Bioactive Brominated Oxindole Alkaloids from the Red Sea Sponge Callyspongia siphonella

Combination of Callyspongia sp. and Stem Cells for Wound Repair and Skin Regeneration: in Vivo and in Silico Evidences

Delayed healing of chronic wounds results in amputation and mortality rates in serious cases. The present study examines the merged wound-restorative efficacy of injectable bone marrow-derived mesenchymal stem cells (BMMSCs) and topical Callyspongia sp. extract in immunocompromised rats. HR-LC-MS analysis of Callyspongia sp. extract tentatively identified twenty-nine compounds (1-29) and highlighted its richness in fatty acids and terpenoids, known for their wound regenerating efficacies. The wound closure was greatly prominent in the BMMSCs/Callyspongia sp. group in contrast to the control group (p<0.001). The RT-PCR gene expression emphasized these results by attenuating the oxidative, inflammatory, and immunity markers, further confirmed by histopathological findings. Additionally, in silico modeling was particularly targeting matrix metalloproteinase-9 (MMP9), a key player in wound healing processes. Computational analysis revealed that compounds 18 and 19 potentially modulate MMP9 activity. The combination of BMMSCs and topical Callyspongia sp. extract holds a promise for regenerative therapy constituting a drastic advance in the wound cure of immunocompromised patients, eventually further safety assessments and clinical trials are required.

Red Sea Sponge Callyspongia siphonella Extract Induced Growth Inhibition and Apoptosis in Breast MCF-7 and Hepatic HepG-2 Cancer Cell Lines in 2D and 3D Cell Cultures

Introduction

The increasing incidence of cancer diseases necessitates the urgent exploration of new bioactive compounds. One of the trends in drug discovery is marine sponges which is gaining significant support due to the abundant production of natural pharmaceutical compounds obtained from marine ecosystems. This study evaluates the anticancer properties of an organic extract from the Red Sea sponge Callyspongia siphonella (C. siphonella) on HepG-2 and MCF-7 cancer cell lines.

Methods

C. siphonella was collected, freeze-dried, and extracted using a methanol-dichloromethane mixture. The extract was analyzed via Liquid Chromatography-Mass Spectrometry. Cytotoxic effects were assessed through cell viability assays, apoptosis detection, cell cycle analysis, mitochondrial membrane potential assays, scratch-wound healing assays, and 3D cell culture assays.

Results

Fifteen compounds were identified in the C. siphonella extract. The extract showed moderate cytotoxicity against MCF-7 and HepG-2 cells, with IC50 values of 35.6 ± 6.9 μg/mL and 64.4 ± 8 μg/mL, respectively, after 48 hours of treatment. It induced cell cycle arrest at the G2/M phase in MCF-7 cells and the S phase in HepG-2 cells. Apoptosis increased significantly in both cell lines, accompanied by reduced mitochondrial membrane potential. The extract inhibited cell migration, with notable reductions after 24 and 48 hours. In 3D cell cultures, the extract had IC50 values of 5.1 ± 2 μg/mL for MCF-7 and 166.4 ± 27 μg/mL for HepG-2 after 7 days of treatment, showing greater potency in MCF-7 spheres compared to HepG-2 spheres.

Discussion and Conclusion

The anticancer activity is attributed to the bioactive compounds. The C. siphonella extract's ability to induce apoptosis, disrupt mitochondrial membrane potential, and arrest the cell cycle highlights its potential as a novel anticancer agent. Additional research is required to investigate the underlying mechanism by which this extract functions as a highly effective anticancer agent.

Metabolomic profiling of Medicago sativa-derived fungal endophytes and evaluation of their biological activities

This study aimed to discover the potential of Medicago sativa-derived fungal endophytes as a prospective source of bioactive metabolites. In the present study, three different strains of fungal endophyte Aspergillus terreus were isolated from leaves L, roots T and stems St of Medicago sativa to explore their biological and chemical diversity. These isolated fungi were exposed to different fermentation conditions by adding various chemical elicitors to their solid fermentation media. According to LC-HRESIMS-based metabolomics and multivariate analysis, each chemical treatment had a different effect on the chemical profiles of the fungi. Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) proposed several compounds with anticancer action against MCF-7 (a human breast cancer cell line) and MDA-MB-231 (a human epithelial breast cancer cell line).

