A new antiplasmodial sterol from Indonesian marine sponge, Xestospongia sp

Testusterol, a new sterol of the sponge species Xestospongia testudinaria from Phu Quoc island, Vietnam

A new sterol, named testusterol (1), and five known compounds (2-6) were isolated from the n-hexane and dichloromethane extracts of the sponge species Xestospongia testudinaria. Their chemical structures were elucidated based on extensive spectroscopic analyses (1D, 2D NMR, ESIMS and HRESIMS) and comparison with published data. The results of in vitro test (utilizing brine shrimp Artemia salina LEACH) showed that three extracts ethanol, dichloromethane, and ethanol/water, significantly inhibited Artemia salina with LC50 values ranging from 6.09 to 16.83 µg/mL. Remarkably, the new compound 1 exhibited potent inhibition against both Gram-positive (Staphyloccocus aureus, Bacillus subtilis, Lactobacillus fermentum), and Gram-negative (Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa) bacteria species, with IC50 values of less than 12.0 nM and MIC ranging from 4.70 to 75.23 nM as determined by the broth-microdilution assay.

Indonesian marine and its medicinal contribution

The archipelagic country of Indonesia is populated by the densest marine biodiversity in the world which has created strong global interest and is valued by both Indigenous and European settlements for different purposes. Nearly 1000 chemicals have been extracted and identified. In this review, a systematic data curation was employed to collate bioprospecting related manuscripts providing a comprehensive directory based on publications from 1988 to 2022. Findings with significant pharmacological activities are further discussed through a scoping data collection. This review discusses macroorganisms (Sponges, Ascidian, Gorgonians, Algae, Mangrove) and microorganism (Bacteria and Fungi) and highlights significant discoveries, including a potent microtubule stabilizer laulimalide from Hyattella sp., a prospective doxorubicin complement papuamine alkaloid from Neopetrosia cf exigua, potent antiplasmodial manzamine A from Acanthostrongylophora ingens, the highly potent anti trypanosomal manadoperoxide B from Plakortis cfr. Simplex, mRNA translation disrupter hippuristanol from Briareum sp, and the anti-HIV-1 (+)-8-hydroxymanzamine A isolated from Acanthostrongylophora sp. Further, some potent antibacterial extracts were also found from a limited biomass of bacteria cultures. Although there are currently no examples of commercial drugs from the Indonesian marine environment, this review shows the molecular diversity present and with the known understudied biodiversity, reveals great promise for future studies and outcomes.

Marine natural products

Covering: January to December 2021This review covers the literature published in 2021 for marine natural products (MNPs), with 736 citations (724 for the period January to December 2021) 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 (1425 in 416 papers for 2021), 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. An analysis of the number of authors, their affiliations, domestic and international collection locations, focus of MNP studies, citation metrics and journal choices is discussed.

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.

Lead/Drug Discovery from Natural Resources

Natural products and their derivatives have been shown to be effective drug candidates against various diseases for many years. Over a long period of time, nature has produced an abundant and prosperous source pool for novel therapeutic agents with distinctive structures. Major natural-product-based drugs approved for clinical use include anti-infectives and anticancer agents. This paper will review some natural-product-related potent anticancer, anti-HIV, antibacterial and antimalarial drugs or lead compounds mainly discovered from 2016 to 2022. Structurally typical marine bioactive products are also included. Molecular modeling, machine learning, bioinformatics and other computer-assisted techniques that are very important in narrowing down bioactive core structural scaffolds and helping to design new structures to fight against key disease-associated molecular targets based on available natural products are considered and briefly reviewed.

New Halogenated Compounds from Halimeda macroloba Seaweed with Potential Inhibitory Activity against Malaria

Malaria is one of the most important infectious diseases worldwide. The causative of the most severe forms of malaria, Plasmodium falciparum, has developed resistances against all the available antimalarial drugs. In the present study, the phytochemical investigation of the green seaweed Halimeda macroloba has afforded two new compounds 1–2, along with 4 known ones 3–6. The structures of the compounds had been confirmed using 1& 2D-NMR and HRESIMS analyses. Extensive machine-learning-supported virtual-screening suggested cytochrome-C enzyme as a potential target for compound 2. Docking, absolute-binding-free-energy (ΔG_binding) and molecular-dynamics-simulation (MDS) of compound 2 revealed the strong binding interaction of this compound with cytochrome-C. In vitro testing for crude extract and isolated compounds revealed the potential in vitro inhibitory activity of both extract and compound 2 against P. falciparum. The crude extract was able to inhibit the parasite growth with an IC₅₀ value of 1.8 ± 0.35 µg/mL. Compound 2 also showed good inhibitory activity with an IC₅₀ value of 3.2 ± 0.23 µg/mL. Meanwhile, compound 6 showed moderate inhibitory activity with an IC₅₀ value of 19.3 ± 0.51 µg/mL. Accordingly, the scaffold of compound 2 can be considered as a good lead compound for the future development of new antimalarial agents.

