Penimethavone A, a flavone from a gorgonian-derived fungus <i>Penicillium chrysogenum</i>

<p>A novel flavone, penimethavone A (<b>1</b>), possessing a rare unique methyl group at ring-B, was isolated from the fungus <i>Penicillium chrysogenum</i> cultured from a gorgonian <i>Carijoa</i> sp. collected from the South China Sea. The structure was elucidated by extensive spectroscopic analysis and by comparison with related known compound. Compound <b>1</b> showed selective and moderate cytotoxicity against cervical cancer (HeLa) and rhabdomyosarcoma cell lines with IC₅₀ values of 8.41 and 8.18 μM, respectively.</p

Cytotoxic 19-oxygenated steroids from the South China Sea gorgonian, <i>Pacifigorgia senta</i>

<p>Bioassay guided chemical investigation of the gorgonian <i>Pacifigorgia senta</i> led to the discovery of a new 19-oxygenated steroid, cholesta-5,24-diene-3<i>β</i>,7<i>β</i>,19-triol (<b>1</b>), as well as three known steroids (<b>2</b>–<b>4</b>). The structure of <b>1</b> was determined by extensive spectroscopic analysis, including NMR and MS spectra. All of the compounds exhibited cytotoxicities against HepG2, Hep3B, MCF-7/ADR, PC-3 and HCT-116 cell lines, with the IC₅₀ values ranging from 7.0 to 29.7 μM. It is the first report on the chemical constituents of the coral species <i>P. senta</i>.</p

Nucleoside derivatives from the marine-derived fungus <i>Aspergillus</i><i>versicolor</i>

<div><p>Four nucleoside derivatives (<b>1</b>–<b>4</b>) were isolated from the fungus <i>Aspergillus versicolor</i> derived from the gorgonian <i>Dichotella gemmacea</i> collected in the South China Sea. Their structures were elucidated by comprehensive spectroscopic method of NMR and MS analysis. All isolated metabolites were evaluated for their cytotoxicity, antibacterial activity and lethality towards brine shrimp <i>Artemia salina</i>. Compounds <b>1</b>/<b>2</b> exhibited selective antibacterial activity against <i>Staphylococcus epidermidis</i> with an MIC value of 12.5 μM. It should be noted that <b>1</b> and <b>2</b>, whose structures were listed in SciFinder Scholar, had no associated reference. This is the first report about their isolation, structure elucidation and biological activities.</p></div

Two benzaldehyde derivatives and their artefacts from a gorgonian-derived <i>Eurotium</i> sp. fungus

<p>Two new benzaldehyde derivatives, named 3′-OH-tetrahydroauroglaucin (<b>1</b>) and(3′<i>S</i>*,4′<i>R</i>*)-6-(3′,5-epoxy-4′-hydroxy-1′-heptenyl)-2-hydroxy-3-(3′′-methyl-2′′-butenyl)benzaldehyde (<b>2</b>), were isolated from a gorgonian-derived <i>Eurotium</i> sp. fungus. Their structures were determined by extensive spectroscopic analysis including NMR and MS spectra. Dissolved <b>1</b> in CDCl₃ for several days could be detected its 2<i>H</i>-chromene skeleton derivatives (<b>1a</b>/<b>1b</b>), a pair of enantiomers with opposite configurations at C-3′. Compound <b>2</b> was also found to chemically convert to a pair of epimers non-enzymatically. The plausible mechanism to form the 2<i>H</i>-chromene artefacts with racemisation at C-3′ undergoing nucleophilic substitution (S_N1) was proposed.</p

Anti-Respiratory Syncytial Virus Prenylated Dihydroquinolone Derivatives from the Gorgonian-Derived Fungus <i>Aspergillus</i> sp. XS-20090B15

Two new prenylated dihydroquinolone derivatives, 22-<i>O</i>-(<i>N</i>-Me-l-valyl)­aflaquinolone B (<b>1</b>) and 22-<i>O</i>-(<i>N</i>-Me-l-valyl)-21-<i>epi</i>-aflaquinolone B (<b>2</b>), and two known analogues, aflaquinolones A (<b>3</b>) and D (or a diastereomer of D, <b>4</b>), were isolated from the mycelia of a gorgonian-derived <i>Aspergillus</i> sp. fungus. The structures of the new compounds were elucidated by spectroscopic methods, ECD spectra, Marfey’s method, and chemical conversion. Compounds <b>1</b> and <b>2</b> display an unusual esterification of <i>N</i>-Me-l-Val to the side-chain prenyl group. Compound <b>2</b> exhibited outstanding anti-RSV activity with an IC₅₀ value of 42 nM, approximately 500-fold stronger than that of the positive control ribavirin (IC₅₀ = 20 μM), and showed a comparatively higher therapeutic ratio (TC₅₀/IC₅₀ = 520)

