Cyclic Heptapeptides, Cordyheptapeptides C–E, from the Marine-Derived Fungus <i>Acremonium persicinum</i> SCSIO 115 and Their Cytotoxic Activities

Three new cycloheptapeptides, cordyheptapeptides C–E (<b>1</b>–<b>3</b>), were isolated from the fermentation extract of the marine-derived fungus <i>Acremonium persicinum</i> SCSIO 115. Their planar structures were elucidated on the basis of extensive MS, as well as 1D and 2D (COSY, HMQC, and HMBC) NMR spectroscopic data analyses. The absolute configurations of the amino acid residues were determined by single-crystal X-ray diffraction, Marfey’s method, and chiral-phase HPLC analysis. Compounds <b>1</b> and <b>3</b> displayed cytotoxicity against SF-268, MCF-7, and NCI-H460 tumor cell lines with IC₅₀ values ranging from 2.5 to 12.1 μM

Cytotoxic pyrone derivatives from the deep-sea-derived fungus <i>Cladosporium halotolerans</i> FS702

Two new compounds (R)-6-((8S)-hydroxypropyl)-2-methyl-5,6-dihydro-4H-pyran-4-one (1) and (R)-6-((8R)-hydroxypropyl)-2-methyl-5,6-dihydro-4H-pyran-4-one (2), together with four known compounds were isolated from the marine-derived fungus Cladosporium halotolerans FS702. The structures of these compounds were determined on the basis of extensive spectroscopic analysis including 1D/2D NMR, IR, UV, HRESIMS, ECD calculations as well as the modified Mosher’s method. Cytotoxic assay results showed that compound 2 had significant cytotoxic activity against SF-268, MCF-7, HepG-2, and A549 cells lines with IC50 values of 0.16, 0.47, 0.33 and 0.23 µM, respectively.</p

Halogenated Anthraquinones from the Marine-Derived Fungus <i>Aspergillus</i> sp. SCSIO F063

Metabolomic investigations focusing on the marine-derived fungus <i>Aspergillus</i> sp. SCSIO F063 have unveiled seven new chlorinated anthraquinones (<b>1</b>–<b>7</b>) related to averantin, together with five known analogues (<b>11</b>–<b>15</b>) when the fungus was fermented using sea salt-containing potato dextrose broth. Through the addition of sodium bromide to the broth, two new brominated anthraquinones (<b>8</b>, <b>9</b>) and one new nonhalogenated anthraquinone (<b>10</b>) were obtained from the fungal mycelia. Their structures were elucidated by extensive spectroscopic analyses including MS and 1D and 2D NMR data. One metabolite, 6-<i>O</i>-methyl-7-chloroaveratin (<b>2</b>), displayed inhibition activity against three human tumor cell lines, SF-268, MCF-7, and NCI-H460, with IC₅₀ values of 7.11, 6.64, and 7.42 μM, respectively

Cytotoxic and Antibacterial Marfuraquinocins from the Deep South China Sea-Derived Streptomyces niveus SCSIO 3406

Four new sesquiterpenoid naphthoquinones, marfuraquinocins A–D (<b>1</b>–<b>4</b>), and two new geranylated phenazines, phenaziterpenes A (<b>5</b>) and B (<b>6</b>), were isolated from the fermentation broth of Streptomyces niveus SCSIO 3406, which originated from a South China Sea sediment sample obtained from a depth of 3536 m. The structures of <b>1</b>–<b>6</b> were elucidated on the basis of extensive MS and one-dimensional and two-dimensional NMR spectroscopic analyses. In a panel of cytotoxicity and antibacterial assays, <b>1</b> and <b>3</b> were found to inhibit a NCI-H460 cancer cell line with IC₅₀ values of 3.7 and 4.4 μM, respectively. Compounds <b>1</b>, <b>3</b>, and <b>4</b> exhibited antibacterial activities against Staphylococcus aureus ATCC 29213 with equivalent MIC values of 8.0 μg/mL; compounds <b>3</b> and <b>4</b> each showed antibacterial activity against methicillin-resistant Staphylococcus epidermidis (MRSE) shhs-E1 with MIC values of 8.0 μg/mL

Cytotoxic pimarane-type diterpenes from the marine sediment-derived fungus <i>Eutypella</i> sp. FS46

