scholarly journals Two New Piperazine-Triones from a Marine-Derived Streptomycetes sp. Strain SMS636

Marine Drugs ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 186 ◽  
Author(s):  
Xiuli Xu ◽  
Jiahui Han ◽  
Rui Lin ◽  
Steven Polyak ◽  
Fuhang Song
Keyword(s):  
Staphylococcus Aureus ◽  
Minimum Inhibitory Concentration ◽  
Secondary Metabolites ◽  
Deep Sea ◽  
Spectroscopic Analysis ◽  
Inhibitory Concentration ◽  
2D Nmr ◽  
Antibacterial Activities ◽  
Bacillus Calmette Guerin ◽  
Methicillin Resistant

Two new piperazine-triones lansai E and F (1, 2), together with four known secondary metabolites lansai D (3), 1-N-methyl-(E,Z)-albonoursin (4), imidazo[4,5-e]-1,2,4-triazine (5), and streptonigrin (6) were isolated from a deep-sea-derived Streptomycetes sp. strain SMS636. The structures of the isolated compounds were confirmed by comprehensive spectroscopic analysis, including HRESIMS, 1D and 2D NMR. Compound 4 exhibited moderate antibacterial activities against Staphylococcus aureus and methicillin resistant S. aureus (MRSA) with Minimum Inhibitory Concentration (MIC) values of 12.5 and 25 μg/mL, respectively. Compound 6 displayed significant antibacterial activities against S. aureus, MRSA and Bacillus Calmette-Guérin (BCG) with MIC values of 0.78, 0.78 and 1.25 μg/mL, respectively.

scholarly journals Novel Substituted Thiophenes and Sulf-Polyacetylene Ester from Echinops ritro L.

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 805 ◽  
Author(s):  
Liang-Bo Li ◽  
Guang-Da Xiao ◽  
Wei Xiang ◽  
Xing Yang ◽  
Ke-Xin Cao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Candida Albicans ◽  
Spectroscopic Analysis ◽  
Inhibitory Concentration ◽  
2D Nmr ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Whole Plant

Three new substituted bithiophenes (1–3), and one new sulf-polyacetylene ester, ritroyne A (16) were isolated from the whole plant of Echinops ritro together with twelve known substituted thiophenes. The structures were elucidated on the basis of extensive spectroscopic analysis including 1D and 2D NMR as well as MS. Furthermore, the absolute configuration of ritroyne A (16) was established by computational methods. In bioscreening experiments, four compounds (2, 4, 12, 14) showed similar antibacterial activity against Staphylococcus aureus ATCC 2592 with levofloxacin (8 µg/mL). Five compounds (2, 4, 9, 12, 14) exhibited antibacterial activities against Escherichia coli ATCC 25922, with minimum inhibitory concentration (MIC) values of 32–64 µg/mL. Three compounds (2, 4, 12) exhibited antifungal activities against Candida albicans ATCC 2002 with MIC values of 32–64 µg/mL. However, compound 16 did not exhibit antimicrobial activities against three microorganisms.

scholarly journals Synthesis and Antimicrobial Studies of Coumarin-Substituted Pyrazole Derivatives as Potent Anti-Staphylococcus aureus Agents

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2758 ◽  
Author(s):  
Rawan Alnufaie ◽  
Hansa Raj KC ◽  
Nickolas Alsup ◽  
Jedidiah Whitt ◽  
Steven Andrew Chambers ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Minimum Inhibitory Concentration ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
Fatality Rate ◽  
Pyrazole Derivatives ◽  
Methicillin Resistant ◽  
Antimicrobial Studies ◽  
Mrsa Strains

In this paper, synthesis and antimicrobial studies of 31 novel coumarin-substituted pyrazole derivatives are reported. Some of these compounds have shown potent activity against methicillin-resistant Staphylococcus aureus (MRSA) with minimum inhibitory concentration (MIC) as low as 3.125 µg/mL. These molecules are equally potent at inhibiting the development of MRSA biofilm and the destruction of preformed biofilm. These results are very significant as MRSA strains have emerged as one of the most menacing pathogens of humans and this bacterium is bypassing HIV in terms of fatality rate.

scholarly journals Chemical Composition and Biological Activities of Metabolites from the Marine Fungi Penicillium sp. Isolated from Sediments of Co To Island, Vietnam

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3830
Author(s):  
Hong Le ◽  
Quynh Do ◽  
Mai Doan ◽  
Quyen Vu ◽  
Mai Nguyen ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Secondary Metabolites ◽  
Inhibitory Concentration ◽  
Biological Activities ◽  
2D Nmr ◽  
Inhibitory Effect ◽  
Marine Microorganisms ◽  
Penicillium Species ◽  
E Coli ◽  
Strong Inhibitory Effect

Marine microorganisms are an invaluable source of novel active secondary metabolites possessing various biological activities. In this study, the extraction and isolation of the marine sediment Penicillium species collected in Vietnam yielded ten secondary metabolites, including sporogen AO-1 (1), 3-indolecarbaldehyde (2), 2-[(5-methyl-1,4-dioxan-2-yl)methoxy]ethanol (3), 2-[(2R-hydroxypropanoyl)amino]benzamide (4), 4-hydroxybenzandehyde (5), chrysogine (6), 3-acetyl-4-hydroxycinnoline (7), acid 1H-indole-3-acetic (8), cyclo (Tyr-Trp) (9), and 2’,3’-dihydrosorbicillin (10). Their structures were identified by the analysis of 1D and 2D NMR data. Among the isolated compounds, 2-[(5-methyl-1,4-dioxan-2-yl)methoxy]ethanol (3) showed a strong inhibitory effect against Enterococcus faecalis with a minimum inhibitory concentration value of 32 µg/mL. Both 2-[(2R-hydroxypropanoyl)amino]benzamide (4) and 4-hydroxybenzandehyde (5) selectively inhibited E. coli with minimum inhibitory concentration values of 16 and 8 µg/mL, respectively. 2’,3’-Dihydrosorbicillin (10) potentially inhibited α-glucosidase activity at a concentration of 2.0 mM (66.31%).

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