Pregnane and pregnane tetraglycoside from Marsdenia roylei

Article abstract of DOI:10.1080/14786419.2010.522189

Pregnane oligoglycoside, namely roylinine (1), and a pregnane derivative, namely marsgenin (11), have been isolated from chloroform-soluble extract of dried stem of Marsdenia roylei, and their structures were determined using 1H-NMR, 13C-NMR, 1H-1H COSY, HSQC, TOCSY and FABMS spectral techniques as well as chemical degradation and derivatisation.

Full text of DOI:10.1080/14786419.2010.522189

This article was downloaded by: [University of Hawaii at Manoa]
On: 24 December 2014, At: 22:58
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered
office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK
Natural Product Research: Formerly
Natural Product Letters
Publication details, including instructions for authors and
subscription information:
http://www.tandfonline.com/loi/gnpl20
Pregnane and pregnane tetraglycoside
from Marsdenia roylei
Versha Gupta a , Alok Kumar b , Anakshi Khare a & Naveen K.
Khare a
a Department of Chemistry , Lucknow University , Lucknow
226007, India
b Department of Chemistry , Northern India Engineering College ,
Lucknow 227105, India
Published online: 31 May 2011.
To cite this article: Versha Gupta , Alok Kumar , Anakshi Khare & Naveen K. Khare (2011) Pregnane
and pregnane tetraglycoside from Marsdenia roylei , Natural Product Research: Formerly Natural
Product Letters, 25:10, 959-973, DOI: 10.1080/14786419.2010.522189
To link to this article: http://dx.doi.org/10.1080/14786419.2010.522189
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the information (the
“Content”) contained in the publications on our platform. However, Taylor & Francis,
our agents, and our licensors make no representations or warranties whatsoever as to
the accuracy, completeness, or suitability for any purpose of the Content. Any opinions
and views expressed in this publication are the opinions and views of the authors,
and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content
should not be relied upon and should be independently verified with primary sources
of information. Taylor and Francis shall not be liable for any losses, actions, claims,
proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or
howsoever caused arising directly or indirectly in connection with, in relation to or arising
out of the use of the Content.
This article may be used for research, teaching, and private study purposes. Any
substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing,
systematic supply, or distribution in any form to anyone is expressly forbidden. Terms &

Conditions of access and use can be found at http://www.tandfonline.com/page/terms-
and-conditions

Natural Product Research
Vol. 25, No. 10, June 2011, 959–973
Pregnane and pregnane tetraglycoside from Marsdenia roylei
a
a
Versha Gupta , Alok Kumar , Anakshi Khare and Naveen K. Khare
b
a
*
b
aDepartment of Chemistry, Lucknow University, Lucknow 226007, India; Department of
Chemistry, Northern India Engineering College, Lucknow 227105, India
(Received 9 April 2010; final version received 19 July 2010)
Pregnane oligoglycoside, namely roylinine (1), and a pregnane derivative,
namely marsgenin (11), have been isolated from chloroform-soluble extract
of dried stem of Marsdenia roylei, and their structures were determined
1
1
using H-NMR, 13C-NMR, H-1H COSY, HSQC, TOCSY and FABMS
spectral techniques as well as chemical degradation and derivatisation.
Keywords: Asclepiadaceae; Marsdenia roylei; steroid; pregnane; pregnane
oligoglycoside; marsgenin; roylinine
1. Introduction
Pregnane and their glycosides (Deepak, Srivastava, & Khare, 1997) have been isolated
from various plant species, mostly belonging to the Asclepiadaceae family. They have
been drawing much attention due to their antifungal (Hu et al., 1999), immunosti-
mulant, antitumour (Pan, Chang, Wei, & Wu, 2003; Qiu et al., 1999), antic-
omplementary, antiepileptic, antiasthmatic, antineoplastic, platelet pro-aggregating
(Piacente, Belisario, Delcastillo, Pizza, & De Feo, 1998) and digitalis receptor-binding
activities (Templeton, Ling, Zeglam, & LaBella, 1993). In the search for these novel
compounds, various species of the genus Marsdenia (Family: Asclepiadaceae) have
been examined chemically and a number of biologically active pregnane glycosides of
deoxy hexoses (Deepak et al., 1997; Hayashi et al., 1981; Luo, Lin, Cordell, Xue, &
Johnson, 1993; Mitsuhashi et al., 1993; Yuan et al., 1991, 1992) and oligosaccharides
(Saner, Zerlentis, Stocklin, & Reichstein, 1969; Singhal, M. Khare, & A. Khare, 1980)
have been isolated. In our previous studies on Marsdenia roylei, four oligosaccharides
(Kumar, N. Khare, & A. Khare, 1999a) as well as one pregnane derivative and two
pregnane glycosides (Gupta, Kumar, Deepak, A. Khare, & N. Khare, 2003) were
reported from the chloroform (CHCl3)-soluble extract. In addition to these, two
pregnane oligoglycosides (Gupta, Kumar, A. Khare, & N. Khare, 2009) were also
reported from the CHCl3-soluble extract. This article illustrates the isolation and
structure elucidation of two novel compounds, pregnane and tetraglycoside, namely
roylinine (1) and marsgenin (11), from M. roylei (Figures 1 and 2).
*Corresponding author. Email: nkhare58@gmail.com
ISSN 1478–6419 print/ISSN 1478–6427 online
ß 2011 Taylor & Francis
DOI: 10.1080/14786419.2010.522189
http://www.informaworld.com

