15 research outputs found
Chemodiversity of Ladder-Frame Prymnesin Polyethers in <i>Prymnesium parvum</i>
Blooms of the microalga <i>Prymnesium
parvum</i> 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 <i>P. parvum</i> 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% <sup>13</sup>C enriched material. B-type prymnesins
lack a complete 1,6-dioxadecalin core unit, which is replaced by a
short acyclic C<sub>2</sub> 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 <i>P. parvum</i> 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