Targeting antimalarial metabolites from the actinomycetes associated with the Red Sea sponge Callyspongia siphonella using a metabolomic method

Malaria is a persistent illness that is still a public health issue. On the other hand, marine organisms are considered a rich source of anti‑infective drugs and other medically significant compounds. Herein, we reported the isolation of the actinomycete associated with the Red Sea sponge Callyspongia siphonella. Using "one strain many compounds" (OSMAC) approach, a suitable strain was identified and then sub-cultured in three different media (M1, ISP2 and OLIGO). The extracts were evaluated for their in-vitro antimalarial activity against Plasmodium falciparum strain and subsequently analyzed by Liquid chromatography coupled with high-resolution mass spectrometry (LC-HR-MS). In addition, MetaboAnalyst 5.0 was used to statistically analyze the LC-MS data. Finally, Molecular docking was carried out for the dereplicated metabolites against lysyl-tRNA synthetase (PfKRS1). The phylogenetic study of the 16S rRNA sequence of the actinomycete isolate revealed its affiliation to Streptomyces genus. Antimalarial screening revealed that ISP2 media is the most active against Plasmodium falciparum strain. Based on LC-HR-MS based metabolomics and multivariate analyses, the static cultures of the media, ISP2 (ISP2-S) and M1 (M1-S), are the optimal media for metabolites production. OPLS-DA suggested that quinone derivatives are abundant in the extracts with the highest antimalarial activity. Fifteen compounds were identified where eight of these metabolites were correlated to the observed antimalarial activity of the active extracts. According to molecular docking experiments, saframycin Y3 and juglomycin E showed the greatest binding energy scores (-6.2 and -5.13) to lysyl-tRNA synthetase (PfKRS1), respectively. Using metabolomics and molecular docking investigation, the quinones, saframycin Y3 (5) and juglomycin E (1) were identified as promising antimalarial therapeutic candidates. Our approach can be used as a first evaluation stage in natural product drug development, facilitating the separation of chosen metabolites, particularly biologically active ones.

Marine-Derived Compounds Applied in Cardiovascular Diseases: Submerged Medicinal Industry

Cardiovascular diseases (CVDs) are among the most impactful illnesses globally. Currently, the available therapeutic option has several side effects, including hypotension, bradycardia, arrhythmia, and alteration in different ion concentrations. Recently, bioactive compounds from natural sources, including plants, microorganisms, and marine creatures, have gained a lot of interest. Marine sources serve as reservoirs for new bioactive metabolites with various pharmacological activities. The marine-derived compound such as omega-3 acid ethyl esters, xyloketal B, asperlin, and saringosterol showed promising results in several CVDs. The present review focuses on marine-derived compounds' cardioprotective potential for hypertension, ischemic heart disease, myocardial infarction, and atherosclerosis. In addition to therapeutic alternatives, the current use of marine-derived components, the future trajectory, and restrictions are also reviewed.

Callyspongia spp.: Secondary Metabolites, Pharmacological Activities, and Mechanisms

One of the most widespread biotas in the sea is the sponge. Callyspongia is a sponge genus found in the seas, making it easily available. In this review, the pharmacological activity and mechanism of action of the secondary metabolites of Callyspongia spp. are addressed, which may lead to the development of new drugs and targeted therapeutic approaches. Several scientific databases, such as Google Scholar, PubMed, ResearchGate, Science Direct, Springer Link, and Wiley Online Library, were mined to obtain relevant information. In the 41 articles reviewed, Callyspongia spp. was reported to possess pharmacological activities such as cytotoxicity against cancer cell lines (36%), antifungal (10%), anti-inflammatory (10%), immunomodulatory (10%), antidiabetic and antiobesity (6%), antimicrobial (8%), antioxidant (4%), antineurodegenerative (4%), antihypercholesterolemic (2%), antihypertensive (2%), antiparasitic (2%), antiallergic (2%), antiviral (2%), antiosteoporotic (2%), and antituberculosis (2%) activities. Of these, the antioxidant, antituberculosis, and anti-inflammatory activities of Callyspongia extract were weaker compared with that of the control drugs; however, other activities, particularly cytotoxicity, show promise, and the compounds responsible may be developed into new drugs.

