Weakly anti-inflammatory limonoids from the seeds of xylocarpus rumphii

Article abstract of DOI:10.1021/np5003687

Seven new limonoids, namely, xylorumphiins E-J (1-2 and 4-7) and 2-hydroxyxylorumphiin F (3), along with three known derivatives (8-10), were isolated from the seeds of Xylocarpus rumphii. 2-Hydroxyxylorumphiin F (3) and xylorumphiin I (6) displayed moder

Full text of DOI:10.1021/np5003687

Article
pubs.acs.org/jnp
Weakly Anti-inflammatory Limonoids from the Seeds of Xylocarpus
rumphii
Chanin Sarigaputi,† Damrong Sommit,‡ Thapong Teerawatananond,§ and Khanitha Pudhom*,§
†Program in Biotechnology and §Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
‡Department of Chemistry, Faculty of Science, Mahanakorn University, Bangkok 10530, Thailand
S
* Supporting Information
ABSTRACT: Seven new limonoids, namely, xylorumphiins E−J (1−2 and 4−7) and 2-hydroxyxylorumphiin F (3), along with
three known derivatives (8−10), were isolated from the seeds of Xylocarpus rumphii. 2-Hydroxyxylorumphiin F (3) and
xylorumphiin I (6) displayed moderate inhibitory activity against nitric oxide production from lipopolysaccharide-activated
macrophages with IC50 values of 24.5 and 31.3 μM, respectively.
esearch on limonoids is of growing interest due to the
range of biological activities, such as insect antifeedant,
3), it was clear that six of the 12 indices of hydrogen deficiency
came from two carbon−carbon double bonds (furan ring) and
four ester carbonyl carbons. Therefore, it required six additional
rings in the structure of 1. The NMR data of 1 and its 2D
correlations (Figure 1) indicated the presence of four tertiary
methyls [δH 0.75 s, 1.04 s (×2), and 1.19 s; δC 21.0, 22.1, 22.2,
and 24.6], a typical β-substituted furan moiety [δH 6.39, 7.39,
and 7.54 s; δC 110.0, 121.0, 141.5, and 142.9], a
methoxycarbonyl (δH 3.70 s; δC 51.9 and 173.9), and two
isobutyryl groups [δH 1.04 br s (6H), 1.10 d (J = 6.8 Hz), 1.21
d (J = 6.8 Hz), 2.53 m, and 2.66 m; δC 17.5, 18.3, 19.1, 20.0,
33.3, 33.9, 174.9, and 177.0]. The aforementioned data strongly
suggested that 1 was a mexicanolide-type limonoid. The NMR
data of 1 were similar to those of xylorumphiin A,11 except for
the presence of a methine (δH 2.61 m; δC 57.1) in place of an
oxygenated carbon in xylorumphiin A. The methine function-
R
growth regulation, antibacterial, antifungal, antimalarial, anti-
cancer, and antiviral activities.1−3 The mangroves of the genus
Xylocarpus are known to produce a large number of limonoids,
particularly mexicanolides and phragmalins.4−8 In our continu-
ing search for new biologically active limonoids from the plants
in this genus, we have reported the isolation of a number of
limonoids from the seed kernels of all three species X.
granatum, X. moluccensis, and X. rumphii, collected from several
areas of the mangrove forests in Thailand.9−13 In this study, we
report the isolation and structural determination of six new
mexicanolides (1−6) and a new phragmalin (7), along with
three known limonoids, xyloccensins X, E, and K (8−10), from
the seeds of X. rumphii collected from Kudee Island, Thailand.
The structures of these compounds were established via
spectroscopic data or by comparison with literature data.9−14
Their anti-inflammatory activities were also evaluated via
suppression of nitric oxide (NO) production in activated
macrophages.
