Cytotoxic Pregnane Steroidal Glycosides from Chonemorpha megacalyx

Article abstract of DOI:10.1021/acs.jnatprod.9b00013

Three new C₂₁ pregnane steroids, chonemorphols A-C (1, 3, and 4), 11 new C₂₁ steroidal glycosides, chonemorphosides A-K (2 and 5-14), and 11 known compounds (15-25) were obtained from the vines and leaves of Chonemorpha megacalyx Pierre. Their structures were established using extensive spectroscopic data. The X-ray crystallographic data of 1 and 3 permitted definition of their absolute configurations. Notably, 1 and 2 possessed an uncommon 6/5/6/5/5-fused steroidal ring system. Compound 7 displayed significant cytotoxicity against several cancer cell lines with IC₅₀ values of 2.0-3.6 μM.

Full text of DOI:10.1021/acs.jnatprod.9b00013

Article
Cite This: J. Nat. Prod. XXXX, XXX, XXX−XXX
pubs.acs.org/jnp
Cytotoxic Pregnane Steroidal Glycosides from Chonemorpha
megacalyx
Fang-Yu Yuan, Xiao-Ling Wang, Tian Wang, Tao Shen, Dongmei Ren,† Hongxiang Lou,†
†
‡
†
†
,
†
and Xiao-Ning Wang*
†Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical
Sciences, Shandong University, 44 West Wen-Hua Road, Jinan 250012, People’s Republic of China
‡
The Second Hospital of Shandong University, 247 Bei-Yuan Street, Jinan 250033, People’s Republic of China
*
S Supporting Information
ABSTRACT: Three new C21 pregnane steroids, chonemor-
phols A−C (1, 3, and 4), 11 new C21 steroidal glycosides,
chonemorphosides A−K (2 and 5−14), and 11 known
compounds (15−25) were obtained from the vines and leaves
of Chonemorpha megacalyx Pierre. Their structures were
established using extensive spectroscopic data. The X-ray
crystallographic data of 1 and 3 permitted definition of their
absolute configurations. Notably, 1 and 2 possessed an
uncommon 6/5/6/5/5-fused steroidal ring system. Com-
pound 7 displayed significant cytotoxicity against several
cancer cell lines with IC50 values of 2.0−3.6 μM.
−
1
1
regnane glycosides are C21 steroidal glycosides that are
(1735 cm ) groups. The H NMR data (Table 2) displayed
P
widely distributed and have been studied extensively in
signals for two methyls [δ 1.05 (s), and 1.35 (d, J = 6.3 Hz)],
H
1
−4
the plant kingdom, especially in the family Apocynaceae.
A
two oxymethines [δ 3.75 (m) and 4.52 (q, J = 6.4 Hz)], one
H
number of studies have demonstrated that they exhibit various
exchangeable proton [δ 5.69 (s)], and a formyl proton [δ
H
H
5,6
7,8
13
kinds of bioactivities such as antiproliferative, antifungal,
9.87 (s)]. The C NMR data (Table 1) contained signals for a
formyl and ester carbonyl groups, a tetrasubstituted double
2
9
anti-inflammatory, antidepressant, and other biological
activities.
consisting of large evergreen woody vines with milky sap
from South and Southeast Asia, the Philippines, and South
China. Among the 20 species worldwide, eight are endemic to
1
0,11
3
3
Chonemorpha (Apocynaceae) is a genus
bond, two methyls, seven sp methylenes, five sp methines, an
3
oxygenated tertiary carbon at δ 82.3, and two sp quaternary
C
carbons. The aforementioned data indicated a C21 steroidal
skeleton. Three spin systems, H -1/H -2/H-3/H -4, H-8/H-
2
2
2
1
2
China,
mainly distributed in the Yunnan, Guangxi,
9/H -11/H -12, and H -15/H -16/H-17/H-20/H -21, were
2 2 2 2 3
1
1
Guangdong, and Hainan provinces. The roots and vines of
C. megacalyx and C. valvata are widely used in Traditional
Chinese Medicine for the treatment of rheumatic diseases,
fracture, and traumatic hemorrhage. However, no phyto-
chemical study on C. megacalyx has been previously reported.
In an ongoing search for potential anticancer agents, the
ethanol extract of the vines and leaves of C. megacalyx was
found to be active against the proliferation/survival of cancer
cells. Further fractionation and separation led to three new C21
steroids (1, 3, and 4), 11 new C21 steroidal glycosides (2 and
established by the H− H COSY spectrum (Figure 1). The
HMBC correlations (Figure 1) of H -19/C-1, C-5, C-9, and C-
3
10; H -4/C-5; and H-6 (δ 9.87)/C-5 (δ 176.5), C-7 (δ
2
H
C
C
12
137.1), and C-8 established the A/B ring system and
confirmed ring B as a cyclopentene ring with C-6 being a
5
(7)
formyl group conjugated with the Δ
double bond. The
HMBC correlations of OH-14/C-8, C-13, C-14, and C-15; H -
2
12/C-13; and H-17/C-13 established the C/D ring system
with an oxygenated tertiary carbon at C-14. The downfield
shift of C-18 (δ 178.8) and C-20 (δ 83.4) and the HMBC
C
C
5
−14), and 11 known ones (Supporting Information).
correlations of H -12/C-18; H-20/C-18; and H -21/C-17 and
2
3
Reported herein are the isolation, structural elucidation, and
cytotoxicity assessment of these compounds.
C-20 led to the determination of an 18,20-lactone ring fused
with the D-ring at C-13 and C-17. Thus, compound 1 was
defined as a C21 steroid featuring a contracted B-ring and a γ-
lactone E-ring.
RESULTS AND DISCUSSION
■
The NOE crosspeaks of H-8/H -19 and OH-14 and OH-
4/H-20 suggested that these protons were cofacial and β-
3
Chonemorphol A (1), colorless needle crystals (MeOH), had
the molecular formula C H O , with eight indices of
1
2
1
28
5
1
3
hydrogen deficiency according to the HRESIMS and
C
NMR data. Its IR spectrum showed absorption bands due to
hydroxy (3500 and 3351 cm ) and α,β-unsaturated formyl
Received: January 5, 2019
−
1
©
XXXX American Chemical Society and
American Society of Pharmacognosy
A
DOI: 10.1021/acs.jnatprod.9b00013
J. Nat. Prod. XXXX, XXX, XXX−XXX

Journal of Natural Products
Article
The HMBC correlations from H-6 (δ 5.36), H-7α (δ 2.29),
H
H
H-9 (δ 1.48), and H-15α (δ 2.05) to the carbon signal at δ
H
H
C
7
4.8 indicated that this hydroxy-bearing tertiary carbon was
located at C-8. The NOESY correlations of OH-8/H -19 and
3
H-20 indicated a β-orientation for OH-8. Configurations at the
remaining stereocenters were determined to be the same as the
known compound based on the NOESY spectrum. The
structure, including the absolute configuration of (3S, 8S, 9R,
1
0R, 13S, 14R, 17S, 20R) of 3 was confirmed by a single-crystal
X-ray diffraction experiment [Flack parameter at 0.19(12)]
Figure 4). Therefore, the structure of compound 3 was
(
defined as 3β,8β,14β-trihydroxypregn-5-ene-18,20R-lactone.