Naturally Occurring Organohalogen Compounds-A Comprehensive Review

The present volume is the third in a trilogy that documents naturally occurring organohalogen compounds, bringing the total number-from fewer than 25 in 1968-to approximately 8000 compounds to date. Nearly all of these natural products contain chlorine or bromine, with a few containing iodine and, fewer still, fluorine. Produced by ubiquitous marine (algae, sponges, corals, bryozoa, nudibranchs, fungi, bacteria) and terrestrial organisms (plants, fungi, bacteria, insects, higher animals) and universal abiotic processes (volcanos, forest fires, geothermal events), organohalogens pervade the global ecosystem. Newly identified extraterrestrial sources are also documented. In addition to chemical structures, biological activity, biohalogenation, biodegradation, natural function, and future outlook are presented.

Marine-derived antimicrobial molecules from the sponges and their associated bacteria

Antimicrobial resistance (AMR) is one of the leading global health issues that demand urgent attention. Very soon the world will have to bear the consequences of increased drug resistance if new anti-infectives are not pumped into the clinical pipeline in a short period. This presses on the need for novel chemical entities, and the marine environment is one such hotspot to look for. The Ocean harbours a variety of organisms, of which from this aspect, "Sponges (Phylum Porifera)" are of particular interest. To tackle the stresses faced due to their sessile and filter-feeding lifestyle, sponges produce various bioactive compounds, which can be tapped for human use. The sponges harbour several microorganisms of different types and in most cases; the microbial symbionts are the actual producers of the bioactive compounds. This review describes the alarming need for the development of new antimicrobials and how marine sponges can contribute to this. Selected antimicrobial compounds from the marine sponges and their associated bacteria have been described. Additionally, measures to tackle the supply problem have been covered, which is the primary obstacle in marine natural product drug discovery.

Exploring Oceans for Curative Compounds: Potential New Antimicrobial and Anti-Virulence Molecules against Pseudomonas aeruginosa

Although several antibiotics are already widely used against a large number of pathogens, the discovery of new antimicrobial compounds with new mechanisms of action is critical today in order to overcome the spreading of antimicrobial resistance among pathogen bacteria. In this regard, marine organisms represent a potential source of a wide diversity of unique secondary metabolites produced as an adaptation strategy to survive in competitive and hostile environments. Among the multidrug-resistant Gram-negative bacteria, Pseudomonas aeruginosa is undoubtedly one of the most important species due to its high intrinsic resistance to different classes of antibiotics on the market and its ability to cause serious therapeutic problems. In the present review, we first discuss the general mechanisms involved in the antibiotic resistance of P. aeruginosa. Subsequently, we list the marine molecules identified up until now showing activity against P. aeruginosa, dividing them according to whether they act as antimicrobial or anti-virulence compounds.

Bioactive Compounds from Marine Sponges and Algae: Effects on Cancer Cell Metabolome and Chemical Structures

Metabolomics represent the set of small organic molecules generally called metabolites, which are located within cells, tissues or organisms. This new “omic” technology, together with other similar technologies (genomics, transcriptomics and proteomics) is becoming a widely used tool in cancer research, aiming at the understanding of global biology systems in their physiologic or altered conditions. Cancer is among the most alarming human diseases and it causes a considerable number of deaths each year. Cancer research is one of the most important fields in life sciences. In fact, several scientific advances have been made in recent years, aiming to illuminate the metabolism of cancer cells, which is different from that of healthy cells, as suggested by Otto Warburg in the 1950s. Studies on sponges and algae revealed that these organisms are the main sources of the marine bioactive compounds involved in drug discovery for cancer treatment and prevention. In this review, we analyzed these two promising groups of marine organisms to focus on new metabolomics approaches for the study of metabolic changes in cancer cell lines treated with chemical extracts from sponges and algae, and for the classification of the chemical structures of bioactive compounds that may potentially prove useful for specific biotechnological applications.