1
ality was assigned to C-2 by the H−1H COSY correlations
from its proton at δH 2.61 to H-3 and H-30 and by its HMBC
correlations to C-1, C-3, and C-30 (Figure 1a). The quaternary
carbon resonance at δC 106.7 was assigned to C-1, a hemiacetal
carbon, by its HMBC correlation with a proton resonance at δH
3.57 (1-OH) that did not show correlation with any carbon in
the HSQC spectrum. The HMBC correlations from H-3 [δH
5.09 d (J = 9.2 Hz)] and H-30 (δH 6.17 br s) to the carbonyl
RESULTS AND DISCUSSION
■
Xylorumphiin E (1), a white, amorphous powder, had the
molecular formula C35H48O11, as established by 13C NMR data
and an HRESIMS m/z 667.2996 [M + Na]+ ion (calcd
667.3089), corresponding to 12 indices of hydrogen deficiency.
Received: April 29, 2014
1
From the H and 13C NMR spectroscopic data (Tables 1 and
© XXXX American Chemical Society and
American Society of Pharmacognosy
A
dx.doi.org/10.1021/np5003687 | J. Nat. Prod. XXXX, XXX, XXX−XXX

Journal of Natural Products
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a
1
Table 1. H NMR Spectroscopic Data of 1−4
1
2
3
4
(mult., J in
(mult., J in
(mult., J in
(mult., J in
position
Hz)
Hz)
Hz)
Hz)
2
3
5
6
2.61, m
2.59, m
5.09, d (9.2)
2.59, m
5.11, d (9.6)
2.61, m
4.89, s
4.89, s
2.64, m
2.64, m
2.32, d (10.0) 2.33, d (9.6)
2.37, dd (9.6, 2.35, m
16.4)
2.28, br s
2.25, d (16.4) 2.27, br s
2.24, m
9
1.44, d (12.4) 1.42, m
1.51, m
1.48, dd (2.8,
12.8)
11
1.92, d (14.0) 1.92, dd (3.6, 1.89, m
13.2)
1.89, m
1.67, m
1.83, d (16.4) 1.83, d (16.4) 1.83, m
1.33, m 1.31, m 1.35, m
2.19, d (10.0) 2.19, d (9.6)
1.66, m
1.69, m
1.69, m
1.85, m
1.33, m
12
14
15
2.75, dd (9.2, 2.22, d (9.6)
19.6)
3.25, d (20.0) 3.26, d (20.0) 2.22, d (9.2)
3.15, d (20.0)
2.73, dd (10.0, 2.73, dd (9.6, 3.13, d (19.6) 2.74, dd (9.6,
20.0)
5.26, s
20.0)
5.25, s
1.05, s
1.04, s
7.53, s
6.39, s
7.39, s
0.75, s
1.19, s
6.17, br s
3.70, s
20.0)
5.18, s
1.05, s
1.12, s
7.53, s
6.39, s
7.40, s
0.73, s
1.25, s
6.24, d (5.2)
3.69, s
4.25, s
17
18
19
21
22
23
28
29
30
5.18, s
1.03, s
1.12, s
7.55, s
6.40, s
7.40, s
0.73, s
1.25, s
6.23, s
3.21, s
4.21, s
3.21, s
1.04, br s
1.04, br s
7.54, s
carbons (C-1′ and C-1″) of the isobutyryl groups confirmed
their location at C-3 and C-30, respectively. The relative
configuration of 1 was established by NOE interactions (Figure
1b). The NOESY spectrum showed close similarity to reported
NOE data of xylorumphiin A.11 The NOE cross-peaks observed
from H-3 to H-2 and H3-29 indicated an α-orientation of these
protons and hence a 3β-isobutyryl group, whereas the lack of an
interaction from H-3 to H-5 indicated a β-orientation of H-5.
The α-orientation of the 30-isobutyryl group was deduced by
the NOE cross-peak between H-5 and H-30, without the
interactions between H-3/H-30 and/or H-2/H-30. On the
basis of the above results, the structure of 1 was elucidated as
shown.