<p>Two new pimarane-type diterpenes, scopararanes H-I (<b>1</b>–<b>2</b>), along with five known ones (<b>3</b>–<b>7</b>) were isolated from the culture broth of a marine sediment-derived fungus <i>Eutypella</i> sp. FS46, which was obtained from the South China Sea. Their structures were established by extensive spectroscopic analysis. All of them were evaluated for their cytotoxic activities against MCF-7, NCI-H460 and SF-268 tumour cell lines. Scopararane I (<b>2</b>) showed moderate inhibitory activities.</p

Heronamides D–F, Polyketide Macrolactams from the Deep-Sea-Derived <i>Streptomyces</i> sp. SCSIO 03032

Three new macrolactams, heronamides D–F (<b>1</b>–<b>3</b>), were isolated from the deep-sea-derived <i>Streptomyces</i> sp. SCSIO 03032 upon changing cultivation conditions. The planar structures of heronamides D–F (<b>1</b>–<b>3</b>) were elucidated by extensive MS and NMR spectroscopic analyses and comparisons with the closely related heronamides A–C. The relative configurations of <b>1</b>–<b>3</b> were deduced by detailed analysis of ³<i>J</i>_HH values and NOESY data. The absolute configurations of <b>1</b> and <b>2</b> were determined by chemical modifications and application of the modified Mosher’s method. None of the compounds exhibited obvious antimicrobial or cytotoxic activities

Fluostatins I–K from the South China Sea-Derived <i>Micromonospora rosaria</i> SCSIO N160

The strain SCSIO N160 was isolated from a South China Sea sediment sample and was characterized as a <i>Micromonospora rosaria</i> species on the basis of its 16S rRNA gene sequence. Three new fluostatins, I–K (<b>1</b>–<b>3</b>), were isolated from the culture of <i>M. rosaria</i> SCSIO N160, together with six known compounds, fluostatins C–F (<b>4</b>–<b>7</b>), rabelomycin (<b>8</b>), and phenanthroviridone (<b>9</b>). The structure of fluostatin D (<b>5</b>) was confirmed by an X-ray crystallographic study. The absolute configuration of <b>1</b> and <b>3</b> was assigned by electronic circular dichroism calculations. Compounds <b>8</b> and <b>9</b> exhibited good antimicrobial activities against <i>Staphylococcus aureus</i> ATCC 29213 with MIC values of 1.0 and 0.25 μg/mL, respectively. Compound <b>9</b> also exhibited significant in vitro cytotoxic activities toward SF-268 (IC₅₀ 0.09 μM) and MCF-7 (IC₅₀ 0.17 μM)

Indimicins A–E, Bisindole Alkaloids from the Deep-Sea-Derived <i>Streptomyces</i> sp. SCSIO 03032

Five new bisindole alkaloids, indimicins A–E (<b>1</b>–<b>5</b>), bearing a unique 1′,3′-dimethyl-2′-hydroindole moiety, were isolated from the marine-derived <i>Streptomyces</i> sp. SCSIO 03032, along with two new compounds, lynamicins F and G (<b>6</b> and <b>7</b>). Their planar structures were elucidated by detailed interpretation of their MS and NMR spectroscopic data, and the absolute configurations were determined by X-ray crystallographic analysis (for <b>1</b>), comparison of CD spectra (for <b>2</b>–<b>4</b>), and quantum chemical calculations (for <b>5</b>). Indimicin B (<b>2</b>) exhibited moderate cytotoxic activity toward the MCF-7 cell line

Variecolortins A–C, Three Pairs of Spirocyclic Diketopiperazine Enantiomers from the Marine-Derived Fungus <i>Eurotium</i> sp. SCSIO F452

Three pairs of spirocyclic diketopiperazine enantiomers, variecolortins A–C (<b>1</b>–<b>3</b>), were isolated from marine-derived fungus <i>Eurotium</i> sp. SCSIO F452. Compound <b>1</b> possesses an unprecedented highly functionalized <i>seco</i>-anthronopyranoid carbon skeleton featuring a 2-oxa-7-azabicyclo[3.2.1]­octane core. Compounds <b>2</b> and <b>3</b> represent rare examples of a 6/6/6/6 tetracyclic cyclohexene–anthrone carbon scaffold. Their structures were determined by spectroscopic analyses, X-ray diffraction, and ECD calculations. Their enantiomers exhibited different antioxidative and cytotoxic activities, and their modes of action were investigated