Koelpinin-A, B and C - Three triterpenoids from Koelpinia linearis

Article abstract of DOI:10.1016/S0031-9422(99)00490-2

Three new triterpenoids, designated as koelpinin - A, B and C and characterised as 28-nor-lup-12,17-dien-3β,16α-diol,3β-acetoxy-28-nor-lup- 12,17-dien-16α-ol and 28-nor-lup-12,17-dien-3β-ol-16-one, respectively, together with 30-nor-lup-3β-ol-20-one, taraxeryl acetate and germanicol, were isolated, from the aerial parts of Koelpinia linearis. ¹³C-NMR shifts were assigned after performing APT and DEPT experiments. (C) 2000 Elsevier Science Ltd.

Full text of DOI:10.1016/S0031-9422(99)00490-2

Phytochemistry 53 (2000) 305±309
www.elsevier.com/locate/phytochem
Koelpinin-A, B and C Ð three triterpenoids from Koelpinia
linearis
a
a,c,
a
a,c
b
b
Summon Koul , T.K. Razdan *, C.S. Andotra , A.K. Kalla , S. Koul , S.C. Taneja ,
b
K.L. Dhar
a
Department of Chemistry, University of Jammu, Ambedkar Road, Jammu 180 004, India
b
Regional Research Laboratory, Canal Road, Jammu 180 002, India
c
University of Kashmir, Hazratbal, Srinagar 190 006, India
Received 1 June 1999; accepted 9 September 1999
Abstract
Three new triterpenoids, designated as koelpinin - A, B and C and characterised as 28-nor-lup-12,17-dien-3b,16a-diol,3b-
acetoxy-28-nor-lup-12,17-dien-16a-ol and 28-nor-lup-12,17-dien-3b-ol-16-one, respectively, together with 30-nor-lup-3b-ol-20-one,
taraxeryl acetate and germanicol, were isolated, from the aerial parts of Koelpinia linearis. C-NMR shifts were assigned after
1
3
performing APT and DEPT experiments. # 2000 Elsevier Science Ltd. All rights reserved.
Keywords: Koelpinia linearis; Compositae; Nor-triterpenoids; Koelpinin-A, B and C; 30-nor-lup-3b-ol-20-one; Taraxerylacetate; Germanicol
1
1. Introduction
turated triterpenoids. The H-NMR (Table 1) of com-
+
pounds 1±3; M at m/z 426.6240, C H O ; 468.7105,
29
46
2
Koelpinia linearis (Compositae) is reported to elabor-
C H O and 424.5043, C H O , respectively;
31 48 3 29 44 2
ate lupeol esters (Razdan, Qurishi & Khuroo, 1990;
Razdan, Kachroo, Qurishi, Kalla & Waight, 1996) and
a stigmastadienol derivative (Shah, Qurishi, Koul &
Dhar, 1996). Herein, we report the isolation and
characterisation of three new 28-nor-lup-12,17-dienes,
designated as koelpinin-A, 1; -B, 2 and -C, 3, together
with 30-nor-lup-3b-ol-20-one, 4 (Thompson & Bowers,
accounted for ®ve tertiary and two secondary geminal
methyls ꢀnmax 1370, 1380 cm� ), d 0:94 (6H, d, J ˆ 4:6
Hz, H-29, H-30); characteristic of lupanes (Williams,
1
Bhacca & Djerassi, 1963); a trisubstituted double bond
� 1
ꢀ
nmax 3020, 1645, 820 cm ), d 6:49±6:64 (1H, t,
J ˆ 11:3, 3.8 Hz, H-12), which was shown to be in het-
eroannular conjugation; l ꢀnm† 238, 244 (in¯); 239,
max
1965), taraxeryl acetate, 5 (Hui & Li, 1976) and germa-
2
50 (in¯) and 308 (Williams & Fleming, 1988), respect-
nicol, 6 (Yamada, Nakamura, Goto & Hirata, 1965).