Therapeutic potential of marine macrolides: An overview from 1990 to 2022

The sea is a vast ecosystem that has remained primarily unexploited and untapped, resulting in numerous organisms. Consequently, marine organisms have piqued the interest of scientists as an abundant source of natural resources with unique structural features and fascinating biological activities. Marine macrolide is a top-class natural product with a heavily oxygenated polyene backbone containing macrocyclic lactone. In the last few decades, significant efforts have been made to isolate and characterize macrolides' chemical and biological properties. Numerous macrolides are extracted from different marine organisms such as marine microorganisms, sponges, zooplankton, molluscs, cnidarians, red algae, tunicates, and bryozoans. Notably, the prominent macrolide sources are fungi, dinoflagellates, and sponges. Marine macrolides have several bioactive characteristics such as antimicrobial (antibacterial, antifungal, antimalarial, antiviral), anti-inflammatory, antidiabetic, cytotoxic, and neuroprotective activities. In brief, marine organisms are plentiful in naturally occurring macrolides, which can become the source of efficient and effective therapeutics for many diseases. This current review summarizes these exciting and promising novel marine macrolides in biological activities and possible therapeutic applications.

Antiproliferative potential of Physalis peruviana-derived magnolin against pancreatic cancer: a comprehensive in vitro and in silico study

Physalis peruviana L. is a common edible fruit in Egypt and other regional countries.

Marine-Derived Indole Alkaloids and Their Biological and Pharmacological Activities

Novel secondary metabolites from marine macroorganisms and marine-derived microorganisms have been intensively investigated in the last few decades. Several classes of compounds, especially indole alkaloids, have been a target for evaluating biological and pharmacological activities. As one of the most promising classes of compounds, indole alkaloids possess not only intriguing structural features but also a wide range of biological/pharmacological activities including antimicrobial, anti-inflammatory, anticancer, antidiabetic, and antiparasitic activities. This review reports the indole alkaloids isolated during the period of 2016–2021 and their relevant biological/pharmacological activities. The marine-derived indole alkaloids reported from 2016 to 2021 were collected from various scientific databases. A total of 186 indole alkaloids from various marine organisms including fungi, bacteria, sponges, bryozoans, mangroves, and algae, are described. Despite the described bioactivities, further evaluation including their mechanisms of action and biological targets is needed to determine which of these indole alkaloids are worth studying to obtain lead compounds for the development of new drugs.

Metabolities from Marine Sponges of the Genus Callyspongia: Occurrence, Biological Activity, and NMR Data

The genus Callyspongia (Callyspongiidae) encompasses a group of demosponges including 261 described species, of which approximately 180 have been accepted after taxonomic reviews. The marine organisms of Callyspongia are distributed in tropical ecosystems, especially in the central and western Pacific, but also in the regions of the Indian, the West Atlantic, and the East Pacific Oceans. The reason for the interest in the genus Callyspongia is related to its potential production of bioactive compounds. In this review, we group the chemical information about the metabolites isolated from the genus Callyspongia, as well as studies of the biological activity of these compounds. Through NMR data, 212 metabolites were identified from genus Callyspongia (15 species and Callyspongia sp.), belonging to classes such as polyacetylenes, terpenoids, steroids, alkaloids, polyketides, simple phenols, phenylpropanoids, nucleosides, cyclic peptides, and cyclic depsipeptides. A total of 109 molecules have been reported with bioactive activity, mainly cytotoxic and antimicrobial (antibacterial and antifungal) action. Thus, we conclude that polyacetylenes, terpenoids and steroids correspond to the largest classes of compounds of the genus, and that future research involving the anticancer action of the species' bioactive metabolites may become relevant.

Marine Indole Alkaloids-Isolation, Structure and Bioactivities

Indole alkaloids are heterocyclic natural products with extensive pharmacological activities. As an important source of lead compounds, many clinical drugs have been derived from natural indole compounds. Marine indole alkaloids, from unique marine environments with high pressure, high salt and low temperature, exhibit structural diversity with various bioactivities, which attracts the attention of drug researchers. This article is a continuation of the previous two comprehensive reviews and covers the literature on marine indole alkaloids published from 2015 to 2021, with 472 new or structure-revised compounds categorized by sources into marine microorganisms, invertebrates, and plant-derived. The structures and bioactivities demonstrated in this article will benefit the synthesis and pharmacological activity study for marine indole alkaloids on their way to clinical drugs.