960
V. Gupta et al.
CH3
OR„
17
OR
14
H
12
1
S4
S3
S2
H3C
S1
10
H3C
OH
H3C
H3C
O
O
3
O
O
O
O
O
O
6
RO
MeO
OMe
OMe
OR
OMe
6„
7„
2„
5„
OC
1„
1. R = H, R„ =
4„
3„
2. R = Ac, R„ = –COC6H5
3. R„ = R = H
Figure 1. Roylinine and its derivatives.
CH
3
OR„
H
OR
R„O
OH
OH
OH
RO
11. R = H, R„ = ikemoyl group, –CO–CH=C(CH )–CH(CH )
3
3 2
12. R = Ac, R„ = ikemoyl group
13. R = R„ = H
Figure 2. Marsgenin and its derivatives.
2. Results and discussion
2.1. Roylinine (1)
Roylinine (1), C56H86O18, [ꢀ]D þ 30ꢀ, displayed a characteristic colour in the tests for
2,6-dideoxy sugars in xanthydrol (Barton, Evans, & Gardner, 1952) and Keller–
Kiliani reactions (Nagata, Tamm, & Reichstein, 1957). It also responded positively
to Liebermann–Burchardt test (Abisch & Reichstein, 1960) for steroids, indicating
1
that it is a steroidal glycoside of 2,6-dideoxy hexose(s). The H-NMR spectrum of 1
showed the presence of four anomeric proton signals as double doublets (J ¼ 10 and
2 Hz), (J ¼ 9.9 and 2 Hz) and (J ¼ 10 and 2 Hz) at ꢁ 5.05, ꢁ 4.88 and ꢁ 4.84 ppm,
respectively, and as doublet (J ¼ 9 Hz) of one proton each at ꢁ 4.59 ppm, suggesting
the presence of four sugar units as ꢂ in 1, which indicated that it is a tetraglycoside.
The tetraglycoside nature of 1 was further supported by the presence of four
anomeric carbon signals at ꢁ 102.1, ꢁ 99.7, ꢁ 99.4 and ꢁ 91.9 ppm in its 13C-NMR
spectrum, which was also confirmed by the HSQC experiment of 1.
The presence of three equatorial and three axial protons at H-2 of 2-deoxy hexoses
was confirmed by multiplets at ꢁ 2.50–2.06 and ꢁ 2.00–1.50 ppm, respectively, in the
1H-NMR spectrum of 1, which ascertained the presence of three out of four hexoses,
1
which are 2-deoxy in nature. The H-NMR spectrum of 1 showed the secondary
methyl group doublets (J ¼ 7 Hz) at ꢁ 1.32 ppm for six protons of sugars S3 and S4 and

Natural Product Research
961
at 1.13 for six protons of sugars S1 and S2. Besides, the spectrum of 1 also showed the
additional secondary methyl group doublet (J ¼ 6.9 Hz) of the aglycon moiety at C-21
for three protons at ꢁ 1.10 ppm, which provided evidence that 1 is a tetraglycoside
involving three 2,6-dideoxy hexoses and one 6-deoxy hexose (chemical shifts of
secondary methyl groups may be interchanged).
The substance
method to yield deacylated product 3. The presence of this benzoyl ester function
1 underwent positive alkaline hydrolysis by Zemplen
1
in 1 was well supported by H-NMR and 13C-NMR spectral data, as well as by
FABMS.
To identify the sugar and aglycon units of 1, compound 3 was hydrolysed with
mild acid (0.05N H2SO4) (Rangaswami & Reichstein, 1949), which resulted in
aglycon (4), and a mixture of two sugars 5 and 6 (TLC), which were preparatively
isolated. The separated sugar displayed characteristic colours in the tests for 2,6-
dideoxy sugars in xanthydrol and Keller–Kiliani reactions. A comparison of optical
rotation and mobility on paper chromatography (PC) of 6 with those of authentic
samples indicated that 6 is D-cymarose (2,6 dideoxy-3-O-methyl-D-ribo hexose)
(Krasso, Weiss, & Reichstein, 1963) (TLC, PC, [ꢀ]D). Further characterisation of the
sugar 6 was done by bromine water oxidation, leading to the formation of the
respective lactone 7, namely D-cymarono-1,4-lactone (Krasso et al., 1963), followed
by treatment with phenyl hydrazine, which resulted in the known D-cymaronic acid
phenyl hydrazide (Krasso et al., 1963) (8), m.p. 152ꢀC, found identical with the
authentic sample (TLC, PC, m.p., m.m.p.). A comparison of relative mobility on PC
of 5, done by taking oleandrose as reference indicated that it was a disaccharide
pachybiose
[4-O-(3-O-methyl-6-deoxy-ꢂ-D-allopyranosyl)-D-oleandropyranose]
(Sauer, Weiss, & Reichstein, 1966). Compound 5, m.p. 157ꢀC, [ꢀ]D – 9.1ꢀ, was
found to be identical with the authentic sample of pachybiose (TLC, [ꢀ]D, m.p. and
m.m.p). To further confirm the disaccharide nature of 5 as pachybiose, it was
hydrolysed with acid under drastic conditions using the method of Kiliani (1930),
which yielded sugar 9, m.p. 114ꢀC, [ꢀ]D þ 6.8ꢀ, exhibiting the same mobility on PC as
3-O-methyl-6-deoxy-D-allose (PC, m.p., m.m.p., [ꢀ]D) (Figure 3). The 2-deoxy
CH
3
OH
CH
3
OH
H
CH
3
O
O
CH
3
H, OH
OMe
5.
H, OH
O
O
HO
OH
OCH
6.
3
HO
HO
OMe
OH
4.
CH
3
CH
O
C
3
HO
H
O
NHNHPh
O
H, OH
O
H
H
HO
H
OCH
3
OMeOH
9.
H
H
H
OH
OCH
7.
3
OH
CH3
8.
CH
3
OH
H
OH
H
C
3
OH
O
O
HO
10.
OMe
Figure 3. Acid hydrolysis products of roylinine.

