumor cell lines indicated a significant cytotoxicity and good tumor selectivity for mansouramycin F (2a), while the activity profile of E (1a) was less attractive.

scholarly journals Bioactive Isocoumarins from a Terrestrial Streptomyces sp. ANK302

2011 ◽  
Vol 6 (1) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Dhafer Saber Zinad ◽  
Khaled A. Shaaban ◽  
Muna Ali Abdalla ◽  
Md. Tofazzal Islam ◽  
Anja Schüffler ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Nmr Spectra ◽  
2D Nmr ◽  
Plasmopara Viticola ◽  
Bacterial Product ◽  
Streptomyces Sp ◽  
Naturally Occurring ◽  
2D Nmr Spectra ◽  
Related Compounds ◽  
Resolution Mass

Four isocoumarins have been isolated from the terrestrial Streptomyces sp. ANK302, namely 6,8-dimethoxy-3-methylisocoumarin (1), 6,8-dihydroxy-3-methylisocoumarin (2), 6,8-dihydroxy-7-methoxy-3-methylisocoumarin (3), and 6,7,8-trimethoxy-3-methylisocoumarin (4). Compound 1 is a new naturally-occurring isocoumarin, and 2 was isolated as a new bacterial product. The structures 1-4 were deduced from high resolution mass, 1D and 2D NMR spectra and by comparison with related compounds from the literature. Compound 2 showed a strong zoosporicidal activity at a concentration of 5 μg/mL against a phytopathogenic oomycete, Plasmopara viticola, and 1 was active against Candida albicans.

scholarly journals A New Aggreceride Analogue and a Peltogynoid Isolated from the Stem Bark of Entada abyssinica (Fabaceae)

2014 ◽  
Vol 9 (10) ◽  
pp. 1934578X1400901
Author(s):  
Raduis Melong ◽  
Deccaux G. F. W. Kapche ◽  
Michel T. Feussi ◽  
Hartmut Laatsch
Keyword(s):  
Nmr Spectra ◽  
Reference Data ◽  
High Resolution Mass Spectrometry ◽  
Optical Rotation ◽  
2D Nmr ◽  
Stem Bark ◽  
Mass Spectrometry Data ◽  
Related Data ◽  
2D Nmr Spectra ◽  
New Compounds

A new monoglyceride, 1′,26′-bis-[( S)-2,3-dihydroxypropyl] hexacosanedioate (1a) and the new peltogynoid, entadanin (3), along with eight known compounds, were isolated from the stem bark of Entada abyssinica (Fabaceae). The structures of the new compounds were determined by detailed analyses of 1D and 2D NMR spectra, in combination with high-resolution mass spectrometry data, and by comparison with related data from the literature. The stereochemistry of 1a was derived by comparison of the optical rotation with reference data. Peltogynoids have been reported previously from other Fabaceae, however this is the first report of a peltogynoid from the genus Entada.

scholarly journals An Imidazopyridinone and Further Metabolites from Streptomycetes [1]

2009 ◽  
Vol 4 (7) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Hafizur Rahman ◽  
Mohamed Shaaban ◽  
Khaled A. Shaaban ◽  
Muhammad Saleem ◽  
Elisabeth Helmke ◽  
...  
Keyword(s):  
Chromatographic Analysis ◽  
Nmr Spectra ◽  
2D Nmr ◽  
Antibiotic Activity ◽  
Streptomyces Sp ◽  
2D Nmr Spectra ◽  
New Compounds ◽  
Related Compounds ◽  
Resolution Mass ◽  
New Metabolites

Screening and chromatographic analysis of the extracts from the terrestrial streptomycete GW5127 and from the marine Streptomyces sp. isolate B7967 yielded four new metabolites, i.e. 8-ethyl-6,11-dihydroxy-1-methoxy-naphthacene-5,12-dione (1a), 4-acetyl-1,3-dihydro-imidazo[4,5-c]pyridin-2-one (4a), 5-hydroxmethyl-4-hydroxy-2,4-dimethyl-2-cyclopentenone (6), and N-[2-(3′-hydroxy-4′-methoxyphenyl)-ethyl]-acetamide (5a), along with five known compounds, β-rubromycin (2), γ-rubromycin (3), 2-(3′-hydroxy-4′-methoxyphenyl)ethanol (5b), uracil, and N-acetyltyramine. The structures of the new compounds were deduced from high resolution mass, 1D and 2D NMR spectra and by comparison with related compounds from the literature. The antibiotic activity of the crude extracts was due to 2 and 3.

