J. Sianturi et al. / Phytochemistry Letters 13 (2015) 297–301
299
ꢁ
1
(
1408 cm 1), and ether groups (1271 and 1110 cmꢁ1). The H NMR
with folding process on amino hidroxyocthylamino chain which
cuased by anisotropy effect (Vise et al., 2005; Ramkumar &
Ramakrishnan, 2008). The gross structure of straight chain with
spectrum of 1 showed the presence of a three overlap signal of
methyl groups, resonating at 2.16 (9H, s) as a singlet, nine
overlap signal of nitrogeneted methylene groups, resonating at
d
H
1
1
d
H
amino hidroxyocthylamino was deduced from the H- H-COSYand
HMBC spectra (Fig 2). The oxygenated methine signals, resonated
3
.49 to 3.60 ppm as doublet signals, five oxygenated methines
0
00
000
0000
0
00
000
0000
consist of four resonating at 3.65 (J = 3.6,11.0 Hz, H
2
-2 , 2 , 2 , 2
-2) as a triplet
signal. Additional functionalities included the signal of two ortho-
protons pattern resonated at 5.69 (1H, d, J = 8.4 Hz) and 8.01 (1H,
d, J = 8.4 Hz) was also obserbved in H NMR spectrum. The presence
of four oxygenated methines at 4.01 to 5.90 and oxygenated
methylene at 3.83 (J = 2.6, 9.8 Hz) and 3.73 (J = 3.3, 9.1 Hz), were
)
at
H
d 3.65 (4H, q, J = 5.2, 11.0 Hz, H-2 , H-2 , H-2 , H-2 ) was
as quinted signals and one at 4.14 (J = 4.5 Hz, H
2
correlated with nitrogenated methylene carbon signals at d
64.5 corresponding to C-2, C-1 , C-3 , C-1 ,C-3 , 1 , 3 , 1 , 3
C
0
0
00
00
000
000
0000
0000
,
d
H
indicated the presence of straight-chain amino hidroxyocthyla-
mino which bonded to hydroxyl group that formed by hydroxyl-
ation reaction.
The HMBC spectrum showing correlations of the overlap
methyl signal with their neighboring carbons, enabled the
assignment of the three singlet methyls. The methyl signals at
1
d
H
d
H
assigned to ribose unit which formed by autohydrolysis reaction of
the O-gycosyl saccharinic acid (Aspinal, 1976), suggesting the
presence of saccharide component in 1.
d
H
2.16 (H
at C-3 ( 38.7) and methine carbons at C-1 (
methylene signals at
to methine carbon signal at C-1 (
3
-4, H
3
-5, H
3
-6) were correlated to quarternary carbons
75.9), whereas the
) and 3.49 (H-2 ) was correlated
75.9), indicated the secondary
d
C
d
C
A total twenty seven carbon resonances were observed in the
1
3
d
H
3.60 (H-2
b
a
C NMR spectrum. These were assigned by DEPT and HMQC
experiments to two olefinic carbons at 102.7 and 142.8, one
quartenary carbon, two amide carbonyl at 166.3 and 152.0,
originating from lactam ring. The presences of four sp oxygenated
methines carbon, nine sp nitrogenated methylenes were assigned
to the presence of straight chain with amino hidroxyocthylamino
formed by asparagine reaction in 1, which continued by hydrolysis
reaction into aliphatic asparagine chain. In addition, four sp
oxygenated methines together with one sp oxygenated methylene
also observed in C NMR, suggested the presence of a ribose ring in
. These functionalities accounted for three out of the total five
degrees of unsaturation. The remaining two degrees of unsatura-
tion were consistent to bisamide aliphatic asparagine chain
derivative with a ribose and lactam ring.
