Electronic supplementary information (ESI) available:
13C-NMR spectra of (a) natural abundance
(−)-trans-blechnic 1 acid, as well as
(−)-trans-blechnic acids 1 obtained following administration
of (b) [1-13C], (c) [2-13C] and (d)
3-13C]-phenylalanine 6 (1 mM) to B. spicant fronds for
5 days; all spectra were recorded under identical conditions. The
relative carbon-13 enrichments noted were higher for (−)-brainic acid
2 than for (−)-trans-blechnic 1 due in large part to the
much higher endogeneous levels of the latter in B. spicant. See
http://www.rsc.org/suppdata/cc/b0/b008174o/