The Geography of Phytochemical Races

238 5 Wide Disjunctions
Table 5.4 Occurrence of acyclic and cyclic polyhalogenated monoterpenes in Plocamium
cartilagineum
Collection site Terpene class Reference
Acyclic Cyclic
Cadiz, Spain 0 2a Gonzalez et al. (1978)
Isle of Wight, UK 0 5 Higgs et al. (1977)
Overton, South Wales, UK 3 3 Higgs et al. (1977)
La Jolla, California 12 0 Mynderse and Faulkner (1975)
Monterey Bay, California 1 1 Crews (1977)
Whidby Island, Washington 2 0 Crews (1977)
Elephant Island, Antarctica 0 2 San-Martin and Rovirosa (1985)
James Island, Antarctica 2 4 Stierle and Sims (1979)
Covadonga Roadstead, Chile 1 0 San-Martin and Rovirosa (1986)
a Number of compounds identifi ed belonging to each class.
terpenes have been identifi ed, with individual profi les consisting of either or both
types in the same specimen as illustrated in Table 5.4.
Variation within a given area has also been documented as exemplifi ed by the fi ndings
of San-Martin and Rovirosa (1986), who studied the chemistry of P. cartilagineum
collected from six sites along the coast of Chile spanning a distance of ca. 1600 km.
Thirteen compounds were identifi ed that differed in degree of halogenation and stereochemistry.
Clear-cut geographical differences were noted based primarily on the
presence or absence of mertensene [484], violacene [487], and compound [481] (see
Fig. 5.11 for structures 477–487). A sample of the qualitative data involving these three
compounds can be found in Table 5.5. Earlier studies of P. violaceum by Crews et al.
(1977) had shown that chemical differences between life stages of an alga also exist.
Following that lead, Rovirosa et al. (1988) examined the composition of halogenated
monoterpene fractions from carposporophytes, tetrasporophytes, and gametophytes of
P. cartilagineum collected from two sites: La Boca and Quintay (both Chile). Analysis
of the Boca material confi rmed the presence of only chlorinated monoterpenes, and that
there were only relatively minor quantitative differences in chemistry among algal life
stages. The Quintay population, however, tested positive for both bromine- containing
Sites (Région) Terpenesa [484] [487] [481]
La Bova (VI) nd nd 5.5b Table 5.5 Variation in selected halogenated monoterpenes in Plocamium cartilagineum collected
from sites in Chile (from San-Martin and Rovirosa, 1986)
Punta de Perros (VI) nd nd 5.7
El Tabo (V) 12.8 40.4 nd
Montemar (V) 11.6 24.0 nd
La Herradura (IV) 18.7 19.3 nd
Chiloé (X) nd nd nd
a [484] = Mertensene; [487] = Violacene; see Fig. 5.11.
b Percentage of total halogenated terpenes; nd = not
detected.