Trisaccharides from Marsdenia roylei

Article abstract of DOI:10.1016/S0031-9422(99)00253-8

The structures of two novel trisaccharides viz. royleose and deniose isolated from Marsdenia roylei were elucidated with the help of modern physico-chemical techniques and chemical transformations. They were defined as O-β-D-oleandropyranosyl(1 → 4)-O-β-D

Full text of DOI:10.1016/S0031-9422(99)00253-8

Phytochemistry 52 (1999) 675±679
Trisaccharides from Marsdenia roylei
Alok Kumar, Anakshi Khare*, Naveen K. Khare
Department of Chemistry, Lucknow University, Lucknow -226 007, India
Received 3 February 1999; accepted 21 April 1999
Abstract
The structures of two novel trisaccharides viz. royleose and deniose isolated from Marsdenia roylei were elucidated with the
help of modern physico±chemical techniques and chemical transformations. They were de®ned as O-b-D-oleandropyranosyl-
(1 4 4)-O-b-D-cymaropyranosyl-(1 4 4)-b-D-oleandropyranose and O-b-D-oleandropyranosyl-(1 4 4)-O-b-D-digitoxopyranosyl-
(1 4 4)-b-D-oleandropyranose respectively. This is the ®rst report on the isolation of trisaccharides of rare deoxy sugars in free
state from nature. # 1999 Elsevier Science Ltd. All rights reserved.
Keywords: Marsdenia roylei; Asclepiadaceae; Trisaccharides; Reducing
1. Introduction
Various species of the genus Marsdenia (Family:
Asclepiadaceae) have been investigated chemically and
a number of pregnane glycosides of deoxy hexoses
(Deepak, Srivastava & Khare, 1997b) and oligosac-
charides (Saner & Allgeier, 1969; Saner, Zerlentis,
Stocklin & Reichstein, 1969; Singhal, Khare & Khare,
1980) have been isolated. Some of the species are
known to possess medicinal properties viz. antiasth-
matic, antifertility, anticancer activity and are also
used against gonorrhea (Kirtikar & Basu, 1984). We
now report the chemical investigation of the hitherto
uninvestigated species, Marsdenia roylei resulting in
the isolation of two novel trisaccharides 1 and 3 in
their native state.
a reducing glycon containing rare 2,6-dideoxy sugar(s).
The 13C NMR spectrum of 1 contains three anomeric
carbons at d 101.46, 99.86 and 91,99 supplemented by
three anomeric proton signals at d 5.05, 4.81 and 4.53
in the 400 MHz 1H NMR spectrum of 1. The mass
ion peak at m/z 473 [M+Na]+ in the FAB mass spec-
trum of 1 also supported the nature of 1 as trisacchar-
ide of the 2,6-dideoxy sugars. The 2,6-dideoxy nature
of sugars was further con®rmed by the presence of
2. Results and discussion
Royleose (1), C21H38O10 reduces Fehlings solution
and gives positive tests in the xanthydrol (Barton,
Evans & Gardner, 1952) and Keller±Kiliani (Ngata,
Tamm & Reichstein, 1957) reactions indicating it to be
* Corresponding author.
0031-9422/99/$ - see front matter # 1999 Elsevier Science Ltd. All rights reserved.
PII: S0031-9422(99)00253-8

676
A. Kumar et al. / Phytochemistry 52 (1999) 675±679
Table 1
13C NMR spectral data for 1 and 3. (Value (ppm) from internal
TMS in CDCl3. cym=D-cymarose, dig=D-digitoxose. ole=D-olean-
characteristic methylene group signals in the region d
2.37±2.32 (1H), 2.22±2.14 (2H) and 1.80±1.75 (1H),
1.68±1.60 (2H) for three equatorial and three axial
protons respectively and three secondary methyl group
doublets (J = 6 Hz) at 1.28, 1.22 and 1.20. The pre-
sence of three singlets of three protons each at 3.53,
3.45 and 3.32 for three methoxy groups in 1 showed
that all the three sugars are methylated.
