Iridoid glucosides from Viburnum prunifolium


Tomassini, L.; Cometa, F.M.; Foddai, S.; Nicoletti, M.

Planta Medica 65(2): 195-195

2007


The chemical composition of the volatile constituents from bracts and leaves of wild and hydroponically cultivated ORIGANUM DICTOMNUS were analysed by GC and GC-MS. Three different levels of nitrogen (100,150, 200 mg/l), were used in the nutrient solution for the cultivation, using the Nutrient Film Technique (N.F.T). Carvacrol was the predominant compound in all cases. The essential oils were investigated for their antimicrobial activity against STAPHYLOCOCCUS AUREUS, STAPHYLOCOCCUS EPIDERMIDIS, STAPHYLOCOCCUS HOMINIS, ESCHEIRICHIA COLI, and PSEUDOMONOS AERUGINOSA.

Notes
Planta
Med.
65
(1999)
195
lridoid
Glucosides
from
Viburnum
prunifolium
Lamberto
Tomassini",
M.
Francesca
Cometa
2
,
Sebastiano
Foddai
l
,
and
Marcell()
Nicoletti
l
Dipartimento
di
Biologia
Vegetale,
Universita
"La
Sapienza",
Rome,
Italy
2
Istituto
di
Farmacologia
e
Farmacognosia,
Universita
"La
Sapienza",
Rome,
Italy
Received:
June
8,
1998;
Revision
accepted:
September
19,
1998
Virurnum
prunifolium
L
(Caprifoliaceae)
stem
bark
is
reported
in
different
Pharmacopoeias
(1,
2)
for
its
spasmolytic
and
uterus-relaxant
properties
(3,
4).
In
this
study,
four
Valeriana-
type
iridoid
glucosides,
characterised
by
a
0-glucopyranosyl
moiety
bound
to
C-il
and
an
esterifying
isovaleric
group
at
C-
1,
have
been
isolated
from
V.
prunifolium.
They
are
(in
order
of
increasing
polarity):
2'-acetyldihydropenstemide
(1,
[46
°
67°,
c
0.5,
Me0H),
the
new
2'-trans-p-coumaroyl-dihydro-
penstemide
(2),
2'-acetylpatrinoside
(3,
toe
:
54.9°,
c
0.5,
Me0H)
and
patrinoside
(4,
[a]g
)
:
45.8°,
c
1.0,
Me0H).
HOH2C
s'
1
R
=
H
R'
=
acetyl
2
R
=
H
;
R'
=p-coumaroyl
3
R
=
OH
;
R'
=
acetyl
4
R
=
OH
;
R'
=
H
7
The
Me0H
extract
of
the
plant
stem
bark
(100g,
supplied
by
the
company
A.
Minardi,
Bagnacavallo,
Italy),
worked
up
as
previously
described
(6),
afforded
pure
1
(85
mg),
2
(180
mg),
3
(60
mg)
and
4
(110
mg).
Compounds
1,
3
and
4
were
identified
by
comparison
of
their
NMR
spectra
with
published
data
(7,
8).
2'-p-Coumaroyldihydropensternide
(2):
Amorphous
powder,
[a0:
59.7°
(c
0.3,
Me0H);
UV:
Al,;
(
a
)
,1
1
(log
E)
=
311
(4.1),
299
(sh.
3.9),
226
nm
(3.0);
1
H-NMR
(500
MHz,
CD
3
OD):
8
=
0.93
(6H,
d,
J
=
6.6
Hz,
Me
2
CHCH
2
-),
1.26
(1H,
bdq,
J
=
12.7
and
6.8
Hz,
H-7a),
1.57
(1H,
bdq,
J
=
12.4
and
6.2
Hz,
H-6a),
1.65
-
1.75
(21-1,
2m,
H-7b
and
H-611),
1.90
(21-I,
m,
H-8
and
H-9),
2.03
(1H,
m,
Me
2
CHCH
2
),
2.19
(2H,
d,
J
