Furanoterpene Diversity and Variability in the Marine Sponge Spongia officinalis, from Untargeted LC-MS/MS Metabolomic Profiling to Furanolactam Derivatives

Anti-inflammatory Steroids from the South China Sea Sponge Spongia officinalis

One new highly degraded steroid, namely 21-nor-4-ene-chaxine A (1) furnishing a 5/6/5-tricyclic, along with one known related analogue (2), were isolated from the South China Sea sponge Spongia officinalis. Their structures including absolute configurations were established by extensive spectroscopic data analysis, TDDFT-ECD calculation, and comparison with the spectral data previously reported in the literature. Compound 1 represent the new member of incisterols family with a highly degradation in ring B. In vitro bioassays revealed compound 2 exhibited significant anti-microglial inflammatory effect on lipopolysaccharide (LPS)-induced inflammation in BV-2 microglial cells.

Spongia Sponges: Unabated Sources of Novel Secondary Metabolites

Marine sponges of the genus Spongia have proven to be unabated sources of novel secondary metabolites with remarkable scaffold diversities and significant bioactivities. The discovery of chemical substances from Spongia sponges has continued to increase over the last few years. The current work provides an up-to-date literature survey and comprehensive insight into the reported metabolites from the members of the genus Spongia, as well as their structural features, biological activities, and structure-activity relationships when available. In this review, 222 metabolites are discussed based on published data from the period from mid-2015 to the beginning of 2024. The compounds are categorized into sesquiterpenes, diterpenes, sesterterpenes, meroterpenes, linear furanoterpenes, steroids, alkaloids, and other miscellaneous substances. The biological effects of these chemical compositions on a vast array of pharmacological assays including cytotoxic, anti-inflammatory, antibacterial, neuroprotective, protein tyrosine phosphatase 1B (PTP1B)-inhibitory, and phytoregulating activities are also presented.

A broad-taxa approach as an important concept in ecotoxicological studies and pollution monitoring

Aquatic invertebrates play a pivotal role in (eco)toxicological assessments because they offer ethical, cost-effective and repeatable testing options. Additionally, their significance in the food chain and their ability to represent diverse aquatic ecosystems make them valuable subjects for (eco)toxicological studies. To ensure consistency and comparability across studies, international (eco)toxicology guidelines have been used to establish standardised methods and protocols for data collection, analysis and interpretation. However, the current standardised protocols primarily focus on a limited number of aquatic invertebrate species, mainly from Arthropoda, Mollusca and Annelida. These protocols are suitable for basic toxicity screening, effectively assessing the immediate and severe effects of toxic substances on organisms. For more comprehensive and ecologically relevant assessments, particularly those addressing long-term effects and ecosystem-wide impacts, we recommended the use of a broader diversity of species, since the present choice of taxa exacerbates the limited scope of basic ecotoxicological studies. This review provides a comprehensive overview of (eco)toxicological studies, focusing on major aquatic invertebrate taxa and how they are used to assess the impact of chemicals in diverse aquatic environments. The present work supports the use of a broad-taxa approach in basic environmental assessments, as it better represents the natural populations inhabiting various ecosystems. Advances in omics and other biochemical and computational techniques make the broad-taxa approach more feasible, enabling mechanistic studies on non-model organisms. By combining these approaches with in vitro techniques together with the broad-taxa approach, researchers can gain insights into less-explored impacts of pollution, such as changes in population diversity, the development of tolerance and transgenerational inheritance of pollution responses, the impact on organism phenotypic plasticity, biological invasion outcomes, social behaviour changes, metabolome changes, regeneration phenomena, disease susceptibility and tissue pathologies. This review also emphasises the need for harmonised data-reporting standards and minimum annotation checklists to ensure that research results are findable, accessible, interoperable and reusable (FAIR), maximising the use and reusability of data. The ultimate goal is to encourage integrated and holistic problem-focused collaboration between diverse scientific disciplines, international standardisation organisations and decision-making bodies, with a focus on transdisciplinary knowledge co-production for the One-Health approach.