Mild acid hydrolysis (0.05 N H2SO4) (Rangaswami
& Reichstein, 1949) of 1 gave D-oleandrose (5)
(Renkonen, Schindler & Reichstein, 1959) and D-cym-
arose (6) (Krasso, Weiss & Reichstein, 1963) (TLC,
PC, [a]D) in the ratio of 2:1. Sugars 5 and 6 were
further characterized by preparing their known phenyl
hydrazides D-oleandronic acid phenyl hydrazide
(Renkonen et al., 1959) mp 133±1368C and D-cymaro-
nic acid phenyl hydrazide (Krasso et al., 1963) mp
150±1548C (mp, mmp, TLC and PC).
a±d
drose. represent assignments in each column that may be inter-
changeable)
1
3
Sugar
ole(S1)
Carbon
Moiety
Sugar
ole(S1)
Carbon
Moiety
1
91.99
31.60a
77.31
82.62
71.61
18.23b
59.01c
99.86
30.20a
76.99
82.42
68.36
22.64b
56.24c
101.46
31.40a
78.39
80.63
75.40
17.96b
58.26c
1
91.90
36.82a
76.99
82.56
67.73
17.95b
58.93c
99.54
33.45a
75.14
82.39
67.73
18.16b
2
2
3
3
4
4
5
5
6
-OCH3
6
-OCH3
cym(S2)
1
dig(S2)
1
2
3
4
5
6
2
3
4
5
The large coupling constants for all the three
anomeric protons present as double doublets at d 5.05,
4.81 and 4.53 (J = 9 Hz and 2 Hz) were typical of an
axial con®guration suggesting that all the three sugars
6
-OCH3
ole(S3)
1
ole(S3)
1
100.34
35.34a
80.45
2
2
3
3
4
were present in C1 (D) conformation having b-glycosi-
dic linkages (Allgeier, 1968).
Compound 1 on acetylation with Ac2O gave di-O-
4
4
78.30
71.84
17.86b
56.35c
5
5
6
-OCH3
6
-OCH3
1
acetyl derivative 2 C25H42O12. The H NMR spectrum
of 2 showed the down®eld shifting of one of the
anomeric proton from d 5.05 to 5.98 (dd, J = 9 Hz
and 2 Hz) and of H-40 proton from 3.15 to 4.64 (t,
J = 9 Hz) showing the reducing nature of the trisac-
charide and the presence of one of the D-oleandrose
1987). The loss of three molecules of CH3OH and one
molecule of HCOOH (see Section 3, Experimental)
further con®rmed the presence of three methoxyl
groups and the reducing nature of the trisaccharide.
The mass spectrum also showed the characteristic frag-
ments of 2,6-dideoxy sugars reported by Pettit and
Brown (Brown, Bruschweiler, Pettit & Teichstein,
1971). In the light of foregoing evidence the structure
of 1 was deduced as O-b-D-oleandropyranosyl-(1 4 4)-
O-b-D-cymaropyranosyl-(1 4 4)-b-D-oleandropyra-
nose.
1
unit at the terminal end. The H NMR also showed
two singlets of three protons each at d 2.10 and 2.00
for two acetoxy methyls besides showing the other sig-
nals. The sugar sequence in 1 was con®rmed by the
very mild acid (0.005
N
H2SO4) hydrolysis
(Rangaswami & Reichstein, 1949) of 2. The hydroly-
zate, after two days, showed three spots on TLC, two
faster moving spots of close mobility and a third spot
which had the same mobility as that of D-cymarose.
The two faster moving spots, after separation, on alka-
line hydrolysis gave D-oleandrose. These results
showed that two D-oleandrose units were joined
through D-cymarose i.e. D-oleandrose-D-cymarose-D-
oleandrose. The 13C NMR spectrum is also in good
agreement with the results deduced from chemical
Deniose (3) C20H36O10, reduced Fehling solution
and gave positive xanthydrol (Barton et al., 1952) and
Keller±Kiliani (Ngata et al., 1957) reactions along with
three secondary methyl group doublets at d 1.32, 1.26,
1.24 (9H, J = 6 Hz) and three double doublets of one
proton each at d 5.06, 4.91, 4.55 and two singlets of
1
three protons at 3.55 and 3.41 in the H NMR spec-
trum which showed that 3 was a reducing trisaccharide
of two 2,6-dideoxy methylated sugars and one 2,6-
1
reactions and the H NMR spectrum. The 13C NMR
shifts have been given in Table 1.
1
dideoxy sugar. All the assignments of H NMR spec-
The FABMS of 1 showed the cationated molecular
ion peaks at m/z 489 and 473 which correspond to
[M+K]+ and [M+Na]+. These in turn further frag-
mented to give the important mass ion fragments. The
mass ion fragment at m/z 425 was obtained by the loss
of 2CH3OH molecules from m/z 489 which further
fragmented to give the fragment ion at m/z 363, 361,
345 and 329 by the usual losses (Khare & Khare,
trum were further con®rmed by the 1H-1H
HOMOCOSY spectrum of 3.
