Farnesides A and B, sesquiterpenoid nucleoside ethers from a marine-derived Streptomyces sp., strain CNT-372 from Fiji.

Farnesides A and B (1, 2), linear sesquiterpenoids connected by ether links to a ribose dihydrouracil nucleoside, were isolated from a marine-derived Streptomyces sp., strain CNT-372, grown in saline liquid culture. The structures of the new compounds were assigned by comprehensive spectroscopic analysis primarily involving 1D and 2D NMR analysis and by comparison of spectroscopic data to the recently reported ribose nucleoside JBIR-68 (3). The farnesides are only the second example of this exceedingly rare class of microbial terpenoid nucleoside metabolites. Farneside A (1) was found to have modest antimalarial activity against the parasite Plasmodium falciparum

Farnesides A and B, Sesquiterpenoid Nucleoside Ethers from a Marine-Derived <i>Streptomyces</i> sp., strain CNT-372 from Fiji

Farnesides A and B (<b>1</b>,<b> 2</b>), linear sesquiterpenoids connected by ether links to a ribose dihydrouracil nucleoside, were isolated from a marine-derived <i>Streptomyces</i> sp., strain CNT-372, grown in saline liquid culture. The structures of the new compounds were assigned by comprehensive spectroscopic analysis primarily involving 1D and 2D NMR analysis and by comparison of spectroscopic data to the recently reported ribose nucleoside JBIR-68 (<b>3</b>). The farnesides are only the second example of this exceedingly rare class of microbial terpenoid nucleoside metabolites. Farneside A (<b>1</b>) was found to have modest antimalarial activity against the parasite <i>Plasmodium falciparum</i>

Seasonal dynamics of chemotypes in a freshwater phytoplankton community – A metabolomic approach

Cyanobacteria are known to produce a huge variety of secondary metabolites. Many of these metabolites are toxic to zooplankton, fish, birds and mammals. Therefore, the toxicity of cyanobacterial blooms is strongly dependent on the cyanobacterial strain composition. These strains produce distinct bouquets of secondary metabolites, and thus constitute different chemotypes. Some of the cyanobacterial metabolites are potent inhibitors of gut proteases of the filter-feeder Daphnia. Here, we investigate the seasonal dynamics of secondary metabolites in a phytoplankton community from a hypertrophic pond, making use of a new metabolomic approach. Using liquid chromatography coupled with high-resolution mass spectrometry (LCMS), we obtained mass spectra of phytoplankton samples taken on different dates throughout the summer season. By applying multivariate statistics, we combined these data with the protease inhibition capacity of the same samples. This led to the identification of metabolites with cyanobacterial origin and as well of distinct cyanobacterial chemotypes being dominant on different dates. The protease inhibition capacity varied strongly with season, and only one out of 73 known cyanobacterial protease inhibitors could be confirmed in the natural samples. Instead, several so far unknown, putative protease inhibitors were detected. In conclusion, the creation of time series of mass spectral data of a natural phytoplankton community proved to be useful for elucidating seasonal chemotype succession in a cyanobacterial community. Additionally, correlating mass spectral data with a biological assay provides a promising tool for facilitating the search for new harmful metabolites prior to structure elucidation. (C) 2014 Elsevier B.V. All rights reserved