New Diterpenes from arenga pinnata (Wurmb.) merr. Fruits

Article abstract of DOI:10.3390/molecules24010087

Three new ent-kauran-type diterpenes (1-3), named arenterpenoids A-C, and five known ones (4-8) were isolated and identified from Arenga pinnata (Wurmb.) Merr. Fruits. The structures of these compounds were established by 1D and 2D NMR spectra and HR-ESI-MS. To the best of our knowledge, this is the first scientific report of diterpenes from Arenga genus.

Full text of DOI:10.3390/molecules24010087

molecules
Article
New Diterpenes from Arenga pinnata (Wurmb.)
Merr. Fruits
1
1
1
1
1,
2,
Ji-Fei Liu , Jin-Hai Huo , Chang Wang , Feng-Jin Li , Wei-Ming Wang * and Lu-Qi Huang *
1
Institute of Chinese Materia Medica, Heilongjiang Academy of Chinese Medicine Sciences,
Harbin 150036, China; liujifei2019@163.com (J.-F.L.); jinhaihuo@126.com (J.-H.H.);
wangchang89993762@126.com (C.W.); wklifengjin@163.com (F.-J.L.)
National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences,
2
Beijing 100700, China
*
Correspondence: zyyjy@163.com (W.-M.W.); huangluqi01@126.com (L.-Q.H.);
Tel.: +86-0451-5566-5478 (W.-M.W.); +86-10-6401-4411 (L.-Q.H.)
ꢀ
ꢁꢂꢀꢃꢄꢅꢆꢇ
Received: 29 November 2018; Accepted: 26 December 2018; Published: 27 December 2018
ꢀ
ꢁꢂꢃꢄꢅꢆ
Abstract: Three new ent-kauran-type diterpenes (1–3), named arenterpenoids A–C, and five known
ones ( ) were isolated and identified from Arenga pinnata (Wurmb.) Merr. Fruits. The structures of
4–8
these compounds were established by 1D and 2D NMR spectra and HR-ESI-MS. To the best of our
knowledge, this is the first scientific report of diterpenes from Arenga genus.
Keywords: Arenga pinnata (Wurmb.) Merr.; ent-kauran-type diterpene; arenterpenoids
1
. Introduction
Arenga pinnata (Wurmb.) Merr. are tall evergreen trees belonging to the genus Arenga of the family
Palmae. They are widely distributed in Southeast Asian countries, including China. A. pinnata fruits
are the fruits of the A. pinnata. [ ]. As a kind of folk medicine, it was first recorded in the Song Dynasty’s
Kai Bao Ben Cao” and the Ming Dynasty’s “Ben Cao Hui Yan” [ ]. In the folk literature, A. pinnata
fruits are made into medicinal liquor, which is rapid and significant in relieving pain [ ]. A. pinnata
fruits have significant effects on local neuropathic pain, rheumatism, bone pain and traumatic pain [ ].
It is abundant and there is a huge development space [ ]. At present, the secondary metabolites from
1
“
2,3
4
5
6
A. pinnata fruits have not been reported, and its main effective medicinal ingredients are still not clear.
Palm plants contain terpenes, alcohols, alkanes, esters, phenols, quinones, aldehydes and alkaloids,
etc [
and in vitro
7
–
9
]. In recent years, studies have shown that diterpenes have excellent anti-tumor effects in vivo
10 11]. The total diterpene of Rabdosia excisa has significant inhibitory effects on P-388,
[
,
H-22, and Lewis B-16 tumor cells [12]; the diterpenes of Pteris semipinnata L. have significant inhibitory
effects on A 549 and CNE-2 tumor cells [13]. This study is the first separation of the Arenga genus by
silica gel and ODS column chromatography. We analyzed the chemical constituents of A. pinnata fruits
and identified three new diterpenes named arenterpenoids A (
pseudaminic acids ( ) [14], 12 -( -D-glucopyranosyl)-7 -hydroxy-kaurenolide (
) [16], agittarioside b ( ) [17], and orychoside B (
1
), B (
2
), and C (
3
) together with known
4
α
β
β
5) [15], paniculoside
(6
7
8
) [18]. This report covers the separation and
structural analysis of these compounds 1–8 Figure 1.
Molecules 2019, 24, 87; doi:10.3390/molecules24010087
www.mdpi.com/journal/molecules

Molecules 2019, 24, 87
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Figure 1. Structures of compounds 1–8 from of Arenga pinnata (Wurmb.) Merr. ruits.