962
V. Gupta et al.
component appeared to be decomposed under this stronger condition, suggesting
that this disaccharide belongs to the class consisting of a normal 6-deoxy hexose at
the non-reducing end and another 2,6-dideoxy hexose at the reducing end, reported
earlier in various Asclepiadaceae plants.
The aglycon moiety (4), C21H34O4, m.p. 235–238ꢀC, [ꢀ]D – 4.3ꢀ, showed positive
result in the Liebermann–Burchardt test for steroids and tetranitromethane test for
the presence of isolated double bond. It did not react with NaIO4 and this indicated
the absence of a vicinal diol group in it. From the m.p. and specific rotation
comparison, compound 4 was found to be boucerin (pregn-5-ene-3ꢂ, 12ꢂ, 14ꢂ, 20ꢂ
tetrol) (TLC, Co-TLC, [ꢀ]D, m.p., m.m.p.).
Chemical support for 1 being a tetraglycoside of two cymaroses and the
disaccharide pachybiose and determination of the sequence of the sugar units came
from the results of very mild acid hydrolysis (0.005N H2SO4) (Rangaswami &
Reichstein, 1949) of its deacylated product 3 on TLC at room temperature, which
resulted in partially and completely hydrolysed products. After 4 days, the reaction
mixture exhibited the appearance of three new spots of disaccharide pachybiose (5),
D-cymarose (6) and presumably a monoglycoside (10), besides the unreacted starting
material (3) on TLC. The hydrolysis was completed in 7 days after the disappearance
of the starting material (3) and presumably a monoglycoside (10) based on the
relative mobility on TLC. The hydrolysate exhibited no additional new spots except
those of the aglycon (4). As disaccharide pachybiose (5) was the first sugar liberated
in the partial hydrolysis of 3, it was concluded to be at the terminal non-reducing end
and the other sugar cymarose was found to be glycosidically linked to the aglycon
moiety, namely boucerin, possibly at C-3 hydroxyl group (Figure 3). Therefore, it
was further concluded that the fourth sugar, cymarose (S2) was sandwiched between
pachybiose (5) and cymarose (6) units in 1.
The presence of three hydroxyl groups in 1 was established by its acetylation with
Ac2O and pyridine at room temperature, yielding a tri-O-acetyl derivative (2),
[ꢀ]D þ 17.4ꢀ, which showed a nine-proton singlet at ꢁ 2.10 ppm for the three acetyl
1
1
groups in the H-NMR spectrum of 2. Comparison of the H-NMR spectrum of 1
and 2 showed the downfield shifting of the methine protons at H-2 of S4 and H-4 of
S4 as double doublets (J ¼ 10 and 2 Hz) and (J ¼ 9 and 2 Hz) at ꢁ 4.80 and ꢁ 4.74 ppm,
respectively, and these could be assigned to the methine protons present at the
1
carbons bearing acetoxy group in the H-NMR spectrum of 2. Likewise, the H-12
methine proton was also shifted downfield as double doublet (J ¼ 9 and 2 Hz) from
ꢁ 4.13 to ꢁ 5.05 ppm in 2, which indicated that the hydroxyl group at C-12 is free in 1.
Therefore, the benzoyl ester group in 1 could only be present at the remaining
available position of the C-20 hydroxyl group since H-20 methine proton appeared
1
downfield as a multiplet of one proton at ꢁ 5.01–4.99 ppm. Besides, the H-NMR
spectrum of 2 also supported the tetraglycoside nature of 1, which showed the four
anomeric protons signals at ꢁ 5.05 ppm (1H, dd, J ¼ 9 and 2 Hz) for S1, ꢁ 4.80 ppm
(1H, dd, J ¼ 10 and 2 Hz) for S2, ꢁ 4.74 ppm (1H, dd, J ¼ 9 and 2 Hz) for S3 and
ꢁ 4.59 ppm (1H, d, J ¼ 9 Hz) for S4, besides other characteristic signals
1
(Section 3.3.4). The H-NMR spectra of the glycoside 1 and 2 not only confirmed
the derived structure but also ascertained the configuration of the glycosidic linkage.
The large values of coupling constants in 1H-NMR spectrum for all the four
anomeric protons in compound 1 were typical of axial configuration of
hexopyranose in 4C1 (D) conformations (Allgeier, 1968), which indicated ꢂ-glycosidic

Natural Product Research
963
linkages in all the four hexoses. The assignments of methine protons of hexoses were
also supported by the COSY, HSQC and TOCSY experiments of 2-D NMR
spectroscopy of 1.
The FAB mass spectrum of 1 did not record the molecular ion peak, but
other prominent ion peaks in the higher mass region, which further substantiated
the derived structure. The individual monosaccharide units break according to
H-transfer mechanism (Srivastava, Deepak, & Khare, 1994), along with the
hydroxyl group displacement every time. It gets detached from the glycosidic
bond. The stepwise elimination of monosaccharide units leads to mass fragment
corresponding to the genin and therefore unambiguously supported the derived
structure 1. In the FAB mass spectrum of 1, the triglycoside was obtained after
the loss of terminal sugar S4 (m/z 161) and its complementary mass ion peak was
obtained at m/z 886. In another fragmentation pathway, the diglycoside was
obtained at m/z 681 (742-2CH3–OCH3) after the loss of disaccharide (sugars S4
and S3) at m/z 305. Likewise, the monoglycoside was obtained at m/z 563
(598-OH–H2O) after the loss of trisaccharide (sugars S4, S3 and S2) at m/z 449
(Schemes 1–4).
Subsequently in another scheme, the genin moiety was obtained at m/z 305
(454-CH(Me)OCOPh) after the loss of tetrasaccharide (sugars S4, S3, S2 and S1) at
561 (593-CH3OH) from substance 1 (Section 3.3).
In the light of foregoing evidences, the structure of roylinine (1) was proposed
as 20-O-benzoyl-boucerin-3-O-6-deoxy-3-O-methyl-O-ꢂ-D-allopyranosyl (1 ! 4)-O-
ꢂ-D-oleandropyranosyl (1 ! 4)-O-ꢂ-D-cymaropyranosyl (1 ! 4)-O-ꢂ-D-cymaro-
pyranoside.
2.2. Marsgenin (11)
Marsgenin (11), C35H54O9, [ꢀ]D ꢁ 15ꢀ, responded positively to Liebermann–
Burchardt test (Abisch & Reichstein, 1960) for steroids and underwent alkaline
hydrolysis by Zemplen method, but did not oxidise with sodium periodate.
The positive alkaline hydrolysis by Zemplen method shown by 11 indicated the
presence of acyl group in it. This acyl group could not be a benzoyl/or cinnamoyl as
1
the ester function in 11, since it did not show the aromatic protons in the H-NMR
spectrum of 11. Due to the 35 carbon atoms (C35H54O9) present in the molecular
formula of compound 11, it may be assumed that there may be two additional
ikemoyl moieties as esters present in 11. The presence of two ikemoyl groups was
1
ascertained by H-NMR and 13C-NMR spectra of 11.
1
The H-NMR spectrum of 11 showed the multiplet of two olefinic protons at
ꢁ 5.47–5.43 ppm for H-20 and H-200, multiplet of two protons appearing in the region
of ꢁ 3.52–3.41 ppm for the methine protons at H-40 and H-400, the 12-proton doublet
(J ¼ 6.5 Hz) at ꢁ 1.25 ppm for the secondary methyl group present at H-50, H-500, H-60
and H-600 and a singlet of six protons of two methyl groups appearing at ꢁ 1.17 ppm
which were present at H-70 and H-700 of the ikemoyl moieties.
The 13C-NMR spectrum of 11 further supported the presence of two ikemoyl
groups in 11, which showed the two olefinic carbon signals at ꢁ 121.7 ppm for C-20
and at ꢁ 122.0 ppm for C-200; two tertiary carbon signals at ꢁ 150.5 ppm were assigned
to C-30 and C-300, two methine carbon signals at ꢁ 38.9 ppm for C-40 and at ꢁ 39.2 ppm