6.39, s
7.39, s
0.75, s
1.19, s
6.17, br s
7-OMe 3.70, s
1-OH
2-OH
3-Acyl
2′
3.57, s
2.53, m
2.65, m
2.61, m
2.35, m
3′
1.10, d (6.8)
1.11, d (6.8)
1.09, d (6.8)
1.41, m
1.65, m
4′
5′
30-Acyl
1.21, d (6.8)
1.21 d (6.8)
1.22, d (6.8)
0.90, t (7.6)
1.21, d (7.2)
Xylorumphiin F (2), a white, amorphous powder, gave a
molecular formula of C36H50O11 as determined by 13C NMR
data and an HRESIMS ion at m/z 657.3270 [M − H]− (calcd
657.3269). The MS and NMR data suggested the presence of
an additional −CH2− unit in 2 compared to xyrolumphiin E
(1).11 The NMR spectroscopic data of 2 (Tables 1 and 3) were
similar to those of 1 except for the replacement of an isobutyryl
group in 1 by a 2-methylbutyryl group at C-30. The existence
2″
3″
2.66, m
2.41, m
2.43, m
2.45, m
1.04, br s
1.66, m
1.67, m
1.28, m
1.42, m
1.28, m
1.67, m
4″
5″
1.04, br s
0.90, t (7.6)
1.20, d (7.2)
0.91, t (7.6)
1.08, d (6.4)
0.91, t (7.6)
1.08, d (7.2)
1
of the 2-methylbutyryl group was confirmed by H−1H COSY
a
Data were measured in CDCl3 at 400 MHz.
correlations between H3-5″/H-2″, H-2″/H2-3″, and H2-3″/H3-
4″. The HMBC correlation from H-30 (δH 6.17 br s) to the
carbonyl carbon (δC 174.9) of the 2-methylbutyryl group
defined its location at C-30. The absolute configuration at C-2″
in the 2-methylbutyryl group could be determined according to
the specific rotation of the corresponding acid derived from the
alkaline hydrolysis of 2 ([α]D −14.3 for (R)-2-methylbutyric
acid and [α]D +19.2 for (S)-2-methylbutyric acid).15,16
Although a 1:1 mixture with isobutanoic acid was obtained
from the hydrolysis, isobutanoic acid is optically active.
Therefore, the absolute configuration at C-2″ in the 2-
data and an HRESIMS m/z 697.3169 [M + Na]+ ion (calcd
1
697.3194). Its H and 13C NMR data (Tables 1 and 3) closely
resembled those of 2, except for the presence of an oxygenated
tertiary carbon (δC 82.1) instead of a methine group in 2. This
carbon was assigned to C-2 due to its HMBC correlation with
H-3 (δH 4.89 s). A proton resonance at δH 3.21 that did not
show correlation with any carbon in the HSQC spectrum was
assigned to 2-OH by its HMBC correlations to C-1, C-2, C-3,
and C-30 (Figure S1a). Similar NOE correlations suggested
that compound 3 possessed the same relative configuration as
those of 1 and 2. The key NOE cross-peak observed in 3 from
2-OH to H-3, along with the lack of correlation from 2-OH to
H-30, confirmed the α-orientation of 2-OH (Figure S1b). The
absolute configuration at C-2″ in the 2-methylbutyryl group
methylbutyryl group was assigned as S from the [α]20 value
D
of +10 (c 0.05, MeOH) of this mixture. Both compounds 1 and
2 shared the same relative configuration, as confirmed by
similar NOE correlations.
2-Hydroxyxylorumphiin F (3), a white, amorphous powder,
was assigned a molecular formula of C36H50O12 by 13C NMR
B
dx.doi.org/10.1021/np5003687 | J. Nat. Prod. XXXX, XXX, XXX−XXX

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1
and H-30 to the respective carbonyl carbon of the 2-
methylbutyryl groups placed these acyl groups at C-3 and C-
30. A proton at δH 4.25, which did not display correlation with
a carbon in the HSQC spectrum, was assigned to 1-OH; the
second 2-methylbutyryl group was thus assumed to be attached
at C-3. In order to clarify the full structure and establish the
relative configuration of 4, single-crystal X-ray diffraction
analysis was utilized. Thus, the 2-methylbutyryl groups at C-3
and C-30 were α-oriented (Figure 2). The absolute
configurations at C-2′ and C-2″ in the respective 2-
Table 2. H NMR Spectroscopic Data of 5−8
5
6
7
8
(mult., J in
(mult., J in
position (mult., J in Hz)
Hz)
(mult., J in Hz)
Hz)
2
3
5
4.85, s
4.83, s
5.11, s
4.80, s
2.61, m
2.66, d
(8.8)
2.99, d (10.0)
2.66, br d
(9.2)
6
2.36, dd (9.2,
16.4)
2.18, m
2.35, m
2.20, m
2.35, m
2.46, dd (10.0,
16.4)
2.36, m
methylbutyryl groups were determined as S due to the [α]20
2.25, d (16.4)
2.24 m
2.16, d
(15.2)
D
value of +15 (c 0.03, MeOH) of the corresponding acid
obtained from alkaline hydrolysis.
