New 23-spirocholestane derivatives from ypsilandra thibetica

Article abstract of DOI:10.1055/s-0032-1328719

Three new unusual 23-spirocholestane derivatives, ypsilanogenin (1), ypsilanogenin 3-O-β-D-glucopyranoside (2), and 4′-acetylypsilanogenin 3-O-β-D-glucopyranoside (3), were isolated from the whole plants of Ypsilandra thibetica. The structures of compounds 1-3 were deduced by spectroscopic and chemical methods, and the structure of 1 was further confirmed by a single-crystal diffraction analysis. All isolates were evaluated for their inhibitory activities against HIV-1. Georg Thieme Verlag KG Stuttgart New York.

Full text of DOI:10.1055/s-0032-1328719

Letters 1063
Fig. 1 Structures of
compounds 1–3.
(Color figure available
online only.)
New 23-Spirocholestane Derivatives
from Ypsilandra thibetica
Bai-Bo Xie1, Chang-Xiang Chen1, Yong-Hui Guo2, Yu-Ye Li3,
Ya-Juan Liu3, Wei Ni1, Liu-Meng Yang3, Ning-Bo Gong2,
Yong-Tang Zheng3, Rui-Rui Wang3, Yang Lü2, Hai-Yang Liu1
1
State Key Laboratory of Phytochemistry and Plant Resources in
West China, Kunming Institute of Botany, Chinese Academy of
Sciences, Kunming, P.R. China
Institute of Materia Medica, Chinese Academy of Medical Sciences,
2
Beijing, P.R. China
Key Laboratory of Animal Models and Human Disease Mechanisms
3
of Chinese Academy of Sciences & Yunnan Province, Kunming Insti-
tute of Zoology, Chinese Academy of Sciences, Kunming, P.R. China
δH 0.78 (d, J = 6.3 Hz), 1.10 (d, J = 6.6 Hz), 1.16 (d, J = 6.6 Hz), and
1.58 (d, J = 6.3 Hz), and an acetal proton at δH 4.58 (d, J = 6.7 Hz)
1
"
Abstract
!
were distinguished by H NMR data (l Table 1). The carbonyl
group accounted for one out of the eight degrees of unsaturation,
and the remaining seven degrees of unsaturation implied com-
pound 1 to be heptacyclic (rings A–G). Interpretation of 1H-1H
COSY spectra of 1 revealed four spin systems (a–d) as shown with
Three new unusual 23-spirocholestane derivatives, ypsilanoge-
nin (1), ypsilanogenin 3-O-β-D-glucopyranoside (2), and 4′-ace-
tylypsilanogenin 3-O-β-D-glucopyranoside (3), were isolated
from the whole plants of Ypsilandra thibetica. The structures of
compounds 1–3 were deduced by spectroscopic and chemical
methods, and the structure of 1 was further confirmed by a sin-
gle-crystal diffraction analysis. All isolates were evaluated for
their inhibitory activities against HIV-1.
"
"
bold bonds in l Fig. 2. Further, the HMBC correlations (l Fig. 2)
from H2-4, H-5, H2-7, and H-8 to C-6, from Me-18 to C-12, C-13,
C-14, and C-17, from Me-19 to C-1, C-5, C-9, and C-10, and from
H-16, H-20, H-24, H-25, and H-2′ to C-23 led to unambiguous as-
signment for the connectivities of the substructures a–c to four
quaternary carbons [δC 210.1 (C-6); δC 40.9 (C-10); δC 42.3 (C-
13); and δC 100.3 (C-23)], and two tertiary methyls. In addition,
the diagnostic HMBC correlation from H-1′ to C-5′ allowed con-
nection of C-1′ to C-5′ by an oxygen bridge. The E-ring and G-ring
were connected by extensive interpretation of the well-resolved
HMBC spectrum. The HMBC correlations of H-1′ (δH 4.58) with C-
24 (δC 85.9), and H-2′ (δH 4.10) with C-23 (δC 100.3) indicated the
linkages in order of C-23-O‑C-2′ and C-24-O‑C-1′. The above data
revealed the planar structure of 1. The different ring junctions
and the stereochemistry around rings A, F, and G were deduced
Key words
Ypsilandra thibetica · Liliaceae · 23‑spirocholestane glycosides ·
anti‑HIV‑1 activity
Supporting information available online at
http://www.thieme-connect.de/ejournals/toc/plantamedica
Ypsilandra thibetica, a perennial plant belonging to the Liliaceae
family, is mainly distributed in southwestern China [1]. The
whole plant has been used for treatment of scrofula, urine nega-
tive, edema, uterine bleeding, and traumatic hemorrhage [2,3].
