272
H. Schulz
was either absent or only present in low amounts. Chromatographic measurements
performed by metzger [112] confirmed this assumption. Furthermore, Raman mapping clearly presented the different distribution of polyacetylenes in wild and orange
carrots. It could be shown that the whole phloem tissue was rich in polyacetylenes,
but the maxima could have been also observed near the pericyclic parenchyma.
An analogous distribution of polyacetylenes has been found in roots of other carrot wild species. In recent studies, Roman et al. [111] show that the distribution of
polyacetylenes within the phloem tissue is not uniform and areas with high amounts
of these compounds may also occur occasionally. In addition, the authors could
not find higher concentration of polyacetylenes close to the periderm. Significant
amounts of falcarindiol detected in wild carrot species are related to their resistance
to some plant diseases such as root knot nematodes [113].
As already mentioned above polyacetylenes mainly occur in plant species from
the Apiaceae family. Recently, parsnip ( Pastinaca sativa), celeriac ( Apium graveolens var. rapaceum), and parsley ( Petroselinum crispum) have been investigated
aiming to show the distribution of the individual polyacetylene substances [114].
the Raman spectra obtained from various areas of the parsnip roots showed distinct
signals in the region of 2,180–2,270 cm
−1
and it has been found that the spectral
profiles as well as band positions depend significantly on the localization within
the root.
Falcarinol, falcarindiol, 8-o-methylfalcarindiol, panaxydiol, falcarinone and
falcarinolone have been detected in celeriac roots applying hPLC, but so far no
quantification of these polyacetylenes has been performed. Raman spectra, measured at different areas of the root have presented more or less the same pattern
and a band maximum at about 2,252 cm
−1
[114]. therefore, the authors assume that
falcarindiol dominates in celeriac root whereas the other polyacetylenes occur only
in lower amounts. Raman mapping has been also performed to study the polyacetylene distribution within the whole transversely cut root. As to be seen in Fig. 9.6,
polyacetylenes are accumulated only in a few small areas occasionally localized
close to the peel [114].
In a similar way, Raman spectra taken from parsley roots mainly show characteristic bands related to falcarinol and falcarindiol, but also several smaller signals
were found which are due to other polyacetylenes or the response of the plant matrix
[114]. A Raman map and the related image of a parsley root is presented in Fig. 9.6
proving a more or less homogeneous distribution of polyacetylenes in the phloem
tissue close to the secondary cambium. Polyacetylenes (falcarinol and panaxydol)
were also successfully detected in ginseng roots applying Raman spectroscopy. the
Raman spectra of the isolated polyacetylenes present signals at about 2,260 cm
−1
,
whereas a significant shift to 2,237 cm
−1
can be observed when the same compound
is measured in the fresh ginseng root. Raman spectra obtained from freeze-dried
ginseng roots show a band with a maximum at 2,258 cm
−1
, while the corresponding
polyacetylene signal measured after hydration of the freeze-dried material again
presents a band at 2,237 cm
−1
[93]. the authors explain this phenomenon with an
assumed interaction between the free π-electrons located at the polyacetylene bonds
and metal ions in presence of water resulting in the formation of a stable metal
H. Schulz
was either absent or only present in low amounts. Chromatographic measurements
performed by metzger [112] confirmed this assumption. Furthermore, Raman mapping clearly presented the different distribution of polyacetylenes in wild and orange
carrots. It could be shown that the whole phloem tissue was rich in polyacetylenes,
but the maxima could have been also observed near the pericyclic parenchyma.
An analogous distribution of polyacetylenes has been found in roots of other carrot wild species. In recent studies, Roman et al. [111] show that the distribution of
polyacetylenes within the phloem tissue is not uniform and areas with high amounts
of these compounds may also occur occasionally. In addition, the authors could
not find higher concentration of polyacetylenes close to the periderm. Significant
amounts of falcarindiol detected in wild carrot species are related to their resistance
to some plant diseases such as root knot nematodes [113].
As already mentioned above polyacetylenes mainly occur in plant species from
the Apiaceae family. Recently, parsnip ( Pastinaca sativa), celeriac ( Apium graveolens var. rapaceum), and parsley ( Petroselinum crispum) have been investigated
aiming to show the distribution of the individual polyacetylene substances [114].
the Raman spectra obtained from various areas of the parsnip roots showed distinct
signals in the region of 2,180–2,270 cm
−1
and it has been found that the spectral
profiles as well as band positions depend significantly on the localization within
the root.
Falcarinol, falcarindiol, 8-o-methylfalcarindiol, panaxydiol, falcarinone and
falcarinolone have been detected in celeriac roots applying hPLC, but so far no
quantification of these polyacetylenes has been performed. Raman spectra, measured at different areas of the root have presented more or less the same pattern
and a band maximum at about 2,252 cm
−1
[114]. therefore, the authors assume that
falcarindiol dominates in celeriac root whereas the other polyacetylenes occur only
in lower amounts. Raman mapping has been also performed to study the polyacetylene distribution within the whole transversely cut root. As to be seen in Fig. 9.6,
polyacetylenes are accumulated only in a few small areas occasionally localized
close to the peel [114].
In a similar way, Raman spectra taken from parsley roots mainly show characteristic bands related to falcarinol and falcarindiol, but also several smaller signals
were found which are due to other polyacetylenes or the response of the plant matrix
[114]. A Raman map and the related image of a parsley root is presented in Fig. 9.6
proving a more or less homogeneous distribution of polyacetylenes in the phloem
tissue close to the secondary cambium. Polyacetylenes (falcarinol and panaxydol)
were also successfully detected in ginseng roots applying Raman spectroscopy. the
Raman spectra of the isolated polyacetylenes present signals at about 2,260 cm
−1
,
whereas a significant shift to 2,237 cm
−1
can be observed when the same compound
is measured in the fresh ginseng root. Raman spectra obtained from freeze-dried
ginseng roots show a band with a maximum at 2,258 cm
−1
, while the corresponding
polyacetylene signal measured after hydration of the freeze-dried material again
presents a band at 2,237 cm
−1
[93]. the authors explain this phenomenon with an
assumed interaction between the free π-electrons located at the polyacetylene bonds
and metal ions in presence of water resulting in the formation of a stable metal