Trends of antimalarial marine natural products: progresses, challenges and opportunities

This review provides an overview of the antimalarial marine natural products, focusing on their chemistry, malaria-related targets and mechanisms, and highlighting their potential for drug development.

Promising antiparasitic agents from marine sponges

Parasitic diseases especially those prevail in tropical and subtropical regions severely threaten the lives of people due to available drugs found to be ineffective as several resistant strains have been emerged. Due to the complexity of the marine environment, researchers considered it as a new field to search for compounds with therapeutic efficacy, marine sponges represents the milestone in the discovery of unique compounds of potent activities against parasitic infections. In the present article, literatures published from 2010 until March 2021 were screened to review antiparasitic potency of bioactive compounds extracted from marine sponges. 45 different genera of sponges have been studied for their antiparasitic activities. The antiparasitic activity of the crude extract or the compounds that have been isolated from marine sponges were assayed in vitro against Plasmodium falciparum, P. berghei, Trypanosoma brucei rhodesiense, T. b. brucei, T. cruzi, Leishmania donovani, L. tropica, L. infantum, L. amazonesis, L. major, L. panamesis, Haemonchus contortus and Schistosoma mansoni. The majority of antiparastic compounds extracted from marine sponges were related to alkaloids and peroxides represent the second important group of antiparasitic compounds extracted from sponges followed by terpenoids. Some substances have been extracted and used as antiparasitic agents to a lesser extent like steroids, amino acids, lipids, polysaccharides and isonitriles. The activities of these isolated compounds against parasites were screened using in vitro techniques. Compounds' potent activity in screened papers was classified in three categories according to IC₅₀: low active or inactive, moderately active and good potent active.

Metabolites from Marine Sponges and Their Potential to Treat Malarial Protozoan Parasites Infection: A Systematic Review

Malaria is an infectious disease caused by protozoan parasites of the Plasmodium genus through the bite of female Anopheles mosquitoes, affecting 228 million people and causing 415 thousand deaths in 2018. Artemisinin-based combination therapies (ACTs) are the most recommended treatment for malaria; however, the emergence of multidrug resistance has unfortunately limited their effects and challenged the field. In this context, the ocean and its rich biodiversity have emerged as a very promising resource of bioactive compounds and secondary metabolites from different marine organisms. This systematic review of the literature focuses on the advances achieved in the search for new antimalarials from marine sponges, which are ancient organisms that developed defense mechanisms in a hostile environment. The principal inclusion criterion for analysis was articles with compounds with IC50 below 10 µM or 10 µg/mL against P. falciparum culture. The secondary metabolites identified include alkaloids, terpenoids, polyketides endoperoxides and glycosphingolipids. The structural features of active compounds selected in this review may be an interesting scaffold to inspire synthetic development of new antimalarials for selectively targeting parasite cell metabolism.

Potentials of marine natural products against malaria, leishmaniasis, and trypanosomiasis parasites: a review of recent articles

Background

Malaria and neglected communicable protozoa parasitic diseases, such as leishmaniasis, and trypanosomiasis, are among the otherwise called diseases for neglected communities, which are habitual in underprivileged populations in developing tropical and subtropical regions of Africa, Asia, and the Americas. Some of the currently available therapeutic drugs have some limitations such as toxicity and questionable efficacy and long treatment period, which have encouraged resistance. These have prompted many researchers to focus on finding new drugs that are safe, effective, and affordable from marine environments. The aim of this review was to show the diversity, structural scaffolds, in-vitro or in-vivo efficacy, and recent progress made in the discovery/isolation of marine natural products (MNPs) with potent bioactivity against malaria, leishmaniasis, and trypanosomiasis.

Main text

We searched PubMed and Google scholar using Boolean Operators (AND, OR, and NOT) and the combination of related terms for articles on marine natural products (MNPs) discovery published only in English language from January 2016 to June 2020.

Twenty nine articles reported the isolation, identification and antiparasitic activity of the isolated compounds from marine environment. A total of 125 compounds were reported to have been isolated, out of which 45 were newly isolated compounds. These compounds were all isolated from bacteria, a fungus, sponges, algae, a bryozoan, cnidarians and soft corals. In recent years, great progress is being made on anti-malarial drug discovery from marine organisms with the isolation of these potent compounds. Comparably, some of these promising antikinetoplastid MNPs have potency better or similar to conventional drugs and could be developed as both antileishmanial and antitrypanosomal drugs. However, very few of these MNPs have a pharmaceutical destiny due to lack of the following: sustainable production of the bioactive compounds, standard efficient screening methods, knowledge of the mechanism of action, partnerships between researchers and pharmaceutical industries.

Conclusions

It is crystal clear that marine organisms are a rich source of antiparasitic compounds, such as alkaloids, terpenoids, peptides, polyketides, terpene, coumarins, steroids, fatty acid derivatives, and lactones. The current and future technological innovation in natural products drug discovery will bolster the drug armamentarium for malaria and neglected tropical diseases.

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.