Biology Reference
In-Depth Information
Furthermore, Knight and Pettit (1969)
investigated
Peniocereus greggii
to find
other 14a-methyl sterols, but failed. They
did, however, isolate peniocerol, desoxyvi-
peridone, viperidone, viperidinone, peni-
ocerol and b-sitosterol, together with an
unusual new 5b-desoxyviperidone (
30
) as
the acetate derivative. Because they argued
that the novel compound was possibly an
artefact obtained during the isolation, they
did not characterize it further.
Although this conclusion cannot be
modified, it is notable that Jiang
et al
.
(2006) have recently isolated two sterols,
opuntisterol (
31
) and opuntisteroside (
32
),
both with a 5b configuration, together with
the known sterols b-sitosterol, 7-oxosito-
sterol, 6b-hydroxystigmast-4-en-3one and
daucosterol, from the aerial parts of the
cactus
Opuntia dillenii
. Even though
opuntisterol and opuntisteroside do not
have a double bond at C-7, their discovery
presents the possibility of finding mole-
cules with the same 5b configuration, sim-
ilar to ecdysteroids, in other plants of
Cactaceae (Fig. 11.8).
Studies on the organ pipe cactus,
Stenocereus thurberi
, yielded a small
amount of cholesterol, campesterol and
sitosterol (Kircher, 1980), together with
large amounts of peniocerol, macdougallin
and three new 3b, 6a-dihydroxysterols,
cyclostenol (
33
), stenocereol (
34
) and thurb-
erol (
35
), the last two with a double bond
at C-8 (Kircher and Bird, 1982) (Fig. 11.9).
Some sterols have been isolated from
pollen from several species of Cactaceae
(Fig. 11.10). In the pollen of
Carnegiea
gigantea
, 24-methylene-cholesterol (
36
)
was found to be the principal pollen sterol
constituent, whereas some other minor
sterols such as 24-dehydropollinastanol
(
37
), b-sitosterol, cycloartenol (
38
), fucos-
terol (
39
) and 31-norcycloartenol (
40
) were
HO
HO
H
H
Locereol (
26
)
5
α
-cholesta-8, 14-dien-3
β
-ol (
27
)
H
HO
HO
H
H
Macdougallin (
29
)
Peniocerol (
28
)
OH
OH
Fig. 11.7.
Delta-8 sterols from Cactaceae.
OH
(a)
(b)
H
H
HO
R = H (
31
)
5
β
-deoxyviperidone (
30
)
H
H
O
R =
β
-D-glucopyranosyl- (
32
)
OR
Fig. 11.8.
5
b
-Derivatives present in Cactaceae. (a) From
Peniocereus greggii
, the first 5
b
-cholesterol.
(b) Opuntisterol (
31
) and opuntisteroside (
32
) from
Opuntia dillenii.
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