Biocatalytic and antimetastatic studies of the marine cembranoids sarcophine and 2-epi-16-deoxysarcophine

The soft coral Sarcophyton glaucum is a rich resource of several bioactive cembranoids. Sarcophytol A (1) and sarcophine (2) are cembranoid diterpenes reported from this soft coral and extensively investigated for their cancer chemopreventive properties. This study aimed at investigating the antimetastatic potential of the major cembranoids, sarcophine (2) and 2-epi-16-deoxysarcophine (3), from the Red Sea soft coral S. glaucum. Biocatalytic transformation of 3 using Rhizopus stolonifer ATCC 6227a and Absidia spinosa ATCC 6648 afforded four new metabolites, 5-7 and 9, along with the known 9α-hydroxysarcophine (8). Sarcophine, 2-epi-16-deoxysarcophine, and metabolites 5-9 revealed significant antimetastatic activity against the highly metastatic mouse melanoma cell line (B16B15b). Cembranoids demonstrate a great potential for further development as antimetastatic agents. © 2006 American Chemical Society and American Society of Pharmacognosy

Bioactive pyrrole alkaloids isolated from the Red Sea : marine sponge Stylissa carteri

Fifteen pyrrole alkaloids were isolated from the Red Sea marine sponge Stylissa carteri and investigated for their biological activities. Four of them were dibrominated [(+) dibromophakelline, Z-3-bromohymenialdisine, (±) ageliferin and 3,4-dibromo-1H-pyrrole-2-carbamide], nine compounds were monobrominated [(-) clathramide C, agelongine, (+) manzacidin A, (-) 3-bromomanzacidin D, Z-spongiacidin D, Z-hymenialdisine, 2-debromostevensine, 2-bromoaldisine and 4-bromo-1H-pyrrole-2-carbamide)] and finally, two compounds were non-brominated derivatives viz., E-debromohymenialdisine and aldisine. The structure elucidations of isolated compounds were based on 1D & 2D NMR spectroscopic and MS studies, as well as by comparison with literature. In-vitro, Z-spongiacidin D exhibited a moderate activity on (ARK5, CDK2-CycA, CDK4/CycD1, VEGF-R2, SAK and PDGFR-beta) protein kinases. Moreover, Z-3-bromohymenialdisine showed nearly similar pattern. Furthermore, Z-hymenialdisine displayed a moderate effect on (ARK5 & VEGF-R2) and (-) clathramide C showed a moderate activity on AURORA-A protein kinases. While, agelongine, (+) manzacidin A, E-debromohymenialdisine and 3,4-dibromo-1H-pyrrole-2-carbamide demonstrated only marginal inhibitory activities. The cytotoxicity study was evaluated in two different cell lines. The most effective secondary metabolites were (+) dibromophakelline and Z-3-bromohymenialdisine on L5178Y. Finally, Z-hymenialdisine, Z-3-bromohymenialdisine and (±) ageliferin exhibited the highest cytotoxic activity on HCT116. No report about inhibition of AURORA-A and B by hymenialdisine/hymenialdisine analogs existed and no reported toxicity of ageliferin existed in literature

Penicillosides A and B: new cerebrosides from the marine-derived fungus Penicillium species

In the course of our ongoing effort to identify bioactive compounds from marine-derived fungi, the marine fungus, Penicillium species was isolated from the Red Sea tunicate, Didemnum species. Two new cerebrosides, penicillosides A and B were isolated from the marine-derived fungus, Penicillium species using different chromatographic methods. Their structures were established by different spectroscopic data including 1D (1H NMR and 13C NMR) and 2D NMR (COSY, HSQC, and HMBC) studies as well as high-resolution mass spectral data. Penicilloside A displayed antifungal activity against Candida albicans while penicilloside B illustrated antibacterial activities against Staphylococcus aureus and Escherichia coli in the agar diffusion assay. Additionally, both compounds showed weak activity against HeLa cells. Keywords: Didemnum, Penicillum, Cerebrosides, Penicillosides, Antimicrobial activity, HeLa cell

Dragmacidoside: a new nucleoside from the Red Sea sponge <i>Dragmacidon coccinea</i>

