Special Issue "Taking On the Challenges of Marine Natural Products Structure Elucidation"

A special issue of Marine Drugs (ISSN 1660-3397).

Deadline for manuscript submissions: 31 May 2021.

Special Issue Editor

Dr. Marie-Lise Bourguet-Kondracki
Website
Guest Editor
Molécules de Communication et Adaptation des Microorganismes, UMR 7245 CNRS, Muséum National d’Histoire Naturelle, 57 rue Cuvier (CP54), 75005 Paris, France
Interests: marine natural product chemistry; marine sponges; marine microbiology; marine chemical ecology; bioactivity
Special Issues and Collections in MDPI journals

Special Issue Information

Dear Colleagues,

Marine Drugs recently released a successful Special Issue “New Challenges in Structure Elucidation of Marine Natural Products: NMR Analyses and Other Advanced Methods” (https://www.mdpi.com/journal/marinedrugs/special_issues/NMR-advanced), collecting state-of-the-art research outcomes in this field. We are glad to say that in response to readers’ great passion for this research topic, we have decided to launch a second edition of the original Special Issue, which will continue focusing on the different challenging strategies used for solving the identification of marine natural products.

Modern analytical techniques and methods, encompassing mass-spectrometry-based omics strategies, advanced NMR methods, computational chemistry procedures, chiroptical methods, and configurational analysis approaches have emerged as powerful tools for the structure elucidation of marine natural products, expanding upon the traditional methods. These innovative approaches will be at the heart of this second edition Special Issue entitled “Taking on the Challenges of Marine Natural Products Structure Elucidation”.

Dr. Marie-Lise Bourguet-Kondracki
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Marine Drugs is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Marine Natural Products
  • Structure Elucidation
  • NMR
  • MS
  • Computational Chemistry Procedure
  • Chiroptical Methods
  • Configurational Analysis

Published Papers (2 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Open AccessFeature PaperArticle
Mass Spectrometry-Based Characterization of New Spirolides from Alexandrium ostenfeldii (Dinophyceae)
Mar. Drugs 2020, 18(10), 505; https://doi.org/10.3390/md18100505 - 02 Oct 2020
Abstract
Spirolides belong to a group of marine phycotoxins produced by the marine planktonic dinophyte Alexandrium ostenfeldii. Composed of an imine moiety and a spiroketal ring system within a macrocylcle, spirolides are highly diverse with toxin types that vary among different strains. This [...] Read more.
Spirolides belong to a group of marine phycotoxins produced by the marine planktonic dinophyte Alexandrium ostenfeldii. Composed of an imine moiety and a spiroketal ring system within a macrocylcle, spirolides are highly diverse with toxin types that vary among different strains. This study aims to characterize the spirolides from clonal A. ostenfeldii strains collected from The Netherlands, Greenland and Norway by mass spectral techniques. The structural characterization of unknown spirolides as inferred from high-resolution mass spectrometry (HR-MS) and collision induced dissociation (CID) spectra revealed the presence of nine novel spirolides that have the pseudo-molecular ions m/z 670 (1), m/z 666 (2), m/z 696 (3), m/z 678 (4), m/z 694 (5), m/z 708 (6), m/z 720 (7), m/z 722 (8) and m/z 738 (9). Of the nine new spirolides proposed in this study, compound 1 was suggested to have a truncated side chain in lieu of the commonly observed butenolide ring in spirolides. Moreover, there is indication that compound 5 might belong to new spirolide subclasses with a trispiroketal ring configuration having a 6:5:6 trispiroketal ring system. On the other hand, the other compounds were proposed as C- and G-type SPX, respectively. Compound 7 is proposed as the first G-type SPX with a 10-hydroxylation as usually observed in C-type SPX. This mass spectrometry-based study thus demonstrates that structural variability of spirolides is larger than previously known and does not only include the presence or absence of certain functional groups but also involves the triketal ring system. Full article
Show Figures

Figure 1

Open AccessArticle
Integrating Molecular Networking and 1H NMR Spectroscopy for Isolation of Bioactive Metabolites from the Persian Gulf Sponge Axinella sinoxea
Mar. Drugs 2020, 18(7), 366; https://doi.org/10.3390/md18070366 - 16 Jul 2020
Abstract
The geographic position, highly fluctuating sea temperatures and hypersalinity make Persian Gulf an extreme environment. Although this unique environment has high biodiversity dominated by invertebrates, its potential in marine biodiscovery has largely remained untapped. Herein, we aimed at a detailed analysis of the [...] Read more.
The geographic position, highly fluctuating sea temperatures and hypersalinity make Persian Gulf an extreme environment. Although this unique environment has high biodiversity dominated by invertebrates, its potential in marine biodiscovery has largely remained untapped. Herein, we aimed at a detailed analysis of the metabolome and bioactivity profiles of the marine sponge Axinella sinoxea collected from the northeast coast of the Persian Gulf in Iran. The crude extract and its Kupchan subextracts were tested in multiple in-house bioassays, and the crude extract and its CHCl3-soluble portion showed in vitro antibacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecium (Efm). A molecular networking (MN)-based dereplication strategy by UPLC-MS/MS revealed the presence of phospholipids and steroids, while 1H NMR spectroscopy indicated the presence of additional metabolites, such as diketopiperazines (DKPs). Integrated MN and 1H NMR analyses on both the crude and CHCl3 extracts combined with an antibacterial activity-guided isolation approach afforded eight metabolites: a new diketopiperazine, (-)-cyclo(L-trans-Hyp-L-Ile) (8); a known diketopiperazine, cyclo(L-trans-Hyp-L-Phe) (7); two known phospholipids, 1-O-hexadecyl-sn-glycero-3-phosphocholine (1) and 1-O-octadecanoyl-sn-glycero-3-phosphocholine (2); two known steroids, 3β-hydroxycholest-5-ene-7,24-dione (3) and (22E)-3β-hydroxycholesta-5,22-diene-7,24-dione (4); two known monoterpenes, loliolide (5) and 5-epi-loliolide (6). The chemical structures of the isolates were elucidated by a combination of NMR spectroscopy, HRMS and [α]D analyses. All compounds were tested against MRSA and Efm, and compound 3 showed moderate antibacterial activity against MRSA (IC50 value 70 μg/mL). This is the first study that has dealt with chemical and bioactivity profiling of A. sinoxea leading to isolation and characterization of pure sponge metabolites. Full article
Show Figures

Graphical abstract

Back to TopTop