None of these compounds has been reported, so far,
from the genus Koelpinia.
ively; and a carbinylic proton, d 3:63, 4.49 and 3.63
1H each, dd, J ˆ 7:6, 4 Hz, H-3, Hui & Moon, 1977),
respectively. The two extra vinylic carbon singlets at
(
13
dC 152:6±158:7, in their C-NMR con®rmed the tetra-
substituted nature of the second double bond.
The HRMS of 1±3 exihibited the typical RDA-frag-
mentation of the ring C to give the respective ion radicals
at m/z 208, 250 and 208 (A/B rings) and 218, 218 and 216
2
. Results and discussion
The compounds 1±6 responded positively to LB, TCA
Bhargava & Sheshadari, 1973) and TNM tests for unsa-
(D/E rings). The base peak ion at m/z 189 resulted from
the loss of H O or HOAc from the prominent RDA-
A/B ring ions at m/z 207 and 249. This fragmentation
(
2
12
*
Corresponding author.
is characteristic of D -pentacyclic triterpenoids
0031-9422/00/$ - see front matter # 2000 Elsevier Science Ltd. All rights reserved.
PII: S0031-9422(99)00490-2

3
06
S. Koul et al. / Phytochemistry 53 (2000) 305±309
Table 1
1
3
H-NMR shifts (CDCl )
H
1
2
3
4
7
8
9
10
H-2 (m)
H-3 (dd, J = 7.6, 4 Hz)
±
±
±
±
±
±
±
±
4.48 (J = 9, 6.5 Hz)
3.63
2.40
6.49
±
4.49
2.40
6.49
±
3.63
2.46
6.64
2.66
±
3.20
±
4.49
2.35
6.54
±
4.48
2.46
6.64
2.66
±
±
2.40 (submerged)
6.23 (dd, J = 11.3, 3.8 Hz)
1/2
H-11 (dd, W = 8.4, 6 Hz)
H-12 (t, J = 11.3, 3.8 Hz)
H-15 (d, J = 9.2 Hz)
H-16 (s )
±
±
±
±
2.68
±
±
4.60
2.24
0.84
0.80
0.97
1.02
1.24
±
±
±
±
±
H-19 (m )
H-23 (s )
2.24
0.85
0.78
0.98
1.00
1.28
±
2.24
0.84
0.80
0.95
0.99
1.36
±
±
2.26
0.85
0.78
0.98
1.01
1.23
±
2.24
0.85
0.78
0.98
1.01
1.30
±
2.20
0.90
0.85
0.80
0.99
1.33
±
±
0.80
0.84
0.88
1.02
0.97
0.95
2.15
±
0.80
0.86
0.88
1.03
0.97
0.78
2.15
±
H-24 (s )
H-25 (s )
H-26 (s )
H-27 (s )
H-28 (s )
H-29 (d, J = 4.6 Hz)
H-30 (d, J = 4.6 Hz)
OAc-3b
0.95
0.95
±
0.94
0.94
2.01
±
0.94
0.94
±
0.94
0.94
2.01
2.20
0.94
0.94
2.01
±
0.93
0.93
±
±
±
OAc-16a
±
±
±
±
±
(
Budzikiewicz, Wilson & Djerassi, 1963) and placed an
Table 2
13
3
C-NMR chemical shifts (CDCl )
oxygen function and the tetrasubstituted double bond
in D/E rings and the second oxygen function (OH or
OAc) in A/B rings, at the usual C-3 position. The
dC
1
2
3
4
7
8
9
lupane skeleton, in 1±3, was forti®ed by the facile loss
1
2
3
4
5
6
7
8
9
38.7 38.5
25.6 23.8
77.5 80.4
38.2 40.7
55.1 48.6
18.4 18.2
34.2 32.3
41.2 39.9
50.7 48.5
36.3 38.5
31.9 32.2
38.1 39.2 38.9 38.4 39.6
25.4 25.2 23.6 23.8 34.2
77.4 76.3 80.8 80.5 217.1
38.6 38.4 40.5 40.2 47.5
55.0 55.2 55.4 55.3 55.9
18.3 18.1 18.5 18.5 19.6
34.2 34.2 32.3 32.6 34.0
41.5 41.1 39.4 41.3 41.3
50.7 50.1 48.2 38.3 48.9
36.0 36.3 38.7 38.2 39.8
31.5 22.6 32.2 31.9 32.7
Á
+
of C H from (M -H O), (M -HOAc) and RDA-D/E
+
3
7
2
ring fragment ions (Thompson & Bowers, 1965). The
presence of seven methyls only, their chemical shifts
and heteroannular conjugation besides MS placed the
tetrasubstituted double bond at C-17 (18). Thus 1±3
were derived from 28-nor-lup-12,17-diene and carried a
hydroxyl or acetoxyl at C-3b equatorial position.