In Situ Capture and Real-Time Enrichment of Marine Chemical Diversity

Analyzing the chemical composition of seawater to understand its influence on ecosystem functions is a long-lasting challenge due to the inherent complexity and dynamic nature of marine environments. Describing the intricate chemistry of seawater requires optimal in situ sampling. Here is presented a novel underwater hand-held solid-phase extraction device, I-SMEL (In Situ Marine moleculELogger), which aims to concentrate diluted molecules from large volumes of seawater in a delimited zone targeting keystone benthic species. Marine benthic holobionts, such as sponges, can impact the chemical composition of their surroundings possibly through the production and release of their specialized metabolites, hence termed exometabolites (EMs). I-SMEL was deployed in a sponge-dominated Mediterranean ecosystem at a 15 m depth. Untargeted MS-based metabolomics was performed on enriched EM extracts and showed (1) the chemical diversity of enriched seawater metabolites and (2) reproducible recovery and enrichment of specialized sponge EMs such as aerothionin, demethylfurospongin-4, and longamide B methyl ester. These EMs constitute the chemical identity of each targeted species: Aplysina cavernicola, Spongia officinalis, and Agelas oroides, respectively. I-SMEL concentrated sponge EMs from 10 L of water in a 10 min sampling time. The present proof of concept with I-SMEL opens new research perspectives in marine chemical ecology and sets the stage for further sustainable efforts in natural product chemistry.

The Chemically Highly Diversified Metabolites from the Red Sea Marine Sponge Spongia sp

A polyoxygenated and halogenated labdane, spongianol (1); a polyoxygenated steroid, 3β,5α,9α-trihydroxy-24S-ethylcholest-7-en-6-one (2); a rare seven-membered lactone B ring, (22E,24S)-ergosta-7,22-dien-3β,5α-diol-6,5-olide (3); and an α,β-unsaturated fatty acid, (Z)-3-methyl-9-oxodec-2-enoic acid (4) as well as five known compounds, 10-hydroxykahukuene B (5), pacifenol (6), dysidamide (7), 7,7,7-trichloro-3-hydroxy-2,2,6-trimethyl-4-(4,4,4-trichloro-3-methyl-1-oxobu-tylamino)-heptanoic acid methyl ester (8), and the primary metabolite 2’-deoxynucleoside thymidine (9), have been isolated from the Red Sea sponge Spongia sp. The stereoisomer of 3 was discovered in Ganoderma resinaceum, and metabolites 5 and 6, isolated previously from red algae, were characterized unprecedentedly in the sponge. Compounds 7 and 8 have not been found before in the genus Spongia. Compounds 1–9 were also assayed for cytotoxicity as well as antibacterial and anti-inflammatory activities.

Metabolomics on the study of marine organisms

BACKGROUND

Marine ecosystems are hosts to a vast array of organisms, being among the most richly biodiverse locations on the planet. The study of these ecosystems is very important, as they are not only a significant source of food for the world but also have, in recent years, become a prolific source of compounds with therapeutic potential. Studies of aspects of marine life have involved diverse fields of marine science, and the use of metabolomics as an experimental approach has increased in recent years. As part of the "omics" technologies, metabolomics has been used to deepen the understanding of interactions between marine organisms and their environment at a metabolic level and to discover new metabolites produced by these organisms.

AIM OF REVIEW

This review provides an overview of the use of metabolomics in the study of marine organisms. It also explores the use of metabolomics tools common to other fields such as plants and human metabolomics that could potentially contribute to marine organism studies. It deals with the entire process of a metabolomic study, from sample collection considerations, metabolite extraction, analytical techniques, and data analysis. It also includes an overview of recent applications of metabolomics in fields such as marine ecology and drug discovery and future perspectives of its use in the study of marine organisms.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The review covers all the steps involved in metabolomic studies of marine organisms including, collection, extraction methods, analytical tools, statistical analysis, and dereplication. It aims to provide insight into all aspects that a newcomer to the field should consider when undertaking marine metabolomics.

An Anti-Inflammatory 2,4-Cyclized-3,4-Secospongian Diterpenoid and Furanoterpene-Related Metabolites of a Marine Sponge Spongia sp. from the Red Sea

Chemical investigation of a Red Sea Spongia sp. led to the isolation of four new compounds, i.e., 17-dehydroxysponalactone (1), a carboxylic acid, spongiafuranic acid A (2), one hydroxamic acid, spongiafuranohydroxamic acid A (3), and a furanyl trinorsesterpenoid 16-epi-irciformonin G (4), along with three known metabolites (-)-sponalisolide B (5), 18-nor- 3,17-dihydroxy-spongia-3,13(16),14-trien-2-one (6), and cholesta-7-ene-3β,5α-diol-6-one (7). The biosynthetic pathway for the molecular skeleton of 1 and related compounds was postulated for the first time. Anti-inflammatory activity of these metabolites to inhibit superoxide anion generation and elastase release in N-formyl-methionyl-leucyl phenylalanine/cytochalasin B (fMLF/CB)-induced human neutrophil cells and cytotoxicity of these compounds toward three cancer cell lines and one human dermal fibroblast cell line were assayed. Compound 1 was found to significantly reduce the superoxide anion generation and elastase release at a concentration of 10 μM, and compound 5 was also found to display strong inhibitory activity against superoxide anion generation at the same concentration. Due to the noncytotoxic activity and the potent inhibitory effect toward the superoxide anion generation and elastase release, 1 and 5 can be considered to be promising anti-inflammatory agents.

