Phorone A and Isophorbasone A, Sesterterpenoids Isolated from the Marine Sponge Phorbas sp

Biological Activity and Structural Diversity of Steroids Containing Aromatic Rings, Phosphate Groups, or Halogen Atoms

This review delves into the investigation of the biological activity and structural diversity of steroids and related isoprenoid lipids. The study encompasses various natural compounds, such as steroids with aromatic ring(s), steroid phosphate esters derived from marine invertebrates, and steroids incorporating halogen atoms (I, Br, or Cl). These compounds are either produced by fungi or fungal endophytes or found in extracts of plants, algae, or marine invertebrates. To assess the biological activity of these natural compounds, an extensive examination of referenced literature sources was conducted. The evaluation encompassed in vivo and in vitro studies, as well as the utilization of the QSAR method. Numerous compounds exhibited notable properties such as strong anti-inflammatory, anti-neoplastic, anti-proliferative, anti-hypercholesterolemic, anti-Parkinsonian, diuretic, anti-eczematic, anti-psoriatic, and various other activities. Throughout the review, 3D graphs illustrating the activity of individual steroids are presented alongside images of selected terrestrial or marine organisms. Additionally, the review provides explanations for specific types of biological activity associated with these compounds. The data presented in this review hold scientific interest for academic science as well as practical implications in the fields of pharmacology and practical medicine. The analysis of the biological activity and structural diversity of steroids and related isoprenoid lipids provides valuable insights that can contribute to advancements in both theoretical understanding and applied research.

Ansellone J, a Potent in Vitro and ex Vivo HIV-1 Latency Reversal Agent Isolated from a Phorbas sp. Marine Sponge

Five new minor sesterterpenoids, ansellones H (4), I (5), J (6), and K (7) and phorone C (8), have been isolated from a Phorbas sp. marine sponge collected in British Columbia. Their structures have been elucidated by detailed analysis of NMR and MS data. Ansellone J (6) and phorone C (8) are potent in vitro HIV-1 latency reversal agents that are more potent than the reference compound and control protein kinase C activator prostratin (3). The most potent Phorbas sesterterpenoid, ansellone J (6), was evaluated for HIV latency reversal in a primary cell context using CD4+ T cells obtained directly from four combination antiretroviral therapy-suppressed donors with HIV. To a first approximation, ansellone J (6) induced HIV latency reversal at levels similar to prostratin (3) ex vivo, but at a 10-fold lower concentration.

Exploring Chemical Diversity of Phorbas Sponges as a Source of Novel Lead Compounds in Drug Discovery

Porifera, commonly referred to as marine sponges, are acknowledged as major producers of marine natural products (MNPs). Sponges of the genus Phorbas have attracted much attention over the years. They are widespread in all continents, and several structurally unique compounds have been identified from this species. Terpenes, mainly sesterterpenoids, are the major secondary metabolites isolated from Phorbas species, even though several alkaloids and steroids have also been reported. Many of these compounds have presented interesting biological activities. Particularly, Phorbas sponges have been demonstrated to be a source of cytotoxic metabolites. In addition, MNPs exhibiting cytostatic, antimicrobial, and anti-inflammatory activities have been isolated and structurally characterized. This review provides an overview of almost 130 secondary metabolites from Phorbas sponges and their biological activities, and it covers the literature since the first study published in 1993 until November 2021, including approximately 60 records. The synthetic routes to the most interesting compounds are briefly outlined.

Bioactive natural products from marine sponges belonging to family Hymedesmiidae

Natural products of marine origin exhibit extensive biological activities, and display a vital role in the exploration of new compounds for drug development. Marine sponges have been reported at the top with respect to the discovery of biologically active metabolites that have potential pharmaceutical applications. The family Hymedesmiidae belonging to the Demospongiae class includes ten accepted genera, of which four genera were explored for their bioactive metabolites, namely Phorbas, Hamigera, Hemimycale, and Kirkpatrickia. Genus Phorbas has received more attention due to the isolation of various classes of compounds with unique structures mainly diterpenes, alkaloids, sesterterpenes, and steroids that exhibited diverse biological activities including: antiviral, antimicrobial, and anti-inflammatory, whereas anticancer compounds predominated. This review focuses on the isolated secondary metabolites from family Hymedesmiidae with their biological potential and covers the literature from 1989 to 2020.

Natural products of marine origin exhibit extensive biological activities, and display a vital role in the exploration of new compounds for drug development.