1
1
1
0
1
2
The compounds 1 and 2 displayed a down®eld car-
binylic proton resonance signal at d 4:60 (1H, s). 2
resisted acetylation with Ac O±C H N, at room tem-
128.6 128.5
149.2 149.3
45.4 45.5
28.3 28.6
78.2 78.2
154.3 154.5
152.6 152.6
47.5 47.5
28.0 28.0
30.6 30.6
48.9 48.8
28.2 27.3
15.6 15.2
16.7 17.1
18.9 18.9
20.3 20.5
130.9 28.7 129.1 131.4 131.6
151.8 37.5 149.6 151.9 151.7
51.4 43.6 49.3 51.2 51.8
33.5 27.4 26.9 33.2 33.3
219.5 35.5 82.3 218.9 219.1
158.7 42.9 152.9 157.9 157.8
155.5 48.2 154.8 155.8 155.7
48.2 47.9 47.7 48.3 48.6
28.2 207.3 29.2 28.4 28.3
31.2 31.0 31.6 31.2 31.4
48.3 40.1 46.2 48.3 48.3
28.2 28.5 27.4 28.3 28.1
15.6 15.4 15.8 15.5 15.5
16.7 16.2 17.3 16.5 16.5
19.2 15.9 18.6 19.1 19.2
23.8 14.5 20.9 23.8 23.6
13
2
5
5
1
4
perature, but 1 formed monoacetate which was identi-
1
15
cal (mp, cotlc, H-NMR) to 2. However, on heating
+
with Ac O±C H N both formed a diacetate 7, M at
1
1
6
7
2
5
5
�
1
m/z 510.6398, C H O , nmax 1730, 1740 cm , d 2:01,
18
19
3
3
50
4
2.20 (3H each). On Sarett oxidation 2 readily gave the
acetoxy ketone 8; M at m/z 466.6160, C H O ,
+
2
0
3
1
46
3
1
21
dC 218:9 (C1O), 170.2, 21.3 (OAc) whose H-NMR
displayed a doublet at d 2:66 (2H, J ˆ 9:5 Hz, H-15).
The chemical shift and multiplicity of the down®eld
carbinylic proton, the resistance to acetylation and the
ease of oxidation of 2 (Schreiber & Eschemnoser,
2
2
2
3
24
25
2
2
2
2
6
7
8
9
1955; Grinner, 1960; Fried & Edwards, 1972; Razdan,
Kachroo, Harkar & Koul, 1982) placed the hydroxyl
at C-16 a axial position in 1 and 2.
±
±
±
18.4
16.8 23.5 16.4 16.5 16.5
±
±
±
16.9 16.8
17.8 17.8
30
OAc (3b)
17.6
±
±
±
±
±
17.8 17.4 17.5
±
±
±
±
170.0 (C1O)
21.2 (CH )
3
±
±
±
±
170.4 170.2
21.3 21.3
±
±
±
±
On treatment with Ac O±C H N, at room tempera-
ture, 3 formed a monoacetate which was identical to 8.