To identify the sugars of 3, it was hydrolysed with
0.05 N H2SO4 (Rangaswami & Reichstein, 1949),
which a€orded two chromatographically pure sugars
in the ratio of 2:1. The sugars were identi®ed as D-
oleandrose (5) (Renkonen et al., 1959) and D-digitox-

A. Kumar et al. / Phytochemistry 52 (1999) 675±679
677
ose (7) (Eppenberger, Kaufmann, Stocklin
&
the losses of H2O, CH3OH and CH3CHO molecules
from M+ in di€erent fragment sequences common to
2,6-dideoxy hexoses (Khare & Khare, 1987). The frag-
mentation routes are also based on the cleavage of tri-
saccharide by repeated H-transfer where elimination of
terminal sugar less water is visualised to give an ion of
the corresponding disaccharide and ®nally of monosac-
charide (Khare & Khare, 1987). The fragment ion
peaks in the lower mass region at m/z 145, 131, 127,
113, 95 and 69 could be interpreted to be arising from
the characteristic fragmentation pattern of 2,6-dideoxy
hexoses reported by Pettit and Brown (Brown et al.,
1971). Thus FABMS of 3 completely supported the de-
rived structure. On the basis of the chemical degra-
dation and spectroscopic evidences the structure of 3
was assigned as O-b-D-oleandropyranosyl-(1 4 4)-O-b-
D-digitoxopyranosyl-(1 4 4)-b-D-oleandropyranose.
Reichstein, 1966) respectively by direct comparison
with the authentic samples (PC, TLC, [a]D). Further
characterization of the sugars was done by their bro-
mine water oxidation, leading to the formation of their
respective lactones, followed by treatment with phenyl
hydrazine, which a€orded the known D-oleandronic
acid phenyl hydrazide mp 133±1368C (Renkonen et
al., 1959) and D-digitoxonic acid phenyl hydrazide mp
121±1228C (Eppenberger et al., 1966) (mp, mmp, TLC
and PC).
Compound 3 on acetylation with Ac2O in pyridine
1
gave 4 C26H42O13. The H NMR spectrum of 4 at 400
MHz revealed the presence of three acetyl groups as
two singlets at d 2.10 (6H) and 2.00 (3H) which
accounted for three acylable hydroxyl groups in 3. The
characteristic down®eld shifting (Kumar, Khare &
Khare, 1999) of the triplet from d 3.31 in 3 to 4.64 in
4 suggested that one of the D-oleandrose unit is at the
terminal end. Two other down®eld shifted protons
were found to be H-3' of D-digitoxose from d 3.26±
3.10 to 5.36 and H-1 of the hexose constituting the
reducing end which shifted from d 5.06 in 3 to 5.96
3. Experimental
General procedures were the same as reported ear-
lier (Deepak, Srivastava & Khare, 1997a). M. roylei
(10 kg) was extracted as reported earlier Kumar et al.,
1999; Shaub, Kaufmann, Stocklin & Reichstein, 1968)
yielding hexane (0.81 g), CHCl3 (9.80 g),
CHCl3:EtOH(4:1) (4.40 g) and CHCl3:EtOH(3:2) (5.84
g) soluble extract. Royleose (44 mg) was isolated by
the repeated column chromatography of CHCl3
extract.
1
(dd, J = 9 Hz and 2 Hz) in 4. The H spectrum of 4
also contained the other ring proton signals.
To identify the sugar at the reducing end 3 was oxi-
dised with Br2 water followed by hydrolysis with 0.05
N H2SO4 which gave three spots on TLC which were
separated and identi®ed as D-oleandrose, D-olean-
drono-1,4-1actone and D-digitoxose on comparison
with authentic samples (TLC, PC). These results led to
the conclusion that D-digitoxose unit was ¯anked on
both sides by D-oleandrose. i.e. D-oleandrose-D-digitox-
ose-D-oleandrose starting from the terminal end.