Integrated analytical workflow for chromatographic profiling and metabolite annotation of a cytotoxic Phorbas amaranthus extract

Phorbas is a widely studied genus of marine sponge and produce structurally rich cytotoxic metabolites. Still, only few studies have assessed metabolites present in Brazilian species. To circumvent redundancy, in this work, we applied and herein report the use of a scouting liquid chromatographic system associate to the design of experiment produced by the DryLab® software to obtain a fast and efficient chromatographic separation of the active hexane fraction, further enabling untargeted high-resolution mass spectrometry (HRMS) data. To this end, a crude hydroalcoholic extract of the sponge Phorbas amaranthus collected in Brazilian coast was prepared and partitioned. The cytotoxicity of the crude extract and the fractions was evaluated using tumor cell culture models. Fragmentation pathways assembled from HRMS data allowed the annotation of 18 known Phorbas metabolites, while 17 metabolites were inferred based on Global Natural Product Social Molecular Networking (GNPS), matching with a further 29 metabolites annotated through molecular subnetwork. The workflow employed demonstrates that chromatographic method development can be accelerated by the use of automated scouting systems and DryLab®, which is useful for profiling natural product libraries, as well as data curation by molecular clusters and should be incorporated to the tools of natural product chemists.

Sesterterpenoids: chemistry, biology, and biosynthesis

Covering: July 2012 to December 2019Over the last seven years, expanding research efforts focused on sesterterpenoids has led to the isolation, identification, and characterization of numerous structurally novel and biologically active sesterterpenoids. These newly reported sesterterpenoids provide diverse structures that often incorporate unprecedented ring systems and new carbon skeletons, as well as unusual functional group arrays. Biological activities of potential biomedical importance including suppression of cancer cell growth, inhibition of enzymatic activity, and modulation of receptor signaling, as well as ecologically important functions such as antimicrobial effects and deterrence of herbivorous insects have been associated with a variety of sesterterpenoids. There has also been a rapid growth in our knowledge of the genomics, enzymology, and specific pathways associated with sesterterpene biosynthesis. This has opened up new opportunities for future sesterterpene discovery and diversification through the expression of new cryptic metabolites and the engineered manipulation of associated biosynthetic machinery and processes. In this paper we reviewed 498 new sesterterpenoids, including their structures, source organisms, country of origin, relevant bioactivities, and biosynthesis.

A biomimetic approach towards phorone sesterterpenoids

We report an investigation towards a unified total synthesis of the Korean sponge derived sesterterpenoids, phorones A (1) and B (2), via a biomimetic strategy. This work has established a new synthetic strategy to the parent ansellane sesterterpenoid skeleton with unanticipated diversion to a biogenetically related pathway.

A new family of sesterterpenoids isolated around the Pacific Rim

Covering: 2009 up to the end of 2017 There has been a recent eruption in the number of known marine sesterterpenoids which have been isolated from Pacific Rim marine organisms. These compounds have novel and unusual structures that exhibit incredibly potent and varied bioactivities. This review details the isolation, biological testing and prospects for this exciting new family with discussion of their potential biogenetic origins.

Natural Products from Sponges

The sponge is one of the oldest multicellular invertebrates in the world. Marine sponges represent one of the extant metazoans of 700–800 million years. They are classified in four major classes: Calcarea, Demospongiae, Hexactinellida, and Homoscleromorpha. Among them, three genera, namely, Haliclona, Petrosia, and Discodemia have been identified to be the richest source of biologically active compounds. So far, 15,000 species have been described, and among them, more than 6000 species are found in marine and freshwater systems throughout tropical, temperate, and polar regions. More than 5000 different compounds have been isolated and structurally characterized to date, contributing to about 30% of all marine natural products. The chemical diversity of sponge products is high with compounds classified as alkaloids, terpenoids, peptides, polyketides, steroids, and macrolides, which integrate a wide range of biological activities, including antibacterial, anticancer, antifungal, anti-HIV, anti-inflammatory, and antimalarial. There is an open debate whether all natural products isolated from sponges are produced by sponges or are in fact derived from microorganisms that are inhaled though filter-feeding or that live within the sponges. Apart from their origin and chemoecological functions, sponge-derived metabolites are also of considerable interest in drug development. Therefore, development of recombinant microorganisms engineered for efficient production of sponge-derived products is a promising strategy that deserves further attention in future investigations in order to address the limitations regarding sustainable supply of marine drugs.

Naturally occurring aromatic steroids and their biological activities

The present review describes the distribution and biological activities of natural mono-, di-, and triaromatic steroids. It is shown that the producers of aromatic steroids are microorganisms, fungi, and marine invertebrates, and also they were found in plants, animals, marine sediments, and karst deposits. Eighty biologically active aromatic steroids likely have an anti-tumor, anti-inflammatory, and neuroprotection activity with a confidence of 78 to 92%. The structures and predicted biological activities of aromatic steroids are available. This review emphasizes the role of aromatic steroids as an important source and potential leads for drug discovery and they are of great interest to chemists, physicians, biologists, pharmacologists, and the pharmaceutical industry.

