Cardenamides from cardenolides: Cardiac and anticancer activities

Article abstract of DOI:10.1135/cccc20020336

Two ways are shown to transform cardioactive cardenolides into cardenamides [17β-(5-oxo-2,5-dihydropyrrol-3-yl)-5β,14β-androstane derivatives], and their derivatives by replacement of their ring oxygen by N-R. Cardioactivity is strongly decreased by this

Full text of DOI:10.1135/cccc20020336

336
Megges et al.:
CARDENAMIDES FROM CARDENOLIDES: CARDIAC AND
ANTICANCER ACTIVITIES+
a2
Rudolf MEGGESa,b1,*, Jürgen WEILANDa1, Rudolf SCHÖN
,
b2
Heinrich REPKE and Kurt R. H. REPKE
a
Max Delbrück Center for Molecular Medicine (MDC), D-13092 Berlin–Buch, Germany;
1
2
e-mail: weiland-berlin@t-online.de, bioland-imkerei_schoen@t-online.de
German-American Institute for Applied Biomedical Research GmbH (GAIFAR),
b
1
2
D-14 473 Potsdam, Germany; e-mail: mmegges4@compuserve.de, office@gaifar.com
Received Novem ber 26, 2001
Accepted February 9, 2002
Two ways are sh own to tran sform cardioactive carden olides in to carden am ides
[17β-(5-oxo-2,5-dih ydropyrrol-3-yl)-5β,14β-an drostan e derivatives], an d th eir derivatives by
replacem en t of th eir rin g oxygen by N–R. Cardioactivity is stron gly decreased by th is
tran sform ation . Th e com paratively easily accessible 21-oxocarden am ides [17β-(2-m aleim idyl)-
steroids] are stron gly th iol reactive an d sh ow rem arkable an tican cer activity.
Keyw ord s: Na+/K+-ATPase in h ibition ; Carden olides; Carden am ides; Steroids; Lactam s;
21-Oxocarden am ides; An tican cer activity.
Carden olides play a cen tral role in th e treatm en t of cardiac failure un til to-
day. Th eir m ain drawback is th eir n arrow th erapeutic ran ge m akin g an op-
tim al treatm en t very difficult. Th is stim ulates a search for better drugs for
replacin g of carden olides – but so far with out a breakth rough 1. Th erefore,
we h ave tried to replace th e rin g oxygen of th e carden olide lacton e rin g by
N–R to get an alogous lactam s (carden am ides, 17β-(5-oxo-2,5-dih ydro-
pyrrol-3-yl)-5β-an drostan e derivatives) an d th eir derivatives an d to see th eir
in fluen ce on th e cardioactivity as m easured by th e in h ibition of guin ea pig
an d/or h um an cardiac ATPase.
+ Presen ted in part at th e IUPAC World Chemistry Congress, Brisbane, Queensland, Australia, July
1–6, 2001, an d th e XIXth Conference on Isoprenoids, Gdansk–Jurata, Poland, September 8–14,
2001.
Collect. Czech. Chem. Commun. (Vol. 67) (2002)
doi:10.1135/cccc20020336

Cardenamides
337
First Method
Th e carden olide digitoxigen in 1 (Sch em e 1) reacts at room tem perature
with am m on ia or m eth ylam in e in m eth an ol to th e h em iacetal am ide 5
(yield 53%) or 6 with lacton e rin g open in g, sh ift of th e C20–C22 double
O
O
O
O
21
20
23
22
H3C
H3C
17
16
H3C
H
H3C
14
OH
5
3
RO
RO
H
1, R = H
3, R = H
2, R = Ac
4, R = Ac
R
N
R
N
OH
CONHR
23
H
O
O
21
H3C
H3C
H3C
22
20
1
O
O
7, R = H
9, R = H
5, R = H
8, R = CH3
10, R = CH3
6, R = CH3
R
N
O
H3C
4
11, R = H
12, R = CH3
O
O
H
O
O
H3C
H3C
H3C
H
O
HO
13
14
SCHEME 1
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

338
Megges et al.:
bon d un der form ation of an aldeh yde group at C21 an d h em iacetal form a-
tion with th e 14-OH group (isom erization ), wh ich subsequen tly con den ses
to th e 14,21-epoxylactam 7 or 8 (refs2,3). With an ilin e, th e lacton e rin g is
n ot attacked even at 100 °C.
From com poun ds 5–8 th e carden am ides 9 or 10 can be form ed by treat-
m en t with SbCl3/SiO2 at 120 °C (54%) or eth an ol/H2SO4 (0.2%) un der re-
flux4 (33%). Un fortun ately, th ese procedures are also associated with th e
loss of 14β-OH an d form ation of th e ∆14-double bon d wh ich is un favour-
able for cardioactivity (cf. Table I: 1 vs 3; 2 vs 4).
TABLE I
In h ibition of th e Na+,K+-ATPase of guin ea pig h eart (GPH) or h um an h eart (HH) by lacton es
an d lactam s (n .d. m ean s n ot determ in ed)
GPH
con cen tration , µm ol l–1
HH
Com poun d
in h ibition , %
I50, µm ol l–1
1
2
1.39
50
50
0.053
0.041
n .d.
n .d.
n .d.
n .d.
0.19
n .d.
65.8
n .d.
n .d.
n .d.
n .d.
n .d.
n .d.
65.8
66
1.23 ± 0.14
3
10
15
4
100
50
13
9
7
10
15
17
18
20
22
23a
23
24
25
26
27
28
30
100
~35
50
1.03 ± 0.19
100
35
100
~30 ± 1
28
100
~75 ± 5
100
50
28 ± 4
50
~56 ± 4
100
30 ± 1
15
100
76
50
~100
50
27
50
n .d.
45
n .d.
n .d.
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

