Triterpene saponins of Maesa lanceolata leaves
Date
2011Author
Manguro, Onyango A
Midiwo, Jacob O
Tietze, Lutz F
Hao, Pang
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
Chemical investigation of
Maesa lanceolata
leaves aqueous MeOH extract has led to the isolation
of eight new triterpene glycosides
identified as 16-oxo-28-hydroxyolean-12-ene 3-
O
-
β
-glucopyranosyl-(1''
→
6')-
β
-glucopyranoside
1
, 16
α
, 28-dihydroxyolean-12-ene 3
-
O
-
β
-[(6''-
O
-galloylglucopyranosyl-(1''
→
2')][
β
-glucopyranosyl-(1'''
→
6')]-
β
-glucopyranoside
2,
16
α
, 22
α
, 28-trihydroxyolean-12-ene 3-
O
-[
β
-glucopyranosyl-(1''
→
2')] [
α
-rhamnopyranosyl-
(1'''
→
6']-
β
-glucopyranoside
3
, 22
α
-acetyl-16
α
-hydroxyolean-12-en-28-al 3-
O
-[
α
-rhamnopyranosyl-
(1''''
6''')-
β
-glucopyranosyl-(1'''
3')] [
β
-glucopyranosyl-(1''
2')]-
β
-arabinopyranoside
4
,
22
α
-acetyl-16
α
,21
β
-dihydroxyoleanane-13
β
:28-olide 3-
O
-[
β
-glucopyranosyl-(1'''
→
6')]
[6''-
O
-coumaroylglucopyranosyl-(1''
→
2')]-
β
-glucopyranoside
5
, 16
α
,22
α
-diacetyl-21
β
-
angeloyloleanane-13
β
:28-olide 3
β
-
O
-[
β
-glucopyranosyl-(1''
→
2')][
β
-glucopyranosyl-
(1'''
→
4')]-
β
-glucopyranoside
6
, 16
α
, 22
α
, 28-trihydroxy -21
β
-angeloyloleanan-12-ene 3
β
-
O
-[
α
-rhamnopyranosyl-(1'''
→
6'')][
β
-glucopyranosyl -(1''
→
2')]-
β
-xylopyranoside
7
, 16
α
,
28-dihydroxy-22
α
-acetyl-21
β
-angeloylolean-12-ene 3-
O
-[
β
-galactopyranosyl-(1''
2')]
[
α
-rhamnopyranosyl-(1'''
4')]-
α
-arabinopyranoside
8
. Together with these were known
compounds quercetin, myricetin, quercetin 3-
O
-rhamnopyranoside, myricetin
3-
O
-
β
-glucopyranoside, gallic acid, sistosterol 3-
O
-
β
-glucopyranoside, rutin, myricetin
3-
O
-
α
-rhamnopyranosyl-(1''
3')-
β
-glucopyranoside and quercetin 3,7-
O
-
β
-diglucopyranoside.
Their structures were determined using spectros
copic methods as well as comparison with data
from known compounds. The
in vitro
antibacterial activity of aque
ous MeOH extract of the leaves
of
M. lanceolata
was also investigated and zone
s of inhibition ranging from 28
0.1 to 10
0.2 mm
were observed. The minimum inhibi
tory concentration (MIC) for
the extract ranged between 100
to 1000 μg/ml with the highest activity being observed with
Vibro cholerae
. Among the pure
isolates, compound
6
was the most active and its highest recorded MIC value was 62.5 μg/ml
URI
http://www.arkat-usa.org/get-file/37654/http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/36197
Publisher
Department of Chemistry