Lipid Annotation by Combination of UHPLC-HRMS (MS), Molecular Networking, and Retention Time Prediction: Application to a Lipidomic Study of In Vitro Models of Dry Eye Disease

Annotation of lipids in untargeted lipidomic analysis remains challenging and a systematic approach needs to be developed to organize important datasets with the help of bioinformatic tools. For this purpose, we combined tandem mass spectrometry-based molecular networking with retention time (t_R) prediction to annotate phospholipid and sphingolipid species. Sixty-five standard compounds were used to establish the fragmentation rules of each lipid class studied and to define the parameters governing their chromatographic behavior. Molecular networks (MNs) were generated through the GNPS platform using a lipid standards mixture and applied to lipidomic study of an in vitro model of dry eye disease, i.e., human corneal epithelial (HCE) cells exposed to hyperosmolarity (HO). These MNs led to the annotation of more than 150 unique phospholipid and sphingolipid species in the HCE cells. This annotation was reinforced by comparing theoretical to experimental t_R values. This lipidomic study highlighted changes in 54 lipids following HO exposure of corneal cells, some of them being involved in inflammatory responses. The MN approach coupled to t_R prediction thus appears as a suitable and robust tool for the discovery of lipids involved in relevant biological processes.

Marine sponges Sarcotragus foetidus, Xestospongia carbonaria and Spongia obscura constituents ameliorate IL-1 β and IL-6 in lipopolysaccharide-induced RAW 264.7 macrophages and carrageenan-induced oedema in rats

Marine sponges are prolific producers of an array of diverse chemical structures containing compounds with multiple biological activities. In this study, whole methanol extracts and fractionated compounds from three marine sponges namely Xestospongia carbonaria, Sarcotragus foetidus and Spongia obscura were thoroughly investigated for their antibacterial, antifungal, antioxidant and anti-inflammatory activities. Methanol extracts and fractionated compounds were characterised using high performance liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. Extracts were checked for cytotoxicity in RAW macrophages by MTT assay, before using them for the treatment study. Enzyme linked immunosorbent assay kits were used to check the effects on inflammatory mediator's levels (PGE₂, COX-2, IL-6, IL-1β, TNF-α) in vitro. The results demonstrated good anti-inflammatory activity of all the three marine sponges; X. carbonaria, S. foetidus and S. obscura suppressed the levels of anti-inflammatory cytokines in vitro. Reverse transcriptase-polymerase chain reaction confirmed the inhibition of IL-1β and IL-6 genes expression by the isolates of X. carbonaria and S. foetidus, while reducing cytokine levels in lipopolysaccharide-induced inflammation in vitro as well as in carrageenan-induced inflammation in rats. Two semi pure compounds isolated from X. carbonaria and S. foetidus also confirmed suppression of IL-1β and IL-6 genes expression in RAW macrophages.

Increasing Metabolic Diversity in Marine Sponges Extracts by Controlling Extraction Parameters

Metabolomics has become an important tool in the search for bioactive compounds from natural sources, with the recent inclusion of marine organisms. Of the several steps performed in metabolomics studies, the extraction process is a crucial step-one which has been overlooked for a long time. In the presented study, a pressurized liquid extraction system was used to investigate the effect of extraction parameters such as pressure, temperature, number of cycles, and solvent polarity on the chemical diversity of the extract obtained from the marine sponge, Xestospongia. For this, a full factorial design (2⁴) was performed using a chemical diversity index, which was found to be a suitable tool to determine the efficiency of the extraction process, as the response variable. This index was calculated using a logarithmic transformation of ¹H NMR signals. Three factors (number of cycles, temperature, and solvent polarity) and two interactions were found to affect the chemical diversity of the obtained extracts significantly. Two individual factors (temperature and solvent polarity) were selected for further study on their influence on sponge metabolites using orthogonal partial least square (OPLS) modeling. Based on the results, the groups of compounds that were most influenced by these parameters were determined, and it was concluded that ethanol as the extraction solvent together with low temperatures were the conditions that provided a higher chemical diversity in the extract.