Cardenamides
339
Th ese tran sform ation s are restricted to th e lactam derivatives: Th e
oxygen an alogue isodigitoxigen in 13 is n ot tran sform ed in to th e
∆14-buten olide 14 un der th ese con dition s. 14β-OH is n ot a prerequisite for
th e form ation of th e ∆14-carden am ides. Th eir form ation (11, 12) works as
well startin g with ∆14-carden olides (3, 4) un der th e sam e con dition s.
Second Method
Avoidan ce of isom erization an d con servation of 14β-OH can be ach ieved by
reaction of th e (21R)-21-brom ocarden olide 16 (Sch em e 2) (from 15 by
brom in ation with N-brom osuccin im ide5) with am m on ia or m eth ylam in e
leadin g to th e (21R)-21-h ydroxycarden am ide 17 (51%) or th e (21R)-21-
Br
Br
O
O
O
O
H3C
H3C
H3C
H
OAc
OAc
OH
OH
AcO
15
19
Br
H
O
CH3NHCO
H3C
O
CONHCH3
OAc
H3C
OAc
OH
OH
20
16
R
N
HO
H
O
H3C
17, R = H
18, R = CH3
OAc
OH
SCHEME 2
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

340
Megges et al.:
h ydroxy-N-m eth ylcarden am ide 18 (60%) con tain in g th e C20–C22 double
bon d an d 14β-OH but an addition al OH group at C21 (ref.6).
Treatm en t of 17 or 18 with NaBH4 does n ot rem ove th e 21-OH group.
Treatm en t of 18 with SOCl2 does n ot lead to th e form ation of th e respec-
tive 21-Cl derivative 21 (Sch em e 3) but of th e (21S)-14,21-epoxylactam 23.
To rem ove 21-OH from 18 it is reacted with tosyl ch loride to th e
(21R)-tosylate 22 (48%) followed by reduction with zin c/acetic acid to give
th e 14β-h ydroxy-N-m eth ylcarden am ide6 24 (43%) an d its 20(22)-dih ydro
derivative (25; 17%).
CH3
N
Cl
O
H3C
18
OAc
OH
21
CH3
N
CH3
TsO
H
N
O
H
O
H3C
H3C
OAc
OAc
OH
O
22
23 (23a: O instead of N-CH3)
CH3
N
CH3
N
O
O
H3C
H3C
H
OAc
OAc
OH
OH
24
25
R
N
O
O
H3C
17, 18
OAc
26, R = H
27, R = CH3
OH
SCHEME 3
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

Cardenamides
341
Oth erwise, oxidation 7 of th e allylic 21-OH of 17 or 18 with active Mn O2
or CrO3·2Py leads to th e 21-oxo derivative 26 (72%) or 27 (70%). In an
an alogous way 30 (31% from 28) is prepared from pen taacetylgitoxin 28 in
order to elucidate th e role of th e sugar ch ain 8 (Sch em e 4). Th e 21,21-di-
brom ogitoxigen in diacetate9 19 (Sch em e 2) reacts with m eth ylam in e to th e
rin g-open ed 21,23-bis-(N-m eth ylam ide)10 20.
O
O
H3C
H3C
H
OAc
OH
CH3
O
O
CH3
O
O
28
OAc
CH3
O
O
OAc
AcO
OAc
CH3
R
N
HO
H
N
O
O
H3C
O
H3C
OAc
OAc
OH
OH
30
29
SCHEME 4
Properties of the Compounds
Th e followin g properties of th e com poun ds are in agreem en t with th e
given structures. Th e ch rom atograph ic m obility in creases in th e followin g
order: diam ide 20 < 21-OH-lactam s 17 < 18 < N-Me-lactam 24 < m aleim ide
26 < lacton e 15 < m aleim ide 27 < 21-tosylate 22 < 14,21-O-N-Me-lactam 23 <
14,21-O-lacton e 23a. Th is m ean s th at lactam s an d m aleim ides are m ore po-
lar th an an alogous lacton es. Th iol reactivity: 26, 27, 30 are m aleim ide de-
rivatives an d as such add, SH groups to th e C20–C22 double bon d as sh own
by treatm en t with H2S/pyridin e at 0 °C: 26 an d (som ewh at faster) 27 form a
m ore polar, sulfur-con tain in g product (TLC). Colour reaction s: Like th e
carden olide rin g, th e carden am ide rin g, too, reacts with 1,3-din itro-
ben zen e/NaOH (Raym on d reaction 11) with th e form ation of a coloured
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

