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Studies of Brazilian Marine Invertebrates. VIII. Zoanthosterol, a New Sterol from the Zoanthid Zoanthus Sociatus (Hexacorallia, Zoanthidea)

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Abstract

The new marine sterol zoanthosterol, 4α-methyl-5α-ergosta-24 (28)-en-3β-ol, has been isolated, together with cholesterol and chalinasterol, from the zoanthid Zoanthus sociatus. The structure of zoanthosterol was deduced from spectroscopic data.

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... The order Zoanthids, belonging to the phylum Cnidarian, represent a rich source of biomolecules due to their high productivity of yielding alkaloids [12], steroids [13], palytoxins [14], serotonin [15] and toxic polypeptides [16]. These bioactive compounds provide promising pharmaceutical benefits and biotechnological potential for humans. ...
... The characterization of these sterols was deduced based on their spectroscopy data, MS and by comparison of the GLC retention time with those of standards. A new sterol zoanthosterol (46) was isolated from the Brazilian zoantharian Zoanthus sociatus along with 19 and 25 [92]. These sterols were isolated as their acetate derivatives and their structures deduced from NMR data and comparison with known analogues. ...
Thesis
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This thesis describes the isolation and identification of marine natural products from five zoantharian species collected off the Marine Protected Area El Pelado located in Santa Elena, Ecuador. A new family of 2-aminoimidazole alkaloids named terrazoanthines A-C were identified from Terrazoanthus patagonichus. Terrazoanthines A and B are characterized by the presence of the 2-aminoimidazole ring fused to a cyclohexane. Additionally, two zoanthoxanthin derivatives named zoamides E and F were isolated from the sister species Terrazoanthus cf. patagonichus. Then, four ecdysteroids derivatives named ecdysonelactones were obtained from Antipathozoanthus hickmani. These compounds feature a γ-lactone ring fused to ring A of the ecdysteroid skeleton. Further investigations on this organism led to the identification of four halogenated tyrosine derivatives named valdiviamides A-D and characterized by the presence of iodine and bromine atoms in the phenol ring. The bioactivity study revealed valdiviamide B to have moderate activity against the liver cancer cell line (HepG2) with an IC50 value of 7.8 µM. Additionally, two halogenated tyramine derivatives containing iodine and bromine atoms were identified from Parazoanthus darwini. The chemical investigation of Zoanthus cf. pulchellus allowed the identification of two members of the bioactive family of zoanthamine alkaloids. These compounds revealed neuroinflammatory activity in microglia BV-2 cells with high inhibitory effects in reactive oxygen species (ROS) and nitric oxide (NO) generation.
... While marine sponges have been deeply studied in the search for bioactive chemical entities, zoantharians are also known to biosynthesize a wide array of natural products with unique structural features and interesting bioactivity, such as zoanthamines [3][4][5]. Other families of natural products have also been isolated from different species of zoantharians, such as alkaloids [3,[6][7][8] including zoanthoxanthins [9,10] and parazoanthines [11] isolated from the Mediterranean zoantharian Parazoanthus axinellae, prostaglandins such as PGA 2 [12], fatty acids or palytoxin [13,14], one of the most toxic compounds, as well as ecdysteroids [15,16]. ...
Article
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Despite a large occurrence, especially over the Pacific Ocean, the chemical diversity of marine invertebrates belonging to the order Zoantharia is largely underexplored. For the two species of the genus Antipathozoanthus no chemical study has been reported so far. The first chemical investigation of Antipathozoanthus hickmani collected at the Marine Protected Area “El Pelado”, Santa Elena, Ecuador, led to the isolation of four new ecdysteroid derivatives named ecdysonelactones. The structures of ecdysonelactones A–D (1–4) were determined based on their spectroscopy data, including 1D and 2D NMR and HRMS. The four compounds of this family of ecdysteroids feature an unprecedented γ-lactone fused at the C-2/C-3 position of ring A. These derivatives exhibited neither antimicrobial nor cytotoxic activities.
... Zoanthus sociatus also belongs to the order Zoanthidea. To date, few chemical studies have been reported from this organism, comprising the isolation and characterization of small non‐ proteinaceous molecules, such as the sterol zoanthosterol [14], as well as the norzoanthamines alkaloids and their analogues [15,16]. In addition to these bioactive compounds, an antifilarial activity from the Z. sociatus chloroform/methanol extract was reported [17]. ...
Article