2
. Results
Compound
m/z 513.2651 [M + H] . The acid hydrolysis of
analysis using an optical rotation detector. 1H-NMR spectrum (Table 1) of
signals at 1.28 (3H, s), 0.86 (3H, s); two olefinic proton signals at 5.0 (1H, br. s), δ
H
1
possessed the molecular formula of C H O according to the HR-ESI-MS at
26 40 10
+
1
liberated D-glucose, which was identified by HPLC
showed two methyl
5.39 (1H,
1
δ
H
δ
H
δ
H
br. s); an anomeric proton signal at
δ
H
4.40 (1H, d, J = 7.8 Hz). The 13C-NMR and DEPT spectrum
(
Table 1) of
carbon signals, five methylene signals at
signals at c 35.2, 43.0, 44.6, 85.4; a carbonyl carbon signal at
at 109.7 and 158.0. The sugar moiety consisted of six carbon signals at
1
showed an ent-kauran-type diterpene skeleton [19]. The compound structure has 26
c 18.4, 19.8, 29.2, 38.4, 39.2; as well as four quaternary carbon
c 184.8; and two olefinic carbon signals
c 100.1, 75.2, 78.1, 71.7, 78.0,
showed the structures A, B and C (Figure 2).
δ
δ
δ
δ
C
δ
1
1
and 62.9 [20]. The H- H COSY and HSQC analysis of
1
The connectivity of these partial structures and their functional groups were investigated by analysis
of HMBC. As shown in Figure 2, the long range correlations were observed between the following
protons and carbon signals: H-18 (CH ) and C-3, C-4, C-5, C-19 (COOH); H-20 (CH ) and C-1, C-5,
3
3
C-9, C-10; H-15 and C-7, C-8, C-9, C-16; H-14 and C-12, C-13, C-16; H-17 and C-16. Thus, structure
was confirmed as shown in Figure 2.
1
1
1
Figure 2. Key HMBC and H- H COSY correlations of compound 1–3.

Molecules 2019, 24, 87
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The coupling constants of H-6 (dd, J5,6 = 6.5 Hz and J6,7 = 6.5 Hz) and H-7 (d, J6,7 = 6.5 Hz)
observed in the 1H-NMR spectrum were the same as those of H-6 (dd, J5,6 = 6.5 Hz and
J6,7 = 6.5 Hz) and H-7 (d, J6,7 = 6.5 Hz) in 7
it was determined that H-6 was in the
β
, 16
α
, 17-trihydroxy-ent-kauran-6
α
, 19-olide [21]. Thus,
-orientation.
β
-orientation and that H-7 was in the α
The relative stereochemistry of
correlations (Figure 3) of H-6/H-18, H-7/H-20 suggested that the configurations of C-18, C-20 were
restricted as 18 , 20 , respectively. Likewise, the NOESY cross-peaks of H-19/H-5, H-5/H-9 and
H-9/H-15 showed that the configurations of C-5, C-9 and C-15 were restricted as 5
respectively. Thus, the structure of was determined to be as shown (Figure 1) and elucidated as 7
-dihydroxy-6 -O- -D-glucopyranosyl-ent-kauran-16-en-19-oic acid, named as arenterpenoid A (
1 was assigned by analysis of the NOESY spectrum. The NOESY
β
α
β, 9β
and 15
β
,
,
1
β
13β
α
β
1
).
Figure 3. Key NOESY correlations of compound 1–3.
Compound 2 possessed the molecular formula of C H O according to the HR-ESI-MS at m/z
20
32
7
+
1
13
3
85.2186 [M + H] . H- and C-NMR spectra indicated that the structure of
except for a 11-methylene group ( 1.52 (m); c 19.8 in ), 16-olefinic proton group (
5.39 (br. s), 5.00 (br. s); c 109.7 in ), as well as presence of a 6
-hydroxy group ( H 3.95 (m); c 65.5 in ), a 16-homomethyl
) and a 17-hydroxy group ( H 3.75 (d); c 68.1 in
spectrum (Table 1) of 2 showed an ent-kauran-type diterpene skeleton [22]. The connectivity of these
partial structures and the functional groups were investigated by analysis of HMBC of . As shown in
Figure 2, long range correlations were observed between the following protons and carbon signals:
H-18 (CH ) and C-3, C-4, C-5, C-19 (COOH); H-20 (CH ) and C-1, C-5, C-9, C-10; H-14 and C-7, C-8,
2
was similar to that of
c 158.0 in ) and
-hydroxy
1,
δ
δ
1
δ
1
H
a 17-olefinic proton group (
group (
group (
δ
δ
1
β
H
δ
4.54 (dd);
δ
c 85.2 in
c 43.1 in
2
), a 11
β
δ
δ
2
H
13
δ
H
2.03 (m),
δ
2
δ
δ
2). C-NMR and DEPT
2
3
3
C-9, C-13; H-15 and C-8, C-15; H-17 and C-13, C-15. Thus, structure
Figure 2.