Anticancer Potential of Green Synthesized Silver Nanoparticles of the Soft Coral Cladiella pachyclados Supported by Network Pharmacology and In Silico Analyses

Cladiella-derived natural products have shown promising anticancer properties against many human cancer cell lines. In the present investigation, we found that an ethyl acetate extract of Cladiella pachyclados (CE) collected from the Red Sea could inhibit the human breast cancer (BC) cells (MCF and MDA-MB-231) in vitro (IC50 24.32 ± 1.1 and 9.55 ± 0.19 µg/mL, respectively). The subsequent incorporation of the Cladiella extract into the green synthesis of silver nanoparticles (AgNPs) resulted in significantly more activity against both cancer cell lines (IC50 5.62 ± 0.89 and 1.72 ± 0.36, respectively); the efficacy was comparable to that of doxorubicin with much-enhanced selectivity. To explore the mode of action of this extract, various in silico and network-pharmacology-based analyses were performed in the light of the LC-HRESIMS-identified compounds in the CE extract. Firstly, using two independent machine-learning-based prediction software platforms, most of the identified compounds in CE were predicted to inhibit both MCF7 and MDA-MB-231. Moreover, they were predicted to have low toxicity towards normal cell lines. Secondly, approximately 242 BC-related molecular targets were collected from various databases and used to construct a protein-protein interaction (PPI) network, which revealed the most important molecular targets and signaling pathways in the pathogenesis of BC. All the identified compounds in the extract were then subjected to inverse docking against all proteins hosted in the Protein Data bank (PDB) to discover the BC-related proteins that these compounds can target. Approximately, 10.74% of the collected BC-related proteins were potential targets for 70% of the compounds identified in CE. Further validation of the docking results using molecular dynamic simulations (MDS) and binding free energy calculations revealed that only 2.47% of the collected BC-related proteins could be targeted by 30% of the CE-derived compounds. According to docking and MDS experiments, protein-pathway and compound-protein interaction networks were constructed to determine the signaling pathways that the CE compounds could influence. This paper highlights the potential of marine natural products as effective anticancer agents and reports the discovery of novel anti-breast cancer AgNPs.

Chemistry of trisindolines: natural occurrence, synthesis and bioactivity

Heterocyclic nitrogen compounds are privileged structures with many applications in the pharmaceutical and nutraceutical industries since they possess wide bioactivities. Trisindolines are heterocyclic nitrogen compounds consisting of an isatin core bearing two indole moieties. Trisindolines have been synthesized by reacting isatins with indoles using various routes and the yield greatly depends on the catalyst used, reaction conditions, and the substituents on both the isatin and indole moieties. Amongst the synthetic routes, acid-catalyzed condensation reaction between isatins and indoles are the most useful due to high yield, wide scope and short reaction times. Trisindolines are biologically active compounds and show anticancer, antimicrobial, antitubercular, antifungal, anticonvulsant, spermicidal, and antioxidant activities, among others. Trisindolines have not previously been reviewed. Therefore, this review aims to provide a comprehensive account of trisindolines including their natural occurrence, routes of synthesis, and biological activities. It aims to inspire the discovery of lead trisindoline drug candidates for further development.

This in-depth review of trisindolines covers their natural occurrence in addition to several routes of synthesis and catalysts used. The biological activities of trisindolines have been discussed with a special emphasis on the structure–activity relationship.

Discovery of cytotoxic natural products from Red Sea sponges: Structure and synthesis

Marine ecosystem continues to produce a great wealth of molecules endowed with cytotoxic activity towards a large panel of tumor cells. Marine sponges, apparently defenseless organisms are endowed through evolution with a range of cytotoxic metabolites for self protection against predators and space competition. Interestingly, high biodiversity of sponges with Demospongiae and Calcarea species that have yielded numerous bioactive compounds have been accorded in different regions of the Red Sea. This review for the first time provides a comprehensive overview of 123 cytotoxic agents derived from Red Sea sponges with diverse chemical structures covered till mid 2020 showing activities ranging from mildly active to very active against different panels of cancer cell lines. It has been divided according to the different classes of compounds including alkaloids, terpenoids (sesquiterpenes, diterpenes, triterpenes, sesterterpenes, norsesterterpenes), peptides and macrolides, lipids (steroids, fatty acids/amides and glycerides) etc. The enhancement in the cytotoxicity with respect to the molecular structure changes have been described in detail. We have also accounted for the total synthesis of cytotoxic molecules, subereamolline A, aerothionin, asmarine B, norrsolide and latrunculin B showing interesting activity against different cancer cell lines.