<div><p>Chemical investigation of the Red Sea sponge <i>Dragmacidon coccinea</i> led to the isolation of a new nucleoside, dragmacidoside (<b>1</b>), along with eight known compounds: adenosine (<b>2</b>), inosine (<b>3</b>), deoxycytidine (<b>4</b>), methyl-α-d-glucopyranoside (<b>5</b>), clionasterol (<b>6</b>), stigmasterol (<b>7</b>), campesterol (<b>8</b>) and brassicasterol (<b>9</b>). The compounds were isolated from chloroform and ethyl acetate fractions of the methanolic extract of the sponge, and their structures were established based on various spectroscopic data including MS, 1D and 2D NMR (COSY, HSQC and HMBC). Biological testing revealed that the chloroform fraction possesses significant anti-inflammatory activity in the carrageenan-induced hind paw oedema in rats.</p></div

New Cerebroside and Nucleoside Derivatives from a Red Sea Strain of the Marine Cyanobacterium Moorea producens

In the course of our ongoing efforts to identify marine-derived bioactive compounds, the marine cyanobacterium Moorea producens was investigated. The organic extract of the Red Sea cyanobacterium afforded one new cerebroside, mooreaside A (1), two new nucleoside derivatives, 3-acetyl-2′-deoxyuridine (2) and 3-phenylethyl-2′-deoxyuridine (3), along with the previously reported compounds thymidine (4) and 2,3-dihydroxypropyl heptacosanoate (5). The structures of the compounds were determined by different spectroscopic studies (UV, IR, 1D, 2D NMR, and HRESIMS), as well as comparison with the literature data. Compounds 1–5 showed variable cytotoxic activity against three cancer cell lines

Urgineaglyceride A: a new monoacylglycerol from the Egyptian <i>Drimia maritima</i> bulbs

<div><p>One new compound, (2<i>S</i>)-1-<i>O</i>-(<i>Z</i>)-tetracos-6-enoate glycerol (<b>1</b>) named urgineaglyceride A, along with six known compounds, 3,5,7,3′,5′-pentahydroxydihydroflavonol (<b>2</b>), stigmasterol (<b>3</b>), (25<i>S</i>)-5β-furostane-3β-22α-26-triol (<b>4</b>), scillaridin A (<b>5</b>), (2<i>S</i>)-(+)-2-hydroxynaringenin-4′-<i>O</i>-β-d-glucopyranoside (<b>6</b>) and quercetin-3′-<i>O</i>-β-d-glucopyranoside (<b>7</b>), were isolated from the EtOAc fraction of <i>Drimia maritima</i> (L.) Stearn bulbs. Their structures were secured based on their IR, UV, 1D and 2D NMR data, in addition to HR-MS data and comparison with the literature data. The isolated compounds were evaluated for their <i>in vitro</i> growth inhibitory activity against A549 non-small cell lung cancer (NSCLC), U373 glioblastoma (GBM) and PC-3 prostate cancer cell lines. Compounds <b>2</b> and <b>3</b> displayed variable activities against the tested cancer cell lines. Compound <b>2</b> was a selective inhibitor of the NSCLC cell line with an IC₅₀ of 2.3 μM, whereas <b>3</b> was selective against GBM with IC₅₀ of 0.5 μM and against PC-3 with 2.0 μM.</p></div

Didemnacerides A and B: two new glycerides from Red Sea ascidian <i>Didemnum</i> species

<div><p>Two new glycerides, didemnacerides A (<b>1</b>) and B (<b>2</b>), together with three known sterols, 24-ethyl-25-hydroxycholesterol (<b>3</b>), cholest-6-en-3,5,8-triol (<b>4</b>) and cholestane-3β,5α,6β-26-tetrol (<b>5</b>), were isolated from the Red Sea ascidian <i>Didemnum</i> sp. Their structures were elucidated by using extensive 1D (¹H, ¹³C) and 2D (¹H–¹H COSY, HSQC and HMBC) NMR studies and mass spectroscopic data (GC-MS and HR-MS) as well as alkaline hydrolysis followed by GC–MS and NMR spectral analyses of the fatty acid methyl esters. This is the first report of compounds <b>3</b>–<b>5</b> from the Red Sea ascidian <i>Didemnum</i> species.</p></div