2
was confirmed as shown in
1
The relative stereochemistry of
and 13C-NMR spectra showed similar data for
-orientation and that H-7 was in the -orientation. The correlations of H-6/H-18 showed that they
were cofacial and were arbitrarily assigned to be -oriented. H-5, H-9 and H-15 were determined by
their correlations with H-18. H-20 and H-11 were determined by their correlations with H-7. Thus,
2
was assigned by analysis of the NOESY spectrum. The H-
1
and 2. Thus, it was determined that H-6 was in the
β
α
β

Molecules 2019, 24, 87
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the structure of
2 was determined to be as shown (Figure 1) and elucidated as, 6α, 7β, 11β, 13β,
1
7-pentahydroxy-ent-kauran-19-oic acid, named as arenterpenoid B (2).
1
13
Table 1. H- and C-NMR Data of 1–3 (CD OD).
3
1
2
3
NO.
δ
(J, Hz)
δ
δ
(J, Hz)
δ
δ
(J, Hz)
δ
C
H
C
H
C
H
1
1.53 (m)
.04 (m)
1.53 (m)
2.01 (m)
38.4
1.88 (m)
1.73 (m)
1.41 (m)
1.83 (m)
1.65 (m)
37.1
1.06 (m)
1.55 (m)
1.54 (m)
2.00 (m)
1.42 (m)
38.4
1
2
3
18.4
29.2
18.6
24.1
18.3
29.2
1
.40 (m)
4
5
6
7
8
9
43.0
52.7
84.9
72.2
44.6
56.2
35.2
19.8
39.2
43.2
51.4
85.2
72.3
48.2
59.7
37.2
65.5
49.7
43.1
52.8
85.2
72.1
48.0
58.8
35.4
18.3
24.4
1.88 (d, 6.5)
4.62 (dd, 6.5, 6.5)
4.26 (d, 6.5)
1.85 (d, 7.3)
4.54 (dd, 7.3, 7.3)
4.14 (d, 7.3)
1.82 (d, 6.5)
4.56 (dd, 6.5, 6.5)
4.23 (d, 6.5)
1.17 (dd, 4.9, 12.1)
1.17 (dd, 4.7, 12.1)
1.17 (m)
1
1
1
0
1
2
1.52 (m)
2.31 (dd, 7.5, 13)
3.95 (m)
1.76 (m)
1.36 (m)
1.79 (m)
1.68 (m)
1.37 (m)
1
1
3
4
85.4
39.9
86.0
47.5
85.4
47.6
2.05 (d, 10.9)
2.12 (d, 13.0)
1.16 (d, 13.0)
2.05 (m)
1.49 (d, 12.6)
2.03 (m)
3.75 (d, 11.5)
3.58 (d, 11.5)
1.34 (s)
2.17 (d, 13.2)
1.16 (d, 13.2)
2.09 (m)
1.53 (m)
2.05 (m)
4.27 (d, 10.4)
3.46 (d, 10.4)
1.27(s)
1
.74 (m)
2.81 (br. d, 14.9)
.78 (m)
1
5
42.0
33.5
33.6
1
1
1
6
7
158.0
109.7
43.1
68.1
43.8
76.2
5.39 (br. s)
5
.00 (br. s)
1.28 (s)
1
1
2
1
2
3
4
5
6
8
9
25.9
184.8
20.9
100.1
75.2
78.1
71.7
78.0
62.9
24.7
185.1
23.4
25.8
185.0
20.9
100.1
75.2
78.1
71.7
78.0
62.9
0
0.86 (s)
4.40 (d, 7.8)
3.16 (m)
3.37 (m)
3.28 (m)
0.98 (s)
0.85 (s)
4.28 (d, 7.7)
3.21 (m)
3.37 (m)
3.28 (m)
3.28 (m)
0
0
0
0
0
0
3.28 (m)
3.83 (dd, 2.1, 12.0)
3.88 (dd, 2.1, 12.0)
3.65 (m)
3
.59 (m)
Compound
m/z 531.2769 [M + H] . The acid hydrolysis of
analysis using an optical rotation detector. H- and C-NMR spectra indicated that the structure
3 possessed the molecular formula of C H O according to the HR-ESI-MS at
26 42 11
+
2
liberated D-glucose, which was identified by HPLC
1
13
of
group (
3
was similar to that of
3.75; c 68.1 in
-glucopyranosyl oxy) group (
2
, except for a 11
), as well as the presence of a 11-methylene group ( H
4.2, 3.46; c 76.2 in ). The connectivity of these partial structures
and the functional groups were investigated by analysis of the HMBC of . As shown in Figure 2, long
range correlations were observed between the following protons and carbon signals: H-18 (CH ) and
β
-hydroxy group ( H
δ
3.95;
δ
c 65.5 in
2
) and 17-hydroxy
δ
δ
2
δ
1.36;
δ
c 18.3 in ), and
3
H
1
7-(
β
δ
H
δ
3
3
3
C-3, C-4, C-5, C-19 (COOH); H-20 (CH ) and C-1, C-5, C-9, C-10; H-15 and C-7, C-8, C-9, C-16; H-7
3
0
and C-8, C-14, C-15; H-17 and C-13, C-16, C-1 . Thus, the structure of
Figure 2.