2
5
5
+
On Sarett oxidation, it gave a diketone 9; M at m/z
OAc (16a)
±
±
172.2
22.5
±
±
4
22.5924, C H O , d 2:40 (2H, m, H-2), 2.68 (2H, d,
2
9
42
2

S. Koul et al. / Phytochemistry 53 (2000) 305±309
307
J ˆ 9:2, H-15); identical (mmp., cotlc) to the diketone
prepared similarly from 1.
The compounds 1±3 were thus characterised as 28-
nor-lup-12,17-dien-3b,16a-diol; 3b-acetoxy-28-nor-lup-
1
one, respectively. The C-NMR shifts (Table 2) have
2,17-dien-16a-ol and 28-nor-lup-12,17-dien-3b -ol-16-
13
been assigned by known techniques (Levy & Nelson,
1
972; Cheung & Williams, 1969; Dantanarayan,
Kumar, Muthukuda & Wazeer, 1982; Stothers, 1972;
Wenkert, Baddeley, Bur®tt & Moreno, 1978), includ-
ing APT and DEPT (908) methods.
3
. Experimental
Mps are uncorr., ‰aŠD was measured in CHCl ; IR
3
1
on KBr discs, UV in MeOH, H-NMR at 250 and 90
MHz, MS at 70 eV and C-NMR, APT and DEPT
908) on Brucker instrument.
13
(
3
.1. Isolation of 1±6
The hot MeOH extract of aerial parts of Koelpinia
linearis was defatted with Pet. ether (bp 40±608C) and
the residue was dissolved in EtOAc, ®ltered and ®lte-
rate subjected to CC over silica get after concentration.
The column was developed with C H ±EtOAc (19:1),
6
6
to give fraction A, and (9:1) to give fraction B. The
fraction A, contained three components (TLC, silica
gel G, C H ±EtOAc±MeOH: 15:4:1 from which 2, 3
6
6
and 4 were recovered by rechromatrography followed
by disc chromatography on silica gel G, using C H ±
6
6
EtOAc±CHCl (14:4:3). The fraction B on disc-chro-
3
matography (C H ±EtOAc±MeOH, 12:4:3) gave 1, 5,
6
6
6
. The compounds were puri®ed by recrystalisation.
3
.1.1. Koelpinin-A, 1
Mp 235±2378C (MeOH±C H ), ‰aŠ + 21.2 C (0.2),
2
D
5
6
6
+
M
4
3
at m/z 426.6240 (calculated for C H O ,
29 46 2
�
1
26.5207), UV: lmax ꢀnm† 238, 244 (in¯). IR: n
cm
480 (br, OH), 3020, 1645, 840 (±CH1C), 1370, 1380
max
1
(d, ±CMe ), 1240, 1160. H-NMR (CDCL ): Table 1.
2 3
MS: m/z at 426 (M , 408 (M -H O), 375 (M -H O-
+
+
+
2
2
C H ), 335, 218 (RDA-D/E rings), 208 (RDA-A/B
3
7
rings), 207, 189 (100%), 175, 135, 121, 109, 95, 83, 44.
3
.1.2. Koelpinin-B, 2
Mp 222±2238C (C H±MeOH), ‰aŠ + 13.88 C
2
D
5
+
0.04), M at m/z 468.7105 (calculated for C H O ,
31 48 3
(
�
1
4
3
68.4790). UV: lmax ꢀnm† 239, 250 (in¯). IR: n
cm
460 (OH, br ), 3010, 1730 (OAc), 1645, 1370, 1380
max
1
(d), 1250, 1160, 1020, 880. H-NMR (CDCl ): Table 1.
3
MS: m/z at 468 (M ), 408 (M -HOAc), 355 (M -
+
+
+
HOAc-C H ), 315, 250 (RDA-A/B rings), 249, 218
3
7
(
5
RDA-D/E rings), 189 (100%) 175, 135, 121, 109, 95,
9, 44.

3
08
S. Koul et al. / Phytochemistry 53 (2000) 305±309
+
+
3
.1.3. Koelpinin-C, 3
Mp 208±2098C (C H ±MeOH), ‰aŠ + 6.5 C (0.01),
Table 1. MS: m/z at 428 (M ), 413 (M -CH ), 410
3
2
D
5
+
+
(M -H O), 395 (M -H O-CH CO), 207, 189 (100%).