Chonemorphol C (4) had the molecular formula C H O
4
2
1
32
+
based on the HRESIMS data [M + Na] at m/z 371.2196
calcd 371.2193). The 1D NMR data indicated that the
structure of 4 was similar to the known compound 3β,14β-
(
14,15
5(6)
dihydroxypregn-5-ene-18,20-lactone,
double bond was replaced by a methine and a methylene (δC
4.3 and 28.2). This was supported by the HMBC correlation
except that the Δ
4
1
1
of H -19 (δ 0.85)/C-5 and H− H COSY correlations of H-5
(
3
H
δ 1.09)/H -6 (δ 1.30 and 1.37) (Figures S29 and S30,
H 2 H
Supporting Information). The NOESY correlations of H-5/H-
indicated an α-orientation for H-5. The configurations at the
9
other carbons were determined to be the same as the known
compound by the NOESY spectrum. Therefore, the structure
of compound 4 was identified as 3β,14β-dihydroxypregn-
1
8,20R-lactone.
Chonemorphoside B (5) had a molecular formula of
+
C H O as deduced by the HRESIMS ([M + Na] at m/z
2
7
36
7
4
2
95.2356, calcd 495.2353). Comparing its NMR (Tables 1 and
4
) and IR data with those of ecdysoside A indicated that they
oriented, whereas NOE cross-peaks of H-3/H-1α; H-9/H-1α
1
shared the same aglycone but different sugar moiety. The H
NMR data of 5 exhibited a resonance for an anomeric proton
at δ 4.96 (dd, J = 10.0, 2.0 Hz), indicating the presence of a
sugar unit with a β-glycosidic linkage. Further analysis of the
2D NMR spectra enabled identification of the sugar unit as a
2,6-dideoxy saccharide, and acid hydrolysis of 5 afforded D-
and H-15α; and H-17/H -21 assigned these protons as α-
3
oriented (Figure 2). The (3S, 8S, 9S, 10R, 13S, 14S, 17S, 20R)
absolute configuration of 1 was confirmed by single crystal X-
ray crystallographic analysis [Flack parameter 0.08(18)]
H
(Figure 3). Therefore, the structure of compound 1 was
defined as (3S,14S)-dihydroxy-6-oxo-5(6→7)abeo-pregn-5(7)-
ene-18,20R-lactone.
2
0
D
13,16
digitoxose ([α]
+48)
as identified by comparison with a
Chonemorphoside A (2) had the molecular formula
C H O based on the HRESIMS data at m/z 527.2617 [M
standard sample. Therefore, the structure of compound 5 was
defined as 3β-hydroxy-16-oxo-pregn-5,14-diene-18,20R-lac-
tone 3-O-β-D-digitoxopyranoside.
2
8
40
8
+
+
Na] (calcd 527.2615). The NMR data (Tables 1 and 2)
resembled those of 1, except for the resonances of seven
The NMR spectroscopic data of 5−7 indicated the presence
additional carbon signals (δ 98.4, 80.6, 75.4, 71.7, 56.4, 35.5,
of the common aglycone, 3β-hydroxy-16-oxo-pregn-5,14-
C
4
and 17.9), which indicated the presence of a 2,6-dideoxy-3-O-
methyl sugar moiety. The anomeric carbon resonance at δC
diene-18,20R-lactone, core. Chonemorphoside C (6) had
the molecular formula C34H O10 based on the HRESIMS [M
48
+
9
2
8.4 and corresponding proton signal at δ 4.63 (dd, J = 9.6,
.1 Hz) indicated a sugar unit with a β-glycosidic linkage.
+ Na] ion at m/z 639.3143 (calcd 639.3140). The sugar
moieties in 6 were established to be canaropyranose and
cymaropyranose by analyzing the H NMR and H− H COSY
spectra of the purified products following acid hydrolysis. The
absolute configurations of the two monosaccharides were both
H
13
1
1
1
Hydrolysis of 2 afforded D-cymarose as the sugar component,
the structure of which was confirmed by comparing its specific
rotation ([α]
2
0
13
1
= +47) and H NMR data with reported
D
2
0
D
data. In addition, the β-D-cymaropyranosyl moiety was located
inferred as D, due to their specific rotation values ([α]
+20
16,17
at C-3 by the HMBC correlations from H-3 (δ 3.75) to C-1′
and +48, respectively).
The sugar sequence of cymaropyr-
H
(
δ
98.4) and from H-1′ (δ 4.63) to C-3 (δC 77.0).
anosyl-(1→4)-canaropyranoside and its linkage at C-3 were
ascertained by HMBC correlations of H-1′ (δ 4.61)/C-3 (δ
C
H
Therefore, the structure of 2 was identified as (3S,14S)-
dihydroxy-6-oxo-5(6→7)abeo-pregn-5(7)-ene-18,20R-lactone
H
C
77.6) and H-1″ (δ 4.66)/C-4′ (δ 88.5). Both β-glycosidic
H
C
3
-O-β-D-cymaropyranoside.
linkages were established from coupling constants of the
Chonemorphol B (3) was obtained as colorless, flaky
anomeric protons at δ 4.61 (dd, J = 9.8, 1.8 Hz) and 4.66 (dd,
H
crystals (MeOH) with the molecular formula C H O
J = 9.8, 2.0 Hz) (Table 3). Thus, compound 6 was
characterized as 3β-hydroxy-16-oxo-pregn-5,14-diene-18,20R-
lactone3-O-β-D-cymaropyranosyl-(1→4)-β-D-canaropyrano-
side.
2
1
30
5
deduced from the HRESIMS and NMR data (Tables 1 and
). The spectroscopic data of 3 closely matched those of the
known compound 3β,14β,20-trihydroxypregn-5-en-18,20-lac-
2
1
4,15
tone,
with minor differences being attributable to a
Chonemorphoside D (7) had the molecular formula of
+
downfield shift of one carbon signal from δ 38.9 to δ 74.8.