Cytotoxic Compounds Derived from Marine Sponges. A Review (2010-2012)

Abstract: This extensive review covers research published between 2010 and 2012 regarding new compounds derived from marine sponges, including 62 species from 60 genera belonging to 33 families and 13 orders of the Demospongia class (Porifera). The emphasis is on the cytotoxic activity that bioactive metabolites from sponges may have on cancer cell lines. At least 197 novel chemical structures from 337 compounds isolated have been found to support this work. Details on the source and taxonomy of the sponges, their geographical occurrence, and a range of chemical structures are presented. The compounds discovered from the reviewed marine sponges fall into mainly four chemical classes: terpenoids (41.9%), alkaloids (26.2%), macrolides (8.9%) and peptides (6.3%) which, along with polyketides, sterols, and others show a range of biological activities. The key sponge orders studied in the reviewed research were Dictyoceratida, Haplosclerida, Tetractinellida, Poecilosclerida, and Agelasida. Petrosia, Haliclona (Haplosclerida), Rhabdastrella (Tetractinellida), Coscinoderma and Hyppospongia (Dictyioceratida), were found to be the most promising genera because of their capacity for producing new bioactive compounds. Several of the new compounds and their synthetic analogues have shown in vitro cytotoxic and pro-apoptotic activities against various tumor/cancer cell lines, and some of them will undergo further in vivo evaluation.

Additional sesterterpenes and a nortriterpene saponin from the sponge Clathria gombawuiensis

Three new terpene metabolites (1-3) were isolated from the marine sponge Clathria gombawuiensis collected from Korean waters. On the basis of the results of combined spectroscopic analyses, the structures of phorone B (1) and ansellone C (2) were determined to be the sesterterpenes of the phorone and ansellone classes, respectively, whereas the saponin gombaside A (3) was a nortriterpene sodium O-sulfonato-glucuronide of the rare 4,4,14-trimethylpregnane class. The absolute configuration of the glucuronate of 3 was assigned by an application of the phenylglycine methyl ester (PGME) method. The new compounds exhibited moderate cytotoxicity against A549 and K562 cell lines, and compound 3 showed antibacterial activity. The cytotoxicity of 1 may be related to the presence of a free phenolic -OH group, as the corresponding O-methoxy derivative 4 is inactive.

Marine natural products

This review covers the literature published in 2012 for marine natural products, with 1035 citations (673 for the period January to December 2012) 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 (1241 for 2012), together with the relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.

Marine low molecular weight natural products as potential cancer preventive compounds

Due to taxonomic positions and special living environments, marine organisms produce secondary metabolites that possess unique structures and biological activities. This review is devoted to recently isolated and/or earlier described marine compounds with potential or established cancer preventive activities, their biological sources, molecular mechanisms of their action, and their associations with human health and nutrition. The review covers literature published in 2003–2013 years and focuses on findings of the last 2 years.

Cytotoxic diterpenoid pseudodimers from the Korean sponge Phorbas gukhulensis

Four new cytotoxic diterpenoid pseudodimers (2-5), along with a previously reported one, gukulenin A (1), were isolated from the marine sponge Phorbas gukhulensis collected off the coast of Gagu-do, Korea. These novel compounds, designated gukulenins C-F (2-5), were determined by extensive spectroscopic analyses to be pseudodimers of the gagunins, like gukulenin A. The termini of the tropolone-containing side chains in gukulenins C-E (2-4) were found to have diverse modifications involving acetamides or taurine, whereas gukulenin F (5) was formed from 1 by the ring-opening of a cyclic hemiketal. The relative and absolute configurations were assigned by Murata's and modified Snatzke's methods using a HETLOC experiment and a CD measurement of a dimolybdenum complex, respectively. All of these compounds exhibited significant cytotoxicity against the K562 and A549 cell lines.

Sesterterpenoids isolated from a northeastern Pacific Phorbas sp

Four new sesterterpenoids, ansellone B (4), phorbadione (5), secoepoxyansellone A (6), and alotaketal C (7), have been isolated from specimens of the sponge Phorbas sp. collected in British Columbia. Ansellone B (4) has an unprecedented heterocyclic skeleton featuring an oxocane ring, and secoepoxyansellone A (6) is the first example of the degraded "secoansellane" sesterterpenoid carbon skeleton. Alotaketal C (7) is an activator of cAMP signaling in HEK cells.

Hirsutellones and beyond: figuring out the biological and synthetic logics toward chemical complexity in fungal PKS-NRPS compounds

Covering: up to early 2013. Fungal polyketides and their hybrid non ribosomal peptide derivatives are characterized by often striking structural features and biological activities. Their diversity and their complexity arise from highly organized and programmable biosynthetic pathways and have been challenged by many synthetic chemists. This review will conceptually illustrate how complexity can be generated, starting from a general biosynthetic purpose (the fundaments of PKS-NRPS assembly lines) and finally showing how the particular class of hirsutellone compounds has emerged from such processes in relation to post-elongation and secondary tailoring events. Synthetic efforts to produce these natural products will be described with a special emphasis on complexity-generating strategies and steps. Thus, the biosynthetic and synthetic works will be analyzed in a continuous flow, focusing on both the logic of Nature and organic chemists.