3
was confirmed as shown in
1
The relative stereochemistry of
and 13C-NMR spectra showed similar data for
in the -orientation and that H-7 was in the -orientation. The NOESY of
between H-6 and H-18, H-5, H-9; H-7 and H-20. The results showed that the stereochemistry of
3
was assigned by analysis of the NOESY spectrum. The H-
3
and
2. Likewise, it was determined that H-6 was
β
α
3
showed the cross-peaks
3

Molecules 2019, 24, 87
5 of 8
is similar to the stereochemistry of
2
. Therefore, the structure of
, 13 -trihydroxy-17-O-
). The other compounds were characterized as pseudaminic acid (
-hydroxy-kaurenolide ( ), paniculoside ( ), agittarioside b ( ), orychoside
) by comparing their NMR spectroscopic data with the literature values (Figures S1–S5 and
Table S1).
All these compounds are reported here for the first time in Arenga genus. The kaurane type
diterpene is a kind of tetracyclic diterpene with hydrogenated phenanthrene as the mother nucleus [23].
According to the structural rule of the kauri-type diterpene, the compounds are all C-20 unoxidized
3
was determined to be as shown
(
Figure 1) and elucidated as, 6
named as arenterpenoid C (
-( -D-glucopyranosyl)-7
α
, 7β
β
β
-D-glucopyranosyl-ent-kauran-19-oic acid,
3
4),
1
2
α
β
β
5
6
7
B (
8
1–8
kauri-type. Most of such structures isolated and artificially synthesized in plants have significant
biological activities, such as antimicrobial activity and cytotoxicity [24]. This study provides an
experimental and scientific basis for drug design and discovery in A. pinnata fruits.
3
. Experimental Section
3
.1. General Experimental Procedures
NMR spectra were measured on a Bruker AV-400 spectrometer (Bruker Company, Waltham MA,
USA) with TMS as an internal standard. High-resolution ESI-MS mass spectra were carried out on an
+
AB SCEIX Triple-TOFTM 5600 instrument (A.B. Company, Milwaukee, WI, USA). UV spectra were
recorded on a PerkinElmer Lambda UV-365 instrument (PE Company, Waltham MA, USA). IR spectra
were recorded on a PerkinElmer Spectrum Two spectrometer (PE Company, Waltham MA, USA) with
KBr disks. Preparative HPLC (515-2414, Waters, Milford, CT, USA) was performed on 5C18 MS-II
(
10
no.: S1119, Kasei Company, Tokyo, Japan), silica gel (200–300 mesh, Haiyang Co, Qingdao, China),
Amberlite IRA-400 (OH-, Alfa Aesar, Heysham, UK) and ODS (50 m, AAG12S50, YMC Company,
µ
m, 20
×
250 mm, cat. no.: 38024-01, COSMOSIL, Tokyo, Japan). NH column (4.6
×
250 mm, cat.
2
µ
Kyoto, Japan) were used for column chromatography. Detectors (2424, ELS, Waters) and (2998, PDA,
Waters) were used in the HPLC. Precoated silica GF 254 plates (Haiyang Company, Qingdao, China)
were used for TLC analysis. All the solvents were of analytical grade (Tianjinfuyu Company Ltd.,
Tianjin, China).
