Chemodiversity of Ladder-Frame Prymnesin Polyethers in Prymnesium parvum

It's only fair to share...Flattr the authorPin on PinterestEmail this to someone
Buffer this pageDigg thisShare on FacebookShare on Google+Tweet about this on TwitterShare on LinkedInShare on YummlyShare on VKShare on RedditShare on StumbleUponPrint this pageShare on Tumblr
Abstract Image

Blooms of the microalga Prymnesium parvum cause devastating fish kills worldwide, which are suspected to be caused by the supersized ladder-frame polyether toxins prymnesin-1 and -2. These toxins have, however, only been detected from P. parvum in rare cases since they were originally described two decades ago. Here, we report the isolation and characterization of a novel B-type prymnesin, based on extensive analysis of 2D- and 3D-NMR data of natural as well as 90% 13C enriched material. B-type prymnesins lack a complete 1,6-dioxadecalin core unit, which is replaced by a short acyclic C2 linkage compared to the structure of the original prymnesins. Comparison of the bioactivity of prymnesin-2 with prymnesin-B1 in an RTgill-W1 cell line assay identified both compounds as toxic in the low nanomolar range. Chemical investigations by liquid chromatography high-resolution mass spectrometry (LC-HRMS) of 10 strains of P. parvum collected worldwide showed that only one strain produced the original prymnesin-1 and -2, whereas four strains produced the novel B-type prymnesin. In total 13 further prymnesin analogues differing in their core backbone and chlorination and glycosylation patterns could be tentatively detected by LC-MS/HRMS, including a likely C-type prymnesin in five strains. Altogether, our work indicates that evolution of prymnesins has yielded a diverse family of fish-killing toxins that occurs around the globe and has significant ecological and economic impact.

Figure

Chemodiversity of Ladder-Frame Prymnesin Polyethers in Prymnesium parvum

Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 221, 2800 Kgs. Lyngby,Denmark
Department of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800 Kgs. Lyngby, Denmark
§ Marine Biological Section, Department of Biology, Copenhagen University, Strandpromenaden 5, 2100 Helsingør,Denmark
J. Nat. Prod., Article ASAP
DOI: 10.1021/acs.jnatprod.6b00345
Publication Date (Web): August 23, 2016
Copyright © 2016 The American Chemical Society and American Society of Pharmacognosy
*Tel (P. J. Hansen): (+45) 35321985. E-mail: pjhansen@bio.ku.dk., *Tel (T. O. Larsen): (+45) 45252632. E-mail: tol@bio.dtu.dk.
 Figure

Figure 1. LC-MS/HRMS screening of 10 P. parvum strains. (A) Summed EICs (doubly charged) of all prymnesin-like molecules in 10 worldwide-distributed strains of P. parvum. Green EIC was created for original prymnesin-1 and -2. Red EICs show B-type prymnesins. Blue EICs show tentatively identified C-type prymnesins. (B) MS/HRMS spectra of [M + 2H]2+: (top) prymnesin-1 and -2, (middle) prymnesin-B1 and -B2, (bottom) tentatively assigned C-type prymnesins. Δ66 shows a loss of a pentose (m/z 66.021, doubly charged) and Δ81 a loss of a hexose (m/z 81.026, doubly charged). Asterisk (*) denotes tentatively characterized by MS/MS, UV, and chiral-phase GC-MS.

aChemical shifts are reported in CD3OD and referenced to δH 3.31 ppm and δC 47.9 ppm at 313 K. n.d. = not detected.
 

////////////Chemodiversity, Ladder-Frame, Prymnesin Polyethers, Prymnesium parvum

It's only fair to share...Flattr the authorPin on PinterestEmail this to someone
Buffer this pageDigg thisShare on FacebookShare on Google+Tweet about this on TwitterShare on LinkedInShare on YummlyShare on VKShare on RedditShare on StumbleUponPrint this pageShare on Tumblr

Leave a Reply

Your email address will not be published. Required fields are marked *