342
Megges et al.:
(violett an d red, respectively) Meisen h eim er com plex, m akin g a specific de-
tection in TLC easy 9, 10, 11, 12, 24, as far as th ere are two h ydrogen s
boun d at C21. Carden am ides with an NH group are detected by th e
ch lorin e–ben zidin e reaction 12. Lacton e tran sform ation in to lactam s sh ifts
th e wavelen gth s of th e UV m axim a by about 10 n m to sh orter wavelen gth s,
wh ich is com pen sated or overcom pen sated by 21-substituen ts. Wave-
len gth s of th e UV m axim a in crease in th e followin g order: lactam s 9, 24 <
21-OH-lactam s 17, 18 < lactones 1, 2, 15, 23a < diam ide 20 < 21-tosylate 22 <
m aleim ide 27. Th e m olar absorption coefficien ts are n early equal for all th e
com poun ds. In th e IR spectra (ν values given in cm –1) th e tran sition from
lacton e to lactam (15 → 24) sh ifts th e O–H-frequen cy to lower values, th e
C=O-frequen cy is n ot stron gly affected except for th e lowerin g in th e case
of th e m aleim ides 26 an d 27. An am ide ban d is foun d between 1 670 an d
1 700 wh ich is m issin g in case of th e m aleim ides 26 an d 27. Th e C=C fre-
quen cy between 1 600–1 635 is stron gly sh ifted to 1 690 by 14,21-epoxide
form ation in case of 23. In MS spectra m ost com poun ds (9, 20, 23, 24, 26)
sh ow th e m olecular ion , oth ers split off H2O or AcOH (17, 18 or 27). Th e
lactam rin g is especially stable as is seen in MS of 9: h ere th e m olecular
peak is th e basic peak. In 1H NMR spectra on ly lactam rin g proton s are
sh ifted com pared with lacton es. Com parin g 15 an d 24 th e values for
C21–H2 are lowered for about 1 ppm . In th e presen ce of a C14–C15 double
bon d th e sam e h olds true (3 vs 9; 4 vs 11; 4 vs 12). Th ese sh ifts are m ore or
less com pen sated by substituen ts at C21 (17, 18, 20, 23).
Biological Activity
Na+/K+-ATPase In h ibition an d Guin ea Pig Auricle Test
As a m easure of cardioactivity th e in h ibition of Na+/K+-ATPase (Na+/K+-
tran sportin g aden osin e triph osph atase, E.C.3.6.1.37) of guin ea pig h eart
(GPH) an d/or h um an h eart13,14 (HH) were determ in ed. Th e obtain ed values
(Table I) are lim ited in n um ber an d, th erefore, allow on ly prelim in ary con -
clusion s as to m ore gen eral structure–activity relation sh ips. Th e ch an ge
from lacton e to lactam decreases th e activity of th e very active 15 by m ore
th an two orders of 10 (15 vs 24), also in th e h um an h eart (15 vs 26, 27, 30),
but m oderate for th e least active 28 (28 vs 30). Th e activity of th e little ac-
tive 3 is n early un ch an ged (3 vs 9, 10), but in creased for th e low active 23a
(23a vs 23, th e m ost active lactam sh own h ere). Th e ch an ge of NH by
N-m eth yl h as n o in fluen ce (9 vs 10; 17 vs 18) or decreases th e activity
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

Cardenamides
343
sligh tly (26 vs 27). Th e h ydrogen ation of th e C20–C22 double bon d in th e
lactam rin g decreases th e activity (24 vs 25) as does th e open in g of th e
lactam e rin g (27 vs 20). Con trary to th e experien ce in th e carden olide field,
substitution at C21 h as n o in fluen ce (24 vs 18) or in creases th e activity
(23a vs 23; 24 vs 22; 24 vs 27). Th e sen sitivity of h um an h eart
Na+/K+-ATPase is som ewh at h igh er th an th at of guin ea pig h eart (27).
Also in th e isolated guin ea pig auricle15, 18 sh ows a very weak activity16
(Table II).
An tican cer Activity
Th e an tican cer activity of m aleim ide derivatives 26, 27, 30 was tested in
th ree can cer cell lin es: Eh rlich m ouse ascites tum or cells (EMAC), m ouse
m elan osarcom a cells (B16) an d h um an m am m ary carcin om a cells8 (MCA).
Th e results are sh own in Table III. For EMAC cells 30 is th e m ost active in -
TABLE II
In otropic an d arrh yth m ogen ic activity of th e 21-h ydroxy-N-m eth yllactam 18 on th e isolated
guin ea pig auricle16 (m eth od15
)
Con cen tration , µm ol l–1
It, %a
At, %b
3
6
3.8
6.6
0
11
6.3
12
11.1
a
b
It m ean s in crease in th e in otropic effect; At m ean s frequen cy of arrh yth m ia.
TABLE III
An tican cer activity (n .d. m ean s n ot determ in ed)
Na+/K+-ATPase
Con cen tra-
tion
Cell proliferation in h ibition , %
in h ibition
H
50, µm ol l–1
Com poun d
µm ol l–1
EMAC
B16
n .d.
MCA
n .d.
EMAC
NCT
26
27
30
12
50
50
50
n .d.
>>30b
89
76a
66c
45a
6.7
1.5
12.6 ± 2.2 56.7 ± 9.8
1.5 n .d.
a
b
c
Guin ea pig h eart; low solubility did n ot allow a m ore precise determ in ation ; h um an
h eart.
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