The con®guration of the glycosidic linkages was
Compound 1, [a]D +128(c, 0.34, CHCl3), Found C
56.08. H 8.40 C21H38O10 requires C 56.00; H 8.44. H
1
NMR of 1 (400 MHz, CDCl3): d 5.05 (1H, dd, J = 9
Hz and 2 Hz, H-1), 4.81 (1H, dd, J = 9 Hz and 2 Hz,
H-1'), 4.53 (1H, dd, J = 9 Hz and 2 Hz, H-10), 4.20±
4.25 (1H, m, H5'), 4.00±3.95 (1H, m, H-3'), 3.92±3.85
(2H, m, H-5, H-50), 3.84±3.78 (2H, m, H-3, H-30),
3.53, 3.45, 3.32 (9H, 3s, 3-OMe), 3.34 (1H, t, J = 9
Hz, H-4), 3.23 (1H, dd, J = 10 Hz and 2 Hz, H-4'),
3.15 (1H, t, J = 9 Hz, H-40), 2.37±2.32 (1H, m, H-
2'eq), 2.22±2,14 (2H, m, H-2eq, H-20eq), 1.80±1.75
(1H, H-2'ax), 1.68±1.60 (2H, H-2ax, H-20ax), 1.28,
1.22, 1.20 (9H, 3d, J = 6 Hz, 3-CH3). FABMS:
489[M+K]+, 473[M+Na]+, 443[489-HCOOH]+,
1
ascertained by the 400 MHz H NMR spectrum of 3.
The three double doublets of one proton each at d
5.06 (J = 9 Hz and 2 Hz), 4.91 (J = 9 Hz and 2 Hz)
and 4.55 (J = 9 Hz and 2 Hz) were interpreted for
three anomeric protons of three sugars. The large
coupling constant (9 Hz) of the three anomeric protons
4
were typical of their axial con®guration in a C1 (D)
conformation, suggesting that all the three sugars
(including reducing end sugar) have b-con®guration
(Allgeier, 1968). The structure of 3 was further sup-
ported by the data of its 13C NMR spectrum. A rela-
tively up®eld appearance of one of the anomeric
carbon at d 91.90 con®rmed 3 to be reducing trisac-
charide. Besides, the spectrum also con®rmed the pre-
sence of two methoxy, three secondary methyls and
three methylene groups in the distinct regions (see
Table 1).
441[473-CH3OH]+,
425[489-2CH3OH]+,
385[443-
CH3CH.CHOH]+,
383[441-CH3CH.CHOH]+,
363[425-CH3CHO,-H2O]+, 361[425-HCOOH,-H2O]+,
349[M-C5H9O2]+, 345[363-H2O]+, 331[349-H2O]+,
329[361-CH3OH]+,
307[M-S2+H]+,
307[383-CH3CHO,-CH3OH]+,
303[349-
305[349-CH3CHO]+,
HCOOH]+, 271[331-H3COCHO and 303-CH3OH],
259[305-HCOOH
and
303-CH3CHO],
206[307-
The FABMS of 3 showed the highest mass ion peak
at m/z 436 corresponding to M+. In the higher mass
region the prominent mass ion peaks were structurally
signi®cant as they could be interpreted as resulting by
C5H9O2]+, 191[206-CH3]+, 175[206-OCH3]+, 173[191-
H2O]+, 159[191-CH3OH]+, 157[175-H2O]+, 147[191-
CH3CHO]+, 145[S3+], 143[175-CH3OH]+. 129[175-
HCOOH]+, 115[159-CH3CHO and 147-CH3OH]+,

678
A. Kumar et al. / Phytochemistry 52 (1999) 675±679
113[145-CH3OH]+, 97[129-CH3OH]+, 95[113-H2O]+,
69[113-CH3CHO]+.
phenylhydrazide (5.2 mg, 59%) mp 150±1548C (mp,
mmp, TLC and PC).
Deniose (72 mg) was isolated by repeated CC of
CHCl3 soluble extract of M. roylei. Deniose, [a]D
+258 (c, 0.40, CHCl3), found C 55.02; H 8.24
C20H36O10 requires C 55.04; H 8.25. It gave blue
coloration with vanillin±perchloric acid spray reagent,
positive tests in xanthydrol and Keller±Kiliani and
3.1. Mild acid hydrolysis of 1
To a solution of 1 (12 mg) in 1,4 dioxane (1 ml) 0.1
N H2SO4 (1 ml) was added and the solution was
warmed for 30 min at 508C. Dioxane was then
removed under reduced pressure. The aq. portion was
neutralized with freshly prepared BaCO3, ®ltered and
concentrated under reduced pressure followed by col-
umn chromatography to a€ord 5 (6.8 mg, 79%) [a]D
128 (c, 1.2, H20) and 6 (3.6 mg, 83% [a]D +538 (c,
0.125, H2O) identi®ed as D-oleandrose and D-cymarose
(2:1) by comparison with authentic samples (PC, TLC,
[a]D).