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Cnidarian constitutes a great source of bioactive compounds. However, research involving peptides from organisms belonging to the order Zoanthidea has received very little attention, contrasting to the numerous studies of the order Actiniaria, from which hundreds of toxic peptides and proteins have been reported. In this work, we performed a mass spectrometry analysis of a low molecular weight (LMW) fraction previously reported as lethal to mice. The low molecular weight (LMW) fraction was obtained by gel filtration of a Zoanthus sociatus (order Zoanthidea) crude extract with a Sephadex G‐50, and then analyzed by matrix‐assisted laser desorption/ionization time‐of‐flight/time‐of‐flight (MALDI‐TOF/TOF) mass spectrometry (MS) in positive ion reflector mode from m/z 700 to m/z 4000. Afterwards, some of the most intense and representative MS ions were fragmented by MS/MS with no significant results obtained by Protein Pilot protein identification software and the Mascot algorithm search. However, microcystin masses were detected by mass‐matching against libraries of non‐ribosomal peptide database (NORINE). Subsequent reversed‐phase C18 HPLC (in isocratic elution mode) and mass spectrometry analyses corroborated the presence of the cyanotoxin Microcystin‐LR (MC‐LR). To the best of our knowledge, this finding constitutes the first report of MC‐LR in Z. sociatus, and one of the few evidences of such cyanotoxin in cnidarians.
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Covering: up to the end of 2018 Zoantharians, also improperly known as zoanthids or colonial anemones, are well known by aquarists because of their ease of use in aquaria but also because of their splendid colours. However, high concentrations of the highly toxic palytoxin found in some species of zoantharians maintained in reef aquaria has raised some issues recently, unveiling at the same time a rather unknown chemical diversity hidden in these marine beauties. Herein, we report the structure of the metabolites described in all species of zoantharians up to the end of 2018 and their associated biological activities. As sessile invertebrates, zoantharians harbour a rich diversity of micro-organisms that can play a role in the biosynthesis of these natural products and we detail the current hypotheses on the metabolic pathways leading to the identified ecdysteroids, zoanthoxanthins, zoanthamines, palytoxins and others. Finally, we assess the possible use of these metabolites in the systematics of such a complex group of marine invertebrates and we discuss their possible ecological roles. Altogether, this review brings some insights into the rich chemical diversity of zoantharians and their potential for marine biodiscovery and marine ecology.
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Eleven new secondary metabolites [kuroshines H-J (1-3), 27-methyl glycinate zoanthenamine (4), 27-hydroxyzoanthenamine (5), 27-methyl glycinate kuroshine A (6), 27-hydroxykuroshine A (7), 3β-hydroxy-28-deoxyzoanthenamine (8), 14α-hydroxy-28-deoxyzoanthenamine (9), 27-hydroxy-28-deoxyzoanthenamine (10), and kuroshine K (11)], along with seven known compounds (12-18), were isolated from the zoantharian Zoanthus vietnamensis. The structures of all isolated components were elucidated by spectroscopic data (IR, MS, NMR, and UV), especially 2D NMR analyses. The relative configurations of 1 and 2 were confirmed by using single-crystal X-ray crystallography. Compounds 1-3 were found to have an unprecedented ether linkage between C-15 and C-28, while the unusual substituent methyl glycinate, attached at C-27 in compounds 4 and 6, was found for the first time in zoanthamine-type alkaloids. The anti-lymphangiogenic activities of 17 isolated compounds were evaluated. Compounds 4, 5, and 10 exerted promising anti-lymphangiogenic functions by reducing cell growth and tube formation of human lymphatic endothelial cells (LECs). In addition, the structure-activity relationships of the isolated alkaloids against lymphangiogenesis of LECs are discussed.
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Our fragmentary and out-of-date knowledge of coelenterate sterols has prompted us to examine in detail the sterols of three zoanthids, from Hawaii, from Eniwetok and a Tahitian .The sterol mixture of consists of four components, 24β-methylcholesta-5,22-dien-3β-ol, choiest-5-en-3β-ol, 24-methyl-cholest-5-en-3β-ol and 24-methylenecholesta-5,24(28)-dien-3β-ol.The sterol mixture isolated from is apparently identical with the previously reported palysterol from . . Its components are 24β-methylcholest-5-en-3β-ol, 24β-methy1cholesta-5, 22-dien-3β-ol, gorgosterol of as yet unknown structure, cholest-5-en-3β-ol and 24-ethylcholest-5-en-3β-ol.24-Methylenecholesta-5, 24(28)-dien-3β-ol was recognized as the sole sterol in the . from Tahiti.This study affords for the first time a detailed knowledge of the sterol mixtures in three members of the coelenterate family Zoanthidae.
“Marine Natural Products-Chemical and Biological Perspectives”, vol 5, Register of Known Compounds
  • A. Kelecom
  • A. M. Sole Cava
  • A. M. Boaventura