344
Megges et al.:
h ibitor, dem on stratin g th e favourable effect of th e acetylated sugar ch ain ,
con trary to its effect in Na+/K+-ATPase in h ibition . Com parison of 26 an d 27
reveals th e favourable effect of N-m eth yl in com parison with NH. Com -
poun d 27 is less active again st B16 but m ore an d equally active again st
EMAC an d MCA. Th e an tican cer active con cen tration s are far below
cardioactive con cen tration s (cf. Na+/K+-ATPase in h ibition ). It seem s th at th e
an tican cer activity is caused by th e th iol reactivity of th e com poun ds. Th e
Na+/K+-ATPase in h ibition by 30 is in GPH twice as stron g as in EMAC.
Discussion
Sh ortly after th e syn th esis of th e carden am ides4,6 9–12, 24 sh own h ere, two
oth er syn th eses17,18 were publish ed in depen den tly. Th ese m eth ods h ave th e
sam e or a h igh er n um ber of steps an d give about th e sam e yield of carden -
am ides sh owin g a stron gly decreased cardiac activity18
.
Th e reaction m ech an ism s of th e first an d secon d m eth od (th is paper)
h ave th e first step in com m on : th e am in olysis of th e lacton e rin g leadin g to
th e 23-am ide2,3, but th ey differ stron gly in th e reaction rate with am in es,
depen din g on th e substiution at C21. Th e reaction tim es are:
for 21-H2: >21days, for 21-Br,H: ≤2 h , for 21-Br2: ≤1 m in (!)
as m easured by con sum ption of th e startin g m aterial, th us dem on stratin g a
steep in crease in th e reactivity caused by th e –I-effect of 21-Br, wh ich in -
creases th e positive partial ch arge at C23.
Furth er in fluen ces are th e carden olide structure,
∆14-carden olide > 14β-OH-carden olide,
th e basicity of th e am in e
CH3–NH2 (pKb 3.35) > NH3 (pKb 5.0) >> C6H5NH2 (pKb 9.30)
an d th e solven t used
Pyridin e–H2O > MeOH > Pyridin e ≈ DMF ≈ DMSO
sh owin g clearly th at protic solven ts are favourable.
Both m eth ods, h owever, differ m arkedly in th e followin g steps:
In th e first m eth od, th e prim arily form ed 23-am ide un dergoes isom er-
ization to 5, 6. On ly h ere th e lactam (cardan am ide) form ation 2,3 (7, 8)
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

Cardenamides
345
seem s possible. Deh ydration of th ese com poun ds un der acid or Lewis acid
catalysis leads to th e carden am ides4 9–12.
Th e easy h ydrolysis of cardan olides m ay be th e cause th at th e oxygen an -
alogue 13 does n ot form th e respective lacton e 14 un der th ese con dition s.
In th e secon d m eth od isom erization is possible in prin ciple, but is over-
com e by th e m uch faster SN2 reaction of th e C23-am ide group with th e
brom o substituen t at C21 with Walden in version form in g on ly th e 21R
epim ers of th e 21-h ydroxycarden am ides6,8 (17, 18) (on ly on e spot foun d in
TLC). Th e 21R con figuration is deduced from th e easy form ation of th e
(21S)-14,21-epoxylactam 23 in an alogy to th e beh aviour of th e (21R/S)-21-
brom ocarden olides: On ly th e (21R)-21-brom o derivative 16 form s quite
easy th e (21S)-14,21-epoxide 23a. Th e 17β-con figuration (excludin g
epim erization at C17 un der am in e treatm en t) of th e carden am ide rin g
is con cluded from 1H NMR (17α-H) an d again th e easy form ation of 23.
In 17α-carden olides th e 14,21-epoxide form ation is im possible for steric
reason s.
Th e reaction of th e 21,21-dibrom ocarden olide9 19 (Sch em e 2) with
m eth ylam in e leads to th e respective 23-N-m eth ylam ide wh ich form s th e
21-COBr derivative by loss of HBr. Th is does n ot react with th e 23-N-
m eth ylam ide group by rin g closure with form ation of 27 (as can be de-
duced from differen t TLC m obility), but with th e stron ger n ucleoph ile
m eth ylam in e un der form ation of th e 21,23-diam ide10 20. Th e am ide ban ds
I an d II in th e IR spectrum of 13 are in com patible with th e structure of a
21,21-bis(m eth ylam in o)carden olide (cf. Experim en tal).
Rem oval of 21-OH
In 21-h ydroxycarden olides, 21-OH is easily rem oved by treatm en t19 with
NaBH4. Th is fails with 21-h ydroxycarden am ides because of th eir less easy
h ydrolysis wh ich m igh t be a prerequisite for th e rem oval. Th erefore, th e re-
duction of th e 21-tosylate was used wh ich is accom pagn ied in part by h y-
drogen ation of th e C20–C22 double bon d, leadin g to th e 20(22)-dih ydro
derivative of 24 (25).
Cardioactivity
Th e reason for th e drop in activity of carden am ides com pared to carden ol-
ides (Table I) is n ot clear at presen t but it dem on strates th e im portan ce of
th e rin g oxygen in th e lacton e rin g for th e activity. Because NH an d
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