Our previous studies on the species have resulted in the isolation
of a series of steroidal saponins with cytotoxic and antifungal ac-
tivities [4–9]. Reinvestigation of the phytochemical constituents
of this plant afforded three new cholestane-type steroids, ypsila-
nogenin (1), ypsilanogenin 3-O-β-D-glucopyranoside (2), and 4′-
"
from detailed analysis of the ROESY experiment (l Fig. 2). The
clear NOE correlations from H-8 to Me-18 and Me-19, from H-
14 to H-9, H-16, and H-17, and from H-5 to H-3 and H-9 in the
ROESY spectrum indicated the usual trans ring fusion for rings
A/B, B/C, and C/D as well as a cis junction for rings D/E and β-con-
figuration for OH-3, and that the rings A–C adopted a chair con-
formation. Moreover, NOEs of H-20 with Me-18 was consistent
with the β-configuration for H-20. In addition, the ROESY corre-
lations of H-17/H‑22α, H2-22/H-2′, H-1′/H-24, H-1′/H-3′, H-1′/H-
5′, H-3′/H-4′, and H-3′/H-5′ indicated that H-24, H-1′, H-3′, H-4′,
and H-5′ were α-oriented, while H-2′ and Me-6′ were β-oriented
and rings F–G also adopted a chair conformation. The oxygen-
bridge between C-23 and C-2′ was α-oriented. Finally, the struc-
ture and relative configuration of 1 were unequivocally con-
"
acetylypsilanogenin 3-O-β-D-glucopyranoside (3) (l Fig. 1).
Compounds 1–3 had a unique 23-spirocholestane skeleton with
a ketal carbon at C-23 to link to C-16 and C-2′ of the fucosyl moi-
ety and an oxygen bridge between C-24 and C-1′ of the fucosyl
moiety. We present herein the isolation, structural elucidation,
and anti-HIV activities of the three new compounds.
"
Compound 1, obtained as colorless prisms, had a molecular for-
mula of C33H52O8 as determined by the HR‑ESI‑MS ion at m/z
575.3580 [M – H]− (calcd. for C33H51O8, 575.3583), thus requiring
eight double-bond equivalents. The IR absorptions implied the
firmed by single-crystal X‑ray diffraction (l Fig. 3). Therefore,
"
the structure of 1 was established as shown in l Fig. 1, and the
compound was named ypsilanogenin.
Compound
2 was obtained as colorless prismatic crystals
presence of hydroxyl (3446 cm−1) and carbonyl (1709 cm−1
)
(MeOH). Its negative ion HR‑ESI‑MS exhibited a quasimolecular
ion peak at m/z 737.4109, consistent with a molecular composi-
tion of C39H61O13 (calcd. 737.4112). The deduced molecular for-
mula was higher by C6H10O5 than that of 1, and the 1H NMR spec-
groups. In accordance with its molecular formula, all 33 carbons
were well resolved in the 13C NMR spectrum (l Table 1) and were
"
further classified by DEPT experiments as six methyls, eight
methylenes, 14 methines (7 oxygenated ones), two quaternary
carbons, an acetal, a ketal, and a carbonyl. In addition, two tertia-
ry methyls at δH 0.73 (s) and 0.77 (s), four secondary methyls at
"
trum (l Table 1) showed a signal for an anomeric proton at 5.04
(d, J = 7.7 Hz), along with signals for five cholestane-type steroid
methyl protons at δH 0.63 (s), 0.70 (s), 0.75 (d, J = 6.6 Hz), 1.08
Xie B-B et al. New 23-Spirocholestane Derivatives… Planta Med 2013; 79: 1063–1067

1064 Letters
Table 1 1H and 13C NMR data of compounds 1–3 in C5D5 N.