2 2 3
6
6
+
M
at m/z 424.5043 (calculated for C H O
44
On acetylation with C H N±Ac O at room tempera-
5 5 2
ture (overnight) it gave colourless needles of 10, mp
+
276±2778C (MeOH±CHCl ) M at m/z 470.3627 (cal-
culated for C H O , 470.3647) IR: n
1722 (OAc), 1705 (C1O), 1245, 870. H-NMR
(CDCl ): Table 1. MS: m/z at 470 (M ), 410 (M -
29
2
�
1
4
24.3341). UV: lmax 308 nm. IR: nmax cm 3440 (OH),
3
010, 1705 (C1O), 1650, 1370, 1380, 1250, 1020, 870.
3
1
+
H-NMR (CDCl ): Table 1. MS: m/z at 422 (M ), 404
� 1
cm 3200,
3
31 50
3
max
+
M -H O), 361, 216 (RDA-D/E rings), 208 (RDA-A/
+
1
(
B rings), 207 (RDA-A/B ), 189 (100%) 173, 133, 123,
2
+
+
3
119, 95, 44.
HOAc), 395, 231, 207, 189, (100%), 157, 133, 105, 95,
9
4, 44.
3.2. Acetylation of 1, 2, 3
1
, 2 and 3 in C H N (2 ml) were treated with Ac O
5 5 2
3
.3.2. Taraxeryl acetate, 5
Mp 301±3028C (C H ±EtOAc), lit. (Hui & Li, 1976)
(
3 ml) and left overnight, at room temperature After
usual work up 1 formed monoacetate identical with 2;
did not undergo any change. The compound 3 gave
monoacetate 8, mp 189±1908C, M at m/z 466.6160
calculated for C H O , 466.2401). UV: lmax 307 nm.
6
6
+
04±2058, M m/z 468.3310 (calculated for C H O
3
4
3
2
52
2
2
68.3381). IR: nmax cm 1720, 1638, 1243, 815. 1H-
�
1
+
NMR (CDCl ): d 0:82 (3H, s, H-28), 0.86 (3H, s, H-
2
H-26), 0.95 (6H, s, H.30), 1.07 (3H, s, H-27), 2.04 (3H, s,
3
(
3
1
46
3
5), 0.88 (3H, s, H-23), 0.90 (3H, s, H-24), 0.91 (3H, s,
�
1
IR: nmax cm
3050, 1730, 1650, 1370, 1360, 1250,
020, 870. H-NMR: Table 1. MS: m/z at 466, 406
1
1
(
(
OCOCH ), 4.46 (1H, dd, J ˆ 11:6, 6.5 Hz, H-3) 5.53
+
3
M -HOAc), 363, 323, 295, 250, 249, 216, 189
100%), 173, 133, 105, 81, 44.
The compound 2 and monoacetate of 1 were heated
+
1H, dd, J ˆ 8:3, 3.7 Hz, H-15). MS: m/z at 468 (M ),
(
+
53, 408 (M -HOAc), 344, 329, 284, 269, 204 (100%).
4
On acetylation with C H N±Ac O, at room tempera-
5
5
2
with C H N and Ac O, on a water bath for 6 h. After
5
5
2
ture (overnight), colourless compound, 11, mp 278±
2
3
usual work up colourless crystals of 7, mp 216±2178C,
�
cm
max
1
798C (MeOH±CHCl ) was recovered. IR: n
+
3
M
5
at m/z 510.6398 (calculated for C H O ;
33 50 4
1
030, 1375, 1640, 1258, 868. H-NMR (CDCl ): d 0:73
3
10.7406) were recovered UV: lmax 247, 250 (in¯.) nm.
IR: nmax cm
1380, 1370, 1245, 870. H-NMR (CDCl ): Table 1.