C H O based on the HRESIMS data [M + Na] at m/z
C
C
35 50 10
B
DOI: 10.1021/acs.jnatprod.9b00013
J. Nat. Prod. XXXX, XXX, XXX−XXX

Journal of Natural Products
Article
Table 1. 13C NMR Spectroscopic Data for Compounds 1−14
a
a
a
a
a
a
a
a
a
b
a
a
a
a
position
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
36.3
31.2
70.7
34.0
176.5
188.9
137.1
52.4
54.1
47.1
21.5
34.8
59.9
82.3
34.9
26.7
56.4
178.8
15.6
83.4
21.3
36.4
29.2
77.0
31.2
176.4
188.7
137.1
52.3
54.1
47.3
21.3
34.8
59.9
82.2
34.9
26.8
56.3
178.7
15.5
83.4
21.5
98.4
35.5
80.6
75.4
71.7
17.9
56.4
37.1
31.0
71.8
42.1
138.9
118.0
32.7
74.8
46.7
38.4
18.2
33.5
61.0
84.8
36.8
25.8
56.5
181.7
18.6
84.8
21.0
37.3
31.4
71.2
34.0
44.3
28.2
27.3
42.6
49.2
35.8
21.1
38.0
59.7
85.5
34.3
26.1
56.3
178.6
12.3
83.4
21.4
37.9
29.4
77.4
37.2
140.5
119.7
29.1
33.8
49.7
38.6
20.0
35.5
54.6
183.8
126.5
205.4
60.9
174.3
19.2
75.8
23.9
95.6
38.2
68.3
73.0
69.2
18.2
37.2
29.4
77.6
38.6
140.5
119.8
29.1
33.8
49.7
37.9
20.0
35.5
54.6
183.7
126.5
205.4
60.9
174.3
19.2
75.7
23.9
97.7
38.7
69.7
88.5
70.4
17.8
36.1
28.7
76.5
36.9
139.5
118.7
28.0
32.8
48.7
37.7
18.9
34.5
53.5
182.7
125.5
204.4
59.9
173.3
18.2
74.7
22.9
95.0
34.7
76.0
81.8
67.4
17.2
57.1
100.4
34.3
79.6
74.4
70.5
17.0
55.3
37.2
29.3
76.7
34.2
44.0
27.7
29.6
37.5
53.7
36.6
20.4
36.2
54.7
184.8
125.4
205.6
61.0
174.6
12.1
75.8
24.0
95.3
38.3
68.3
73.0
69.2
18.2
36.6
29.3
76.9
34.2
44.0
27.7
29.6
37.5
53.7
37.1
20.4
36.2
54.7
184.8
125.4
205.6
61.0
174.6
12.1
75.8
24.0
95.4
37.2
66.3
82.6
68.0
18.3
36.8
29.1
77.0
34.1
43.7
27.6
29.3
37.4
53.5
36.2
20.1
35.5
54.8
185.1
124.8
206.6
60.5
175.2
11.0
76.1
22.5
95.7
35.3
77.1
82.5
68.5
17.0
57.1
101.4
36.0
80.2
75.6
71.9
17.1
56.0
36.8
29.5
76.1
34.4
43.6
27.8
29.6
37.5
53.1
36.5
20.4
35.1
54.6
184.1
125.7
205.9
60.2
175.0
12.2
76.1
23.9
97.1
37.1
80.5
75.6
72.0
18.6
56.9
37.5
29.5
77.6
38.6
140.0
120.7
26.7
39.1
45.7
37.4
20.7
33.5
59.6
85.5
34.7
26.0
56.1
178.5
19.4
83.2
21.5
95.9
35.5
77.0
82.5
68.5
18.2
57.9
99.4
33.7
72.4
77.4
70.7
18.3
57.2
37.4
29.4
77.6
38.6
140.0
120.7
26.7
39.1
45.8
37.4
20.7
33.5
59.6
85.5
34.7
26.0
56.2
178.5
19.4
83.2
21.5
95.7
37.1
66.3
82.6
68.0
18.3
37.4
29.5
77.5
38.6
140.0
120.7
26.7
39.1
45.7
37.4
20.7
33.5
59.7
85.5
34.7
26.0
56.2
178.5
19.4
83.2
21.5
95.8
35.5
77.0
82.5
68.5
18.2
58.2
99.7
35.5
76.8
82.6
68.3
18.3
57.9
101.5
35.3
80.6
75.4
71.5
18.0
56.3
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
1
2
3
4
5
6
3
1
2
3
4
5
6
3
1
2
3
4
5
6
3
0
1
2
3
4
5
6
7
8
9
0
1
′
′
′
′
′
′
′-OCH3
″
″
″
″
″
″
″-OCH3
‴
‴
‴
‴
‴
‴
99.1
33.6
77.2
72.2
71.3
18.0
57.4
98.0
33.7
77.3
72.3
71.0
18.2
57.4
98.0
33.8
77.3
72.3
71.0
18.2
57.4
‴-OCH3
a
b
Data were measured in CDCl at 150 MHz. Data were measured in methanol-d at 150 MHz.
3
4
6
53.3300. Cymarose and an oleandrose moieties were
NMR spectroscopic data of 8 (Tables 1 and 3) were closely
5
(6)
determined by analysis of the NMR data in combination
with acid hydrolysis. Both of the sugar units were established
to be D-configured by comparison of the specific rotation
comparable to those of 5, except that the Δ
double bond
1
1
was hydrogenated, which was confirmed by the H− H COSY
correlations of H-5 (δH 1.13)/H-6β (δH 1.94) and HMBC
correlations of H -19 (δ 0.96)/C-5 (δ 44.0) and H -1/C-5
2
0
values ([α]
+48 and −12, respectively) with those
D
3
H
C
2
1
6
reported. The sugar sequence oleandropyranosyl-(1→4)-
cymaropyranoside and its linkage at C-3 were established by
HMBC correlations of H-1′ (δ 4.80)/C-3 (δ 76.5) and H-1″
(Figures S61 and S62, Supporting Information). Compound 8
also shared the same saccharide moiety as 5 by comparison of
the NMR spectroscopic data (Tables 1−3). Therefore, the
structure of 8 was assigned as 3β-hydroxy-16-oxo-pregn-14-
ene-18,20R-lactone 3-O-β-D-digitoxopyranoside.
H
C
(δ
4.43)/C-4′ (δ 81.8). The coupling constants of the
H
C
anomeric protons at δ 4.80 (dd, J = 9.6, 1.9 Hz) and 4.43 (dd,
H
J = 9.7, 1.9 Hz) indicated the anomeric β-configurations for
these two sugars. Therefore, the structure of 7 was defined as
The NMR data indicated that compounds 9−11 shared the
common 3β-hydroxy-16-oxo-pregn-14-ene-18,20R-lactone
aglycone moiety with 8. The molecular formula of
chonemorphoside F (9) was determined as C H O by
3
β-hydroxy-16-oxo-pregn-5,14-diene-18,20R-lactone 3-O-β-D-
oleandropyranosyl-(1→4)-β-D-cymaropyranoside.
