Chemistry and biological activities of the marine sponges of the genera mycale (Arenochalina), Biemna and Clathria

Over the past seven decades, particularly since the discovery of the first marine-derived nucleosides, spongothymidine and spongouridine, from the Caribbean sponge Cryptotethya crypta in the early 1950s, marine natural products have emerged as unique, renewable and yet under-investigated pools for discovery of new drug leads with distinct structural features, and myriad interesting biological activities. Marine sponges are the most primitive and simplest multicellular animals, with approximately 8900 known described species, although more than 15,000 species are thought to exist worldwide today. These marine organisms potentially represent the richest pipeline for novel drug leads. Mycale (Arenochalina) and Clathria are recognized marine sponge genera belonging to the order Poecilosclerida, whereas Biemna was more recently reclassified, based on molecular genetics, as a new order Biemnida. Together, these sponge genera contribute to the production of physiologically active molecular entities with diverse structural features and a wide range of medicinal and therapeutic potentialities. In this review, we provide a comprehensive insight and up-to-date literature survey over the period of 1976–2018, focusing on the chemistry of the isolated compounds from members of these three genera, as well as their biological and pharmacological activities, whenever available. © 2018 by the authors.Acknowledgments: This work was supported by the mission sector of the Ministry of High Education of the Arab Republic of Egypt (Egyptian cultural bureau in Paris and Athens); Amr El-Demerdash’s, and Mohamed Tammam’s joint supervision were fully funded and supported

Integrin α5β1 Function Is Regulated by XGIPC/kermit2 Mediated Endocytosis during Xenopus laevis Gastrulation

During Xenopus gastrulation α5β1 integrin function is modulated in a temporally and spatially restricted manner, however, the regulatory mechanisms behind this regulation remain uncharacterized. Here we report that XGIPC/kermit2 binds to the cytoplasmic domain of the α5 subunit and regulates the activity of α5β1 integrin. The interaction of kermit2 with α5β1 is essential for fibronectin (FN) matrix assembly during the early stages of gastrulation. We further demonstrate that kermit2 regulates α5β1 integrin endocytosis downstream of activin signaling. Inhibition of kermit2 function impairs cell migration but not adhesion to FN substrates indicating that integrin recycling is essential for mesoderm cell migration. Furthermore, we find that the α5β1 integrin is colocalized with kermit2 and Rab 21 in embryonic and XTC cells. These data support a model where region specific mesoderm induction acts through kermit2 to regulate the temporally and spatially restricted changes in adhesive properties of the α5β1 integrin through receptor endocytosis

Formic acid as a sustainable and complementary reductant: an approach to fused benzimidazoles by molecular iodine-catalyzed reductive redox cyclization of o-nitro-t-anilines

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Redox condensation of o-halonitrobenzene with 1,2,3,4-tetrahydroisoquinoline: involvement of an unexpected auto-catalyzed redox cascade

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Crambescidin Acid from the French Polynesian Monanchora n. sp. Marine Sponge

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Fatty acids pattern from the French Polynesian Monanchora n. sp. marine sponge

WOS:000449495400028International audienceMarine sponges are prolific producers of physiologically active secondary metabolites [1, 2]. The chemical exploration of fatty acids derived from of marine organisms is a vital research area [3,4,5]. Fatty acids and lipids obtained from marine sources display unique molecular diversity, including saturated, mono-, di-, and polyunsaturated, branched, halogenated, hydroxylated, methoxylated, epoxide, and non-methylene-interrupted structure [6]. Marine fatty acids exhibit a variety of bioactivities, including antifungal, antibacterial, antimalarial [7], and anticancer [8]. Among the marketed eight marine-derived drugs, the ethyl esters of several omega-3 fatty acids from fish oils, in particular, ethyl esters of the major constituents eicosapentaenoic acid and docosahexaenoic acid, are approved as anti-hypertriglyceridemia and antibacterial drugs [9,10,11]

Acetylated Nucleoside Derivatives from a Shallow-Water Marine Bivalve Codakia orbicularis

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Novel Alkaloids of the Aaptamine Class from an Indonesian Marine Sponge of the Genus Xestospongia

International audienceFour novel alkaloids of the aaptamine class have been isolated in addition to the known aaptamine, isoaaptamine, demethyl(oxy)aaptamine and its dimethylketal from an unidentified species of Indonesian marine sponge of the genus Xestospongia. Their structures were elucidated on the basis of detailed 1D and 2D NMR spectroscopic data. Their antimicrobial activity was tested towards Gram (+) (S. aureus), Gram (−) (E. coli, V. anguillarum) bacterial strains, a fungus (C. tropicalis); their cytotoxic activity was evaluated against KB cells

Marine natural occurring 2,5-diketopiperazines : isolation, synthesis and optical properties

Seven 2,5-diketopiperazines (DKPs) were isolated from the Fijian marine sponge Acanthella cavernosa. NMR and circular dichroism (CD) comparison with synthetic L-L DKPs allowed us to determine unambiguously the L-L absolute configuration of the natural DKPs. This work initiated the setting up of an optical properties database of natural DKPs, including specific rotation and CD