1
reduced Fehling solution. H NMR (400 MHz): d 5.06
(1H, dd, J = 9 Hz and 2 Hz, H-1), 4.91 (1H, dd,
J = 9 Hz and 2 Hz, H-10), 4.55 (1H, dd, J = 9 Hz
and 2 Hz, H-1'), 4.25 (1H, m, H-3), 4.19 (1H, m, H-5),
3.89 (1H, m, H-30), 3.83 (1H, m, H-50), 3.55, 3.41 (6H,
2s, 2-OMe), 3.40 (1H, m, H-5')), 3.31 (1H, t, J = 9
Hz, H-40), 3.26±3.10 (3H, m, H-3', H-4', H-4), 2.37±
2.32 (1H, m, H-2'eq), 2.22±2.10 (2H, m, H-2eq, H-
20eq), 1.82±1.70 (2H, m, H-2, H-20), 1.54±1.48 (1H, H-
2'ax), 1.32, 1.26, 1.24 (9H, 3d, J = 6 Hz, 3-CH3).
FABMS: 436[M]+, 419[436-OH]+, 387[419-CH3OH]+,
369[387-H2O]+, 355[387-CH3OH]+, 351[369-H2O]+,
343[387-CH3CHO]+, 335[436-C5H9O2]+, 329[387-
CH3CH.CHOH]+, 307[351-CH3CHO]+, 292[436-S+3 ],
3.2. Acetylation of 1
Compound 1 (15 mg) was acetylated with Ac2O (2
ml) in pyridine (2 ml) at 1008C for 1 h. The reaction
mixture after usual work up gave 2 (15.8 mg, 88%)
[a]D +48 (c, 0.76, CHCl3). found C 56.15, H 7.85
requires C25H42O12 C 56.18; H 7.86. 1H NMR (400
MHz, CDCl3): d 5.98 (1H, dd, J = 9 Hz and 2 Hz, H-
1), 4.78 (1H, dd, J = 9 Hz and 2 Hz, H-1'), 4.64 (1H,
t, J = 9 Hz, H-40), 4.50 (1H, dd, J = 9 Hz and 2 Hz,
H-10), 4.08±4.00 (1H, m, H-5'), 3.92±3.83 (3H, m, H-
3', H-5, H-50), 3.82±3.77 (2H, m, H-3, H-30), 3.48,
3.46, 3.34 (9H, 3s, 3-OMe), 3.36 (1H, dd, J = 10 Hz
and 2 Hz, H-4'), 3.25 (1H, t, J = 9 Hz, H-4), 2.35±
2.30 (1H, m, H-2'eq), 2.22±2.14 (2H, m, H-2eq, H-
20eq), 2.10, 2.00 (6H, 2s, -OCOCH3), 1.80±1.75 (1H,
H-2'ax), 1.68±1.60 (2H, H-2ax, H-20ax), 1,32, 1.22,
1.20 (9H, 3d, J = 6 Hz, 3-CH3).
289[335-HCOOH]+,
275[307-CH3OH
and
335-
H3CCHO]+, 273[335-H2O, ±CH3CHO]+, 257[275-
H2O and 289-CH3OH], 243[275-CH3OH], 239[257-
H2O], 225[257-CH3OH], 213[273-H3COCHO and 257-
CH3CHO]+,
199[243-CH3CHO]+,
195[239-
CH3CHO]+, 181[213-CH3OH]+, 137[181-CH3CHO]+,
131[292-S+2 ], 145[S3+], 113[145-CH3OH and 131-
H2O]+,127[145-H2O]+, 95[127-CH3OH and 113-
H2O]+, 69[113-CH3CHO]+.
3.5. Mild acid hydrolysis of 3
To a solution of 3 (10 mg) in 1,4 dioxane (1.5 ml)
0.1 N H2SO4 (1.5 ml) was added and the solution was
warmed for 30 min at 508C and left at room tempera-
ture. The hydrolysate after usual work up and CC
gave 5 (6.4 mg, 86%) [a]D 128(c, 1.1, H2O) and 7
(2.8 mg, 83%) [a]D +42.98 (c, 0.16, MeOH), in 2:1,
identi®ed as D-oleandrose and D-digitoxose respectively
by comparison with the authentic samples (TLC, PC,
[a]D).