A comparison of the NMR data of 1 with uridine (Jian et al.,
010), revealed that the structures of the two compounds are
closely related in both lactam and ribose ring and different in
aliphatic asparagine chain. Position of two amide carbonyl group at
C-1 and C-4 together with ribose unit were confirmed on basis
d
C
d
C
hydroxyl and nitrogenated methylene at C-1 and C-2, respectively.
d
C
1
1
3
Through analysis of the DEPT, H- H-COSY, HMQC and HMBC
spectra allowed the complete assignment of all protons and
carbons (Table 1). The present of amino hidroxyocthylamino chain
3
1
1
was shown in the H- H-COSY spectra (Fig. 2). The orientation of
3
0
00
000
0000
hydroxyl groups at H-2 , H-2 , H-2 , H-2 at
1
H
d 3.65 (J = 5.2,
b-orientation
3
1.0 Hz) and H-1 at 4.14 (J = 4.5 Hz) were assigned for
13
on the basis of coupling constant values. The presence of a ribose
moeity in compound 1 was confirmed by acid hydrolysis of 1
yielded a compound which was identified as ribose by comparison
of HPLC retention time with standard compound, therefore the
structure of 1 was established as new bisamide derivative and was
1
named eximiamide A.
D
2
Compound 2 was obtained as yellow oil. ½
aꢀ
ꢁ24.6 (c, 0.1,
2
0
MeOH), the molecular formula of 2 was established to be
ꢁ
C18H31N O from HR-TOFMS spectrum which showed a [M ꢁ H]
3 8
0000
00000
8 31 3 8
pseudo molecular ion peak m/z 416.4528 (calcd. for C1 H N O m/
1
1
of HMBC and H- H-COSY spectra (Fig. 2). The down field chemical
shift of C-1
which bonded with a nitrogen atom. The proton of H-1
z 417.4540) together with NMR data (Table 1), thus requiring five
degrees of unsaturation. UV spectrum showed absorption peak at
lmax nm (log e) 268 (5.23) suggesting the presence of an a,b-
unsaturation ketone group. The presences of hydroxyl, NH
0
00000
at
d
H
90.7 was assigned for oxygenated methine
0
00000
at (
142.8),
152.0), suggested the ribose ring was bonded in
d
H
0
0000
00000
5
.90, J = 4.5 Hz) was correlated to C-2
(d
C
102.7), C-3
(
d
C
0
0000
d
and C-4
(
C
asymmetric, amide carbonyl, NH bending, and ether groups in 2
0
00000
000000
lactam ring. The down field chemical shift of H-5
3.83 and 3.73, was correlated to C-3
6.4), and C-2
a
and H-5
71.4) and C-4
(d 75.9) through a long-range correlation,
b
at
were evidence by IR absorption at vmax 3409, 2935,1678,1411,1271,
0
00000
000000
d
d
8
H
(d
C
(
C
ꢁ1
1
13
1
110 cm , respectively. The H and C NMR spectrum of 2
0
00000
C
resembled that of 1 except for signal of straight-chain with amino
supported the presence of a ribose ring. The relative stereochem-
hidroxyocthylamino. The presence of nitrogenated methylene at
d
H
000000
istry of 1, was established by coupling constant of proton H-1
0
0
3
.50 and 3.54 corresponding to H-1
a
/H-3
a
and H-1
b
/H-3
b
,
0
00000
d
H
5.90, J = 4.5 Hz and comparison of the typical 13C
1,2
and H-2 at
NMR resonance of C-1
Jian et al., 2010), indicated that 1
conformation of axial-equatorial of H-1
field chemical shift of nitrogenated methylenes at
different to nitrogenated methylenes in aglaithioduline at
Saifah et al., 1999) due to effect of oxygenated methine which
respectively, together with an oxygenated methine at
d
H
4.14
0
00000
C
at d 90.7 and other related compounds
(
J = 5.2 Hz) identified that the straight-chain of compound 2 is
0
00000
(
to be S configuration and
0
straight-chain with amino hidroxyethylamino. The Proton of H-2
and H-3 at
0
00000
000000
and H-2 . The down
64.5 of 1
40.1
0
d
H
3.62 (J = 5.8,10.5 Hz) and H-1 at 4.14 (J = 5.2 Hz) were
d
C
assigned for
b-configuration. Therefore the chemical structure of 2
d
C
was established as new bismide derivative was named as an
eximiamide B.
(
bonded in straight chain with amino hidroxyocthylamino together
O
N
NH
NH
NH
NH
OH
OH
OH
OH
OH
OH
N
O
O
1
HMBC
COSY
OH
OH
Fig. 2. Selected HMBC correlations for 1.