A New C-Glucosylflavone from Sorindeia juglandifolia

2013 ◽  
Vol 68 (5-6) ◽  
pp. 169-174 ◽  
Author(s):  
Joseph T. Ndongo ◽  
Joséphine N. Mbing ◽  
Dominique N. Bikobo ◽  
Alex de T. Atchadé ◽  
Mohamed Shaaban ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Methyl Gallate ◽  
Phytochemical Investigation ◽  
2D Nmr Spectra ◽  
Related Compounds

Phytochemical investigation of the leaves of Sorindeia juglandifolia A. Rich. led to the isolation and identifi cation of a new C-glucosylfl avone, 2´´,6´´-di-O-acetyl-7-O-methyl vitexin (1), together with seven known compounds, 2´´-O-acetyl-7-O-methyl vitexin (2), mearnsitrin (3), robustafl avone (4), 3-O-galloyl catechin (5), tachioside (2-methoxy-benzene-1,4-diol-1- O-β-glucopyranoside) (6), 3β-O-D-glucopyranosyl-β-stigmasterol (7), and methyl gallate (8). The structures of 1 and the known compounds were established by IR, UV, MS, 1D, and 2D NMR spectra and by comparison with those of related compounds.

scholarly journals Isolation and Structural Elucidation of Nitrogenous Secondary Metabolites from Terrestrial and Marine Streptomyces spp

2017 ◽  
Vol 12 (3) ◽  
pp. 1934578X1701200
Author(s):  
Mohamed Shaaban ◽  
Khaled A. Shaaban ◽  
Elisabeth Helmke ◽  
Iris Grün-Wollny ◽  
Hartmut Laatsch
Keyword(s):  
Carboxylic Acid ◽  
Nmr Spectra ◽  
Acid Methyl Ester ◽  
2D Nmr ◽  
Benzene Derivatives ◽  
Streptomyces Spp ◽  
Acid Methyl ◽  
2D Nmr Spectra ◽  
New Compounds ◽  
Related Compounds

Screening and chromatography of extracts from a terrestrial and a marine-derived streptomycete yielded two new nitrogenous benzene derivatives, namely ( S)- N-[3-hydroxy-1-(4-hydroxyphenyl)-propyl]-acetamide (1a), and ( R)-2-(1-methyl-2-oxopropylamino)-benzoic acid (2). Additionally, eight known compounds were isolated, 2-acetamidophenol, phenazine-1-carboxylic acid, phenazine-1-carboxylic acid methyl ester, perlolyrin, tyrosol, uracil, and anthranilic acid. The structures of the new compounds were deduced from high resolution mass, 1D and 2D NMR spectra and by comparison with related compounds from the literature. The absolute configuration of 1a and 2 was determined by comparison of experimental and calculated CD and ORD data.

scholarly journals CONTRIBUTE TO STUDY ON CHEMICAL CONSTITUENTS OF DESMODIUM GANGETICUM (L.) DC. OF VIETNAM

2019 ◽  
Vol 57 (1) ◽  
pp. 1
Author(s):  
Le Minh Ha ◽  
Ngo Thi Phuong ◽  
Do Thi Thanh Huyen ◽  
Duong Bich Ngoc ◽  
Nguyen Minh Nguyet ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Nmr Spectra ◽  
Ethyl Acetate Extract ◽  
Chemical Constituents ◽  
2D Nmr ◽  
2D Nmr Spectra ◽  
First Time