MS: m/z at 510 (M ), 450, (M -HOAc), 407 (M -
HOAc-C H ), 367, 260 (RDA, D/E rings), 250, 249,
7
(
0
2
3H, s, H-23), 0.84 (3H, s, H-28), 0.85 (3H, s, H-25),
.91 (3H, s, H-24), 0.93 (3H, s, H-26), 0.96 (3H, s, H-
9), 1.02 (3H, s, H-30), 1.08 (3H, s, H-27), 2.05 (3H, s,
�
1
3010, 1730, 1740 (2 Â AOC), 1645,
1
3
+
+
+
Á
OCOCH ) 4.49 (1H, dd, J ˆ 11:5, 6.2 Hz, H-3), 4.86
3
3
+
+
1H, s, H-19). MS: m/z at 468, 453 (M -CH ), 408
(
(
3
(
5
RDA-A /B rings), 217, 189 (100%), 177, 135, 109,
9, 44.
+
M -HOAc), 231, 218, 207, 204, 189 (100%).
3.3. Sarett oxidation of 1, 2 and 3
3
.3.3. Germanicol, 6
Mp 175±1768C (MeOH±CHCl ), lit. (Yamada et al.,
1, 2 and 3 in CHCl were stirred with freshly pre-
pared CrO ±C H N complex at room temperature for
3
3
+
1965) 176±1778, M at m/z 426.3926 (calculated for
3
5
5
2
D
5
2
and crystalised from petrol±MeOH. 1 and 3 gave iden-
h. After usual work up the products were recovered
C H O, 426.3936), ‰aŠ + 6.0 (C.O. 40). IR: nmax
30
�
50
1
cm 3600, 3030, 2940, 2850, 1630, 1450, 1360, 1040,
+
1
tical diketone 9, mp 185±1868C, M at m/z 422.5924
855 H-NMR (CDCl ): d 0:75 (3H, s, H-23), 0.77 (3H, s,
3
(
calculated for C H O , 422.4730). UV: l
310, 260
H-25), 0.88 (3H, s, H-24), 0.95 (6H, s, H-28), 0.98 (3H, s,
H-28), 1.03 (3H, s, H-29), 1.08 (3H, s, H-30), 3.96 (1H,
dd, J ˆ 11:5, 6.2 Hz, H-3), 4.86 (1H, s, H-19), MS: m/z at
2
9
42
2
1
max
�
(
1
in¯.) nm. IR: nmax cm 3015, 1705, 1695, 1640, 1370,
1
360, 1045, 890. H-NMR (CDCl ): Table 1. MS: 422
3
Á
+
+
M ), 407 (M -CH ), 394 (M -CH -CO ), 379, 216
+
+
+
+
(
(
1
426 (M ), 411 (M -Me), 408, (M -H O), 231, 218,
3
3
2
RDA-D/E), 206 (RDA-A/B) 205 (100%), 190, 173,
62, 133, 113, 105, 95, 94, 44. The compound 2 formed
189, 77.
1
a monoketone, mp 189±1908C, which had UV, IR, H-
NMR and MS similar to 8. Its identity was con®rmed
by Co-TLC and mmp.
Acknowledgements
We are thankful to Prof. B.L. Kalsotra, Ex-H.O.D.
Chemistry, and Prof. Rajive Gupta, H.O.D.
Chemistry, University of Jammu, for providing Lab.
facilities. We remain indebted to Prof. E.S. Waight,
Imperial College of Science and Technology, London,
for recording NMR, APT and DEPT spectral data.
3
.3.1. 30-nor-lupan-3b-ol-20-one, 4
Mp 238±2398C, lit. (Thompson & Bowers, 1965)
25
+
2
37±2398C ‰aŠ � 10.2 (C.O. 30), M at m/z 428.4996
D
�
1
(
calculated for C H O 428. 3581). IR: nmax cm
2
9
48
2
1
3
457, 3200, 1687 (C10), 1037, 870. H-NMR (CDCl ):
3

S. Koul et al. / Phytochemistry 53 (2000) 305±309
309
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