Position
1
2
3
δ
H (J in Hz)
δC
37.0
δ
H (J in Hz)
δC
36.7
δ
H (J in Hz)
δC
36.9
1α
1β
2α
2β
3
1.18 m
1.66 m
2.05 m
1.67 m
3.84 m
2.31 m
1.91 m
2.25 m
1.03 m
1.52 m
2.05 m
1.57 m
3.98 m
2.37 m
1.72 m
2.08 m
1.00 m
1.52 m
2.04 m
1.57 m
3.95 m
2.36 m
1.72 m
2.01 m
31.8
29.5
29.5
70.0
31.3
76.6
27.0
76.8
27.1
4α
4β
5
56.9
210.1
46.9
56.4
209.7
46.8
56.5
209.7
46.8
6
7α
7β
8
2.38 m
1.98 m
1.60 m
1.15 m
2.36 m
1.99 m
1.57 m
1.11 m
2.36 m
1.97 m
1.60 m
1.09 m
26.0
53.8
40.9
21.6
26.0
53.7
40.9
21.5
26.1
53.8
40.9
21.5
9
10
11α
11β
12α
12β
13
14
15α
15β
16
17
18
19
20
21
22α
22β
23
24
25
26
27
1′
1.52 m
1.27 m
1.77 m
1.09 m
1.45 m
1.22 m
1.74 m
1.05 m
1.43 m
1.21 m
1.73 m
1.03 m
40.2
40.1
40.1
42.3
52.5
32.8
42.2
52.5
32.7
42.2
52.5
32.7
0.90 m
1.87 m
1.20 m
4.47 m
0.80 m
0.73 s
0.89 m
1.87 m
1.18 m
4.48 m
0.80 m
0.70 s
0.87 m
1.84 m
1.18 m
4.43 m
0.80 m
0.71 s
71.4
58.8
14.9
13.3
37.0
20.9
37.3
71.4
58.8
14.9
13.1
36.9
20.9
37.3
71.5
58.8
14.9
13.1
36.7
20.9
37.4
0.77 s
0.63 s
0.64 s
1.82 m
0.78 d (6.3)
2.23 m
1.09 m
1.77 m
0.75 d (6.6)
2.21 m
1.10 m
1.76 m
0.83 d (6.1)
2.38 m
1.23 m
100.3
85.9
28.2
18.1
22.9
101.4
72.3
73.6
73.0
73.5
17.2
100.3
85.9
28.2
18.1
22.9
101.4
72.3
73.6
73.0
73.5
17.2
102.2
75.4
78.7
71.8
78.7
63.0
100.5
86.1
28.2
18.1
22.9
101.2
70.0
74.0
74.3
71.8
16.6
102.2
75.4
78.7
71.9
78.6
63.0
3.59 d (5.1)
2.08 m
3.58 d (6.2)
2.07 m
3.58 d (4.6)
2.09 m
1.10 d (6.6)
1.16 d (6.6)
4.58 d (6.7)
4.10 m
1.08 d (6.5)
1.14 d (6.5)
4.56 d (6.3)
4.12 m
1.09 d (6.7)
1.15 d (6.7)
4.59 d (7.9)
4.29 m
2′
3′
4.12 m
4.12 m
4.00 m
4′
4.05 brs
4.07 brs
5.60 d (3.4)
3.98 m
5′
3.86 (m)
3.87 m
6′
1.58 d (6.3)
1.57 d (5.9)
5.04 d (7.7)
4.05 m
1.32 d (6.3)
5.01 d (7.6)
4.04 m
1′′
2′′
3′′
4′′
5′′
6′′a
6′′b
Ac
4.30 m
4.28 m
4.23 m
4.24 m
4.00 m
4.00 m
4.61 d (11.2)
4.39 dd (12.5, 5.6)
4.61 m
4.40 m
2.19 s
171.0
21.0
(3H, d, J = 6.5 Hz), and 1.14 (d, J = 6.5 Hz). On comparison of the
anomeric center of the glucopyranosyl was supported by the rel-
atively large J value of the anomeric proton (J = 7.7 Hz). The HMBC
spectrum showed a long-range correlation peak from the ano-
meric proton of the glucopyranosyl group at δH 5.04 to C-3 of
the aglycone at δC 76.6. Consequently, these considerations es-
whole 13C NMR spectrum of 2 with 1 (l Table 1), a set of six sig-
"
nals corresponding to a D-glucopyranosyl moiety were observed
at δC 102.2 (d), 75.4 (d), 78.7 (d), 71.8 (d), 78.7 (d), and 63.0 (t),