From the ethyl acetate extract of the leaves of Desmodium gangeticum collected in Me Linh, Ha Noi, we isolated 5 compounds including luteolin (1), luteolin tetramethyl ether (2),  N,N-dimethyl tetradecane-1-amin (3), D-pinitol (4)  and stigmasterol (5). In which, luteolin (1) was isolated from Desmodium gangeticum for the first time, luteolin tetramethyl ether (2) and  N,N-dimethyl tetradecane-1-amin (3) were first isolated from genus Desmodium. Their structures were determined by 1D and 2D NMR spectra.

Differential Analysis of 2D NMR Spectra: New Natural Products from a Pilot-Scale Fungal Extract Library

2007 ◽  
Vol 46 (6) ◽  
pp. 901-904 ◽  
Author(s):  
Frank C. Schroeder ◽  
Donna M. Gibson ◽  
Alice C. L. Churchill ◽  
Punchapat Sojikul ◽  
Eric J. Wursthorn ◽  
...  
Keyword(s):  
Natural Products ◽  
Nmr Spectra ◽  
2D Nmr ◽  
Pilot Scale ◽  
Differential Analysis ◽  
Fungal Extract ◽  
2D Nmr Spectra

scholarly journals New Antimalarial and Antimicrobial Tryptamine Derivatives from the Marine Sponge Fascaplysinopsis reticulata

Marine Drugs ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 167 ◽  
Author(s):  
Pierre-Eric Campos ◽  
Emmanuel Pichon ◽  
Céline Moriou ◽  
Patricia Clerc ◽  
Rozenn Trépos ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Minimum Inhibitory Concentration ◽  
Marine Sponge ◽  
Nmr Spectra ◽  
Inhibitory Concentration ◽  
Chemical Study ◽  
2D Nmr ◽  
Antimicrobial Activities ◽  
2D Nmr Spectra ◽  
Ic50 Values

Chemical study of the CH2Cl2-MeOH (1:1) extract of the sponge Fascaplysinopsis reticulata collected in Mayotte highlighted three new tryptophan derived alkaloids, 6,6′-bis-(debromo)-gelliusine F (1), 6-bromo-8,1′-dihydro-isoplysin A (2) and 5,6-dibromo-8,1′-dihydro-isoplysin A (3), along with the synthetically known 8-oxo-tryptamine (4) and the three known molecules from the same family, tryptamine (5), (E)-6-bromo-2′-demethyl-3′-N-methylaplysinopsin (6) and (Z)-6-bromo-2′-demethyl-3′-N-methylaplysinopsin (7). Their structures were elucidated by 1D and 2D NMR spectra and HRESIMS data. All compounds were evaluated for their antimicrobial and their antiplasmodial activities. Regarding antimicrobial activities, the best compounds are (2) and (3), with minimum inhibitory concentration (MIC) of 0.01 and 1 µg/mL, respectively, towards Vibrio natrigens, and (5), with MIC values of 1 µg/mL towards Vibrio carchariae. In addition the known 8-oxo-tryptamine (4) and the mixture of the (E)-6-bromo-2′-demethyl-3′-N-methylaplysinopsin (6) and (Z)-6-bromo-2′-demethyl-3′-N-methylaplysinopsin (7) showed moderate antiplasmodial activity against Plasmodium falciparum with IC50 values of 8.8 and 8.0 µg/mL, respectively.

scholarly journals Advanced solvent signal suppression for the acquisition of 1D and 2D NMR spectra of Scotch Whisky

2017 ◽  
Vol 55 (9) ◽  
pp. 785-796 ◽  
Author(s):  
Will Kew ◽  
Nicholle G.A. Bell ◽  
Ian Goodall ◽  
Dušan Uhrín
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Signal Suppression ◽  
2D Nmr Spectra ◽  
Solvent Signal Suppression ◽  
Scotch Whisky
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