=
2.7
Hz,
Me
2
CHCH
2
-),
2.62
(1H,
q-shaped
m,
H-5),
3.34
(1H,
ddd,
J
=
2.2,
5.5
and
9.4
Hz,
H-5'),
3.40
(3H,
m,
H
2
-10
and
H-4'),
3.62
(1H,
dd,
J
=
8.6
and
9.4
Hz,
H-3'),
3.70
(1H,
dd,
J
=
5.5
and
12.0
Hz,
H-6'a),
3.91
(1H,
dd,
J
=
2.2
and
12.0
Hz,
H-6'b),
4.04
(1H,
d,
J
=
11.6
Hz,
H-11a),
4.22
(1H,
d,
J
=
11.6
Hz,
H-11b),
4.55
(11-I,
d,
J
=
7.8,
1-1-11,
4.81
(1H,
dd,
J
=
7.8
and
8.6
Hz,
H-2'),
5.90
(1H,
d,
J
=
4.411z,
H-1),
6.30
(1H,
bs,
H-3),
6.35
(1H,
di
=
15.8
Hz,
H-a),
6.81
(2H,
d,
J
=
8.4
Hz,
H-3"
and
H-5"),
7.46
(2H,
d,
J
=
8.4
Hz,
H-2"
and
H-6"),
7.64
(1H,
d,
J
=
15.8
Hz,
H-(3).
13
C-NMR
(125
MHz,
CD
3
0D):
S
=
22.8
(Me
2
CHCH
2
-),
26.9
(Me
2
CHCH
2
),
28.3
(C-7),
30.9
(C-6),
36.8
(C-5),
43.8
(C-8),
44.3
(Me
2
CHCH
2
-),
45.0
(C-9),
62.8
(C-
6'),
66.5
(C-10),
69.0
(C-11),
71.9
(C-4'),
75.4
(C-2'),
76.2
(C-3'),
78.1
(C-5'),
93.1
(C-1),
101.7
(C-1
114.9
(C-a),
115.4
(C-4),
117.0
(C-3"
and
C-5"),
127.3
(C-1"),
131.3
(C-2"
and
C-6"),
140.7
(C-3),
146.9
(C-0),
161.4
(C-4"),
168.4
(p-coum.-000-),
173.6
(isoval-COO-).
Complete
information
on
the
work-up
procedure
and
copies
of
the
original
spectra
are
obtainable
from
the
author
of
correspondence.
HO
H
6
0
2
0
OR'
H2
8
0
HOH2C
io
OC
H3
0
C
H3
The
NMR
data
of
2
showed
close
similarity
with
those
of
dihydropenstemide
(5),
with
differences
attributed
to
the
additional
presence
of
a
trans-p-coumaroyl
group
at
position
2',
i.e.,
downfield
shift
for
H-2'
(double
doublet
at
6
4.81),
downfield
a-shift
of
0.2
ppm
(C-2')
and
upfield
/3-shifts
of
1.8
and
1.7
ppm
(C-1'
and
C-3',
respectively).
NOE-difference
NMR
experiments
allow
us
to
obtain
the
relative
stereo-
chemical
assignment
for
the
chiral
centre
at
C-8,
which
is
also
consistent
with
the
configuration
of
dihydropenstemide.
It
is
noteworthy
that
compound
2,
when
left
in
contact
with
polar
solvents,
tends
to
isomerize.
In
fact,
after
recording
the
NMR
spectrum,
pure
2
was
left
in
CD
3
OD
solution
at
room
temperature
for
one
week_
The
repeated
NMR
spectrum
showed
that
2
had
been
transformed
in
part
into
the
cis-p-
coumaroyi
form,
reaching
at
equilibrium
a
trans/cis
ratio
of
about
2
:
1.
This
isomerization
is
certainly
due
to
resonance
in
the
stable
anion
which
is
formed
by
the
loss
of
the
labile
phenolic
hydrogen.
Planta
Medica
65
(1999)
195
©
Georg
Thieme
Verlag
Stuttgart
New
York
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L.
Tomassini
Dipartimento
di
Biologia
Vegetale
Universita
"La
Sapienza"
P.
le
Aldo
Moro,
5
1-00185
Rome
Italy
E-mail:
tomassini@axrma.uniromal.it
Fax:
+39-6-49912195