3
4
50 10
Chonemorphoside E (8) had a molecular formula of
the HRESIMS ([M + Na]+ ion at m/z 641.3292, calcd
+
C H O (m/z 475.2686 [M + H] , calcd 475.2686). The
641.3296). According to the large coupling constants of the
2
7
38
7
C
DOI: 10.1021/acs.jnatprod.9b00013
J. Nat. Prod. XXXX, XXX, XXX−XXX

Journal of Natural Products
Article
1
a
Table 2. H NMR Spectroscopic Data for Compounds 1−5
position
1
2
3
4
5
1
α
β
α
β
1.29, m
1.97, m
1.98, m
1.74, m
3.75, m
3.43, m
2.24, m
1.29, m
1.96, m
2.11, m
1.79, m
3.75, m
3.43, m
2.26, m
1.10, td (13.4, 3.6)
1.88, m
1.84, m
1.61, m
3.54, m
0.97, m
1.78, m
1.81, m
1.42, m
3.58, m
1.63, m
2.24, m
1.09, m
1.37, m
1.30, m
1.97, m
1.07, m
1.85, td (12.0, 3.9)
0.83, td (11.7, 3.0)
1.52, m
1.89, m
1.30, m
1.13, td (13.5, 3.6)
1.93, dt (13.2, 3.4)
1.97, dt (12.4, 3.3)
1.63, m
3.59, dd (9.5, 2.9)
2.40, m
1
2
2
3
4
4
5
6
6
7
7
8
9
1
1
1
1
1
1
1
1
1
1
1
2
2
1
2
2
3
4
5
6
3
α
β
2.34, m, 2H
2.27, m
α
β
α
β
9.87, s
9.87, s
5.36, m
5.42, m
2.29, m
2.11, m
3.52, d (3.1) (−OH)
1.48, dd (13.4, 3.4)
1.60, m
2.23, m
1.40, dd (13.9, 3.7)
2.05, m
2.09, m
2.29, m
2.94, tdd (10.0, 5.0, 1.5)
1.29, m
1.73, m
2.41, m
2.46, m
1.68, m
3.16, dd (12.3, 4.0)
1.32, m
1.48, m
2.07, m
1.58, m
2.08, m
5.69, s
1.96, m
1.31, m
2.00, m
1.91, m
2.16, td (7.7, 4.1)
1.05, s, 3H
4.52, dq (6.9, 6.4)
1.35, d (6.3), 3H
3.16, m
1.32, m
1.47, m
2.06, m
1.30, m
1.96, m
5.67, s
1.96, m
1.30, m
2.00, m
1.91, m
2.16, m
1α
1β
2α
2β
4-OH
5α
5β
6α
6β
7
9
0
1
′
′α
′β
1.37, m
2.05, m
1.95, m
2.07, m
1.87, m
1.80, m
1.98, m
2.05, m
1.78, m
5.88, d (1.9)
2.21, m
2.15, m
2.53, d (2.6)
1.16, s, 3H
4.70, qd (6.5, 2.8)
1.53, d (6.5), 3H
4.96, dd (10.0, 2.0)
2.10, m
1.04, s, 3H
1.19, s, 3H
4.49, dq (7.0, 6.4)
1.39, d (6.4), 3H
0.85, s, 3H
4.37, dq (6.8, 6.2)
1.34, d (6.3), 3H
4.51, dq (6.9, 6.4)
1.35, d (6.4), 3H
4.63, dd (9.6, 2.1)
2.33, dq (12.3, 2.0)
1.51, m
3.21, m
3.18, dd (8.8, 2.4)
3.32, m
1.76, m
′
′
′
′
4.14, q (3.0)
3.34, dd (9.5, 2.7)
3.74, m
1.34, d (6.1), 3H
3.40, s, 3H
1.30, d (6.3), 3H
′-OCH3
a
Data were measured in CDCl at 600 MHz.
3
1
1
Figure 1. Selected HMBC (H → C) and H− H COSY (H−H)
correlations of 1, 3, and 9.
anomeric protons at δ 4.95 (dd, J = 9.7, 2.0 Hz) and 4.74 (dd,
H
Figure 2. Selected NOESY correlations (H↔H) of 1 and 3.
J = 9.8, 1.8 Hz), β-orientations were deduced for them. The
absolute configuration of these two sugars were assigned after
acid hydrolysis of 9, and subsequent chromatographic
D
DOI: 10.1021/acs.jnatprod.9b00013
J. Nat. Prod. XXXX, XXX, XXX−XXX

Journal of Natural Products
Article
Analysis of the NMR data indicated that compounds 12−14
shared a common 3β,14β-dihydroxypregn-5-ene-18,20R-lac-
14
tone aglycone moiety. The molecular formula of chonemor-
phoside J (13) was established as C H O from its
3
4
52 10
+
HRESIMS data (m/z 643.3450 [M + Na] , calcd 643.3453).
Concerning the glycosidic residues, a disaccharide unit
analogous to that of compound 9 was indicated from the
comparable NMR data (Tables 1, 3, and 4). Thus, 13 was
characterized as 3β,14β-dihydroxypregn-5-ene-18,20R-lactone
3
-O-β-D-cymaropyranosyl-(1→4)-β-D-digitoxopyranoside.
Chonemorphoside K (14) was assigned the molecular
Figure 3. ORTEP drawing of 1.
formula C H O by the HRESIMS data (observed
4
2
66 13
801.4398; calcd 801.4396). The NMR data (Tables 1 and 4)
suggested that compound 14 differed from 12 in the presence
of one additional sugar unit. Analysis of the NMR data and
acid hydrolysis verified that one oleandropyranose unit was
present besides the two cymaropyranose units, and their D-
configurations were identified by the specific rotation values of
2
0
D
the purified saccharides ([α] +50 and −12 for cymaropyr-
13
anose and oleandropyranose, respectively). The unambig-
uous HMBC correlations from H-1′ (δ 4.85) to C-3 (δC
H
7
7.5), from H-1″ (δ 4.76) to C-4′ (δ 82.5), and from H-1‴
H
C
Figure 4. ORTEP drawing of 3.
(δ 4.50) to C-4″ (δ 82.6) showed that a trisaccharide moiety
H
C
was connected to the 3-hydroxy group. Coupling constants of
the anomeric protons (δ 4.85, dd, J = 9.6, 1.8 Hz; 4.76, dd, J
separation afforded digitoxose and cymarose, which were both
H
20
= 9.7, 1.9 Hz; and 4.50, dd, J = 9.6, 1.8 Hz) revealed β-
glycosidic linkages. Therefore, compound 14 was characterized
as 3β,14β-dihydroxypregn-5-ene-18,20R-lactone 3-O-β-D-ole-
andropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cym-
aropyranoside.