964
V. Gupta et al.
CH3
OH
O
C
O
Ph
CH3
CH3
O
CH3
CH3
OH
O
O
O
O
O
O
OMe
O
HO
MeO
H
OH
OMe
OMe
1.
H-transfer
CH3
CH3
CH3
CH3
OH
CH3
O
O
C Ph
O
O
O
O
O
O
OMe
O
HO
MeO
OH
OH
OMe
OMe
HO
[m/z 593]
– C H ( M e ) O C O P h
– C H 3
m/z 305
[m/z 454]
m/z 403
–2H2O
– C H 3OH
Frag 'B' ring
m/z 561
5
2CH OH
–
3
RDA at
m/z 497
– C H 3CHO
m/z 453
HO
H
HO
CH3
O
m/z 139
OH
m/z 137
– H 2O
C
O
Ph
HO
– H 2O
m/z 138
– H 2O
OH
[m/z 316]
– C H ( M e ) O C O P h
H
m/z 120
– C H 3
m/z 121
m/z 119
m/z 167
– C H 3
m/z 152
m/z 105
Scheme 1. FAB mass fragments of roylinine.
for C-400 and the two secondary methyl carbon signals at ꢁ 22.7 ppm at C-50 and C-500.
The remaining two secondary methyl carbons appeared at ꢁ 23.2 ppm for C-60 and
C-600, two methyl carbon signals at ꢁ 11.9 ppm for C-70 and at 12.1 for C-700 and the
esterified C-10 and C-100 carbon signals appeared at ꢁ 174.5 and ꢁ 174.9 ppm,
respectively.
To know where the two ikemoyl ester groups are attached, the compound 11 was
subjected to alkaline hydrolysis by Zemplen method which yielded an amorphous
substance (13), m.p. 221–224ꢀC, [ꢀ]D þ 37.1ꢀ. The compound 13 showed positive
Liebermann–Burchardt test for steroids and also underwent sodium periodate
oxidation. The m.p., m.m.p., TLC and [ꢀ]D comparison with the authentic sample
confirmed that 13 was stephnol (pregn-5-ene-3ꢂ, 8ꢂ, 11ꢀ, 12ꢂ, 14ꢂ, 17ꢂ, 20-heptol.
Thus, it was considered that the substance 1 was a di-O-ikemoyl derivative of

Natural Product Research
965
CH3
OH
OCOPh
CH3
CH3
CH3
CH3
OH
O
O
O
O
O
O
O
OMe
O
HO
MeO
H
OH
OMe
OMe
1.
H-transfer
CH3
OCOPh
CH3
OH
CH3
CH3
O
O
O
O
O
OMe
CH3
OH
HO
MeO
O
O
OH
OMe
HO
m/z 417
m/z 449
– H 2O
OMe
[m/z 598]
–CH3OH
m/z 431
– O H
– H 2O
2CH
–
3
– B z O H
m/z 441
– O C H 3
m/z 410
m/z 563
–CH3OH
m/z 531
– C H 3CHO
m/z 401
–CH3OH
m/z 369
m/z 487
2CH
–
3
m/z 457
Scheme 2. FAB mass fragments of roylinine.
stephnol (C21H34O7). The difference of C14H20O2 between the molecular formulae of
11 and 13 further supported the presence of two-ikemoyl ester functions in 11.
The position of two ikemoyl groups was suggested to be present at C-11 and C-12
1
hydroxyl groups by the H-NMR spectrum of 11 which showed the downfield-
shifted characteristic triplet (J ¼ 10 Hz) of one methine proton for H-11 at
ꢁ 5.20 ppm, as well as the doublet (J ¼ 10 Hz) of one methine proton for H-12 at
ꢁ 4.60 ppm.
The 1H-NMR spectrum of 11 showed the other characteristic signals
(Section 3.4). The characteristic carbon signals in 13C-NMR spectrum of 11 were
in support of the derived structure as shown in Table 1.
The position of two ikemoyl groups in substance 11 was proposed based on
acetylation with acetic anhydride and pyridine, at room temperature, to its acetate
(12) as amorphous substance, [ꢀ]D þ 40ꢀ. The 1H-NMR spectrum of 12, which
contained a singlet of six protons of two methyl groups of acetate function at
ꢁ 2.03 ppm, suggested the presence of two acylatable hydroxyl groups in 11.
Comparison of 1H-NMR spectrum of 11 and 12 showed the downfield shifting of
the methine proton from the region of ꢁ 3.81–3.79 to ꢁ 4.91–4.81 ppm for the

966
V. Gupta et al.
CH3
OH
OCOPh
CH3
CH3
CH3
CH3
OH
O
O
O
O
O
O
OMe
O
O
HO
MeO
OH
OMe
H-transfer
H
OMe
1.
CH3
OH
OCOPh
CH3
CH3
O
O
OMe
CH3
O
CH3
O
OH
O
O
O
HO
MeO
H
HO
OH
H
OMe
OMe
[m/z 742]
– C H 3OH
m/z 273
m/z 305
– 2 C H 3
– O C H 3
m/z 681
– H 2O
– 2 C H 3
m/z 243
CH3
O
m/z 663
m/z 161
OMe
– 2 C H 3
CH3
CH3
Aglycon
CH3
– C H 3OH
HO
O
+
O
O
m/z 633
– C H 3OH
O
m/z 145
– H 2O
CH3
m/z 129
HO
HO
– C H 3OH
OCH3
OCH3
m/z 113
– H 2O
CH3
– H 2O
m/z 289
m/z 601
+
m/z 479
O
– B z O H
m/z 111
– C H 3OH
m/z 257
OMe
m/z 127
– C H 3OH
CH3
– C H 3CHO
m/z 557
+
O
– H 2O
m/z 95
+
O
m/z 239
m/z 95
Scheme 3. FAB mass fragments of roylinine.
multiplet of H-3 methine proton as well as the downfield shift of a quartet
(J ¼ 6.9 Hz) from ꢁ 4.36 to ꢁ 5.35 ppm for the H-20 methine proton, which suggested
that C-3 and C-20 secondary hydroxyl groups are free and that they underwent
acetylation in 12. This also suggested that ikemoyl groups could not be present at
C-3 and C-20 positions of 11. Moreover, the presence of the two ikemoyl groups in
11 at C-8, C-14 and C-17 was also ruled out due to the presence of tertiary hydroxyl
groups at these positions.
The triplet (J ¼ 10 Hz) for H-11 methine proton and the doublet (J ¼ 10 Hz) for
H-12 methine proton did not show any downfield shifting upon acetylation in 12.
Therefore, the position of two ikemoyl groups has been proposed at C-11 and C-12
hydroxyl groups.
The FAB mass spectrum of 11 not only supported the derived structure but also
indicated the presence and position of two ikemoyl groups. The FAB mass spectrum