Amelioration effect of black seed oil against high-fat diet-induced obesity in rats through Nrf2/HO-1 pathway

Obesity is a chronic inflammatory disease that represents a risk factor for number of diseases including diabetes, steatohepatitis, and cancer. Using safe natural compounds to ameliorate obesity and its related metabolic syndrome is an interesting spot for research. We investigated the regulatory role and the underlying mechanism of black seed oil (BSO) on high-fat diet (HFD)-induced obesity in rats. The study included two models: the first one aimed to study the prophylactic effect of BSO (BSO administration for 10 weeks along with HFD) while the second one aimed to study the treatment role of BSO (BSO administration starting from the 10th week for 4 weeks along with HFD). BSO significantly decreased insulin resistance and body weight characteristics in both models. It also normalized lipid profile. Moreover, histopathological examination confirmed these results as BSO significantly decreased adipocyte size and hepatic lipid deposition. Besides, BSO alleviated HFD-induced oxidative stress as indicated by significant increase in the total antioxidant capacity and significant decrease in liver malondialdehyde. Moreover, BSO decreased significantly liver gluconeogenic enzymes mRNA expressions (phosphoenolpyruvate carboxykinase and glucose-6-phosphatase) and increased significantly heme oxygenase-1 (HO-1), nuclear factor erythroid-2-related factor-2 (Nrf2) and insulin receptor mRNA expressions. In conclusion, BSO represents a natural therapy that has the ability to prevent and treat HFD-induced obesity in rats that may be mediated through Nrf2/HO-1 pathway's activation and insulin receptor expression's increase. To our best knowledge, this study represents a novel study that investigates the regulatory role of BSO on Nrf2 pathway in preventing and treating HFD-induced obesity. PRACTICAL APPLICATIONS: Black seed oil is a natural available safe supplement, thus it can be used for prevention from obesity and even treatment of obesity and obesity related complications. Introducing of black seed oil in the treatment regimen of obese patients may be promising.

Cytotoxic Alkaloids Derived from Marine Sponges: A Comprehensive Review

Marine sponges (porifera) have proved to be a prolific source of unique bioactive secondary metabolites, among which the alkaloids occupy a special place in terms of unprecedented structures and outstanding biological activities. Identification of active cytotoxic alkaloids extracted from marine animals, particularly sponges, is an important strive, due to lack of knowledge on traditional experiential and ethnopharmacology investigations. In this report, a comprehensive survey of demospongian bioactive alkaloids in the range 1987-2020 had been performed with a special emphasis on the potent cytotoxic activity. Different resources and databases had been investigated, including Scifinder (database for the chemical literature) CAS (Chemical Abstract Service) search, web of science, Marin Lit (marine natural products research) database. More than 230 representatives of different classes of alkaloids had been reviewed and classified, different genera belonging to the phylum porifera had been shown to be a prolific source of alkaloidal molecules, including Agelas sp., Suberea sp., Mycale sp., Haliclona sp., Epipolasis sp., Monanchora sp., Crambe sp., Reniera sp., and Xestospongia sp., among others. The sufficient production of alkaloids derived from sponges is a prosperous approach that requires more attention in future studies to consider the constraints regarding the supply of drugs, attained from marine organisms.