D-configured based on specific rotation values ([α] +46 for
D
1
1
both). The HMBC correlations between H-1′ (δ 4.95) and
H
C-3 (δ 76.9) and between H-1″ (δ 4.74) and C-4′ (δ 82.6)
C
H
C
showed that a disaccharide moiety was connected to the
hydroxy group at C-3. Therefore, the structure of 9 was
characterized as 3β-hydroxy-16-oxo-pregn-14-ene-18,20R-lac-
tone 3-O-β-D-cymaropyranosyl-(1→4)-β-D-digitoxopyranoside.
Chonemorphoside G (10) had the molecular formula
By analysis and comparison of the NMR data with the
reported spectroscopic data, the 11 known compounds were
identified as 3-hydroxy-6-oxo-5(6→7)abeo-stigmast-5(7)-ene
1
8
14
+
(15), 3β,14β-dihydroxypregn-5-ene-18,20-lactone (16),
C H O based on the HRESIMS [M + Na] ion at m/z
3
5
52 10
3 19
ecdysantheroside A (17), β-sitosterol (18), 7-ketositosterol
6
55.3450 (calcd 655.3453). The sugar moieties were
1
9
(
19),
3α,7α-dihydroxy-4α,14α-dimethyl-5α-ergosta-
determined to be identical to those in compound 7 by analysis
of the NMR data (Tables 1 and 3). Therefore, compound 10
was characterized as 3β-hydroxy-16-oxo-pregn-14-ene-18,20R-
lactone 3-O-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyrano-
side.
20 19
8
,24(28)-dien-11-one (20), 7β-hydroxysitosterol (21),
21
(
(
(
24S)-3β-hydroxy-5α-stigmastan-6-one (22), ecdysoside A
4 4
23),2 ecdysoside B (24), and stigmast-4-en-6β-ol-3-one
2
25).
The antiproliferative activity of compounds 1−14 was
The HRESIMS data of chonemorphoside H (11) showed an
M + Na] ion at m/z 511.2660 (calcd 511.2666),
+
assayed, and compound 7 exhibited significant inhibitory
activities, with IC50 values of 2.4, 2.0, and 3.6 μM against the
A-549, Hep G2, and PC3 cancer cell lines, respectively, as
[
corresponding to the molecular formula C H O . The
28
40
7
NMR data (Tables 1 and 4), acid hydrolysis, and specific
2
0
D
13
compared to the WI-38 normal human fibroblast cells (IC50
=
rotation ([α] +48) all supported the presence of a 3-O-β-
1
0
5.5 μM). Doxorubicin was used as positive control (IC 0.5−
D-cymaropyranosyl moiety in this compound, which was
identical to that in compound 2. Therefore, 11 was
characterized as 3β-hydroxy-16-oxo-pregn-14-ene-18,20R-lac-
tone 3-O-β-D-cymaropyranoside.
50
.8 μM for the cancer cell lines). Other compounds were
inactive (IC50 > 50.0 μM) in the above assay. Many pregnane
glycosides from the families Apocynaceae and Asclepiadaceae
5
,23
exhibited antiproliferative activity,
and it is interesting to
Chonemorphoside I (12) exhibited a molecular ion at m/z
57.3608 [M + Na] in the HRESIMS, suggesting a molecular
+
find that a pregnane glycoside with an 18,20-lactone moiety,
such as 7, exhibits potent antiproliferative activity. The enone
6
formula of C H O . The aglycone of 12 was identified as
3
5
54 10
5
moiety in the D-ring and Δ -double bond may both contribute
3
β,14β-dihydroxypregn-5-ene-18,20R-lactone from the 1D
14
to the activity, as compounds 8−11 or compounds 12−14,
with either of the functionalities, showed weak activity. The
sugar moiety may also be important as for compounds 5 and 6.
The other two members of the series with different sugar
moieties were inactive. Further work is needed to confirm the
structure−activity relationship of these compounds.
NMR data (Tables 1 and 4), and the two sugar moieties
were both identified as D-cymarose ([α]
20
+45) after acid
D
1
3
hydrolysis. The HMBC correlations between H-1′ (δ 4.85)
H
and C-3 (δ 77.6) and between H-1″ (δ 4.67) and C-4′ (δ
C
H
C
8
2.5) revealed the linkages of the disaccharide moiety.
Coupling constant values of the anomeric protons at δ 4.85
H
(
dd, J = 9.7, 2.0 Hz) and 4.67 (dd, J = 9.7, 2.0 Hz) suggested
EXPERIMENTAL SECTION
General Experimental Procedures. An X-6 melting-point
apparatus was used to measure the melting points. A Shimadzu
β-glycosidic linkages. Therefore, the structure of 12 was
defined as 3β,14β-dihydroxypregn-5-ene-18,20R-lactone 3-O-
β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside.
■
E
DOI: 10.1021/acs.jnatprod.9b00013
J. Nat. Prod. XXXX, XXX, XXX−XXX

Journal of Natural Products
Article
1
Table 3. H NMR Spectroscopic Data for Compounds 6−10
a
a
a
a
b
position
6
7
8
9
10
1
α
β
α
β
1.12, td (13.5, 3.7)
1.92, dt (13.2, 3.5)
1.65, m
1.97, m
3.57, m
1.04, td (13.5, 3.6)
