Gschwend%20thesis.pdf

-108-
(Müller and Jaenicke, 1973). Fucoserraten, as this structure is called,
was obtained from Dr. Müller and its GC and spectral properties ascertained.
The authentic compound elutes later than ethyl benzene (RICA* = lOI) on the
SE54 column (RICA* = llO) but its CI-CH4 spectrum is very similar to that
of the unknown (figure 3-12). The only difference is that the authentic
fucoserraten has m/e 95 about 2 times m/e 93, while the compound found in
this study showed the reverse. This suggests that the unknown compound
is a closely related isomer of fucoserraten, e.g., trans, trans-I,3,5-
octatriene.
By GCMS analysis, one may estimate that the February 22, 1978 sample
contained a 60:40 mixture of the unknown and ethyl benzene. This estimate of
the concentration of ethyl benzene corresponds to that which one might expect from
the typical isomer ratio of this compound and the xylenes. This suggests
that one may obtain an idea of the temporal variation of the "octatriene"
by plotting the deviation of ethyl benzene from that expected from the
other C2-benzenes versus time (figure 3-l3). A peak in concentration of
this material occurred in late February and March.
Mathieson et al. (l976) have reported that sunlight may be the key
environmental variable controlling the release of gametes by Fucus spp.
The solar irradiance level, which they found to be critical, occurred
at the beginning of February at CD. Thus it is possible that this unknown
was related to the algal sexual activity. Isomerization of fucoserraten
(especially in sunlight) may have quickly produced the unknown observed
in this year-round study. This compound was also observed in surface
seawater from the upwelling region off Peru (chapter 2).
* RICA: retention index relative to the l-chloro-n-alkane standards, e.g.,
110means that the compound eluted LO% of the way between the lst i. s.
(l-cl-n-hexane) and the 2nd (l-cl-n-octane).