3
.2. Plant Material
The A. pinnata fruits were collected from Guangxi in China during September 2017, and
authenticated by Prof. Weiming Wang of the Heilongjiang Research institute of Chinese Medicine.
The fruitage had been deposited at the Heilongjiang Research institute of Chinese Medicine.
3
.3. Extraction and Isolation
The A. pinnata fresh fruits (30.0 kg) were extracted with 70% EtOH (200 L
×
3 h
×
3 times).
The combined extract was concentrated under vacuum yielding a residue (3.0 kg) which was dissolved
in H O (12 L) and extracted sequentially with petroleum, chloroform, ethyl acetate and n-butanol (12 L
2
×
3 h
×
5 times). The eluate was separately concentrated in vacuo to give a petroleum syrup (109.0 g),
chloroform syrup (123.0 g), ethyl acetate syrup (205.0 g), and an n-butanol syrup (380.0 g). In this
study, we only separated the n-butanol layer. The n-butanol (380.0 g) extract was subject to column
chromatography on silica gel (4460.0 g) and eluted with CH Cl /MeOH (20:1 (80.0 L), 10:1 (110.0 L),
2
2
5:1 (120.0 L), 3:1 (100.0 L), 2:1 (80.0 L) and 1:1 (60.0 L), v/v) to afford six fractions (fractions A (36.0 g),
B (96.7 g), C (90.2 g), D (40.1 g), E (21.2 g), F (20.1 g). The TLC and HPLC were used to observe each
of the fractions, and similar fractions were combined to afford A1-A6, B1-B5, C1-C6, D1-D6, E1-E10,
F1-F6. Fraction B4 (21.7 g) was eluted by Rp-18 (600.0 g) (MeOH/H O 2:8 (1.4 L)
→
3:7 (2.0 L)
1:0 (1.0 L), v/v) to afford nine
subfractions (subfractions B4-1–B4-9). Subfraction B4–6 further purified by a preparative RP-HPLC
55% MeOH/H O, flow rate 5 mL/min) to give (100.12 mg, tR = 23 min). Subfractions B4–5 were
→
4:6
2
(2.7 L)
→
5:5 (2.0 L)
→
6:4 (2.0 L)
→
7:3 (1.4 L)
→
8:2 (1.4 L)
→
9:1 (0.8 L)
→
(
1
2

Molecules 2019, 24, 87
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further purified by a preparative RP-HPLC (55% MeOH/H O, flow rate 5 mL/min) to give
2
(9.52 mg,
2
tR = 42 min). Fraction C1 (8.0 g) was eluted by Rp-18 (600.0 g) (MeOH/H2O 2:8 (1.4 L)
2.7 L) 5:5 (2.7 L) 6:4 (2.0 L) 7:3 (1.4 L) 8:2 (1.4 L) 9:1 (0.8 L) 1:0 (1.0 L), v/v) to afford nine
subfractions (subfractions C1-1–C1-9). Subfractions C1–3 were further purified by a preparative
RP-HPLC (20% MeOH/H O, flow rate 5 mL/min) to give (11.89 mg, t = 30 min). Subfraction
→
3:7 (2.0 L)
→
4:6
(
→
→
→
→
→
→
4
2
R
C1–5 were further purified by a preparative RP-HPLC (45% MeOH/H O, flow rate 5 mL/min) to
2
give
5
(8.50 mg, t = 25 min). Fraction D3 (18.0 g) was eluted by Rp-18 (600.0 g) (MeOH/H O 2:8
R
2
(
(
1.4 L)
→
3:7 (2.0 L)
→
4:6 (2.7 L)
→
5:5 (2.7 L)
→
6:4 (2.7 L)
→
7:3 (1.4 L)
→
8:2 (1.4 L)
→
9:1 (0.8 L)
→
1:0
1.0 L), v/v) to afford nine subfractions (subfractions D3-1–D3-9). Subfractions D3–6 were further
(10.61 mg, tR
32 min). Subfraction D3–6 were further purified by a preparative RP-HPLC (45% MeOH/H O,
purified by a preparative RP-HPLC (40% MeOH/H O, flow rate 5 mL/min) to give
=
3
2
2
flow rate 5 mL/min) to give
8 (4.51 mg, t = 41 min). Subfractions D3–4 were further purified by
R
a preparative RP-HPLC (60% MeOH/H O, flow rate 5 mL/min) to give
6 (70.67 mg, t = 29 min).