1.85, dt (13.4, 3.7)
1.55, m
1.90, m
3.49, m
1.02, m
1.80, m
1.54, m
1.92, m
3.65, t (4.8)
1.71, m
1.31, m
1.13, m
1.63, m
1.94, m
1.13, m
1.40, m
2.86, m
0.96, m
1.73, m
2.17, qd (13.6, 3.8)
1.62, m
2.44, dt (13.3, 3.3)
5.84, d (1.6)
2.50, d (2.7)
0.96, s, 3H
4.66, qd (6.4, 2.8)
1.52, d (6.6), 3H
4.96, dd (9.5, 1.9)
2.07, m
1.01, m
1.80, dt (13.2, 3.4)
1.90, m
1.53, m
3.83, m
1.71, m
1.60, m
1.10, m
1.60, m
1.93, m
1.13, m
1.40, m
2.86, m
0.96, m
1.73, m
2.16, m
1.62, m
2.44, dt (13.3, 3.3)
5.83, d (1.7)
2.50, d (2.8)
0.95, s, 3H
4.66, qd (6.4, 2.6)
1.52, d (6.3), 3H
4.95, dd (9.7, 2.0)
2.10, m
1.72, m
4.24, q (3.2)
3.21, m
3.80, m
1.25, d (6.3), 3H
0.99, dd (13.7, 3.9)
1.72, dt (13.3, 3.7)
1.77, m
1.37, m
3.54, m
1.66, m
1.59, m
1.08, m
1.57, m
1.76, m
1.87, m
1.38, m
2.74, m
0.93, m
1.67, m
2.02, qd (13.4, 3.8)
1.60, m
2.33, dt (13.3, 3.2)
5.78, d (1.8)
2.61, d (2.8)
0.85, s, 3H
4.51, qd (6.4, 2.8)
1.39, d (6.6), 3H
4.79, d (9.5, 2.0)
1.96, ddd (13.8, 3.7, 2.0)
1.44, m
3.75, q (3.0)
3.16, m
3.71, m
1.11, d (6.4), 3H
3.33, s, 3H
4.50, dd (9.8, 1.9)
2.23, ddd (12.3, 5.1, 1.9)
1.25, m
1
2
2
3
4
4
5
6
6
7
7
8
9
1
1
1
1
1
1
1
2
2
1
2
2
3
4
5
6
3
1
2
2
3
4
5
6
3
α
β
2.39, m
2.29, m
2.18, m
2.31, m
α
β
α
β
5.42, m
5.35, m
2.09, m
2.30, m
2.94, m
1.29, m
1.72, m
2.41, m
2.46, dt (13.2, 3.6)
1.67, m
5.87, d (1.9)
2.53, d (2.6)
1.16, s, 3H
4.69, qd (6.6, 2.7)
1.53, d (6.6), 3H
4.61, dd (9.8, 1.8)
2.22, ddd (12.8, 5.4, 2.0)
1.60, m
2.00, m
2.21, m
2.86, td (11.2, 1.8)
1.22, m
1.67, m
1α
1β
2α
2β
5
7
9
0
2.33, m
2.39, dt (13.4, 3.3)
1.60, td (13.5, 4.5)
5.81, d (1.9)
2.46, d (2.7)
1.09, s, 3H
4.63, qd (6.4, 2.6)
1.46, d (6.4), 3H
4.80, dd (9.6, 1.9)
2.04, ddd (13.8, 3.7, 1.7)
1.53, m
3.75, q (3.2)
3.17, dd (9.7, 3.0)
3.81, m
1.17, d (6.4), 3H
3.39, s, 3H
1
′
′α
′β
′
′
′
′
′-OCH3
″
″α
″β
″
″
″
″
1.72, m
3.60, m
2.96, dd (8.8, 8.8)
3.32, m
4.13, q (3.1)
3.34, dd (9.1, 3.0)
3.73, m
1.29, d (6.2), 3H
1.30, d (5.8), 3H
4.66, dd (9.8, 2.0)
2.30, m
1.63, m
3.65, q (3.1)
3.24, m
3.70, m
4.43, dd (9.7, 1.9)
2.26, ddd (12.4, 4.5, 1.9)
1.45, m
3.11, m
3.07, dd (8.9, 8.9)
3.23, m
4.74, dd (9.8, 1.8)
2.25, m
1.62, m
3.63, m
3.19, m
3.61, m
1.28, d (6.3), 3H
3.44, s, 3H
3.10, m
2.87, dd (8.8, 8.8)
3.16, m
1.18, d (6.2), 3H
3.32, s, 3H
1.32, d (6.2), 3H
3.45, s, 3H
1.26, d (6.1), 3H
3.32, s, 3H
″-OCH3
a
b
Data were measured in CDCl at 600 MHz. Data were measured in methanol-d at 600 MHz.
3
4
UV-2450 spectrophotometer was used to record the UV data, and a
Nicolet iN 10 Micro FTIR spectrometer to acquire the IR data. The
NMR spectra in methanol-d or CDCl were recorded on a Bruker
Natural Products Chemistry, School of Pharmaceutical Sciences,
Shandong University, P. R. China.
Extraction and Isolation. The dried and powdered plant material
4
3
of C. megacalyx (4 kg) was extracted with 95% EtOH (4 × 20 L). The
Avance DRX-600 spectrometer. HRESIMS spectra were obtained
using an LTQ-Orbitrap XL instrument. An Agilent 1200 series
instrument equipped with Eclipse XDB-C 5 μm columns (4.6 × 250
95% EtOH extract (407 g) was suspended in warm water and
partitioned with EtOAc (5 × 1 L) to obtain an EtOAc-soluble (163 g)
fraction. The EtOAc-soluble fraction was preliminarily separated via
silica gel CC through a gradient elution with a solvent of petroleum
ether−EtOAc (100:1 → 1:1) to obtain 10 fractions (Y1−10).
Fraction Y9 (4.1 g) was subjected to an RP-18 silica gel column
1
8
mm and 9.4 × 250 mm) was used for HPLC separations. All reagents
were of analytical grade. In addition, several conventional packing
materials were used for column chromatography (CC), such as silica
gel (200−300 mesh), Sephadex LH-20 (25−100 μm; Pharmacia
Biotech), and reverse-phased C18 (150−200 mesh, Pharmacia
Biotech). Compounds were colored by spraying with anisaldehyde−
H SO chromogenic agent followed by heating. X-ray diffraction data
(
H O−MeOH, 7:3 to 0:10) to afford 10 subfractions (Y9-1−10).
2
Subfraction Y9-7 (450 mg) was applied to a Sephadex LH-20 column
MeOH−CHCl , 1:1) to afford a major fraction (90 mg), which was
(
3
2
4
purified by HPLC (46% MeCN−H O) to afford 13 (20.0 mg), 6
2
were measured on a Bruker D8 Venture diffractometer equipped with
an APEXII CCD using Cu Kα radiation (λ = 1.541 78 Å) at 296(2)
K.