Natural Product Research
967
– H 2O
m/z 862
m/z 880
CH3
OCOPh
– C H ( M e ) O C O P h
– O H
OH
CH3
CH3
O
OMe
CH3
O
CH3
O
OH
O
O
O
H
O
O
HO
OH
OMe
OMe
MeO
1.
H-transfer
CH3
OCOPh
OH
CH3
O
CH3
O
OMe
CH3
O
CH3
O
+
OH
O
O
O
HO
MeO
HO
OH
OMe
OMe
m/z 161
– C H 3OH
–3CH3
m/z 732
– C H 3OH
– C 6H5COOH
m/z 764
m/z 687
m/z 886
CH3
– C H 3
– O C H 3
– H 2O
+
O
m/z 714
m/z 810
m/z 840
HO
– 2 C H 3
– C H ( M e ) O C O P h
m/z 691
OH
m/z 129
– 2 C H 3
– H 2O
m/z 684
CH3
O
+
– H 2O
m/z 673
OH
m/z 111
– O C H 3
– H 2O
– O H
– 2 C H 3
m/z 565
m/z 547
m/z 642
m/z 612
– 2 C H 3
Scheme 4. FAB mass fragments of roylinine.
of 11 did not record the Mþ but the highest mass ion fragment recorded at m/z 539
(Mþ–CHOHCH3ꢁ2 ꢂ OH) due to the loss of hydroxy ethyl side chain present at
C-17 plus two hydroxyl groups, which confirmed the presence of hydroxy ethyl side
chain at C-17 in the aglycon moiety and at least two hydroxyl groups in 11. The
highest mass ion peak at m/z 539 further fragmented to give the mass ion peaks at
m/z 522 (539-OH) and 507 (522-CH3), due to the subsequent loss of hydroxy plus
methyl group, respectively. The mass ion peak at m/z 507 further fragmented to give
the mass ion peaks at m/z 379 (507-(CH3)2CH–C(CH3)¼CHCOOH) and 361
(379-H2O), due to the subsequent loss of ikemic acid and one water molecule,
respectively, confirmed the presence of at least one ikemoyl group in 11. The third
route of the fragmentation pathway showed the mass ion peak at m/z 445
(Mþ–CHOHCH3–(CH3)2CH–C(CH3)¼CHCOOH) due to the loss of hydroxy ethyl
side chain present at C-17 plus one ikemic acid molecule, which further confirmed
the presence of hydroxy ethyl side chain at C-17 in the aglycon moiety and at least

968
V. Gupta et al.
Table 1. 13C-NMR chemical shifts of substance 11.
Chemical shifts
of aglycon (ꢁ)
Chemical shifts
of aglycon (ꢁ)
Carbon
Carbon
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
37.0
29.9
78.9
42.7
140.1
121.7
29.9
78.9
53.9
42.7
71.8
73.9
51.9
84.5
31.8
33.2
84.3
10.3
19
20
21
10
14.8
71.5
18.9
174.5
174.9
121.7
122.0
150.5
150.5
38.9
39.2
22.7
22.7
23.2
23.2
11.9
12.1
1000
2
2000
3
3000
4
400
50
5000
6
6000
7
700
one ikemoyl group in 11. The mass ion peak at m/z 445 again fragmented to give the
mass ion peaks at m/z 415 (445-2CH3), 361 (415-3H2O), 233 (361-(CH3)2
CH–C(CH3)¼CHCOOH) and 215 (233-H2O), due to the subsequent loss of two
methyl groups plus four water molecules and one ikemic acid molecule. The above-
described fragmentation pathway again supported the presence of two ikemoyl
groups and at least two methyl groups plus four hydroxyl groups in 11.
In the light of foregoing evidences, the structure of marsgenin (11) was
established as pregn-5-ene-11ꢀ, 12ꢂ-di-O-ikemoyl, 3ꢂ, 8ꢂ, 14ꢂ, 17ꢂ, 20 pentol
(11, 12-di-O-ikemoyl stephnol).
3. Experimental
3.1. General experimental procedures
Procedures were the same as those reported earlier (Kumar, N. Khare, & A. Khare,
1
1999a, 1999b). H-NMR, 13C-NMR and 2-D spectra were recorded with Avance
DRX 300 MHz Bruker spectrometers in CDCl3 using TMS as the internal standard.
FAB mass spectra were recorded with a Jeol mass spectrometer model JMS-SX-102
with DA-6000 data system and a Jeol mass spectrometer D-300 with IMA-2000 data
system, respectively. Optical rotations were measured with an automatic polarimeter
AA-5 series of optical activity, UK. TLC was performed on silica gel G (Qualigens)
and column chromatography (CC) was done over silica gel 60–120 mesh (Qualigens).
The sugars were visualised with 50% aqueous H2SO4 reagent on TLC and with
vanillin–perchloric acid and partridge reagent on PC.

