The Geography of Phytochemical Races
The Geography of Phytochemical Races
The Geography of Phytochemical Races
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
22 2 Examples Within Continents<br />
Table 2.3 Levels <strong>of</strong> selected compounds and total monoterpenes, sesquiterpenes, and triketones<br />
from Leptospermum scoparium (from Perry et al., 1997a)<br />
Compound Australian N.Z. North. N.Z. East Cape N.Z. South<br />
α-Pinene 17.3(7.3) a 22.5(3.7) 0.7(0.9) 2.9(3.8)<br />
p-Cymene 4.2(3.6) 0.8(0.8) 0.2(0.0) 0.6(0.7)<br />
1, 8-Cineole 19.9(16.6) 1.6(0.3) 0.3(0.1) 0.7(1.0)<br />
Leptospermone 0.4(0.6) 0.8(0.5) 18.9(0.7) 1.7(1.1)<br />
Isoleptospermone 0.4(0.6) 0.0(0.1) 5.3(0.9) 0.5(0.6)<br />
Flavesone 0.1(0.2) 0.1(0.1) 8.3(0.3) 0.1(0.2)<br />
Total monoterpenes 50.6(24.4) 39.9(4.6) 3.0(1.1) 11.8(9.1)<br />
Total sesquiterpenes 24.7(16.0) 42.1(6.0) 53.7(3.0) 64.7(10.3)<br />
Total triketones 1.2(0.9) 1.0(0.5) 32.5(1.9) 2.4(1.6)<br />
a Percentage <strong>of</strong> total gas chromatography (GC) peak area (standard deviation).<br />
chemotype characterized by the highest level <strong>of</strong> sesquiterpenes observed in the<br />
study, along with an array <strong>of</strong> monoterpenes (Fig. 2.11). Values for the levels <strong>of</strong> the<br />
defi ning compounds <strong>of</strong> these chemotypes, along with those <strong>of</strong> the three classes <strong>of</strong><br />
compounds, are summarized in Table 2.3.<br />
Included in the table are data for L. scoparium obtained from fi ve sites in<br />
Australia. <strong>The</strong> Australian material exhibited a level <strong>of</strong> α-pinene approaching that<br />
<strong>of</strong> the northern race from New Zealand, but was clearly characterized by the highest<br />
level <strong>of</strong> 1,8-cineole observed in the study, along with the highest value for total<br />
monoterpenes and lowest value for total sesquiterpenes. <strong>The</strong> authors noted the need<br />
for further taxonomic study, particularly <strong>of</strong> the Australian material.<br />
Häberlein and Tschiersch (1998) have documented geographical variation in the<br />
external leaf fl avonoids <strong>of</strong> L. scoparium. Plants representing a range <strong>of</strong> climatic<br />
and geological situations were collected from seven sites from the north and three<br />
from the northern part <strong>of</strong> the south islands <strong>of</strong> New Zealand (Fig. 2.11). Detailed<br />
isolation and structural studies afforded an array <strong>of</strong> O- and C-methylated B-ring<br />
deoxyfl avones and fl avanones, including a very unusual member <strong>of</strong> the latter class<br />
(see Fig. 2.11 for structures 53–56). Characteristic <strong>of</strong> these are 5-hydroxy-6,8-di-<br />
C-methyl-7-methoxyfl avone [53], 5,7-dimethoxyfl avanone [54], and the unusual<br />
fl avanone 2,5-dihydroxy-6,8-di-C-methyl-7-methoxyfl avan-3-one [55]. Plants from<br />
the four most northerly sites, Auckland, Coromandel, Rawhiti, and Whangaruru<br />
North, exhibited the highest concentrations <strong>of</strong> fl avonoids, as well as the full range<br />
<strong>of</strong> compounds identifi ed, four fl avones and fi ve fl avanones, including the unusual<br />
compound [54]. Plants from the other six locations afforded lower amounts <strong>of</strong> fl avonoid<br />
material and simpler pr<strong>of</strong>i les. <strong>The</strong> least complex pr<strong>of</strong>i les, comprising only two<br />
compounds, 5,7-dimethoxy-6-C-methylfl avanone [56] and 5,7- dimethoxyfl avanone,<br />
were two from the North Island (Te Urewara and Tongariro) and one from the South<br />
Island (Marlborough Administrative Region). <strong>The</strong> unusual fl avanone was observed<br />
in fi ve <strong>of</strong> the northern plants and one <strong>of</strong> the southern ones, which excluded it as a<br />
marker. <strong>The</strong> possibility that these pigment pr<strong>of</strong>i les represent adaptations to local<br />
conditions was not pursued, although the authors clearly indicated that they were<br />
aware that environmental factors might play an important part in this system.<br />
Returning to the terpenes for a moment, it is interesting to note that Perry et al.<br />
(1997b) also examined the essential oils <strong>of</strong> Kunzea ericoides (A. Rich.) J. Thompson