9
1.48, dd (2.4,
12.8)
2.21, d
(10.0)
Xylorumphiin H (5), a white, amorphous powder, had a
molecular formula of C33H44O12 as determined by 13C NMR
data and HRESIMS based on the molecular ion m/z 631.2781
[M − H]− (calcd 631.2749). The NMR spectroscopic data of 5
(Tables 2 and 3) were similar to those of xylorumphiin A,11
with the only difference being the presence of an acetyl rather
than an isobutyryl group at C-3. This deduction was validated
by the HMBC correlation from H-3 to the acetyl carbonyl (δC
171.3). The relative configuration of 5 was identical to that of
xylorumphiin A based on analysis of the NOESY data.
11
1.90, dd (3.2,
13.2)
2.06, m
2.34, m
1.69, m
1.81, m
2.04, m
1.40, m
1.67, m
1.80, m
2.05, m
1.39, m
12
1.83, m
1.51, m
1.33, m
1.20, m
14
15
2.21, d (9.2)
3.11, d (19.6)
2.09, d (2.4)
5.06, br s
6.01, s
6.07, s
2.74, d (9.2,
19.6)
17
18
19
21
22
23
28
29
5.21, s
1.05, s
1.12, s
7.55, s
6.39, s
7.40, s
0.72, s
1.24, s
4.92, s
1.22, s
1.14, s
7.48, s
6.41, s
7.41, s
0.78, s
1.30, s
5.58, s
4.91, s
1.21, s
1.14, s
7.48, s
6.41, s
7.41, s
0.79, s
1.31, s
1.05, s
Xylorumphiin I (6) was obtained as a white, amorphous
powder. It gave a molecular formula of C37H50O12 as
established by 13C NMR and an HRESIMS ion at m/z
685.3266 [M − H]− (calcd 685.3219). The NMR spectro-
scopic data of 6 (Tables 2 and 3) were similar to those of 4,
except for the presence of a Δ14,15 double bond (δH 6.01 s; δC
118.3 and 158.6). The location of the Δ14,15 double bond was
corroborated by HMBC correlations from H-15 to C-8 and C-
16 (Figure 3). The presence of two 2-methylbutyryl groups was
confirmed by 1H−1H COSY correlations. Their positions at C-
3 and C-30 were validated by the HMBC correlations from H-3
and H-30 to the respective 2-methylbutyryl carbonyls, C-1′ and
C-1″. The absolute configurations at C-2′ and C-2″ in the
respective 2-methylbutyryl groups were assigned as S from the
[α]20D value of +18 (c 0.05, MeOH) of the corresponding acid.
The similar NOE correlations suggested that compound 6
possessed the same relative configuration as those of 3−5.
