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HO
HO
HO
H
OH
Cyclostenol (
33
)
H
H
OH
OH
Thurberol (
35
)
Stenocereol (
34
)
Fig. 11.9.
Sterols from the organ pipe cactus. The cholest-8-en-3,6-diol system is a special feature in Cactaceae.
H
HO
HO
24-methyllene-cholesterol (
36
)
24-dehydro-pollinastanol (
37
)
H
HO
HO
Fucosterol (
39
)
Cycloartenol (
38
)
HO
HO
25(27)-dehydrolanost-8-enol (
41
)
31-norcycloartenol (
40
)
Fig. 11.10.
Sterols from the pollen of Cactaceae.
found in
Opuntia phaeacantha
and
Opuntia
versicolor
, and 25(27)-dehydrolanost-8-
enol (
41
) was found in pollen of
Pachycereus
pringlei
(Standifer and Barbier, 1968; Nes
and Schmidt, 1988; Lusby
et al
., 1993).
Finally, continuing with the survey of
the chemistry of columnar cacti from Mexico,
we have recently isolated peniocerol and
macdougallin from roots of
Myrtillocactus
geometrizans
(Céspedes
et al
., 2005) and
have evidence of the presence of other poly-
hydroxylated sterols from roots and aerial
parts of this species (data not published).
The examples mentioned above only
show some aspects of the chemistry of
sterols presents in Cactaceae but were
obtained in a very limited sample of spe-
cies and tissues, not being representative
of a particular clade nor for the whole
family. With information available from
samples of eight species of cacti (Salt
et al
., 1987), plus those reviewed above,
apparently the delta-5 sterols are the most
representative of the family. There is,
however, also a high prevalence of delta-7
and delta-8 sterols.
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