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

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

New fatty acids from the Red Sea sponge <i>Mycale euplectellioides</i>

<div><p>Chemical investigation of the Red Sea sponge <i>Mycale euplectellioides</i> afforded two new compounds; hexacosa-(6<i>Z</i>,10<i>Z</i>)-dienoic acid methyl ester (<b>1</b>) and hexacosa-(6<i>Z</i>,10<i>Z</i>)-dienoic acid (<b>2</b>), along with two known compounds: icosa-(8<i>Z</i>,11<i>Z</i>)-dienoic acid methyl ester (<b>3</b>) and β-sitosterol (<b>4</b>). The structures were elucidated by the interpretation of their spectral data. The total methanol extract (TME) of the sponge exhibited potent antimicrobial activity against the different strains at a concentration of 100 mg/mL. All tested fractions did not exhibit any activity against <i>Serratia marcescens</i> and tested fungal strains. The TME and different fractions displayed anti-inflammatory and antipyretic activities at doses of 100 and 200 mg/kg compared with indomethacin (8 mg). The TME exhibited a remarkable hepato-protective effect in CCl₄-induced liver damage compared with silymarin. Furthermore, compounds <b>1</b> and <b>2</b> displayed weak activity against A549 non-small cell lung cancer, the U373 glioblastoma and the PC-3 prostate cancer cell lines.</p></div

2,3-Seco-2,3-dioxo-lyngbyatoxin A from a Red Sea strain of the marine cyanobacterium <i>Moorea producens</i>

<div><p>Chemical investigation of the organic extract of a Red Sea strain of the cyanobacterium <i>Moorea producens</i> has afforded 2,3-seco-2,3-dioxo-lyngbyatoxin A (<b>1</b>). Five known compounds including lyngbyatoxin A (<b>2</b>), majusculamides A and B (<b>3</b> and <b>4</b>), aplysiatoxin (<b>5</b>) and debromoaplysiatoxin (<b>6</b>) were also isolated. Their structures were elucidated by using HR-FAB-MS, 1D and 2D NMR analyses. The compounds were evaluated for antiproliferative activity against HeLa cancer cells. Lyngbyatoxin A (<b>2</b>) showed potent activity, with an IC₅₀ of 9.2 nM, while <b>5</b> and <b>6</b> displayed modest activity with IC₅₀ values of 13.3 and 3.03 μM, respectively. In contrast, compounds <b>1</b>, <b>3</b> and <b>4</b> were inactive, with IC₅₀ values greater than 50 μM. The lack of cytotoxicity for 2,3-seco-2,3-dioxo-lyngbyatoxin A (<b>1</b>) demonstrates that the indole moiety in lyngbyatoxin (<b>2</b>) is essential for its cytotoxicity, and suggests that detoxification of <b>2</b> may be carried out by biological oxidation of the indole moiety to yield <b>1</b>.</p></div