R
2
Subfractions D3–5 were further purified by a preparative RP-HPLC (60% MeOH/H O, flow rate
2
5
mL/min) to give 7 (4.32 mg, t = 37 min).
R
Arenterpenoids A (1). Yellow amorphous powder. Gave [α] +10.0 (c = 1.76, MeOH); IR (KBr)
436, 2946, 2835, 1719, 1635, 1467, 1231, and 1069 cm 1; 1H- and C-NMR (MeOH, 400, 100 MHz)
2
5
D
−
13
3
+
data, see Table 1; HR-ESI-MS m/z 513.2651 [M + H] (calc. for C H O , 513.2655) (Figures 1 and 2).
2
6
40 10
2
5
Arenterpenoids B (2). Yellow amorphous powder. Gave [α]
−
31.6 (c = 0.66, MeOH); IR (KBr)
D
−
1 1
13
3
381, 2931, 1730, 1664, 1451, 1229, and 1039 cm ; H- and C-NMR (MeOH, 400, 100 MHz) data, see
+
Table 1; HR-ESI-MS m/z 385.2186 [M + H] (calc. for C H O , 385.2182) (Figures 1 and 2).
2
0
32
7
2
5
Arenterpenoids C (
3). White amorphous powder. Gave [α]
−
21.6 (c = 0.48, MeOH); IR (KBr)
D
−
1 1
13
3
358, 2949, 1716, 1662, 1460, 1225, and 1070 cm ; H- and C-NMR (MeOH, 400, 100 MHz) data, see
+
Table 1; HR-ESI-MS m/z 531.2769 [M + H] (calcd. for C H O , 531.2761) (Figures 1 and 2).
2
6
42 11
3
.4. Acid Hydrolysis and HPLC Analysis
The isolated compounds ( ) (2.0 mg) were in 1.0 mL HCl and were each heated under reflux for
h. After cooling, the two mixtures were separately filtered with Amberlite IRA-400 to give a solution.
1,3
3
Assigned with AcOEt to get two layers. The aqueous layer was evaporated to dryness under vacuum,
and then subjected to HPLC analysis using an NH column and an optical-rotation detector. D-glucose
2
was confirmed by comparison of the t with that of an authentic sample (mobile phase: MeCN/H O
R
2
8
5: 15 (v/v); flow rate: 0.8 mL/min; t = 12.8 min (D-glucose, positive optical rotation))
R
4
. Conclusions
As a traditional Chinese medicine, A. pinnata fruits were mainly used to treat rheumatism and
bone pain. This study obtained eight diterpene compounds from A. pinnata fruits, including three
new diterpenes and five known ones. This also reveals some structural characteristics of the chemical
constituents in the A. pinnata fruit, which provides some clues for further clarifying the composition
of the components and correlations of the relative plant species. In this study we have made this
contribution to discover active ingredients and leading compounds and additionally provided an
experimental and scientific basis of drug design and drug discovery of the A. pinnata fruits.
Supplementary Materials: The following are available online: Figures S1–S5 and Table S1: The 13C-NMR data of
Compounds 4–8.
Author Contributions: W.-M.W. and L.-Q.H. designed the experiments; J.-F.L. and C.W. performed the
experiments; J.-F.L. wrote the paper. W.-M.W., F.-J.L. and J.-H.H. modified the paper; All authors read and
approved the manuscript.
Funding: This work was financed by key projects at the central government level: The ability establishment of
sustainable use for valuable Chinese medicine resources (2060302) and Supported by China Agriculture Research
System (CARS-21).
Conflicts of Interest: The authors declare no conflict of interest.

Molecules 2019, 24, 87
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Abbreviations
The following abbreviations are used in this manuscript:
HR-ESI-MS
NMR
High-resolution electrospray ionization mass spectrometry
Nuclear magnetic resonance
DEPT
HMBC
NOESY
Distortionless Enhancement by Polarization Transfer
Heteronuclear multiple bond correlation
Nclear overhauser effect spectroscopy
1
1
H- H COSY Correlation spectroscopy
HSQC
tR
Heteronuclear multiple quantum coherence
Retention time
UV
Ultraviolet
TMS
Tetramethylsilane
HPLC
ODS
High performance liquid chromatography
Octadecylsilyl
EtOH
TLC
MeOH
MeCN
AcOEt
Ethyl alcohol
Thin Layer Chromatography
Methanol
Methyl cyanide
Ethyl acetate
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Sample Availability: Samples of the compounds are available from the authors.
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