3.3. Very mild acid hydrolysis of 2
To a solution of 2 (10 mg) in 1,4 dioxane (2 ml)
0.01 N H2SO4 (2 ml) was added and the solution was
warmed for 30 min. at 508C. The hydrolysate after
usual work up and CC a€orded two faster moving
spots of close mobility, which on alkaline hydrolysis
gave single product i.e. D-oleandrose(5)(4.2 mg) [a]D
128 (c, 1.2, H2O) and a polar spot identi®ed as D-
cymarose(6)(2.8 mg) [a]D +538 (c, 0.125, H2O) by
comparison with authentic samples (TLC, PC, [a]D).
3.6. Bromine water oxidation of 3
A solution of 3 (10 mg) in water (0.2 ml) was mixed
with bromine (2 ml) and shaken in the dark at room
temperature for 24 h in a stoppered ¯ask. The excess
bromine was then removed under reduced pressure
and the acidic reaction mixture was neutralised with
freshly precipitated silver carbonate and ®ltered, H2S
was then passed through the ®ltrate and again ®ltered.
This ®ltrate was evaporated to dryness under reduced
pressure yielding a dark brown syrupy residue which
gave one spot on TLC. This syrup was subjected to
3.4. Acid phenylhydrazides
Solutions of separated sugars 5 and 6 (6 mg each) in
H2O (0.8 ml) when oxidised with Br2 water (12 ml) sep-
arately using the usual method yielded respective lac-
tones which on treatment with phenylhydrazine
yielded known D-oleandronic acid phenylhydrazide
(5.8 mg, 65%) mp 133±1368C and D-cymaronic acid

A. Kumar et al. / Phytochemistry 52 (1999) 675±679
679
mild acid hydrolysis as usual yielded three spots on
Acknowledgements
TLC and PC, which were identi®ed as D-oleandrose
(5), D-digitoxose (7) and D-oleandrono-1,4-1actone.
The identity of lactone was further con®rmed by con-
verting into D-oleandronic acid phenyl hydrazide mp
133±1368C (mp, mmp, TLC and PC).
Authors are thankful to the University Grants
Commission, New Delhi for ®nancial assistance and
Regional Sophisticated Instrumentation Centre,
Central Drug Research Institute, Lucknow for success-
ful running of NMR and Mass spectra.
3.7. Acetylation of 3
References
Compound 3 (4 mg) was acetylated with Ac2O (0.5
ml) in pyridine (0.5 ml) at 1008C which after usual
work up gave 4 (4.2 mg, 82%) [a]D +338 (c, 0.3,
CHCl3), found C 55.49; H 7.46 C26H42O13 requires C
55.52, H 7.47. 1H NMR (400 MHz, CDCl3): d 5.96
(1H, dd, J = 9 Hz and 2 Hz, H-1), 5.36 (1H, m, H-3'),
4.87 (1H, dd, J = 9 Hz and 2 Hz, H-10), 4.64 (1H, t,
J = 9 Hz, H-40), 4.56 (1H, dd, J = 9 Hz and 2 Hz, H-
1'), 4.25 (1H, m, H-3), 4.02 (1H, m, H-5), 3.87 (1H, m,
H-30), 3.83 (1H, m, H-50), 3.46, 3.34 (6H, 2s, 2-OMe),
3.41 (1H, m, H-5'), 3.27 (1H, t, J = 9 Hz, H-4), 3.20
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2'eq), 2.22±2.10 (2H, m, H-2eq, H-20eq), 2.10, 2.00
(9H, 2s, 3-OCOCH3), 1.87±1.75 (2H, m, H-2, H-20),
1.70±1.52 (1H, H-2'ax), 1.25, 1.15 (9H, 2d, J = 6 Hz,
3-CH3).
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3.8. Acid phenylhydrazides
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Saner, A., & Allgeier, H. (1969). Chemical and Pharmaceutical
Solutions of separated sugars 5 and 7 (4 mg each) in
H2O when oxidised with Br2 water separately using the
usual method yielded respective lactones which on
treatment with phenythydrazine yielded known D-
oleandronic acid phenylhydrazide (2.8 mg, 47%) mp
133±1368C and D-digitoxonic acid phenylhydrazide
(3.1 mg, 33%) mp 121±1228C (mp, mmp, TLC and
PC).
Bulletin, 52, 1655.
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