346
Megges et al.:
N-m eth yl derivatives do n ot differ essen tially in th eir activity (Table I) addi-
tion al h ydrogen bon d form ation by NH is n ot respon sible.
X-Ray structures of 15 (ref.20) an d 26 (ref.21) do n ot sh ow serious differ-
en ces with respect to bon d len gth s an d an gles. A possible reason m igh t be
th e ch an ge in th e D-rin g sh ape (in 15: 13α,14β-h alf ch air, in 26: between
13α,14β-h alf ch air an d 14β-en velope), as lon g as it also exists in solution .
17α-Con figuration as a possible reason for loss of activity is likewise ex-
cluded as sh own above (17α-carden olides are kn own as in active). It is re-
m arkable th at, con trary to th e carden olide series, th e presen ce or absen ce of
14β-OH h as n o in fluen ce on th e activity. Th erefore, an electron ic effect in
th e carden eam ide rin g could be taken in to con sideration . Ch an ges in th e
wavelen gth s of th e UV-absorption m axim um reflect electron ic ch an ges in
th is ch rom oph ore. In th is con n ection it is in terestin g to see th e parallelism
between th e wavelen gth of UV-absorption m axim a an d biological activity:
lactam s (≈205 n m ), low activity; lacton es (≈217 n m ), active; bufadien olides
(≈300 n m ), m ore active.
An tican cer Activity
Th e th iol reactivity of th e m aleim ide derivatives 26, 27, 30 is sim ilar to th e
well-kn own m aleim ide derivative sh owdom ycin 22. In th is com poun d, th e
m aleim ide rin g is lin ked to a ribofuran osyl residue in a “C-glycosidic” m an -
n er. Th is com poun d is well kn own as a broad-spectrum an tibiotic an d
sh ows furth erm ore oth er biologic activities in cludin g an titum or activity22
.
Com poun ds 26, 27, 30 also sh ow th is activity wh ich seem s to be attractive
for an in -depth in vestigation . In com parison to sh owdom ycin , 30 is m uch
less polar wh ich causes a stron gly differen t distribution in th e body. Th e
question of addition al activities n eeds furth er research .
EXPERIMENTAL
Th in layer ch rom atograph y (TLC) was don e on TLC plates (Kieselgel 60 F254 Merck).
Mobile ph ases: a, ch loroform –aceton e (95 : 5); b, ch loroform –aceton e (90 : 10); c, ch loro-
form –aceton e (70 : 30); d, ch loroform –eth an ol (97.5 : 2.5); e, ch loroform –eth an ol (95 : 5);
f, ch loroform –eth an ol (80 : 20). In brackets (n ×): n um ber of developm en ts if n > 1. Detec-
tion : H3PO4/UV 266 n m (ref.23), 1,3-din itroben zen e (m-DNB)/NaOH (ref.11), fluorescein /
H2O2 (ref.24) (results given in brackets in th is ran ge with out specification of th e reagen t).
With specification of th e reagen t: SbCl3 (ref.25), trich loroacetic acid–ch loroam in e T (TCE)26
,
fluorescein –brom in e (detection of isolated double bon ds, ref.27), UV fluorescen ce at 366 n m
(UV), ch lorin e–ben zidin e (detection of NH, ref.12). Th e relative m obility (Rx=100) related to a
stan dard substan ce is given . Colours: blue (bl), brown (br), dark (d), yellow (y), green (gr),
red (r), m auve (m ), violet (v), oran ge (or), n egative (n eg.), positive (pos.), brigh t (bt). Pre-
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

Cardenamides
347
parative layer ch rom atograph y (PLC) was don e at an alytical TLC plates (0.25 m m th ickn ess)
with loadin g up to 50 m g. High er am oun ts (up to 200 m g) were separated at plates of 2 m m
th ickn ess (Merck). Detection : UV 254 an d/or 366 n m or sprayin g H2O or I2- vapour con tact.
Elution : aceton e. Corrected m eltin g poin ts (m .p.) were determ in ed with th e Boetius m eltin g
poin t m icroscope apparatus (VEB An alytik, Dresden ). Solven t for crystallization is given in
paren th eses. To detect decom position th e m elt was in vestigated by TLC. Ultraviolet spectra
[λm ax in n m (log ε)] were recorded with th e spectral-ph otom eter DK-2A (Beckm an In stru-
m en ts In c., Fullerton , U.S.A.) in eth an ol. In frared spectra (KBr, waven um bers in cm –1) were
recorded on Specord 75 IR (VEB Carl Zeiss, Jen a, Germ an y) or Spectrom om 2000 (MOM,
Budapest, Hun gary). In ten sities: stron g (st), very stron g (vst), weak (w), m edium (m ), sh oul-
der (sh ), sh arp (s), broad (br).
Electron im pact m ass spectra (MS, m/e is given ) were recorded with a m ass spectrom eter
MS 902 S (AEI, Man ch ester, G.B.). Th e com position of th e im portan t ion s is secured by h igh
resolution : resolution 10 000, 10% valley. Differen ce between foun d an d calculated values
m axim al ±3 m illim asses. Electron en ergy: 70 eV. Source tem perature is given at each com -
poun d. 1H NMR spectra were m easured on an NMR spectrom eter KRH 100 (Cen tral Scien -
tific In strum en ts Con struction , Academ y of Scien ces, Berlin , Germ an y) an d BS 497 (TESLA,
Brn o, Czech oslovakia) at 100 MHz in th e con tin uous wave m ode in CDCl3. Ch em ical sh ifts
in ppm (δ-scale) were referred to in tern al TMS. Couplin g con stan ts (J) were given in Hz.
Aqueous solution s used: Na2S2O3 (5%), KHCO3 (10%). Solution s in organ ic solven ts were
dried with an h ydrous Na2SO4. Pyridin e was rem oved by wash in g with con cen trated CuSO4
solution . Solven ts were rem oved usin g a rotatory evaporator at 13 m m Hg an d low bath
tem peratures.
17β-(5-Oxo-2,5-dih ydropyrrol-3-yl)-5β-an drost-14-en -3β-ol (9)
First method: A solution of 1 (250 m g, 0.92 m m ol) in m eth an ol (MeOH) (12 m l) was satu-
rated with gaseous NH3 at 0 °C. Th e m ixture was h eated in a steel autoclave at 110 °C for
17 h . Th e evaporation residue is crude2,3 5 (271 m g). To its solution in eth an ol (27 m l),
H2SO4 (2%, 2.7 m l) was added an d th e m ixture was h eated to reflux for 2 h . Th e m ajor part
of eth an ol was distilled off at 25 °C, to th e residue ch loroform was added an d wash ed un til
n eutral. PLC (b, 3 ×) yields 9 (77 m g, 33%, 0.22 m m ol).
Second method: Crude 5 (100 m g, 0.27 m m ol) was dissolved in CH2Cl2 (10 m l), m ixed
with silica gel (5 g) an d SbCl3 (100 m g, 0.44 m m ol) an d h eated at 120 °C for 20 m in .
Elution with aceton e with 4% of pyridin e, wash in g an d PLC yields 9 (56 m g, 54%). TLC (b,
3 ×): R1: 58 (SbCl3: bl, m-DNB: r). UV: ≤205. IR: 3 400 (sh ), 3 250 (st, N–H), 1 715 (vst),
1 640 (vst, am ide I), 1 600 (m , ∆20(22)), 1 445 (st), 1 375 (w), 1 270 (st, am ide III), 1 065,
1 040, 760, 700. MS (170 °C): 355 BP (M), 340 vst (M – CH3), 337 vst (M – H2O), 322 vst
(M – H2O – CH3), 283 st (M – H2O – C4H6: rin g A), 203 w, 110 (C6H8NO: buten am ide rin g +
17-CH + 16-CH2 + H). 1H NMR: 5.91 (s, 1 H, 22-H); 5.20 (m , 2 H, 15-H2); 4.12 (s, 1 H,
3α-H); 3.95 (s, 2 H, 21-H2); 2.88 (m , 1 H, 17α-H); 2.65 (s, NH); 1.02 (s, 3 H, 19-H3); 0.79 (s,
3 H, 18-H3).
17β-(5-Oxo-2,5-dih ydropyrrol-3-yl)-5β-an drost-14-en -3β-yl Acetate (11)
Com poun d 4 (827 m g, 2.08 m m ol) was dissolved in MeOH (200 m l) an d saturated with gas-
eous NH3 at 0 °C. Evaporation at room tem perature after 5 days gave 992 m g residue. To its
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