Xylorumphiin J (7), a white solid, had the molecular formula
C35H42O15 as established by 13C NMR and HRESIMS (m/z
701.2471 [M − H]−, calcd 701.2440) data. Analysis of 1D and
2D NMR spectroscopic data revealed that 7 was a phragmalin
ortho ester. The existence of an ortho acetate group was
characterized by a methyl singlet at δH 1.73, showing an HMBC
correlation with a quaternary carbon at δC 119.4. This was
further supported by the presence of three oxygenated tertiary
carbons at δC 85.4, 85.1 and 86.8, assigned as C-1, C-8, and C-
9, respectively, by HMBC correlations of H-14/C-8, H-30/C-8,
H3-19/C-1, H3-19/C-9, and H2-29/C-1 (Figure 4a). These data
suggested that 7 was a phragmalin 1,8,9-ortho acetate. The
NMR data of 7 (Tables 2 and 3) were similar to those of
xyloccensin E,13 except for the presence of an oxygenated
methine (δH 5.06 br s; δC 64.2) instead of the C-15 methylene
group in xyloccensin E. HMBC cross-peaks from a hydroxy
proton at δH 3.12, which was not correlated with any carbon in
the HSQC spectrum, to C-14, C-15, and C-16 confirmed the
location of this hydroxy group at C-15. Similar NOE
correlations suggested that compound 7 possessed the same
relative configuration as xyloccensin E.13 The α-orientation of
H-15 was established by its NOE correlation with H-14 (Figure
4b).
1.16, s
7.56, s
6.48, s
7.42, s
0.89, s
1.98, d (11.2)
1.68, d (11.2)
6.32, s
30
32
6.19, s
5.61, s
5.58, s
1.73, s
7-OMe 3.70, s
3.69, s
4.52, s
3.90, s
3.68, s
3.68, s
4.66, s
4.13, s
1-OH
2-OH
15-OH
3-Acyl
2′
4.25, s
3.27, s
3.12, br s
2.26, s
2.07, 5
2.30, m
2.29, m
3′
1.66, m
1.65, m
1.40, m
1.40, m
4′
5′
0.90, t (7.2)
0.90, t (7.2)
1.14, d (6.8)
1.15, d
(7.2)
30-Acyl
2″
2.65, m
2.30, m
1.94, s
2.54, m
3″
1.09, d (6.4)
1.66, m
1.12, d (7.2)
1.40, m
4″
5″
1.11, d (6.4)
0.92, t (7.6)
1.15, d (6.8)
1.10, d
(7.2)
2-Acyl
2‴
2.16, s
a
Data were measured in CDCl3 at 400 MHz.
was determined as S, the same as that in 2, from the [α]20
value of +12 (c 0.05, MeOH) of the corresponding acid.
D
Xylorumphiin G (4) was obtained as colorless crystals. The
molecular formula C37H52O12 was assigned by 13C NMR and an
HRESIMS ion at m/z 687.3390 [M − H]− (calcd 687.3381).
The NMR data (Tables 1 and 3) indicated that 4 was similar to
3, except for the presence of a 2-methylbutyryl group in place
of the isobutyryl group in 3. The HMBC correlations from H-3
C
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Table 3. 13C NMR Spectroscopic Data of 1−8
position
1
2
3
4
5
6
7
8
1
106.7
57.1
73.4
38.1
40.5
32.5
173.9
82.4
64.4
43.7
19.6
35.9
36.3
46.6
29.0
169.9
77.1
21.0
22.2
121.0
141.5
110.0
142.9
24.6
22.1
75.9
106.6
57.1
73.5
38.0
40.4
32.5
173.9
82.3
63.4
43.7
19.6
35.9
36.3
46.6
29.0
170.0
77.1
22.2
21.0
121.0
141.5
110.0
143.0
22.1
24.6
75.8
107.2
82.1
80.3
38.9
40.3
32.3
173.9
81.1
63.3
42.6
19.7
35.8
36.3
46.5
29.0
169.6
77.2
22.2
21.0
120.8
141.6
109.9
143.1
24.2
22.0
76.7
107.2
82.1
80.3
38.9
40.4
32.3
173.8
81.1
63.3
42.6
19.7
35.9
36.3
46.5
29.1
169.5
77.0
22.1
21.0
120.9
141.5
109.3
143.1
24.2
22.0
75.6
107.1
82.2
80.5
38.7
40.3
32.3
173.9
81.0
63.3
42.6
19.7
35.9
36.2
46.4
29.0