Chromone Derivatives from a Sponge-Derived Strain of the Fungus <i>Corynespora cassiicola</i>

Twelve new chromone derivatives, corynechromones A–L (<b>1</b>–<b>12</b>), were isolated from the sponge-derived fungus <i>Corynespora cassiicola</i> XS-200900I7. Among them, <b>1</b>/<b>2</b>, <b>3</b>/<b>4</b>, <b>5</b>/<b>6</b>, and <b>7</b>/<b>8</b> were pairs of epimers. The planar structures were determined by extensive NMR spectroscopic data. The absolute configurations of <b>1</b>–<b>10</b> were assigned by the modified Mosher’s method and TDDFT ECD calculations together with comparison of their CD spectra. These are the first chromone derivatives reported from the genus <i>Corynespora</i>. A possible rule to determine the absolute configurations at C-2 in chromone derivatives by CD was proposed

A new sesquiterpene from the Hainan gorgonian <i>Menella kanisa</i> Grassoff

<div><p>Chemical investigation of the gorgonian <i>Menella kanisa</i> Grassoff collected from the South China Sea led to the isolation of a new sesquiterpene, menecubebane A (<b>1</b>), together with three known compounds, 8-methoxy-<i>trans</i>-calamenene (<b>2</b>), 8,9-dihydro-linderazulene (<b>3</b>) and (3β)-oleanan-3-ol (<b>4</b>). The structure of <b>1</b> was determined by detailed analysis of the spectroscopic data especially the NOESY spectrum. All the compounds were evaluated for their cytotoxic, brine shrimp lethal and antifouling activities.</p></div

A new hexahydrobenzopyran derivative from the gorgonian-derived Fungus <i>Eutypella</i> sp

<p>A new hexahydrobenzopyran derivative cytosporin L (<b>1</b>), and another eight known compounds were isolated from the gorgonian-derived fungus <i>Eutypella</i> sp. collected from the South China Sea. The structure of <b>1</b> was elucidated by comprehensive spectroscopic data. The absolute configuration of <b>1</b> was determined by a chemical reaction and the modified Mosher’s method. The isolated secondary metabolites were evaluated for their antibacterial activities. Compound <b>1</b> showed antibacterial activity towards <i>Micrococcus lysodeikticus</i> and <i>Enterobacter aerogenes</i> with the same MIC values of 3.12 μM. Compounds <b>1</b>–<b>3</b> were evaluated for antiviral activities. Compounds <b>1</b> and <b>2</b> obviously inhibited the respiratory syncytial virus (RSV) with the IC₅₀ values of 72.01 and 30.25 μM, respectively.</p

Structure and Absolute Configuration of Fumiquinazoline L, an Alkaloid from a Gorgonian-Derived <i>Scopulariopsis</i> sp. Fungus

Fumiquinazoline L (<b>1</b>), an alkaloid with a heptacyclic skeleton formed via a bridging hemiaminal linkage, was isolated from a gorgonian-derived <i>Scopulariopsis</i> sp. fungus. The structure and absolute configuration of the new compound were identified by comprehensive spectroscopic data and X-ray diffraction analysis. During acid hydrolysis of <b>1</b>, the isomerization of the valine residue was observed and also studied in different conditions. Fumiquinazoline L (<b>1</b>) showed no cytotoxic or antibacterial activities

Aspergivones A and B, two new flavones isolated from a gorgonian-derived <i>Aspergillus candidus</i> fungus

<p>Two new flavones, aspergivones A (<b>1</b>) and B (<b>2</b>), were isolated from the fungus <i>Aspergillus candidus</i> cultured from the gorgonian coral <i>Anthogorgia ochracea</i> collected from the South China Sea. The structures of <b>1</b> and <b>2</b> were elucidated by NMR and MS methods and comparison with relatively known compounds. Only <b>2</b> showed slight inhibitory activity against alpha-glucosidase with an IC₅₀ value of 244 μg/mL. Compounds <b>1</b> and <b>2</b> were also evaluated for their cytotoxic and antibacterial activities.</p