The Geography of Phytochemical Races

210 4 Intercontinental Disjunctions
Compound
Table 4.6 Flavonoid profi les of Nothofagus subsp. Fuscospora
Nothofagus speciesa ALE FU1 FU2 GUN SOL
Galangin + + + + +
3-Methyl ether + vb v − +
7-Methyl ether
8-Hydroxygalangin:
v v + + +
3-Methyl ether + + + − −
8-Methyl ether + + + + +
3,7-Dimethyl ether − − − − +
3,8-Dimethyl ether + + + − +
7,8-Dimethyl ether − − − − +
3,7,8-Trimethyl ether − − − − +
5-Hydroxy-7,8-dimethoxy fl avone − − − − +
Pinocembrin v + + + +
7-Methyl ether − − − − +
3-Acetate − − − − +
2′,4′-Dihydroxy-6′-methoxychalcone v + + v −
Pinosylvin
vydroxy-7, 8-d
+ + + + v
a ALE = N. alessandri; FU1 = N. fusca; FU2 = N. fusca; GUN = N. gunnii; SOL = N. solandri.
b Variable among populations.
4.5 Western Pacifi c: Eastern Asia, Japan, and the Philippines
4.5.1 Euchresta (Fabaceae)
Euchresta is a genus of legumes consisting of fi ve species native to the Southeastern
Asian mainland, Japan, the Philippine Islands, and parts of Indonesia. It has been
the subject of morphological and pollen studies as well as an examination of its
fl avonoid chemistry, which is what concerns us here (Matsuura et al., 1994). These
workers undertook the chemical study in an effort to resolve the issue of relationships
in the face of differing views based on the published studies of Ohashi and
Sohma (1970) and Chen et al., (1992). An extensive series of papers dealing with the
fl avonoid chemistry of the entire genus has appeared (see Matsuura et al., 1994 for
complete citations). The genus proved to be a source of both apigenin O-glycosides
and C-glycosides, in addition to an abundant source of C-prenylated fl avanones,
for example, [375], C-prenylated isofl avones, [376], and C-prenylated coumaronochromones
(picture a prenyl group at C-3′ in 374) (see Fig. 4.16 for structures). In
addition to fl avonoids based upon the normal 2′,4′,6′,4-tetrahydroxychalcone, certain
members of the genus can also make the 6′-deoxychalcone from which the 5deoxyfl
avanone was formed. Following the formation of the two types of fl avanones
[372 and 5-deoxy derivatives), biosynthetic activities continue in all species to produce
isofl avones [373 and 5-deoxy derivatives], and in four species to produce the
corresponding coumaranochromones, for example, [374]. A particularly rich source