A metabolomic approach to target antimalarial metabolites in the Artemisia annua fungal endophytes

Fungal endophytes are a major source of anti-infective agents and other medically relevant compounds. However, their classical blinded-chemical investigation is a challenging process due to their highly complex chemical makeup. Thus, utilizing cheminformatics tools such as metabolomics and computer-aided modelling is of great help deal with such complexity and select the most probable bioactive candidates. In the present study, we have explored the fungal endophytes associated with the well-known antimalarial medicinal plant Artemisia annua for their production of further antimalarial agents. Based on the preliminary antimalarial screening of these endophytes and using LC-HRMS-based metabolomics and multivariate analyses, we suggested different potentially active metabolites (compounds 1–8). Further in silico investigation using the neural-network-based prediction software PASS led to the selection of a group of quinone derivatives (compounds 1–5) as the most possible active hits. Subsequent in vitro validation revealed emodin (1) and physcion (2) to be potent antimalarial candidates with IC₅₀ values of 0.9 and 1.9 µM, respectively. Our approach in the present investigation therefore can be applied as a preliminary evaluation step in the natural products drug discovery, which in turn can facilitate the isolation of selected metabolites notably the biologically active ones.

Marine natural products

This review covers the literature published in 2019 for marine natural products (MNPs), with 719 citations (701 for the period January to December 2019) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1490 in 440 papers for 2019), together with the relevant biological activities, source organisms and country of origin. Pertinent reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. Methods used to study marine fungi and their chemical diversity have also been discussed.

In silico identification of SARS-CoV-2 spike (S) protein-ACE2 complex inhibitors from eight Tecoma species and cultivars analyzed by LC-MS

Coronavirus (CoV) is a positive RNA genome virus causing a global panic nowadays. Tecoma is a medicinally-valuable genus in the Bignoniaceae family, with some of its species exhibiting anti-HIV activity. This encouraged us to conduct an in silico exploration of some phytocompounds in Tecoma species cultivated in Egypt, namely Tecoma capensis and its four varieties i.e. yellow, harmony, pink and red, T. grandiflora Loisel., T. radicans L., and one hybrid i.e. Tecoma × smithii W. Watson. LC/MS-based metabolite profiling of the studied Tecoma plants resulted in the dereplication of 12 compounds (1-12) belonging to different phytochemical classes viz. alkaloids, iridoids, flavonoids and fatty acid esters. The in silico inhibitory action of these compounds against SARS-CoV-2 spike protein C-terminal domain in complex with human ACE2 was assessed via molecular docking. Succinic acid decyl-3-oxobut-2-yl ester (10), a fatty acid ester, possessed the best binding affinity (-6.77 kcal mol-1), as compared to hesperidin (13) (-7.10 kcal mol-1).

Recent Advances on Marine Alkaloids from Sponges

Alkaloids from marine secondary metabolites have received extensive attention from pharmacists in recent years. Miscellaneous alkaloids derived from marine sponges possessed various pharmacological activities including cytotoxicity, antimicrobial, antioxidant, and so on. Herein, we summarized 149 marine alkaloids from sponges based on their structures and bioactivities reported from 2015 to 2020 and analyzed the production environment of marine sponges with rich alkaloids. Moreover, we discussed biosynthesis routes of pyrrole and guanidine alkaloids from marine sponges Agelas and Monanchora. This article will be beneficial for future research on drugs from marine natural products.

Natural Products Repertoire of the Red Sea

Marine natural products have achieved great success as an important source of new lead compounds for drug discovery. The Red Sea provides enormous diversity on the biological scale in all domains of life including micro- and macro-organisms. In this review, which covers the literature to the end of 2019, we summarize the diversity of bioactive secondary metabolites derived from Red Sea micro- and macro-organisms, and discuss their biological potential whenever applicable. Moreover, the diversity of the Red Sea organisms is highlighted as well as their genomic potential. This review is a comprehensive study that compares the natural products recovered from the Red Sea in terms of ecological role and pharmacological activities.

Collective Locomotion of Human Cells, Wound Healing and Their Control by Extracts and Isolated Compounds from Marine Invertebrates

The collective migration of cells is a complex integrated process that represents a common theme joining morphogenesis, tissue regeneration, and tumor biology. It is known that a remarkable amount of secondary metabolites produced by aquatic invertebrates displays active pharmacological properties against a variety of diseases. The aim of this review is to pick up selected studies that report the extraction and identification of crude extracts or isolated compounds that exert a modulatory effect on collective cell locomotion and/or skin tissue reconstitution and recapitulate the molecular, biochemical, and/or physiological aspects, where available, which are associated to the substances under examination, grouping the producing species according to their taxonomic hierarchy. Taken all of the collected data into account, marine invertebrates emerge as a still poorly-exploited valuable resource of natural products that may significantly improve the process of skin regeneration and restrain tumor cell migration, as documented by in vitro and in vivo studies. Therefore, the identification of the most promising invertebrate-derived extracts/molecules for the utilization as new targets for biomedical translation merits further and more detailed investigations.