Plant Material. The vines and leaves of C. megacalyx identified by
one of the authors (T.S.) was collected in July 2009 from
Xishuangbanna County, Yunnan Province, P. R. China, and a voucher
specimen (CM01-2009-07) has been stored at the Department of
(13.0 mg), 7 (12.5 mg), and 10 (1.8 mg). RP-18 silica gel (H O−
2
MeOH, 7:3 to 0:10) and Sephadex LH-20 columns (MeOH) were
used to separate the subfraction Y9-5 (402 mg) and afforded two
major fractions, Y9-5-1 and Y9-5-2. Fraction Y9-5-1 (55 mg) was
separated by HPLC (39% MeCN−H O) to give 9 (12.5 mg), while
2
Y9-5-2 (35 mg) was separated by HPLC (30% MeOH−H O) to give
2
5 (4.9 mg) and 8 (1.5 mg). Subfraction Y9-9 was purified using
F
DOI: 10.1021/acs.jnatprod.9b00013
J. Nat. Prod. XXXX, XXX, XXX−XXX

Journal of Natural Products
Article
1
a
Table 4. H NMR Spectroscopic Data for Compounds 11−14
position
11
12
13
14
position
11
1.16, m
3.10, m
2.82, m
12
1.59, m
3.81, q (3.0)
3.22, dd (9.7,
3.0)
3.85, m
1.21, d (6.3),
3H
3.42, s, 3H
13
14
1α
1.00, dd (13.7,
1.07, td (13.8,
3.6)
1.88, m
1.95, m
1.61, m
3.54, m
2.34, ddd (13.3, 2.39, m
.7, 2.1)
2.23, m
1.07, td
(13.7, 3.7)
1.90, m
1.92, m
1.61, m
3.55, m
1.07, td
(13.8, 3.6)
1.88, m
1.94, m
1.60, m
3.55, m
2.35, td
(13.7, 1.8)
2.23, m
2′β
1.74, m
4.23, q (3.0) 3.81, m
3.21, dd
(9.5, 3.0)
3.79, m
1.24, d (6.3), 1.22, d
1.59, m
3
.9)
3
4
′
′
1
2
2
3
4
β
α
β
1.71, m
1.76, m
1.36, m
3.56, m
1.67, m
3.22, dd
(8.2, 3.0)
3.85, m
5′
6′
3.14, m
1.16, d (6.0),
3
H
3H
(6.5), 3H
3.45, s, 3H
α
β
4
3′-
3.30, s, 3H
OCH3
4
5
6
7
7
8
9
1.15, m
1.12, m
1.34, m, 2H
1.89, m
1.37, m
2.68, m
0.98, m
2.22, m
1″
4.67, dd (9.7,
4.74, dd
(9.8, 2.1)
2.25, m
1.63, dd
(9.8, 2.0)
3.63, m
4.76, dd
(9.7, 1.9)
2.13, m
1.64, m
2
.0)
5.40, m
1.86, m
2.27, m
1.99, m
5.39, m
1.80, m
2.23, m
1.97, m
1.13, td
(11.8, 4.2)
5.39, m
1.85, m
2.26, m
1.96, m
1.13, td
(11.8, 4.2)
2
2
″α
″β
2.25, m
α
β
1.64, dd (9.7,
2
.6)
3
″
″
3.20, m
3.81, dd
(7.0, 3.2)
3.23, dd
(9.4, 3.0)
1.13, td (11.8,
4
.1)
4
3.62, q (3.0)
3.56, m
1.25, d (6.3),
3H
3.19, dd
(10.3, 3.3)
3.62, m
1.28, d (6.2), 1.23, d
1
1
1α
1β
1.66, m
1.95, qd (13.4,
1.51, m
2.09, m
1.53, m
2.11, m
1.51, m
2.10, m
5″
3.85, m
3
.8)
6″
1
1
2α
2β
1.68, m
2.41, dt (13.3,
1.34, m
2.25, m
1.35, m
2.25, m
1.35, m
2.02, m
3H
(6.5), 3H
3.45, s, 3H
3″-
OCH
3
3.45, s, 3H
3.44, s, 3H
3
.2)
1
1
1
1
1
1
2
5α
5β
6α
6β
7
5.92, d (1.6)
1.96, m
1.85, m
1.79, m
2.04, m
2.21, m
1.03, s, 3H
4.40, dq (6.7,
6.4)
1.36, d (6.3),
3H
1.96, m
1.85, m
1.98, m
2.06, m
2.20, m
1.03, s, 3H
4.40, dq
(6.9, 6.3)
1.35, d (6.3), 1.35, d
3H
1.96, m
1.85, m
1.97, m
2.06, m
2.20, m
1.03, s, 3H
1‴
4.50, dd
(
9.6, 1.8)
2
2
3
4
‴α
‴β
‴
2.33, m
1.51, m
3.17, m
3.13, dd
2.82, d (2.8)
0.84, s, 3H
‴
9
0
(8.9, 8.8)
4.57, qd (6.6,
4.39, dq
(6.7, 6.3)
5
6
‴
‴
3.29, m
1.31, d
2
.7)
2
1
2
1
1.42, d (6.8),
(6.0), 3H
3
H
(6.2), 3H
4.85, dd
(9.6, 1.8)
3
‴-
3.39, s, 3H
′
4.60, d (9.3,
.0)
4.85, dd (9.7,
2.0)
4.94, dd
(9.6, 2.0)
2.12, m
OCH3
2
′α
2.12, ddd (12.0, 2.11, m
.8, 1.4)
2.09, m
4
a
Data were measured in CDCl at 600 MHz.
3
−
1
1
13
HPLC (71% MeCN−H O) to yield 14 (46.0 mg). Fraction Y7 (17.1
3412, 2934, 1732, 1343, 1037, 920 cm ; H and C NMR (CDCl )
2
3
+
g) was fractionated by silica gel CC (petroleum ether−EtOAc, 20:1 to
data, see Tables 1 and 2; HRESIMS m/z 371.2196 [M + Na] (calcd
0
:1) to give 12 subfractions (Y7-1−12). Subfraction Y7-12 (1.6 g)
for C H O , 371.2193).
2
1
32
4
was subjected to an RP-18 silica gel column (MeOH−H O, 3:7 to
1
Y7-12-1 (280 mg) was purified by HPLC (55% MeOH−H O) to give
1
Chonemorphoside B (5): white, amorphous solid; UV (MeOH)
λmax (log ε) 242 (3.78), 238 (3.77) nm; [α] +18 (c 0.1 MeOH); IR
νmax 3527, 3495, 2938, 2857, 1754, 1696, 1088, 1068, 1053 cm ; H
and C NMR (CDCl ) data, see Tables 1 and 2; HRESIMS m/z
2
2
0
0:0) to obtain three additional subfractions (Y7-12-1−3). Fraction
D
−
1 1
2
(13.2 mg), 2 (5.0 mg), and 3 (15.5 mg). Fraction Y7-12-2 (134 mg)
13
3
was separated by HPLC (77% MeOH−H O) to give 12 (25.0 mg).
+
2
495.2356 [M + Na] (calcd for C H O , 495.2353).
27 36 7
Compounds 4 (5.5 mg) and 11 (11.0 mg) were obtained from
Chonemorphoside C (6): white, amorphous solid; UV (MeOH)
λmax (log ε) 243 (3.91), 228 (3.90), 234 (3.89), 213 (3.82) nm;
α] + 18 (c 0.1 MeOH); IR ν 3405, 2933, 1751, 1711, 1067,
038, 998 cm ; H and C NMR (CDCl ) data, see Tables 1 and 3;
fraction Y7-12-3 (80 mg) by HPLC (43% MeCN−H O).
2
Chonemorphol A (1): colorless needles (MeOH); mp 222−223
20
[
1
2
0
D
max
°
(
1
C; UV (MeOH) λmax (log ε) 260 (3.93), 219 (3.39) nm; [α] −45
−1
1
13
D
3
+
c 0.1 MeOH); IR νmax 3500, 3351, 2977, 2937, 2860, 1735, 1640,
HRESIMS m/z 639.3143 [M + Na] (calcd for C H O ,
−
1
1
13
34 48 10
600, 1443, 1414, 1385, 1060 cm ; H and C NMR (CDCl ) data,
3
639.3140).