Natural Product Research
969
3.2. Plant extraction
The plant M. roylei was collected in bulk (about 40 kg) from Dehradun, India, and
was identified by Dr S.C. Saini, Botanist, Birbal Sahni Institute of Paleobotany
(BSIP), Lucknow. A specimen (No. BSIP 11870) of the plant was submitted to the
Herbarium of BSIP, Lucknow. Shade-dried chopped plant (8 kg) was extracted by
the method used for pregnane glycosides (N. Khare, M. Khare, & A. Khare, 1984)
using 50–95% ethanol. The combined ethanolic extract was concentrated under
reduced pressure and the concentrate was exhaustively extracted successively with
hexane (0.72 g), CHCl3 (7.80 g), CHCl3 : EtOH (4 : 1) (4.00 g) and CHCl3 : EtOH
(3 : 2) (4.72 g). Roylinine (1) (90 mg) and marsgenin (11) (100 mg) were isolated by the
repeated CC of the CHCl3-soluble extract.
3.3. Roylinine (1)
Amorphous substance, [ꢀ]D þ 30ꢀ (c 0.1, CH2Cl2), gave a pink colour in xanthydrol
test and a blue colour in the Keller–Kiliani reaction, (Anal. Calcd for C56H86O18 : C,
64.17; H, 8.25. Found: C, 64.22; H, 8.28%). 1H-NMR: ꢁ 6.97–6.59 (aromatic
protons), 5.27–5.26 (1H, m, H-6), 5.05 (1H, dd, J ¼ 10 and 2 Hz, H-1 of S1), 5.01–
4.99 (1H, m, H-20), 4.88 (1H, dd, J ¼ 9.9 and 2 Hz, H-1 of S2), 4.84 (1H, dd, J ¼ 10
and 2 Hz, H-1 of S3), 4.59 (1H, d, J ¼ 9 Hz, H-1 of S4), 4.25–4.17 (2H, m, H-5 of S1
and S2), 4.13 (1H, dd, J ¼ 8 and 2 Hz, H-12), 3.88–3.74 (5H, m, H-3; H-3, H-5 of S4;
H-3 of S1 and S2), 3.66 (3H, s, –OMe), 3.64–3.57 (3H, m, H-2 of S4, H-4 of S1 and
S2), 3.54 (3H, s, –OMe), 3.43 (3H, s, –OMe), 3.39 (3H, s, –OMe), 3.35–3.13 (4H, m,
H-3 of S3, H-5 of S3, H-4 of S3, H-4 of S4), 2.50–2.06 (3H, m, H-2eq of S1, S2 and S3),
2.00–1.50 (3H, m, H-2ax of S1, S2 and S3), 1.32 (6H, d, J ¼ 7 Hz, 6-CH3), 1.13 (6H, d,
J ¼ 7 Hz, 6-CH3), 1.10 (3H, d, J ¼ 6.9 Hz, 21-CH3), 0.95 (3H, s, 19-CH3) and 0.88
(3H, s, 18-CH3). FABMS: m/z 1046 [M]þ (not observed), 886 (S3þS2þS1þgenin)þ,
880 (Mþ–OH–CH(Me)OCOPh)þ, 862(880-H2O)þ, 840 (886-CH3–OCH3)þ, 764
(886-C6H5COOH)þ, 732 (764-CH3OH)þ, 714 (732-H2O)þ, 691 (840-CH(Me)
OCOPh)þ, 687 (732-3CH3)þ, 684 (714-2CH3)þ, 681 (742-2CH3-OCH3)þ, 673
(691-H2O)þ, 663 (681-H2O)þ, 642 (673-OCH3)þ, 633 (663-2CH3)þ, 612
(642-2CH3)þ, 601 (633-CH3OH)þ, 565 (612-OH–2CH3)þ, 563 (598-OH–H2O)þ,
561 (593-CH3OH)þ, 557 (601-CH3CHO)þ, 547 (565-H2O)þ, 531 (563-CH3OH)þ, 497
(561-2CH3OH)þ, 487 (531-CH3CHO)þ, 479 (601-BzOH)þ, 457 (487-2CH3)þ, 453
(497-CH3CHO)þ, 449 (S4þS3þS2)þ, 441 (563-BzOH)þ, 431 (449-H2O)þ, 410
(441-OCH3)þ, 403 (454-CH3–2H2O)þ, 401 (431-2CH3)þ, 369 (401-CH3OH)þ, 305
(S4þS3)þ, 289 (S2þS1)þ, 273 (305-CH3OH)þ, 257 (289-CH3OH)þ, 243 (273-2CH3)þ,
239 (257-H2O)þ, 167 (316-CH(Me)OCOPh)þ, 161 (S4)þ, 152 (167-CH3)þ, 145 (S3)þ,
129 (161-CH3OH)þ, 127 (145-H2O)þ, 113 (145-CH3OH)þ, 111 (129-H2O)þ and 95
(127-CH3OH)þ.
3.3.1. Alkaline hydrolysis of 1
Compound 1 (40 mg) was dissolved in 5% methanolic KOH (4 mL) and refluxed for
2 h. After adding H2O (4 mL), MeOH was removed under reduced pressure. The
aqueous concentrate was extracted with CHCl3 : MeOH (9 : 1), (3 ꢂ 10 mL), dried

970
V. Gupta et al.
over anhydrous Na2SO4, filtered and evaporated to dryness, yielding the deacylated
product 3 (22 mg).
3.3.2. Mild hydrolysis of roylinine (3) with acid
To a solution of 3 (22 mg) in 1,4-dioxane (1 mL), 0.01N H2SO4 (1 mL) was added and
the solution was warmed for 30 min at 50ꢀC. Dioxane was then removed under
reduced pressure. The aqueous portion was repeatedly extracted with CHCl3 and the
organic layer was washed in turn with H2O, 1 M Na2CO3 and again with H2O, dried
over anhydrous Na2SO4 and evaporated to yield aglycon (4) (7.3 mg), m.p. 235–
238ꢀC, [ꢀ]D – 4.3ꢀ (MeOH). The aqueous hydrolysate was neutralised with freshly
prepared barium carbonate, filtered and concentrated under reduced pressure to
yield the mixture of two sugars. These sugars were separated through CC yeilding 5
(6.2 mg), m.p. 157ꢀC, [ꢀ]D – 9.1ꢀ, and 6 (6.4 mg), [ꢀ]D þ 49.2ꢀ (c 0.18, H2O). Both the
sugars gave positive colouration in the xanthydrol and Keller–Kiliani reactions.
The specific rotation, TLC and PC comparison of 6 showed them to be identical to
D-cymarose and 5 was identified as pachybiose by comparing its relative
mobility and [ꢀ]D with the authentic samples of pachybiose (TLC, Co–TLC, PC,
Co–PC, [ꢀ]D). The sugars 5 and 6 were further identified with the help of their
derivatives.
3.3.3. Kiliani hydrolysis of 5
Sugar 5 (5.6 mg) was dissolved in Kiliani mixture (0.25 mL; AcOH:H2O:HCl, 7:11:2)
and heated at 100ꢀC for 1 h followed by evaporation under reduced pressure. It was
dissolved in 2 mL of water and extracted twice with 5 mL of CHCl3. The aqueous
residual solution was made neutral by the addition of 2N NaOH to it and evaporated
under reduced pressure to yield 3-O-methyl-6-deoxy-D-allose (9) (3.0 mg), m.p.
114ꢀC, [ꢀ]D þ 6.8ꢀ, and this was found to be identical with the authentic sample
(TLC, PC, [ꢀ]D, m.p., m.m.p.).
3.3.4. Tri-O-acetyl roylinine (2)
Substance 1 (5 mg) was acetylated with Ac2O (0.4 mL) in pyridine (0.4 mL) and the
mixture kept for 24 h at 60ꢀC, yielding acetate (2) (4.5 mg), [ꢀ]D þ 17.4ꢀ (c 0.23,
1
CH2Cl2). ꢁ in CDCl3 (ppm): H-NMR: ꢁ 6.99–6.52 (aromatic protons), 5.35–5.34
(1H, m, H-6), 5.05 (2H, dd, J ¼ 9 and 2 Hz, H-1 of S1, H-12), 5.01–4.99 (1H, m,
H-20), 4.80 (2H, dd, J ¼ 10 and 2 Hz, H-1 of S2, H-2 of S4), 4.74 (2H, dd, J ¼ 9 and
2 Hz, H-1 of S3, H-4 of S4), 4.59 (1H, d, J ¼ 9 Hz, H-1 of S4), 4.29–4.16 (2H, m, H-5
of S1 and S2), 3.93–3.74 (5H, m, H-3, H-3 of S4, H-5 of S4, H-3 of S1 and S2), 3.54–
3.38 (4 ꢂ –OMe), 2.10 (9H, s, 3 ꢂ –OAc) and 1.33–0.89 (21H, m, 7 ꢂ Me).
3.3.5. Very mild acid hydrolysis of 3
To a solution of 3 (20 mg) in 80% aqueous 1,4-dioxane (2.5 mL), 0.001N H2SO4
(2.5 mL) was added and the solution was kept at room temperature. After 4 days, the
reaction mixture exhibited the appearance of three new spots of disaccharide