New Cytotoxic Natural Products from the Red Sea Sponge Stylissa carteri

Bioactivity-guided isolation supported by LC-HRESIMS metabolic profiling led to the isolation of two new compounds, a ceramide, stylissamide A (1), and a cerebroside, stylissoside A (2), from the methanol extract of the Red Sea sponge Stylissa carteri. Structure elucidation was achieved using spectroscopic techniques, including 1D and 2D NMR and HRMS. The bioactive extract's metabolomic profiling showed the existence of various secondary metabolites, mainly oleanane-type saponins, phenolic diterpenes, and lupane triterpenes. The in vitro cytotoxic activity of the isolated compounds was tested against two human cancer cell lines, MCF-7 and HepG2. Both compounds, 1 and 2, displayed strong cytotoxicity against the MCF-7 cell line, with IC50 values at 21.1 ± 0.17 µM and 27.5 ± 0.18 µM, respectively. They likewise showed a promising activity against HepG2 with IC50 at 36.8 ± 0.16 µM for 1 and IC50 30.5 ± 0.23 µM for 2 compared to the standard drug cisplatin. Molecular docking experiments showed that 1 and 2 displayed high affinity to the SET protein and to inhibitor 2 of protein phosphatase 2A (I2PP2A), which could be a possible mechanism for their cytotoxic activity. This paper spreads light on the role of these metabolites in holding fouling organisms away from the outer surface of the sponge, and the potential use of these defensive molecules in the production of novel anticancer agents.

Discovery of Two Brominated Oxindole Alkaloids as Staphylococcal DNA Gyrase and Pyruvate Kinase Inhibitors via Inverse Virtual Screening

In the present study, a small marine-derived natural products library was assessed for antibacterial potential. Among 36 isolated compounds, a number of bis-indole derivatives exhibited growth-inhibitory activity towards Gram-positive strains (Bacillus subtilis and multidrug-resistant Staphylococcus aureus). 5- and 6-trisindoline (5-Tris and 6-Tris) were the most active derivatives (minimum inhibitory concentration, MIC, 4–8 µM) that were subsequently selected for anti-biofilm activity evaluation. Only 5-Tris was able to inhibit the staphylococcal biofilm formation starting at a 5 µM concentration. In order to investigate their possible molecular targets, both natural products were subjected to in silico inverse virtual screening. Among 20 target proteins, DNA gyrase and pyruvate kinase were the most likely to be involved in the observed antibacterial and anti-biofilm activities of both selected natural products. The in vitro validation and in silico binding mode studies revealed that 5-Tris could act as a dual enzyme inhibitor (IC₅₀ 11.4 ± 0.03 and 6.6 ± 0.05 µM, respectively), while 6-Tris was a low micromolar gyrase-B inhibitor (IC₅₀ 2.1 ± 0.08 µM), indicating that the bromine position plays a crucial role in the determination of the antibacterial lead compound inhibitory activity.

New cytotoxic polyacetylene alcohols from the Egyptian marine sponge Siphonochalina siphonella

Three new polyacetylenic alcohols, siphonellanols A-C (1-3), together with two known polyacetylenic alcohols (4-5), were isolated from the CHCl₃-soluble fraction of the methanolic extract of the marine sponge Siphonochalina siphonella, collected in Egypt. The structures of 1-3 were determined by spectroscopic analyses of their 1D-, 2D-NMR, and MS spectra and by comparisons with reported data. The cytotoxicity assay revealed that 1-3 exhibited moderate cytotoxic activities against a human cervical cancer cell line (HeLa), a human breast cancer cell line (MCF-7), and a human lung cancer cell line (A549) with IC₅₀ values ranging from 25.9 to 69.2 μM.