scholarly journals New Sulfur-Containing Polyarsenicals from the New Caledonian sponge Echinochalina bargibanti

2018 ◽  
Author(s):  
Petri Tähtinen ◽  
Graziano Guella ◽  
Giacomo Saielli ◽  
Cécile Debitus ◽  
Edouard Hnawia ◽  
...  
Keyword(s):  
2D Nmr ◽  
Antibacterial Activities ◽  
The Novel ◽  
1H And 13C Nmr ◽  
Combined Use ◽  
Computational Testing ◽  
Td Dft ◽  
Bioassay Guided Fractionation ◽  
Sulfur Containing ◽  
Structural Definition

Isolated from a New Caledonian collection of the poecilosclerid sponge Echinochalina bargibanti, arsenicin A (C3H6As4O3) was described as the first natural organic polyarsenic compound. Continuing on bioassay guided fractionation of the organic extracts of this sponge, we describe here the isolation and structural elucidation of the first sulfur-containing organic polyarsenicals ever found in nature. The novel metabolites, called arsenicin B and arsenicin C, are built on a noradamantane type framework and they further distinguish from the adamantane type framework of arsenicin A by a different heteroatom composition and by the presence of an unusual As-As bonding. Extensive 1D and 2D-NMR measurements, in combination with tandem APCI mass spectra, allowed to establish the structure of arsenicin B (C3H6As4S2) as 2. The scarcity of arsenicin C and and its intrinsic chemical instability, only allowed to collect partial spectral data which prevented the full structural definition. After extensive computational testing of several putative structures, structure 3 for arsenicin C (C3H6As4OS) was inferred by comparing experimental with DFT-calculated 1H and 13C NMR spectra. Finally, the absolute configuration of 2 and 3 were determined with a combined use of experimental and TD-DFT calculated ECD spectra and observed specific rotations. These findings pose great challenges for both the biosynthesis of these metabolites and the cycle of Arsenic in nature. Arsenicin B and arsenicin C showed strong antifungal and antibacterial activities, especially against S. aureus comparable to the antibiotic gentamycin.

scholarly journals New Sulfur-Containing Polyarsenicals from the New Caledonian Sponge Echinochalina bargibanti

Marine Drugs ◽  
2018 ◽  
Vol 16 (10) ◽  
pp. 382 ◽  
Author(s):  
Petri Tähtinen ◽  
Graziano Guella ◽  
Giacomo Saielli ◽  
Cécile Debitus ◽  
Edouard Hnawia ◽  
...  
Keyword(s):  
Mass Spectra ◽  
Density Functional ◽  
Antimicrobial Activities ◽  
Functional Theory ◽  
1H And 13C Nmr ◽  
Combined Use ◽  
Computational Testing ◽  
Td Dft ◽  
Sulfur Containing ◽  
Structural Definition

Arsenicin A (C3H6As4O3) was isolated from the New Caledonian poecilosclerid sponge Echinochalina bargibanti, and described as the first natural organic polyarsenic compound. Further bioguided fractionation of the extracts of this sponge led us to isolate the first sulfur-containing organic polyarsenicals ever found in Nature. These metabolites, called arsenicin B and arsenicin C, are built on a noradamantane-type framework that is characterized by an unusual As–As bonding. Extensive NMR measurements, in combination with mass spectra, enabled the assignment of the structure for arsenicin B (C3H6As4S2) as 2. The scarcity of arsenicin C and its intrinsic chemical instability only allowed the collection of partial spectral data, which prevented the full structural definition. After the extensive computational testing of several putative structures, structure 3 was inferred for arsenicin C (C3H6As4OS) by comparing the experimental and density functional theory (DFT)-calculated 1H and 13C NMR spectra. Finally, the absolute configurations of 2 and 3 were determined with a combined use of experimental and time-dependent (TD)-DFT calculated electronic circular dichroism (ECD) spectra and observed specific rotations. These findings pose great challenges for the investigation of the biosynthesis of these metabolites and the cycle of arsenic in Nature. Arsenicins B and C showed strong antimicrobial activities, especially against S. aureus, which is comparable to the reference compound gentamycin.

scholarly journals Phytochemical Investigation of the Australian Lichens Ramalina glaucescens and Xanthoria parietina

2009 ◽  
Vol 4 (7) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Daniel A. Dias ◽  
Sylvia Urban
Keyword(s):  
Antibacterial Properties ◽  
Usnic Acid ◽  
2D Nmr ◽  
Antibacterial Activities ◽  
2D Nmr Spectroscopy ◽  
Full Characterization ◽  
Phytochemical Investigation ◽  
Xanthoria Parietina ◽  
Shift Assignment

Phytochemical investigation of the Australian lichen, Ramalina glaucescens resulted in the isolation of a new halogenated depside, 5-chlorosekikaic acid 5, together with (+)-usnic acid 1, sekikaic acid 2, atranorin 6 and parietin 7, the latter of which was isolated from the associated (co-occurring) lichen, X. parietina. Compound 5 is suspected to be an artifact of the isolation procedure. All structures were assigned using spectroscopic methods and mass spectrometry. In addition to the full characterization of 5, this report represents the first application of 2D NMR spectroscopy to complete the unequivocal chemical shift assignment for compounds 2 and 7. Compounds 1-2 and 5-7 all displayed varying degrees of antitumor activity (ranging from an IC50 of 15 μM to >44 μM) with compounds 1, 2 and 5 also displaying antibacterial properties. Of these, (+)-usnic acid 1 displayed the most significant antitumor and antibacterial activities.