348
Megges et al.:
solution in ch loroform (50 m l), SbCl3 (992 m g, 4.35 m m ol) an d SiO2 (50 g) were added an d
th e m ixture was evaporated. Heatin g th e residue at 120 °C for 20 m in , elution with aceton e
with 4% of pyridin e, evaporation , solution in ch loroform , wash in g successively with dilute
HCl, KHCO3 an d water, evaporation . Colum n ch rom atograph y (silica gel 0.03–0.2 m m ,
Merck) with ch loroform –aceton e gave 11 (693 m g, 81%). TLC (c, 3 ×): RF 0.42; R1 89
(m-DNB: r). MS (170 °C): 411 (M), 393 (M – H2O), 110 (C6H8ON: buten am ide rin g + 17-CH +
16-CH2 + H). Th e byproduct was 9 (59 m g, 8%) with properties as above.
17β-(1-Meth yl-5-oxo-2,5-dih ydropyrrol-3-yl)-5β-an drost-14-en -3β-yl Acetate (12)
Com poun d 15 (500 m g, 1.26 m m ol) was dissolved in pyridin e (15 m l), m eth ylam in e (33%
in water, 3.5 m l, 37.1 m m ol) was added an d after 2 days at room tem perature th e m ixture
was evaporated. To a solution of th e residue (1.07 g) in pyridin e (10 m l), acetic an h ydride
(10 m l) an d, after 16 h , MeOH (6 m l) were added. On e h our later th e m ixture was evapo-
rated. Th e residue (1.123 g) was dissolved in ch loroform (20 m l), silica gel (11 g) an d SbCl3
(1.13 g, 4.96 m m ol) were added an d th e solven t was rem oved. Treatm en t as above (secon d
m eth od) an d colum n ch rom atograph y (silica gel 0.03–0.2 m m , Merck) with ch loroform –
aceton e yields 12 (215 m g, 41%). TLC (c, 3 ×): RF 0.71, R1 120 (SbCl3: bl, m-DNB: r, NH:
n eg.). MS (170 °C): 411 w (M), 396 st (M – CH3), 397 st (M – H2O), 378 vst (M – H2O –
CH3), 351 vst (M – AcOH), 297 st (M – Ac2O – C4H6: rin g A), 203 w, 124 (C7H10NO:
N-Me-buten am ide rin g + 17-CH + 16-CH2 + H).
14-Hydroxy-17β-[(2R)-2-h ydroxy-5-oxo-2,5-dih ydropyrrol-3-yl]-5β,14β-an drostan e-
3β,16β-diyl Diacetate (17)
3,16-Diacetylgitoxigen in 15 (140 m g, 0.29 m m ol) in 14 m l CCl4 (distilled from P2O5) was
brom in ated with N-brom osuccin im ide (158 m g, 0.89 m m ol) un der reflux an d illum in ation
with a 250 W tun gsten lam p for 20 m in . Succin im ide was filtered off an d th e filtrate was
wash ed successively with Na2S2O3, KHCO3 an d water, an d evaporated. To a solution of th e
crude brom in ation product 16 in ch loroform (14 m l), a solution of NH3 in MeOH (7.5%,
0.84 m l, 3.4 m m ol) was added. After 25 h , th e m ixture was filtered an d th e filtrate was evap-
orated. PLC of th e crude product (165 m g) gave 17 (75 m g, 51%). From ch loroform –eth er
clusters of n eedles, m .p. 185–196 °C (decom p.: 3 less polar products). TLC (d, 2 ×): R15 41
(SbCl3: bt-bl, m-DNB: n eg., NH: pos.). UV: 212 (4.142). IR: 3 400 (st, br), 3 280 (sh , N–H),
1 740–1 680 (vst, br), 1 630 (m , sh ), 1 445 < 1 380 (acetyl), 1 250–1 230 (vst, br), 1 150 (w),
1 090 (st), 1 025 (st), 700 (w). MS (180 °C): 471 (M – H2O), 453 (M – 2 H2O), 429 (M –
AcOH), 411 (M – AcOH – H2O). 1H NMR: 6.74 (s, NH, disappeared in D2O); 6.17 (s, 1 H,
22-H); 5.28 (m , 1 H, 16α-H); 5.26 (s, 1 H, 21α-H); 5.12 (s, 1 H, 3α-H); 3.23 (d, 1 H, 17α-H);
2.15 (q, 1 H, 15α-H); 2.07 (s, 3 H, 3β-OAc); 2.04 (s, 3 H, 16β-OAc); 0.99 (s, 1 H, 19-CH3);
0.95 (s, 3 H, 18-CH3).
14-Hydroxy-17β-[(2R)-2-h ydroxy-1-m eth yl-5-oxo-2,5-dih ydropyrrol-3-yl]-
5β,14β-an drostan e-3β,16β-diyl Diacetate (18)
To a solution of th e crude brom in ation product of 15 (663 m g, 1.40 m m ol) in ch loroform
(2 m l) an d dioxan e (8 m l), a solution of m eth ylam in e (33% in water, 0.61 m l, 6.47 m m ol)
was added an d th e m ixture was evaporated after 15 h . PLC (d, 3 ×) gave 18 (404 m g, 60%).
From ch loroform –eth an ol colum n s with in clin ed en ds, m .p. 146–152 °C. TLC (d, 2 ×): R15
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