and the signals due to C-3 of the aglycone and its neighboring
carbon varied, while all other signals remained almost unaf-
fected. Acid hydrolysis of 2 with 4 M TFA released D-glucose resi-
due, as determined by GC analysis of the corresponding trimeth-
ylsilated L-cysteine adduct [10]. The β-configuration of the
"
tablished the structure of 2 as indicated in l Fig. 1, and the com-
pound was named ypsilanogenin 3-O-β-D-glucopyranoside.
Compound 3 was obtained as white amorphous powder and had
the molecular formula C41H64O14 on the basis of the negative ion
Xie B-B et al. New 23-Spirocholestane Derivatives… Planta Med 2013; 79: 1063–1067

Letters 1065
Fig. 2 Selected 2D NMR correlations of compound
1. (Color figure available online only.)
Fig. 3 Single-crystal X‑ray structure of compound
1.
HR‑ESI‑MS (m/z 779.4201 [M – H]−; calcd. 779.4217). Compari-
son of the 1H- and 13C NMR spectra of 3 with those of 2 showed
their considerable structural similarity. However, 3 had an addi-
tional acetyl group, which was supported by the NMR signals at
The powdered air-dried whole plants of Y. thibetica (30 kg) were
extracted with 70% EtOH (3 × 180 L, total amount 540 L) under re-
flux for a total of 6 h. After removal of the solvent in vacuo, the
residue was suspended in H2O (20 L) and successively extracted
with petroleum ether (3 × 15 L), EtOAc (3 × 15 L), and n-BuOH
(3 × 15 L). TLC of the EtOAc extract showed different spots from
the reported steroidal saponins isolated from the species. The
solvent was removed to give the EtOAc extract (820 g), of which
800 g was further defatted over a column (10 × 140 cm) of MCI gel
CHP20P (4 L) eluted with 90% methanol (25 L) and then applied to
silica gel column chromatography (20 × 120 cm, 200–300 mesh,
6.4 kg; gradient CHCl3-MeOH, 20:1 → 0:1, 300 L) to afford frac-
tions 1–8. Fr. 4 (8.0 g) was further separated by RP-18 column
chromatography (3 × 48 cm, 150 g; 70–90% aqueous MeOH, 10 L)
to afford 1 (30 mg). Fr. 5 (15 g) was repeatedly purified by silica
gel (5 × 60 cm, 300 g; CHCl3-MeOH = 12:1, 15 L), Sephadex LH-
20 (3 × 180 cm, MeOH, 1.5 L), and then semiprep. HPLC
(MeOH‑H2O = 75:25, flow rate 3 mL/min) to yield 3 (10 mg). Fr.
6 (3.3 g) was subjected to silica gel CC (2.5 × 60 cm, 100 g), eluted
with CHCl3-MeOH (10:1, 5.5 L) and then Sephadex LH-20
(1.5 × 180 cm, MeOH, 0.5 L) to give 2 (100 mg).