Design and Synthesis of Novel Sulfonamide-Derived Triazoles and Bioactivity Exploration

2020 ◽  
Vol 16 (1) ◽  
pp. 104-118 ◽  
Author(s):  
Shi-Chao He ◽  
Hui-Zhen Zhang ◽  
Hai-Juan Zhang ◽  
Qing Sun ◽  
Cheng-He Zhou
Keyword(s):  
Chlorosulfonic Acid ◽  
Antibacterial Activities ◽  
Structural Features ◽  
The Novel ◽  
E Coli ◽  
Design And Synthesis ◽  
Chemical Studies ◽  
Antimicrobial Evaluation ◽  
Better Than

Objective: Due to the incidence of resistance, a series of sulfonamide-derived 1,2,4- triazoles were synthesized and evaluated. Method: The novel sulfonamide-derived 1,2,4-triazoles were prepared starting from commercial acetaniline and chlorosulfonic acid by sulfonylation, aminolysis, N-alkylation and so on. The antimicrobial activity of the synthesized compounds were evaluated in vitro by two-fold serial dilution technique. Results: In vitro antimicrobial evaluation found that 2-chlorobenzyl sulfonamide 1,2,4-triazole 7c exhibited excellent antibacterial activities against MRSA, B. subtilis, B. typhi and E. coli with MIC values of 0.02−0.16 μmol/mL, which were comparable or even better than Chloromycin. The preliminary mechanism suggested that compound 7c could effectively bind with DNA, and also it could bind with human microsomal heme through hydrogen bonds in molecular docking. Computational chemical studies were performed on compound 7c to understand the structural features that are essential for activity. Additionally, compound 7c could generate a small amount of reactive oxygen species (ROS). Conclusion: Compound 7c could serve as a potential clinical antimicrobial candidate.

scholarly journals Two New Prenylated Isoflavonoids from Erinacea anthyllis with Antioxidant and Antibacterial Activities

2017 ◽  
Vol 12 (7) ◽  
pp. 1934578X1701200 ◽  
Author(s):  
Soumia Mouffouk ◽  
Laurence Marcourt ◽  
Mohammed Benkhaled ◽  
Kaouthar Boudiaf ◽  
Jean-Luc Wolfender ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Optical Rotation ◽  
2D Nmr ◽  
Antibacterial Activities ◽  
Total Phenolic ◽  
Aerial Parts ◽  
Whole Plant ◽  
The Family ◽  
Chemotaxonomic Markers ◽  
Phenolic And Flavonoid

Two new prenylated isoflavonoids, namely Erinasone A and Erinasone B along with 19 known secondary metabolites, including twelve isoflavonoids, three polyphenols, one flavonol, two flavanones and three steroids, were isolated from the whole plant (roots and aerial parts) of Erinacea anthyllis. Structures of all isolated compounds were elucidated by spectroscopic analysis, including 1D and 2D NMR (1H, 13C, COSY, HSQC, TOCSY, HMBC and NOESY), mass spectrometry (ESI-MS), UV-Vis, measurement of optical rotation [α]D and by comparison with the literature data. The total phenolic and flavonoid contents were determined in this study. Furthermore, the antioxidant and antibacterial activities of the EtOAc and n-BuOH extracts of E. anthyllis were evaluated. These extracts exhibited moderate antibacterial and antioxidant activities. Their IC50 values were approximately 0.04 mg/mL ( n-BuOH) and 0.037 mg/mL (EtOAc). Consequently, Erinacea anthyllis is a rich source of polyphenolic compounds particularly isoflavonoids used as chemotaxonomic markers for the subfamily Papilionoideae of the family Fabaceae.

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 New Antiplasmodial Diterpenes from Gutierrezia Sarothrae

2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100
Author(s):  
Qingxi Su ◽  
Seema Dalal ◽  
Michael Goetz ◽  
Maria B. Cassera ◽  
David G. L Kingston
Keyword(s):  
Mass Spectrometry ◽  
Plasmodium Falciparum ◽  
Spectroscopic Data ◽  
2D Nmr ◽  
Antiplasmodial Activity ◽  
Drug Resistant ◽  
Meoh Extract ◽  
Bioassay Guided Fractionation ◽  
Gutierrezia Sarothrae ◽  
Related Compounds