Natural Product Research
971
pachybiose (5), D-cymarose (6) and presumably a monoglycoside (10) along with the
unreacted starting material (3) on TLC. The hydrolysis was completed in 7 days after
the disappearance of the starting material (3) and monoglycoside (10). The
hydrolysate exhibited no additional new spots except those of the aglycon (4). As
disaccharide pachybiose (5) was the first sugar liberated in the partial hydrolysis of 3,
it was found to be at the terminal non-reducing end and it was concluded that the
other sugar cymarose was glycosidically linked to the aglycon moiety, namely
boucerin, possibly at C-3 hydroxyl group. It was further concluded that the fourth
sugar, cymarose (S2), was sandwiched between pachybiose (5) and cymarose (6) units
in 1. The reaction mixture was then concentrated under reduced pressure to remove
dioxane. The aqueous portion was repeatedly extracted with CHCl3:MeOH (97:3)
and the organic layer was washed in sequence with H2O, 2N Na2CO3, again with
H2O, dried over Na2SO4 and evaporated, followed by CC, which resulted in an
aglycon (4) (6.0 mg), identified as boucerin, and two chromatographically pure
sugars as viscous syrups, namely 5 (4.8 mg) and 6 (4.7 mg), identified as pachybiose
and D-cymarose, respectively.
3.4. Marsgenin (11)
Amorphous solid, [ꢀ]D ꢁ 15ꢀ (c 0.4, CH2Cl2), gave positive results in Liebermann–
Burchardt test for steroids. It also underwent NaIO4 oxidation and positive alkaline
hydrolysis with methanolic KOH (Anal. Calcd for C35H54O9: C, 67.89; H, 8.71.
1
Found: C, 67.93; H, 8.79%). H-NMR: ꢁ 5.47–5.43 (3H, m, H-6, H-20 and H-200),
5.20 (1H, t, J ¼ 10 Hz, H-11), 4.60 (1H, d, J ¼ 10 Hz, H-12), 4.36 (1H, q, J ¼ 6.9 Hz,
H-20), 3.81–3.79 (1H, m, H-3), 3.52–3.41 (2H, m, H-40, H-400), 1.25 (12H, d,
J ¼ 6.5 Hz, H-50, H-500, H-60, H-600), 1.17 (6H, s, H-70, H-700), 1.08 (3H, s, 19-CH3),
0.99 (3H, d, J ¼ 6 Hz, 21-CH3) and 0.98 (3H, s, 18-CH3). FABMS: m/z 618 [M]þ (not
observed), 539 (618-CHOHCH3–2OH)þ, 522 (539-OH)þ, 507(522-CH3)þ, 473 (618–
(CH3)2CHC(CH3)¼CHCOOH–OH)þ, 445 (618-CHOHCH3–(CH3)2CHC(CH3)¼
CHCOOH)þ, 439 (473-2OH)þ, 424 (439-CH3)þ, 415 (445-2CH3)þ, 391 (424-CH3–
H2O)þ, 379 (507-(CH3)2CHC(CH3)¼CHCOOH))þ, 361 (379-H2O)þ, 352 (480-
(CH3)2CHC(CH3)¼CHCOOH))þ, 307 (352-CHOHCH3)þ, 289 (307-H2O)þ, 273
(307-2OH)þ, 263 (391–(CH3)2CHC(CH3)¼CHCOOH))þ, 233 (361-(CH3)2CHC
(CH3)¼CHCOOH))þ,
128 (143-CH3)þ.
215
(233-H2O)þ,
161
(289-(CH3)2CHC(CH3)¼
CHCOOH))þ, 145 (273-(CH3)2CHC(CH3)¼CHCOOH))þ, 143 (161-H2O)þ and
3.4.1. NaIO4 oxidation of 11
Substance 11 (4 mg) was dissolved in MeOH (0.4 mL) and a solution of NaIO4
(7.2 mg) in water (1 mL) was added to it. The reaction mixture was allowed to stand
at room temperature for 4 h (TLC) and diluted with water (2.0 mL). MeOH was then
removed under reduced pressure. The aqueous concentrate was then extracted with
CHCl3 (3 mL), dried over Na2SO4 and evaporated. The residue (1.3 mg) was
obtained which showed the formation of a new spot on TLC with complete
disappearance of the starting material spot.