δ
H 2.19 (3H, s), δC 21.0 (q), and δC 171.0 (s), and by the mass dif-
ference of m/z = 42 between 3 and 2. The above evidence sug-
gested that compound 3 is a monoacetate of 2. The acetoxyl group
was positioned at C-4′ on the basis of HMBC correlations of H-4′
(δH 5.60) with the acetyloxy group (δC 171.0), C-2′ (δC 70.0), C-3′
(δC 74.0), and C-5′ (δC 71.8). Accordingly, the structure of 3 was
"
assigned as depicted in l Fig. 1, and the compound was named
4′-acetylypsilanogenin 3-O-β-D-glucopyranoside.
To the best of our knowledge, helojaposide [11] obtained from
Heloniopsis japonica (Liliaceae) was the only example having the
same skeleton as compounds 1–3, but it possessed a hydroxyl
group at C-22 and a β-orientation for the oxygen-bridge between
C-23 and C-2′. Compounds 1–3 were tested for cytotoxicities
against C8166 cells (CC50), and anti-HIV-1 activities were eval-
uated by the inhibition assay for the cytopathic effects of HIV-1
(EC50), using AZT as a positive control. Each experiment was re-
"
peated three times. The results (l Table 2) indicated that only
compound 1 showed weak anti-HIV-1 activity with an EC50 value
of 19.34 µg/mL and a therapy index (TI) of 6.57.
Isolates
Ypsilanogenin (1): colorless prisms (CHCl3-MeOH 4:1); mp 208–
Materials and Methods
209°C; [α]2D5 + 5.3 (c 0.76, pyridine); IR (KBr) vmax 3446, 2957,
2870, 1709, 1454, 1383, 1061 cm−1
;
1H NMR (pyridine-d5,
!
13
"
The whole plants of Y. thibetica were collected in Zhaotong,
Yunnan Province, China, in May 2011, and were identified by
one of the authors, Prof. Chang-Xiang Chen. A voucher specimen
(No. 0303771) was deposited at the Herbarium of the Depart-
ment of Taxonomy, Kunming Institute of Botany, Chinese Acade-
my of Sciences.
400 MHz) and C NMR (pyridine-d5, 100 MHz), see l Table 1;
FAB‑MS (negative): m/z 575 [M – H]−; HR‑ESI‑MS m/z 575.3580
[M – H]− (calcd. for C33H51O8, 575.3583).
Ypsilanogenin 3-β‑D-glucopyranoside (2): colorless prisms
(MeOH); mp 228–229°C; [α]2D2 − 25.7 (c 0.70, pyridine); IR (KBr)
vmax 3456, 2951, 2872, 1703, 1456, 1389, 1370, 1062, 892 cm−1
;
1H NMR (pyridine-d5, 400 MHz) and 13C NMR (pyridine-d5,
Xie B-B et al. New 23-Spirocholestane Derivatives… Planta Med 2013; 79: 1063–1067

1066 Letters
Compound
EC50a (µg/mL)
CC50b (µg/mL)
ꢀTIc
Table 2 Anti-HIV‑1 activities of
compounds 1–3.
1
19.34 2.16
127.05 12.11
> 200
6.57
> 2.07
> 2.89
2
96.33 7.83
3
69.24 4.46
> 200
AZTd
0.00351 0.00034
1210.00 74.68
344729.34
a
EC50: effective concentration required to protect C8166 cells against the cytopathogenicity of HIV-1 by 50%. b CC50: cytotoxic concen-
tration required to reduce C8166 cell proliferation by 50% tested by the MTT method. c TI: therapeutic index, ratio of the CC50 value/EC50
value. d AZT was used as a positive control
−
"
100 MHz), see l Table 1; FAB‑MS (negative): m/z 737 [M – H] ;
determined by comparison of the retentions times of the corre-
sponding derivatives with those of standard D-glucose giving a
single peak at 19.01 min.
HR‑ESI‑MS m/z 737.4109 [M
– ,
H]− (calcd. for C39H61O13
737.4112).