169.5
77.1
22.2
21.0
120.8
141.6
110.0
143.0
23.8
21.9
75.6
108.4
80.9
85.4
86.0
81.1
46.2
35.5
33.3
172.6
85.1
86.8
45.8
25.5
28.8
36.2
53.0
64.2
174.2
78.8
19.2
16.7
120.5
141.0
109.6
143.2
14.6
40.1
69.8
119.4
20.9
52.0
108.5
81.0
2
3
82.4
82.6
4
38.7
38.7
5
40.3
40.3
6
31.9
31.9
7
173.7
80.4
173.7
80.4
8
9
51.5
51.5
10
11
12
13
14
15
16
17
18
19
20
21
22
23
28
29
30
31
32
7-OMe
3-Acyl
1′
42.2
42.3
15.1
15.1
25.1
25.0
38.9
38.9
158.6
118.3
163.1
81.2
158.5
118.4
163.1
81.3
19.6
19.6
20.6
42.3
119.9
141.3
109.9
142.9
24.5
120.0
141.3
109.9
142.9
24.5
21.7
21.7
75.4
75.4
51.9
51.9
52.0
51.9
51.9
51.9
51.9
177.0
33.3
18.3
20.0
177.2
33.9
18.3
20.0
177.6
33.9
18.2
20.2
177.1
40.5
16.8
25.3
11.2
171.3
21.3
176.7
40.9
26.1
11.4
16.2
170.0
21.0
176.8
41.0
26.1
11.4
16.1
2′
3′
4′
5′
30-Acyl
1″
2″
3″
4″
5″
2-Acyl
1‴
2‴
174.9
33.9
19.1
17.5
174.9
40.6
25.3
11.2
16.4
174.3
40.7
27.2
12.0
14.9
174.1
40.6
27.0
11.9
14.8
174.5
34.0
17.9
19.5
174.7
40.9
26.4
11.6
15.7
168.2
21.0
175.2
34.3
18.8
19.0
170.4
21.7
a
Data were measured in CDCl3 at 100 MHz.
Xyloccensin X (8) was obtained as colorless crystals, mp
EXPERIMENTAL SECTION
■
214−216 °C. Compound 8 was first reported in 2006 as a
General Experimental Procedures. Melting points were
determined on a Stuart Scientific melting point apparatus and are
uncorrected. Optical rotations were measured on a PerkinElmer 341
polarimeter at 20 °C. UV spectra were recorded on a Shimadzu UV-
160 UV−visible spectrometer. IR spectra were measured on a Nicolet
6700 FT-IR spectrophotometer. NMR spectra were acquired on a
Varian Mercury-400 Plus NMR spectrometer with TMS as internal
standard. HRESIMS was carried out on a micrOTOF-Q II ESI mass
spectrometer. Single-crystal X-ray diffraction analysis was performed
on an Oxford Gemini S Ultra diffractometer.
mixture with xyloccensin Y.17 In the current study, the H and
1
13C NMR data for compound 8 (Tables 2 and 3) were assigned
unambiguously.
All isolated compounds were evaluated for their anti-
inflammatory activities by monitoring the inhibition of LPS-
induced NO production in J774.A1 macrophages. Only 2-
hydroxyxylorumphiin F (3) and xylorumphiin J (6) exhibited
moderate anti-inflammatory activities, with IC50 values of 24.5
and 31.3 μM, respectively, while the remaining compounds did
not show any significant effects at a dose of 50 μM.
Plant Material. The fruits of X. rumphii were collected in February
2011 from Kudee Island, Thailand, and authenticated by the Royal
Forest Department, Bangkok, Thailand. A voucher specimen (BKF
D
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Article
Figure 1. (a) Selected HMBC and COSY correlations of 1. (b) Diagnostic NOE correlations of 1.
No. 1638) was deposited at the Forest Herbarium, Royal Forest
Department, Bangkok, Thailand.
Extraction and Isolation. The air-dried, powdered seeds of X.
rumphii (5 kg) were extracted three times with MeOH (10 L, each for
3 days) at room temperature. The extract was concentrated under
reduced pressure. The combined MeOH extract was partitioned
between EtOAc and H2O to obtain the EtOAc crude extract (107 g).