Cardenamides
349
52, R17 205 (SbCl3: y, m-DNB: n eg., NH: n eg.). UV: 211 (4.061). IR: 3 450 (st, br), 1 740–
1 690 (vst, br), 1 630 (m , sh ), 1 450 (N–Me, in com parison to 17 con siderably in creased),
1 450 < 1 385 (acetyl), 1 255–1230 (vst, br), 1 158 (w), 1 098 (st), 1 030 (st), 710 (w). MS
(160 °C): 485 st (M – H2O), 467 (M – 2 H2O), 443 (M – AcOH), 425 BP (M – AcOH – H2O),
410 st (M – AcOH – H2O – CH3), 365 vst (M – 2 AcOH – H2O), 350 (M – 2 AcOH – H2O –
CH3), 314 vst (M – H2O – AcOH – lactam rin g), 203 st (C12H13NO2: rin g D-∆14,16 + 12-CH2
+
18-CH3 + 21-OH,N-CH3-buten am ide rin g), 113 (C5H7NO2: 21-OH,N-CH3-buten am ide rin g +
H), 95 (113 – H2O). 1H NMR: 7.54 (d, J = 12, 21-OH, + D2O: extin guish ed); 6.17 (s, 1 H,
22-H); 5.18 (tr, 1 H, 16α-H); 5.10 (s, 1 H, 3α-H); 4.82 (d, J = 11, 1 H, 21α-H, + D2O: 4.87 s);
3.47 (q, 1 H, assign m en t un clear); 3.20 (d, 1 H, 17α-H); 2.94 (s, 3 H, N-CH3); 2.62 (q, 1 H,
15α-H); 2.04 (s, 3 H, 3β-OAc); 1.99 (s, 3 H, 16β-OAc); 0.88 (s, 3 H, 18-H3); 0.57 (s, 3 H,
19-H3).
14,2′-Epoxy-17β-[(2′S)-1′-m eth yl-5′-oxo-2′,5′-dih ydropyrrol-3′-yl]-5β,14β-an drostan e-
3β,16β-diyl Diacetate (23)
A solution of 18 (100 m g, 0.2 m m ol) in CH2Cl2 (9 m l) was cooled to –70 °C an d th e m ixture
of CH2Cl2 (0.84 m l), SOCl2 (0.15 m l, 1.18 m m ol) an d DMF (0.01 m l) was added. After 4.5 h
at 22 °C th e m ixture was wash ed un til n eutral. PLC (a, 2 ×) of th e residue gave 23 (68.5 m g,
71%). Clusters of fin e n eedles (aceton e), m .p. 236–238 °C (decom p.). TLC (a, 2 ×): R15 151,
R7 83, R18 490 (SbCl3: y, m-DNB: n eg., NH: n eg., ∆: n eg.). UV: 211 (4.080). IR: 1 738 (vst),
1 705 (vst), 1 690 (vst, br), 1 450 < 1 388 (acetyl), 1 255 (vst, br), 1 150 (w), 1 070 (st), 1 025
(st), 880 (m ), 698 (w). MS (175 °C): 485 (M), 467 (M – H2O), 443 (M – keten e), 425 BP (M –
AcOH), 365 vst (M – 2 AcOH), 350 (M – 2 AcOH – CH3), 314 vst (M – lactam rin g – 14-O –
AcOH), 203 s (C15H23: rin gs A, B, C – AcOH – C14, an d C12H13NO2 [cf. MS of 18] 1 : 2).
14-Hydroxy-17β-[(2R)-1-m eth yl-5-oxo-2-(tosyloxy)-2,5-dih ydropyrrol-3-yl]-
5β,14β-an drostan e-3β,16β-diyl Diacetate (22)
Com poun d 18 (from 500 m g 15, 1.05 m m ol) was dissolved in pyridin e (2 m l) cooled to
–70 °C an d tosyl ch loride (2.43 g, 1.28 m m ol, in 2.5 m l pyridin e) was added. After 15 h at
room tem perature MeOH (2 m l) was added an d after 30 m in all solven ts were rem oved. PLC
(b, 2 ×) gave 22 (230 m g, 29% from 15, 48% from 18). Sh ort prism s from aceton e–pen tan e,
m .p. 205–209 °C (decom p.). TLC (b, 2 ×): R18 610, R15 137 (SbCl3: y, m-DNB: n eg., NH:
n eg.). UV: 220 (4.216). IR: 3 250 (br), 1 730 (st), 1 700 (vst), 1 590 (m ), 1 445, 1 380,
1 245–1 225 (vst, br), 1 070, 1 020; O-Ts: 1 565 (w), 1 320 (st), 1 175 (vst), 1 110 (m ), 815
(m ), 735 (m ), 650 (m ). MS (160 °C): 501 (M – C7H7OS), 441 st (501 – AcOH), 425 vst (M –
C7H7O2S – AcOH), 381 vst (501 – 2 AcOH), 314 vst (M – lactam e rin g – AcOH – H2O), 265 st
(M – TsOH – 2 AcOH), 203 BP (C15H23: rin gs A, B, C – AcOH – C14), 155 (C7H7O2S: Ts), 139
(C7H7OS), 91 (C7H7: tropylium ion ). 1H NMR: 7.74–7.92 (m , Ar-H); 7.26–7.40 (m , Ar-H);
7.00 (s, 3 H, N-CH3); 6.60 (s, 1 H, 22-H); 5.45 (tr, 1 H, 16α-H); 5.15 (s, 1 H, 3α-H); 4.76 (m ,
1 H, 21α-H, + D2O: s); 3.27 (d, 1 H, 17α-H); 2.44 (s, 3 H, Ar-CH3); 2.05 (s, 3 H, 3β-OAc); 1.96
(s, 3 H, 16β-OAc); 0.98 (s, 1 H, 19-H3); 0.90 an d 0.87 (s, 3 H, 18-H3).
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