4′-Acetylypsilanogenin 3-β‑D-glucopyranoside (3): colorless amor-
phous powder; [α]2D6 − 13.3 (c 0.95, pyridine); IR (KBr) vmax 3443,
Anti-HIV‑1 assay
2957, 2872, 1743, 1711, 1454, 1382, 1371, 1061, 892 cm−1
;
1H
The cytotoxicity assay against C8166 cells (CC50) was performed
using the MTT method, and anti-HIV-1 activity was evaluated by
the inhibition assay for cytopathic effects of HIV-1 (EC50) [13].
Three tested compounds gave a single peak upon HPLC analysis,
and their purity was therefore at least 98%. AZT (Sigma, 98%) was
used as the positive control.
NMR (pyridine-d5, 400 MHz) and 13C NMR (pyridine-d5,
−
"
100 MHz), see l Table 1; FAB‑MS (negative): m/z 779 [M – H] ,
737 [M – H – 42]−, 617 [M – H – 162]−, 575 [M – H – 42–162]−;
HR‑ESI‑MS m/z 779.4201 [M
– ,
H]− (calcd. for C41H63O14
779.4217).
X‑ray crystal structure analysis
Supporting information
Colorless crystals of 1 were obtained from the mixture of chloro-
1D and 2D NMR spectra of compounds 1–3 and crystal data of 1
form and methanol. Diffraction intensity data were collected
are available as Supporting Information.
with
a MAC DIP-2030K diffractometer employing graphite
monochromated Mo Kα radiation and operating in the ω scan
mode. The crystal structure was solved by the direct method
SHELXS-97 [12], expanded by using difference Fourier tech-
niques and refined by the program and method NOMCSDP and
full-matrix least-squares calculations. The hydrogen atoms were
fixed at their calculated positions.
Crystal data: C33H52O8·CH3OH·CHCl3, MW = 576.77 (no solvent of
crystallization); monoclinic system, space group P21; crystal cell
parameters a = 15.161 (2) Å, b = 8.649 (1) Å, c = 15.652 (2) Å,
β = 108.44 (2)°; V = 1947.0 (3) Å3, Z = 2, Dcalc = 1.122 g/cm3. A
crystal of dimensions 0.20 × 0.50 × 1.50 mm was used for mea-
surements (2θmax = 50.0°). The total number of independent re-
flections measured was 3319, of which 3306 were observed
(|F|2 ≥ 3σ |F|2). The final indices were R1 = 0.0684, wR2 = 0.1904,
and S = 1.001. Crystallographic data for 1 has been deposited in
the Cambridge Crystallographic Data Centre with the deposition
number CCDC 885109. These data can be obtained free of charge
from the Cambridge Crystallographic Data Centre via http://
www.ccdc.cam.ac.uk/data_request/cif.
Acknowledgements
!
This work was financially supported by the National Natural Sci-
ence Funding of China (No. 31170333, 81102483), the Natural
Science Foundation of Yunnan Province (No. 2009CC019), the
West Light Foundation of the Chinese Academy of Sciences
(No. 2908025712W1), and the 973 Program (2009CB522300).
Conflict of Interest
!
The authors declare no conflict of interest in this work.
