0
121
V[ Anjaneyulu et al[:Phytochemistry 49 "0888# 0118Ð0125
−
0
−0
tiary hydroxyl group[ Therefore\ compound B is a
ketohydroxy derivative of a saturated pentacyclic tri!
terpenoid\ probably of ursane or taraxastane skeleton[
cm # besides a broad band at 0634 cm for ester car!
0
bonyl in its IR spectrum[ A close examination of its H
NMR spectrum revealed that it might be a mixture of
at least two compounds[ The presence of cyclopropane
methylene protons at d 9[24\ 9[44 and 9[66 as three doub!
lets indicated that it might be a mixture of 2!oxo "d 9[44
and 9[66# and 2!acetoxy "d 9[24 and 9[44# derivatives
of cycloartane skeleton[ It is further con_rmed by the
observation of two vinyl methyls "d 0[71 and 0[74#\ two
ole_nic protons "d 5[54 "t# and 5[69 "d## and three acetoxy
methyls "d 1[94\ 1[09 and 1[00#[ Further the C NMR
spectrum of compound C acetate displayed 2!acetoxy
carbonyl signals "d 060[0\ 069[8 and 069[1#\ two carboxyl
carbon resonances at d 061[4 and 069[4 and one carbonyl
carbon resonance "d 105[5#[ Hence it was concluded that
compound C acetate is a mixture of ketol monoacetate
and diol diacetate of cycloart!13!en!15!oic acid[
The C NMR data of compound C acetate was com!
pared with those of mangiferonic acid "09# and 2a\11"R
or S#!dihydroxy cycloart!13!en!15!oic acid "00# "Anjane!
yulu et al[\ 0878# in Table 1[ One set of carbon resonances
are in close agreement with those of known 00[ The other
set of carbon resonances of the nucleus were identical
with those of 09 and those of the side chain di}er from
both those of 09 and 00[ Hence the second component of
compound C may be a new keto hydroxy carboxylic acid[
The position of the acetoxyl group in the side chain of
the second component of compound C acetate is deduced
as being at C!12 by the multiplicity of one of the ole_nic
0
The methyl pattern in H NMR of compound B indicated
that it might be a taraxastane derivative[ The mass spec!
trum of compound B showed no molecular ion but the
¦
heaviest fragment is at m:z 313 "M !07# which cor!
responds to the loss of a molecule of water from the
molecular ion[ The prominent mass fragment ions of
saturated pentacyclic triterpenes "Budzikiewicz\ Wilson\
02
+
Djerassi\ 0852# at m:z 194 due to the cleavage of ring
C indicates the carbonyl group in ring A:B and 078 con!
taining the ring D:E with the loss of a molecule of water[
¦
The base mass fragment ion at m:z 260 ðM !C H OŁ "4#
3
6
and its formation can be explained by onium cleavage
Anjaneyulu et al[\ 0874#[ This fragment locates the ter!
"
tiary hydroxyl in ring E at C!08 or C!19[ However\ the
presence of Retro!Diel|s!Alder fragment ion at m:z 71 in
its mass spectrum _xes the hydroxyl at C!19 of ring E of
the taraxastane skeleton[ Based on the above spectral
data\ the structure 2!oxo!taraxastane!19"R or S#!ol "5# is
assigned to compound B[
02
Dehydration of compound B with thionyl chloride
gave colourless needles\ m[p[ 064Ð065>C identi_ed as c!
taraxastenone "6# by direct comparison with an authentic
sample "Anjaneyulu + Row\ 0854#[ On reduction with
LAH it a}orded a diol\ m[p[ 169Ð163>C\ characterised as
c!taraxastane!2b\ 19!diol "7# by direct comparison with
an authentic sample "Anjaneyulu et al[\ 0874# and also
0
0
from H NMR spectrum[ Bhattacharya et al[ "Hinge\
protons as doublet at d 5[69 in its H NMR spectrum[ The
Paknikar\ Das\ Bose\ + Bhattacharya\ 0855# reported the
isolation of epi!c!taraxastanonol\ m[p[ 146Ð148>C\ ðaŁD
side chain carbon resonances of the second constituent of
compound C acetate are assigned by placing the acetoxyl
group at C!12 and taking substitution e}ects into con!
sideration[ Hence it is concluded that compound C is a
mixture of a known 00 and a new 2!oxo!12"R or S#!
hydroxycycloart!13!en!15!oic acid "01#[
¦14[2> from Indian black dammar resin[ Careful com!
parison of physical constants and spectral data of com!
pound B and the reported ketol "00# revealed that these
two were identical\ the only di}erence being that the
tertiary hydroxyl groups at C!19 were epimeric[ Hence
compound B is a new compound and named as c!tar!
axastanonol "5#[ The carbon resonances of compound
B were assigned in Table 0 by comparing the carbon
resonances with those of taraxasterol "Amarendra\
Compound D\ m[p[ 168Ð170>C analysed for C H O [
2
9
37
3
Its IR spectrum showed absorption bands for hydroxyl
−
0
"2599 cm #\ a\b!unsaturated carboxyl "2299Ð1499\ 0584
−
0
−0
cm # and conjugated double bond "0539 cm #[ Its
absorption at 106 nm in the UV region con_rmed that
0
Mukhopadhyay\
+
Mitra\ 0870# and taraxarone
it is an a\b!unsaturated carboxylic acid[ The H NMR
"Sakurai\ Yaguchi\ + Inoue\ 0876# and also taking C!19
spectrum of compound D exhibited characteristic ABq
"d 9[24 and 9[44# for cyclopropane methylene protons[ A
vinyl methyl at d 0[75 as singlet\ _ve methyls at d 9[79\
9[74 and 9[84 and an ole_nic proton as doublet at d 5[59[
It also showed an axial hydroxy methine proton at d
2[19 as a multiplet and another hydroxy methine proton
hydroxy substitution e}ects into consideration[
The isolation of 5b!hydroxy stigmast!3!en!2!one "8#
and 13!methylenecycloartane!2b\15!diol "2# are reported
for the _rst time from the stem!bark of M[ indica and its
0
2
C NMR data presented for the _rst time in Table 0[
Compound C has been isolated as semisolid and
02
buried under the DMSO peak[ The C NMR spectrum
2
resisted crystallisation from several solvent systems[
Attempts to separate the mixture into its constituents by
column chromatography were unsuccessful[ Therefore\ it
was acetylated with acetic anhydrideÐpyridine at room
temperature for 13 h[ Compound C acetate showed a
showed two sp resonances at d 67[9 "d# and d 55[4 "d#
which con_rmed the presence of two secondary hydroxyls
in the molecule[ Based on the above data\ it was deduced
that compound D is a dihydroxy derivative of cycloart!
13!en!15!oic acid[
−0
ketonic carbonyl "0694 cm #\ a\b!unsaturated acid car!
The mass spectrum of compound D showed no molec!
−
0
¦
bonyl "0589 cm # and a conjugated double bond "0539
ular ion\ but the fragment ion at m:z 343 "M !H O#
1