Bioassay guided fractionation of the MeOH extract of the plant Gutierrezia sarothrae (Asteraceae) using an assay for antiplasmodial activity against the drug-resistant Dd2 strain of Plasmodium falciparum led to the isolation of the two new diterpenes 3α-angeloyloxy-15-hydroxylabda-7,13-dien-16,15-olid-18-oic acid (1) and 3α-angeloyloxy-15-methoxylabda-7,13-dien-16,15-olid-18-oic acid (2). The structures of 1 and 2 were elucidated by interpretation of ID and 2D NMR spectroscopic data, mass spectrometry, and comparison with the data of related compounds reported in the literature. Compound 1 exhibited moderate antiplasmodial activity with an IC50 values of 10.4 ± 4.3 μM.

scholarly journals Marine Organisms from the Yucatan Peninsula (Mexico) as a Potential Natural Source of Antibacterial Compounds

Marine Drugs ◽  
2020 ◽  
Vol 18 (7) ◽  
pp. 369 ◽  
Author(s):  
Dawrin Pech-Puch ◽  
Mar Pérez-Povedano ◽  
Patricia Gómez ◽  
Marta Martínez-Guitián ◽  
Cristina Lasarte-Monterrubio ◽  
...  
Keyword(s):  
Marine Organism ◽  
Yucatan Peninsula ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Marine Sponges ◽  
Marine Organisms ◽  
Human Pathogens ◽  
Yucatán Peninsula ◽  
Bioassay Guided Fractionation ◽  
Agelasine B

A total of 51 sponges (Porifera) and 13 ascidians (Chordata) were collected on the coast of the Yucatan Peninsula (Mexico) and extracted with organic solvents. The resulting extracts were screened for antibacterial activity against four multidrug-resistant (MDR) bacterial pathogens: the Gram-negative Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa and the Gram-positive Staphylococcus aureus. The minimum inhibitory concentrations (MICs) of the organic extracts of each marine organism were determined using a broth microdilution assay. Extracts of eight of the species, in particular the Agelas citrina and Haliclona (Rhizoniera) curacaoensis, displayed activity against some of the pathogens tested. Some of the extracts showed similar MIC values to known antibiotics such as penicillins and aminoglycosides. This study is the first to carry out antimicrobial screening of extracts of marine sponges and ascidians collected from the Yucatan Peninsula. Bioassay-guided fractionation of the active extracts from the sponges Amphimedon compressa and A. citrina displayed, as a preliminary result, that an inseparable mixture of halitoxins and amphitoxins and (-)-agelasine B, respectively, are the major compounds responsible for their corresponding antibacterial activities. This is the first report of the antimicrobial activity of halitoxins and amphitoxins against major multidrug-resistant human pathogens. The promising antibacterial activities detected in this study indicate the coast of Yucatan Peninsula as a potential source of a great variety of marine organisms worthy of further research.

scholarly journals A Synthetic Butenolide Diterpene is now a Natural Product Isolated from Metaporana sericosepala, a Plant from the Madagascar Dry Forest [1a]

2015 ◽  
Vol 10 (9) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Christopher C. Presley ◽  
L. Harinantenaina Rakotondraibe ◽  
Peggy J. Brodie ◽  
Martin W. Callmander ◽  
Richard Randrianaivo ◽  
...  
Keyword(s):  
Natural Product ◽  
Ovarian Cancer Cell Line ◽  
Cancer Cell Line ◽  
Ethanolic Extract ◽  
2D Nmr ◽  
Dry Forest ◽  
Synthetic Compound ◽  
Nmr Data ◽  
Bioassay Guided Fractionation ◽  
Product Compound

Antiproliferative bioassay-guided fractionation of the ethanolic extract of the endemic Madagascan plant Metaporana sericosepala led to the first natural product isolation of a butenolide diterpene, which was synthesized during an anti-inflammatory study in 1988. The structure of the compound was elucidated as 3-homofarnesyl-4-hydroxybutenolide (1) by analysis of its spectroscopic data, including 1D- and 2D-NMR data and chemical evidence. The once synthetic compound can now also be considered as a natural product. Compound 1 had modest antiproliferative activity towards the A2780 ovarian cancer cell line with an IC50 value of 8 μM.

Activity of Armillarisin B in vitro against Plant Pathogenic Fungi

2009 ◽  
Vol 64 (11-12) ◽  
pp. 790-792 ◽  
Author(s):  
Jin-Wen Shen ◽  
Bing-Ji Ma ◽  
Wen Li ◽  
Hai-You Yu ◽  
Ting-Ting Wu ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Methanolic Extract ◽  
Pathogenic Fungi ◽  
2D Nmr ◽  
Spectroscopic Studies ◽  
Gibberella Zeae ◽  
Plant Pathogenic Fungi ◽  
Fruiting Bodies ◽  
Bioassay Guided Fractionation

The methanolic extract of the fruiting bodies of the mushroom Armillariella tabescens was found to show antifungal activity against Gibberella zeae. The active compound was isolated from the fruiting bodies of A. tabescens by bioassay-guided fractionation of the extract and identifi ed as armillarisin B. Armillarisin B eventually corresponds to 2-hydroxy-2- phenylpropanediamide and its structure was confi rmed on the basis of spectroscopic studies including 2D NMR experiments.

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