The Geography of Phytochemical Races

4.1 Across the Atlantic Ocean 181
caused by some combination of the nitrogenous components of the species, ephedrine
derivatives taken as a case in point. A recent paper by Caveney et al. (2001)
surveyed 26 species of Ephedra for nitrogenous compounds. Several interesting
differences among different groups of species were observed, but the observation
of interest to us here is the presence of ephedrine [(–)-1-phenyl-1-hydroxy-2-Nmethylaminopropane]
and pseudo-ephedrine [the ( + )-isomer] in Eurasian species
and their nearly total absence from New World species. The only exception was the
detection of a trace of pseudo-ephedrine (>0.01% wet mass) in E. californica.
4.1.6 Cactaceae and Aizoaceae
An early review of chemistry of disjunct (allojunct in the paper) taxa was that of
Turner (1972), one of the strongest proponents of the chemotaxonomic school of
the 1960s and 1970s. One of the subjects he discussed was the disjunct family
pair Cactaceae and Aizoaceae. His story started with a reference to a much earlier
paper by Vierhapper (1919) that suggested that these two families were disjuncts.
Both are succulents, with Aizoaceae predominantly South African in distribution,
whereas Cactaceae is predominantly New World. As emphasized by Turner,
Vierhapper’s suggestion was remarkably prescient considering that plate tectonic
theory lay well in the future and, in line with our concerns in this review, nothing
was yet known about the unusual secondary chemistry that links these families and
ties them together with others in Caryophyllalles (Centrospermae) (Wohlpart and
Mabry, 1968). The chemistry to which we refer here, of course, is the presence of
betacyanins (betalains is the more general term) as fl oral pigments in place of the
more common anthocyanins. Figure 4.5 illustrates the two compound types, with
betanin [312] representing the betacyanins and cyanidin [313] representing the typical
anthocyanins.
Fig. 4.5 Compounds 312 and 313, typical betacyanin and anthocyanin, respectively. Compounds
314 and 315 from Trachylobium