References
1 Hou KZ. Dictionary of the families and genera of Chinese seed plants,
2nd edition. Beijing: Science Press; 1982: 521–522
2 Jiangsu New Medicinal College. Dictionary of traditional Chinese mate-
ria medica. Shanghai: Shanghai Scientific and Technological Press;
1977: 1841–1841
3 Yunnan Food and Drug Administration. The Yunnan Chinese materia
medica standards, Volume 6 (Yi Nationality Medicine, III). Kunming:
Yunnan Scientific and Technological Press; 2010: 5–6
4 Xie BB, Liu HY, Ni W, Chen CX, Lü Y, Wu L, Zheng QT. Five new steroidal
compounds from Ypsilandra thibetica. Chem Biodivers 2006; 3: 1211–
1218
5 Xie BB, Liu HY, Ni W, Chen CX. Ypsilandrosides C–G, five new spirostanol
saponins from Ypsilandra thibetica. Steroids 2009; 74: 950–955
6 Lu Y, Chen CX, Ni W, Hua Y, Liu HY. Spirostanol tetraglycosides from
Ypsilandra thibetica. Steroids 2010; 75: 982–987
7 Lu Y, Xie BB, Chen CX, Ni W, Hua Y, Liu HY. Ypsilactosides A and B, two
new C22-steroidal lactone glycosides from Ypsilandra thibetica. Helv
Chim Acta 2011; 94: 92–97
8 Liu HY, Chen CX, Lu Y, Yang JY, Ni W. Steroidal and pregnane glycosides
from Ypsilandra thibetica. Nat Prod Bioprospect 2012; 2: 11–15
9 Zhang XD, Chen CX, Yang JY, Ni W, Liu HY. New minor spirostane glyco-
sides from Ypsilandra thibetica. Helv Chim Acta 2012; 95: 1087–1093
10 Hara S, Okabe H, Mihashi K. Gas-liquid chromatographic separation of
aldose enantiomers as trimethylsilyl ethers of methyl 2-
(polyhydroxyalkyl)-thiazolidine-4(R)-carboxylates. Chem Pharm Bull
1987; 35: 501–506
Acid hydrolysis
Compounds 2 and 3 (3 mg) were refluxed with 4 M TFA-dioxane
(1:1 v/v, 2 mL) in a water bath for 2 h. After cooling, the reaction
mixture was extracted with EtOAc (3 × 5 mL). The aqueous layer
was evaporated to dryness with MeOH until neutral. The dried
residue was dissolved in 0.5 mL anhydrous pyridine and treated
with L-cysteine methyl ester hydrochloride (1.0 mg) stirred at
60°C for 1 h. Trimethylsilylimidazole (0.5 mL) was added to the
reaction mixture which was then kept at 60°C for 30 min. The
supernatants (2 µL) were analyzed by GC, respectively, under the
following conditions: H2 flame ionization detector; column:
30QC2/AC‑5 quartz capillary column (30 m × 0.32 mm); column
temperature: 180–280°C with the rate of 3°C/min, and carrier
gas N2 (1 mL/min); injector temperature: 250°C; split ratio: 1/
50. The configuration of D-glucose for compounds 2 and 3 was
Xie B-B et al. New 23-Spirocholestane Derivatives… Planta Med 2013; 79: 1063–1067

Letters 1067
11 Shingu K, Mito K, Yahara S, Nohara T, Ono M, Kawasaki T, Nakano K, To-
mimatsu T, Haratake M, Marubayashi N, Ueda I. A novel cholestane de-
rivative as root growth inhibitor from Heloniopsis japonica. Tetrahe-
dron Lett 1992; 33: 2529–2530
12 Sheldrick GM. SHELXL97, Program for crystal structure solution. Göt-
tingen: University of Göttingen; 1997
13 Wang RR, Yang LM, Wang YH, Pang W, Tam SC, Tien P, Zheng YT. Sifuvir-
tide, a potent HIV fusion inhibitor peptide. Biochem Biophys Res Com-
mun 2009; 382: 540–544
received January 23, 2013
revised
May 10, 2013
accepted May 20, 2013
Bibliography
DOI http://dx.doi.org/10.1055/s-0032-1328719
Published online July 1, 2013
Planta Med 2013; 79: 1063–1067
© Georg Thieme Verlag KG Stuttgart · New York ·
ISSN 0032‑0943
Correspondence
Dr. Hai-Yang Liu
State Key Laboratory of Phytochemistry and Plant Resources in West China
Kunming Institute of Botany, Chinese Academy of Sciences
132# Lanhei Road
Kunming 650201
P.R. China
Phone: + 8687165223246
Fax: + 8687165223245
haiyangliu@mail.kib.ac.cn
Xie B-B et al. New 23-Spirocholestane Derivatives… Planta Med 2013; 79: 1063–1067

Copyright of Planta Medica is the property of Georg Thieme Verlag Stuttgart and its content
may not be copied or emailed to multiple sites or posted to a listserv without the copyright
holder's express written permission. However, users may print, download, or email articles for
individual use.