The EtOAc extract was fractionated over a column of silica gel with a
gradient of EtOAc−n-hexane (from 1:9 to 1:0) to give 14 fractions,
A−N. Fraction G (7.84 g) was subjected to passage over a column of
Sephadex LH20 (MeOH) to afford four fractions (G1−G4), and
fraction G2 (376.31 mg) was rechromatographed over silica gel eluting
with an EtOAc−n-hexane gradient (from 3:7 to 1:1) to yield seven
subfractions (G2a−G2g). Fraction G2a (47.9 mg) was purified by
silica gel CC (EtOAc−n-hexane, from 2:3 to 1:1) to give 4 (4.3 mg).
Fraction G2e (74.6 mg) was chromatographed over a silica gel column
with MeOH−CH2Cl2 (2:98), and the major fraction (G2e.4) was
rechromatographed with EtOAc−n-hexane (from 3:7 to 1:1) to obtain
compounds 6 (7.7 mg) and 8 (19.3 mg). Fraction G2f (22.0 mg) was
purified by CC over silica gel with EtOAc−n-hexane (2:3) to give
compounds 1 (2.9 mg) and 3 (11.3 mg). Using the same procedure,
fraction G2g (19.7 mg) yielded compound 2 (11.2 mg). Fraction J was
recrystallized from MeOH to give xyloccensin E (9, 178.8 mg).
Fraction K (3.44 g) was subjected to a column of Sephadex LH-20
with MeOH to afford six fractions, K1−K6. Fraction K2 (115.6 mg)
was further purified by silica gel CC eluted with MeOH−CH2Cl2
(4:96) to yield compounds 5 (7.6 mg) and 7 (9.9 mg). Fraction K4
was recrystallized from MeOH to afford xyloccensin K (10, 85.3 mg).
Xylorumphiin E (1): white, amorphous powder; [α]20D −13 (c 0.03,
MeOH); UV (MeOH) λmax (log ε) 209 (3.24) nm; IR (neat) νmax
3370 (br), 2974, 2933, 2878, 1715, 1453, 1377, 1295, 1264, 1195,
Figure 2. ORTEP drawing of 4.
Figure 3. Selected HMBC and COSY correlations of 6.
Figure 4. (a) Selected HMBC and COSY correlations of 7. (b) Diagnostic NOE correlations of 7.
E
dx.doi.org/10.1021/np5003687 | J. Nat. Prod. XXXX, XXX, XXX−XXX

Journal of Natural Products
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1
1143, 1061 cm−1; H and 13C NMR spectroscopic data (see Tables 1
and then activated with 1 μg/mL of LPS for 20 h. Indomethacin (IC50
= 28.56 μM) was used as a positive control. The culture supernatant
(50 μL) of each well was collected, and the concentration of NO was
further measured by using Griess reagent. The absorbance was
measured at 540 nm with a microplate reader. The nitrite level in the
samples was calculated from the standard curve created from known
concentrations of sodium nitrite.
and 3); HRESIMS m/z 667.2996 [M + Na]+ (calcd for C35H48O11Na,
667.3089).
Xylorumphiin F (2): white, amorphous powder; [α]20 +18 (c 0.1,
D
MeOH); UV (MeOH) λmax (log ε) 208 (3.50) nm; IR (neat) νmax
3424 (br), 2970, 2928, 2863, 1726, 1461, 1383, 1302, 1189, 1140,
1059 cm−1; 1H and 13C NMR spectroscopic data (see Tables 1 and 3);
HRESIMS m/z 657.3270 [M − H]− (calcd for C36H49O11, 657.3269).
2-Hydroxyxylorumphiin F (3): white, amorphous powder; [α]20
ASSOCIATED CONTENT
* Supporting Information
D
■
−19 (c 0.1, MeOH); UV (MeOH) λmax (log ε) 209 (3.61) nm; IR
S
(neat) νmax 3404, 2970, 2934, 2876, 1720, 1454, 1379, 1392, 1227,
1D and 2D NMR spectra of compounds 1−7 and CIF file for
compound 4. These materials are available free of charge via the
Internet at http://pubs.acs.org.