+
see Tables 1 and 2; HRESIMS m/z 383.1826 [M + Na] (calcd for
Chonemorphoside D (7): white, amorphous solid; UV (MeOH)
C H O , 383.1829).
21
28
5
20
λmax (log ε) 226 (3.76), 214 (3.71) nm; [α] +16 (c 0.1 MeOH); IR
D
Chonemorphoside A (2): white, amorphous solid; UV (MeOH)
−
1
1
13
λmax (log ε) 259 (3.95), 222 (3.38) nm; [α]20 −18 (c 0.1 MeOH);
νmax 3527, 2960, 2930, 1752, 1699 cm ; H and C NMR (CDCl )
3
D
+
data, see Tables 1 and 3; HRESIMS m/z 653.3300 [M + Na] (calcd
IR νmax 3395, 2930, 2873, 1752, 1638, 1596, 1458, 1401, 1380, 1101,
−
1
1
13
for C H O , 653.3296).
3
5
50 10
1
065, 988 cm ; H and C NMR (CDCl ) data, see Tables 1 and 2;
3
+
Chonemorphoside E (8): white, amorphous solid; UV (MeOH)
λmax (log ε) 244 (3.51), 203 (3.52), 214 (3.43) nm; [α] +19 (c 0.1
MeOH); IR ν 3399, 2927, 1754, 1711, 1605, 1086 cm ; H and
C NMR (CDCl ) data, see Tables 1 and 3; HRESIMS m/z
HRESIMS m/z 527.2617 [M + Na] (calcd for C H O , 527.2615).
2
8
40
8
2
0
D
Chonemorphol B (3): colorless, flaky crystals (MeOH); mp 220−
−
1 1
2
0
2
21 °C; UV (MeOH) λ (log ε) 202 (4.26) nm; [α] +40 (c 0.1
max
max
D
1
3
MeOH); IR ν
3465, 3255, 2932, 1727, 1351, 1051, 1008, 900
3
+
max
13
−
1
1
cm ; H and C NMR (CDCl ) data, see Tables 1 and 2;
HRESIMS m/z 385.1985 [M + Na] (calcd for C H O , 385.1985).
475.2686 [M + H] (calcd for C27
H
O
38
7
, 475.2686).
3
+
Chonemorphoside F (9): white, amorphous solid; UV (MeOH)
λmax (log ε) 244 (3.77), 211 (3.56) nm; [α] +25 (c 0.1 MeOH); IR
νmax 3460, 2929, 1757, 1705, 1069, 1001 cm ; H and C NMR
2
1
30
5
2
0
Chonemorphol C (4): white, amorphous solid; UV (MeOH) λ
D
max
2
0
−1
1
13
(
log ε) 237 (3.55) nm; [α]
+21 (c 0.1 MeOH); IR νmax 3446,
D
G
DOI: 10.1021/acs.jnatprod.9b00013
J. Nat. Prod. XXXX, XXX, XXX−XXX

Journal of Natural Products
Article
(
CDCl ) data, see Tables 1 and 3; HRESIMS m/z 641.3292 [M +
3
Hongxiang Lou: 0000-0003-3300-1811
Xiao-Ning Wang: 0000-0001-5032-5135
Notes
+
Na] (calcd for C H O , 641.3296).
34
50 10
Chonemorphoside G (10): white, amorphous solid; UV (MeOH)
λmax (log ε) 227 (3.56), 216 (3.53) nm; [α]20D +11 (c 0.1 MeOH); IR
−1 1
νmax 3452, 2931, 2855, 1758, 1709, 1604, 1451, 1388, 1060 cm ; H
The authors declare no competing financial interest.
and 13C NMR (methanol-d ) data, see Tables 1 and 3; HRESIMS m/
4
+
z 655.3450 [M + Na] (calcd for C H O , 655.3453).
ACKNOWLEDGMENTS
3
5
52 10
■
Chonemorphoside H (11): white, amorphous solid; UV (MeOH)
The financial support from National Natural Science
Foundation of China (Nos. 21877071, 81673558, and
21472113) and Young Scholars Program of Shandong
University (No. 2015WLJH50) is gratefully acknowledged.
λmax (log ε) 244 (3.84), 210 (3.59) nm; [α]20D +19 (c 0.1 MeOH); IR
−1 1
νmax 3549, 3411, 2933, 2855, 1751, 1699, 1452, 1383, 1005 cm ; H
and 13C NMR (CDCl ) data, see Tables 1 and 4; HRESIMS m/z
3
+
5
11.2660 [M + Na] (calcd for C H O , 511.2666).
2
8
40
7
Chonemorphoside I (12): white, amorphous solid; UV (MeOH)
λmax (log ε) 279 (3.68), 274 (3.61) nm; [α]20D +9 (c 0.1 MeOH); IR
REFERENCES
■
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1 1
νmax 3445, 2929, 1741, 1453, 1366, 1088, 1061, 1002, 927 cm ; H
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54 10
Chonemorphoside J (13): white, amorphous solid; UV (MeOH)
2
0
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D
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−
1
1
13
2
884, 1755, 1368, 1084, 1002, 927 cm ; H and C NMR (CDCl )
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34
52 10
Chonemorphoside K (14): white, amorphous solid; UV (MeOH)
2
0
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D
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13
−
1
1
2
(
932, 1745, 1452, 1367, 1057, 1001, 927 cm ; H and C NMR
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3
+
Na] (calcd for C H O , 801.4396).
42
66 13
X-ray Crystallographic Analysis of Compounds 1 and 3.
Crystallographic data of 1 and 3 (Supporting Information) have been
included in the Cambridge Crystallographic Data Centre with the
numbers CCDC 1881130 and 1881135, respectively.
Acid Hydrolysis of Compounds 2, 5−7, 9, 11, 12, and 14.
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(
(
5
(
(
2
011, 4, 170−175.
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2
2
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(
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1
(
1
cancer cell line Hep G2, prostatic carcinoma cell line PC3, and normal
human fibroblast cells WI-38 was tested using the MTT assay.
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(
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performed as previously described.
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5−48.
ASSOCIATED CONTENT
■
(15) Luger, P.; Weber, M.; Nguyen, X. D.; Pham, T. K.; Chinh, L. T.
*
S
Supporting Information
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(
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AUTHOR INFORMATION
■
Corresponding Author
Tel: +86 531 88382012. Fax: +86 531 88382548. E-mail:
(
*
Med. 2015, 40, 4639−4644.
wangxn@sdu.edu.cn (X.-N. Wang).
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ORCID
Tao Shen: 0000-0002-5474-2646
Dongmei Ren: 0000-0002-1717-2429
H
DOI: 10.1021/acs.jnatprod.9b00013
J. Nat. Prod. XXXX, XXX, XXX−XXX