Induced production of cytochalasans in co-culture of marine fungus <i>Aspergillus flavipes</i> and actinomycete <i>Streptomyces</i> sp.

<p>Secondary metabolites profiles of co-culture of <i>Aspergillus flavipes</i> and <i>Streptomyces</i> sp. that isolated from the same habitat showed an induced production of a series of cytochalasans (five aspochalasins and rosellichalasin, determined by MS and NMR analysis). These cytochalasans were found to be produced by <i>A. flavipes</i> in LC–MS comparison analysis, and biological activity assays revealed that they were able to cause cytotoxic effects against <i>Streptomyces</i> sp. within a wide range of concentrations without causing any effect to the producer <i>A. flavipes</i>, which favoured the producer in competition. Further induction mechanism study applying membrane-separated culture and morphology study with scanning electron microscopy (SEM) suggested that the successful induction of active secondary metabolites required microbial physical contact.</p

Chemical constituents of the fermentative extracts of marine fungi <i>Phoma</i> sp<i>.</i> CZD-F11 and <i>Aspergillus</i> sp<i>.</i> CZD-F18 from Zhoushan Archipelago, China

<p>A new diphenyl ether (<b>1</b>) as well as 20 other compounds were identified from the fermentative extracts of marine-derived fungi <i>Phoma</i> sp. CZD-F11 (Compounds <b>1</b>–<b>8</b>) and <i>Aspergillus</i> sp. CZD-F18(Compounds <b>9</b>–<b>21</b>). Their structures were elucidated on the basis of extensive spectroscopic analysis. The broth extracts of the fungi exhibited very good anticancer activity against H1975 cells with 5.62 and 25.8% viability at concentration of 10 μg/mL for <i>Phoma</i> sp. CZD-F11 and <i>Aspergillus</i> sp. CZD-F18, respectively. The inhibitory activity of all compounds against PC-3 cell lines, BRD4 and aromatase were evaluated. The results showed compound <b>7</b> exhibited moderate anticancer activity with 66.1% inhibition against PC-3 cell lines at the concentration of 10 μg/mL. Compound <b>7</b> and <b>8</b> exhibited favourable BRD4 inhibitory activity with 78.5 and 76.4% inhibition at the concentration of 10 μg/mL.</p

New asymmetrical bispyrrolidinoindoline diketopiperazines from the marine fungus <i>Aspergillus</i> sp. DX4H

<p>Known diketopiperazine WIN 64821 and its asymmetric stereoisomers (<b>1</b>–<b>3</b>) had been isolated from the culture broth of a marine gut fungus <i>Aspergillus</i> sp. DX4H. The planar and stereochemistry for new compounds were determined by a suite of techniques including mass, NMR and CD spectra together with Marfey’s method. Their inhibitory activity against PC3 cell line had been tested.</p

One new indolocarbazole alkaloid from the <i>Streptomyces</i> sp. A22

<p>One new indolocarbazole alkaloid, 12-N-methyl-k252c, together with eight known indolocarbazoles were isolated from the rice solid fermentation of the marine-derived <i>Streptomyces</i> sp<i>.</i> A22. Their structures were elucidated on the basis of spectroscopic methods (UV, IR, HRESITOF MS, 1D NMR and 2D NMR). All of these compounds were evaluated for bromodomain-containing protein 4 (BRD4) inhibitory activities and cytotoxic activity assay, respectively. Compounds <b>4</b> and <b>5</b> showed moderate cytotoxic activity with an IC₅₀ value of 3.52 and 3.93 μM, respectively. Additionally, compound <b>1</b> also was tested for enzyme inhibition activities of protein kinases and showed moderate activity with IC₅₀ values of 0.91–1.84 μM.</p

Physapubescin B Exhibits Potent Activity against Human Prostate Cancer In Vitro and In Vivo

The present data showed that a natural compound isolated from the plant <i>Physalis pubescens</i> L. (Solanaceae), physapubescin B, exhibited antitumor activity against prostate cancer in vitro and in vivo. Treating prostate cancer cells with physapubescin B resulted in the accumulation of cells in the G2/M phase, which was associated with reduced Cdc25C levels and increased levels of CyclinB1, P21 as well as p-Cdk1 (Tyr15). Additionally, reactive oxygen species (ROS) generation was increased in physapubescin B-treated PC-3 cells. Furthermore, the physapubescin B-induced decrease of Cdc25C protein expression together with the G2/M phase cell cycle arrest were significantly abrogated by antioxidant NAC and GSH. Our data also demonstrated that physapubescin B exhibited strong in vivo antitumor efficacy in human prostate cancer PC3 xenograft. In conclusion, our results provide clear evidence that physapubescin B exhibits antitumor activity both in vitro and in vivo and deserves further development as an anticancer agent

New brefeldins and penialidins from marine fungus <i>Penicillium janthinellum</i> DT-F29

<p>A fermentation of marine fungus <i>Penicillium janthinellum</i> DT-F29 on solid rice medium led to the isolation of three new compounds, brefeldin D (<b>1</b>) and penialidins D-E (<b>5–6</b>), along with other five known brefeldins and penialidins. The structures of above compounds were determined on the basis of MS and NMR analysis.</p

Angucycline antibiotics and its derivatives from marine-derived actinomycete <i>Streptomyces</i> sp. A6H

<p>Vineomycin A₁ (<b>1</b>) and B₂ (<b>2</b>) were isolated from the culture broth of marine actinomycete <i>Streptomyces</i> sp. A6H. Five hydrolysis products were obtained by rational hydrolysis and methanolysis of the fermentation extract. Their structures were characterised as aquayamycin (<b>3</b>), vineomycinone B₂ (<b>4</b>), 9-C-_D-olivosyltetrangulol (<b>5</b>), 7-O-methylgaltamycinone (<b>6</b>) and vineomycinone B₂ methyl ester (<b>7</b>). In addition to these compounds, two ester derivatives, vineolactone A (<b>8)</b> and vineomycinone B₂ benzyl ester (<b>9</b>) of compound <b>4</b> were generated semisynthetically. Compound <b>6</b> is a new analogue of galtamycinone, while compounds <b>8</b> and <b>9</b> are new members of vineomycins. Cytotoxic activities and antimicrobial activities were determined for all compounds. The results indicate that only compound <b>1</b> showed significant activities with IC₅₀ value of 0.34 μM against H1975 and MIC value of 4 μg/mL against <i>Staphylococcus aureus.</i></p