1
1143, 1062 cm−1; H and 13C NMR spectroscopic data (see Tables 1
and 3); HRESIMS m/z 697.3169 [M + Na]+ (calcd for C36H50O12Na,
697.3194).
Xylorumphiin G (4): colorless crystals (MeOH); mp 162−164 °C;
[α]20D −68 (c 0.1, MeOH); UV (MeOH) λmax (log ε) 208 (3.51) nm;
IR (neat) νmax 3410 (br), 2967, 2924, 2883, 1720, 1457, 1377, 1292,
AUTHOR INFORMATION
Corresponding Author
*Tel: +66-2-2187641. E-mail: khanitha.p@chula.ac.th.
Notes
■
1
1189, 1147, 1066 cm−1; H and 13C NMR spectroscopic data (see
Tables 1 and 3); HRESIMS m/z 687.3390 [M − H]− (calcd for
C37H51O12, 687.3381).
Xylorumphiin H (5): white, amorphous powder; [α]20 +12 (c 0.1,
The authors declare no competing financial interest.
D
MeOH); UV (MeOH) λmax (log ε) 210 (3.64) nm; IR (neat) νmax
3440 (br), 2967, 2931, 2883, 1717, 1461, 1370, 1260, 1224, 1137,
1014 cm−1; 1H and 13C NMR spectroscopic data (see Tables 2 and 3);
HRESIMS m/z 631.2781 [M − H]− (calcd for C33H43O12, 631.2749).
ACKNOWLEDGMENTS
■
The authors are grateful for the financial support from Thailand
Research Fund and Chulalongkorn University through the
Royal Golden Jubilee Ph.D. Program (PHD/0009/2553) and
the 90th Anniversary of Chulalongkorn University Fund
(Ratchadaphiseksomphot Endownment Fund). This research
has also been partially supported by the Ratchadaphiseksom-
phot Endowment Fund of Chulalongkorn University
(RES560530208-AS).
Xylorumphiin I (6): white, amorphous powder; [α]20 +4 (c 0.1,
D
MeOH); UV (MeOH) λmax (log ε) 209 (4.16) nm; IR (neat) νmax
3375 (br), 2973, 2934, 2876, 1720, 1461, 1377, 1289, 1260, 1143,
1062 cm−1; 1H and 13C NMR spectroscopic data (see Tables 2 and 3);
HRESIMS m/z 685.3266 [M − H]− (calcd for C37H49O12, 685.3319).
Xylorumphiin J (7): white solid; decomposed at 238 °C; [α]20D −7
(c 0.1, MeOH); UV (MeOH) λmax (log ε) 210 (3.64) nm; IR (neat)
νmax 3492, 2957, 2924, 2850, 1730, 1460, 1428, 1370, 1311, 1240,
1088 cm−1; 1H and 13C NMR spectroscopic data (see Tables 2 and 3);
HRESIMS m/z 701.2471 [M − H]− (calcd for C35H41O15, 701.2440).
X-ray Crystallographic Analysis of 4. The single-crystal X-ray
diffraction data were collected at 296 K on a Bruker APEX-II CCD
diffractometer with Mo Kα radiation (λ = 0.710 73 Å). The crystal
structure was solved by direct methods using SHELXS-9718 and
refined with full-matrix least-squares on all F2 data using SHELXS-97
to final R values.19 All non-hydrogen atoms were anisotropically
refined, except for the oxygen C-3A atom, which was refined
isotropically. The C-3A atom is disordered over two positions with
site occupancies of 0.52 and 0.48. All hydrogen atoms were added at
calculated positions and refined using a rigid model, with C−H = 0.93
Å (aromatic), 0.97 Å (CH2), and 0.98 Å (CH3) and O−H = 0.82 Å.
Crystallographic data for 4 have been deposited with the Cambridge
Crystallographic Data Centre under the deposition number CCDC
998571.
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D
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dx.doi.org/10.1021/np5003687 | J. Nat. Prod. XXXX, XXX, XXX−XXX