68 research outputs found

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

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    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 α5ÎČ1 Function Is Regulated by XGIPC/kermit2 Mediated Endocytosis during Xenopus laevis Gastrulation

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    During Xenopus gastrulation α5ÎČ1 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 α5ÎČ1 integrin. The interaction of kermit2 with α5ÎČ1 is essential for fibronectin (FN) matrix assembly during the early stages of gastrulation. We further demonstrate that kermit2 regulates α5ÎČ1 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 α5ÎČ1 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 α5ÎČ1 integrin through receptor endocytosis

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

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

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    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

    Benzazoles from Aliphatic Amines and <i>o</i>‑Amino/Mercaptan/Hydroxyanilines: Elemental Sulfur as a Highly Efficient and Traceless Oxidizing Agent

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    A novel remarkably simple solvent-free and catalyst-free synthesis of benzazoles from alkylamines and <i>o</i>-hydroxy/amino/mercaptan anilines using elemental sulfur as traceless oxidizing agent has been developed
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