972
V. Gupta et al.
3.4.2. Alkaline hydrolysis of 11
Compound 11 (4 mg) was dissolved in 5% methanolic KOH (1 mL) and refluxed for
2 h. After adding H2O (1 mL), MeOH was removed under reduced pressure. The
aqueous concentrate was extracted with CHCl3 : MeOH (9 : 1), (3 ꢂ 4 mL), dried over
anhydrous Na2SO4 filtered and evaporated to dryness. It yielded the deacylated
product (13) (3 mg), m.p. 221–224ꢀC, [ꢀ]D þ 37.1ꢀ (MeOH), which was identified as
stephnol by comparison with an authentic sample. (TLC, [ꢀ]D, m.p., m.m.p.).
3.4.3. Di-O-acetyl marsgenin (12)
Substance 11 (5 mg) was acetylated with Ac2O (0.4 mL) in pyridine (0.4 mL) and the
mixture kept for 24 h at 60ꢀC, yielding its acetate (12) (5.2 mg), [ꢀ]D þ 40ꢀ(c 0.2,
1
CH2Cl2). ꢁ in CDCl3 (ppm): H-NMR: ꢁ 5.51–5.48 (3H, m, H-6, H-20, H-200), 5.35
(1H, q, J ¼ 6.2 Hz, H-20), 5.22 (1H, t, J ¼ 10 Hz, H-11), 4.91–4.81 (1H, m, H-3), 4.66
(1H, d, J ¼ 10 Hz, H-12), 2.03 (6H, s, 2 ꢂ –OAc), 1.28 (12H, d, J ¼ 7 Hz, H-50, H-500,
H-60, H-600), 1.15 (6H, s, H-70, H-700), 1.05 (3H, s, 19-CH3), 1.02 (3H, s, 18-CH3) and
1.01 (3H, d, J ¼ 7 Hz, 21-CH3).
References
Abisch, E.,
& Reichstein, T. (1960). Orientierende chemische untersuchung einiger
apocynaceen. Helvetica Chimica Acta, 43, 1844–1861.
Allgeier, H. (1968). Struktur der Pachybiose und Asclepobiose, Desoxyzucker, 44. Mitteilung.
Helvetica Chimica Acta, 51, 311–325.
Barton, G.M., Evans, R.S., & Gardner, J.A.F. (1952). Paper chromatography of phenolic
substances. Nature, 170, 249–250.
Deepak, D., Srivastava, S., & Khare, A. (1997). Pregnane glycosides. Progress in the
Chemistry of Organic Natural Products, 71, 169–325.
Gupta, V.S., Kumar, A., Deepak, D., Khare, A., & Khare, N.K. (2003). Pregnanes and
pregnane glycosides from Marsdenia roylei. Phytochemistry, 64, 1327–1333.
Gupta, V., Kumar, A., Khare, A., & Khare, N.K. (2009). Two pregnane oligoglycosides from
Marsdenia roylei. Natural Product Research, 23, 1342–1354.
Hayashi, K., Wada, K., Mitsuhasi, H., Bando, H., Takase, M., Terada, S., . . . , Mizuno, D.
(1981). Further investigation of antitumor condurango glycosides with C-18 oxygenated
aglycon. Chemical & Pharmaceutical Bulletin, 29, 2725–2730.
Hu, K., Yao, X.S., Dong, A.J., Kobayashi, H., Iwasaki, S., & Jing, Y.K. (1999). New
pregnane glycosides from Dioscorea collettii. Journal of Natural Products, 62, 299–301.
Khare, N.K., Khare, M.P., & Khare, A. (1984). Two pregnane ester glycosides from
Pergularia pallida. Phytochemistry, 23, 2931–2935.
Kiliani, H. (1930). Uber Digitalinum verum. Berichte der Deutschen Chemischen Gesellschaft,
63, 2866–2869.
Krasso, A.F., Weiss, Ek., & Reichstein, T. (1963). Die Cardenolide von Beaumontia
grandiflora Wallich. 2. Mitteilung: Strukturaufklarung von wallichosid, beaumontosid.
glykoside and aglykone, 250. Mitteilung. Helvetica Chimica Acta, 46, 1691–1696.
Kumar, A., Khare, N.K., & Khare, A. (1999a). Trisaccharides from Mardenia roylei.
Phytochemistry, 52, 675–679.
Kumar, A., Khare, N.K., & Khare, A. (1999b). Two oligosaccharides from Marsdenia roylei.
Phytochemistry, 50, 1353–1357.

Natural Product Research
973
Luo, S.Q., Lin, Z.L., Cordell, G.A., Xue, L., & Johnson, M.E. (1993). Polyoxypregnanes from
Marsdenia tenacissima. Phytochemistry, 34, 1615–1620.
Mitsuhashi, H., Mizuno, D., Hayashi, K., Abe, S., Takase, M., & Narita, T. (1993).
Condurangoglycoside E 01. Chemical Abstracts, 98, 132–306.
Nagata, W., Tamm, C., & Reichstein, T. (1957). Die Glykoside von Erysimum crepidifolium
H.G.L. Reichenbach. Glykoside und Aglykone 169. Mitteilung. Helvetica Chimica
Acta, 40, 41–61.
Pan, W., Chang, F., Wei, L., & Wu, Y. (2003). Flavans spirostanol sapogenins and a pregnane
genin from Tupistra chinensis and their cytotoxicity. Journal of Natural Products, 66,
161–168.
Piacente, S., Belisario, M.A., Delcastillo, H., Pizza, C., & De Feo, V. (1998). Croton ruizianus:
platelet proaggregating activity of two new pregnane glycosides. Journal of Natural
Products, 61, 318–322.
Qiu, S.-X., Cordell, G.A., Kumar, B.R., Rao, Y.N., Ramesh, M., & Kokate, C. (1999).
Studies on the C-21 steroids from Asclepiadaceae plants bisdesmosidic pregnane
glycosides from Caralluma lasiantha. Phytochemistry, 50, 485–491.
Rangaswami, S., & Reichstein, T. (1949). Konstitution von Odorosid A und Odorosid B. Die
Glykoside von Nerium odorum Sol., 2 Mitteilung. Glykoside und Aglykone, 45.
Mitteilung. Helvetica Chimica Acta, 32, 939–949.
Saner, A., Zerlentis, C., Stocklin, W., & Reichstein, T. (1969). Die Glykoside von Marsdenia
erecta R. Br. 1.Mitteilung: Isolierungen. Glykoside und Aglykone, 325. Mitteilung.
Helvetica Chimica Acta, 53, 221–245.
Sauer, H.H., Weiss, Ek., & Reichstein, T. (1966). Die Struktur der Drevogenine. 2. Mitteilung
Strucktur von Drevogenin P. Glykoside und Aglykone. 278. Mitteilung. Helvetice
Chimica Acta, 49, 1632–1655.
Singhal, S., Khare, M.P., & Khare, A. (1980). Structure of a new disaccharide methyl
glycoside from seeds of Marsdenia tenacissima. Indian Journal of Chemistry, 19,
425–428.
Srivastava, S., Deepak, D., & Khare, A. (1994). Three novel pregnane glycosides from
Leptadenia reticulate Wight and Arn. Tetrahedron, 50, 789–798.
Templeton, J.F., Ling, Y., Zeglam, T.H., & LaBella, F.S. (1993). Synthesis of 20-hydroxy-,
20-amino-, and 20 nitro-14-hydroxy-21-nor-5ꢂ, 14ꢂ-pregnane C-3 glycosides and
related derivatives: structure–activity relationships of pregnanes that binds to the
Digitalis receptor. Journal of Medicinal Chemistry, 36, 42–45.
Yuan, J.L., Ding, W.P., Shi, J.P., Lu, Z.Z., Zhou, B.N., Erdelmeier, C.A., . . . , Farnsworth,
N.R. (1991). Studies on the antifertility compounds from Marsdenia koi. Journal of
Tongji Medical University, 11, 165–168.
Yuan, J.L., Lu, Z.Z., Che, G.X., Ding, W.P., Zhou, B.N., & Erdelmeier, C.A.J. (1992). The
pregnane glycoside marsdekoiside
1058–1060.
A from Marsdenia koi. Phytochemistry, 31,