350
Megges et al.:
14-Hydroxy-17β-(1-m eth yl-5-oxo-2,5-dih ydropyrrol-3-yl)-5β,14β-an drostan e-3β,16β-diyl
Diacetate (24) an d 14-Hydroxy-17β-[1-m eth yl-5-oxotetrah ydropyrrol-3ξ-yl]-
5β,14β-an drostan e-3β,16β-diyl Diacetate (25)
Crude 22 (from 500 m g gitoxigen in (deacetyl-15), 1.28 m m ol) was dissolved in MeOH
(2 m l) an d after addition of AcOH (1 m l), H2O (0.1 m l) an d Zn dust (1 g) sh aken for 11.5 h .
Th e evaporation residue of th e filtrate was suspen ded in ch loroform an d wash ed. PLC (e,
3 ×) of th e residue gave 24 (45 m g, 12% from 15, 43% from 22) an d 25 (64 m g, 17% from
15). Com poun d 24: C28H41NO6 (487.63), crystal warts (aceton e–dieth yl eth er–pen tan e), m .p.
198–203 °C. TLC (e, 2 ×): R15 74, R18 122 (SbCl3: UV br-bl, day ligh t: green , m-DNB: r-v, NH:
n eg.). UV: 207. IR: 3 250 (st), 1 735 (vst), 1 670* (vst), 1 620 (sh , m ), 1 477, 1 370 , 1 405*
(w), 1 250–1 230 (vst, br), 1 100 (m ), 1 030 (st), 735* (w) (* m ean s addition al ban ds com -
pared to 15). MS (170 °C): 487 st (M), 427 vst (M – AcOH), 409 vst (M – AcOH – H2O),
367 st (M – 2 AcOH), 349 (M – 2 AcOH – H2O), 203 st (C15H23: rin gs A, B, C – AcOH – C14),
196 vst (C10H14O3N: N-Me-buten am ide rin g + 17-CH + 16-CH-OAc + 15-CH2 + H), 141 st
(C11H13O2N: ∆16-rin g-D + 14-OH + N-Me-buten am ide rin g + 18-CH3), 137 BP (C8H10NO:
196 + H – AcOH). 1H NMR: 5.52 (tr, 1 H, 16α-H); 5.10 (s, 1 H, 3α-H); 4.83 (s, 1 H, 22-H);
3.87 (s, 2 H, 21-H2); 3.06 (s, 3 H, N-CH3); 2.65 (q, 1 H, 15α-H); 2.20 (d, 1 H, 17α-H); 2.04 (s,
3 H, 3β-OAc); 1.88 (s, 3 H, 16β-OAc); 0.97 (s, 3 H, 19-H3); 0.89 (s, 3 H, 18-H3).
14-Hydroxy-17β-(2′m aleim idoyl)-5β,14β-an drostan e-3β,16β-diyl Diacetate (26)
Com poun d 17 (500 m g, 1.02 m m ol) was dissolved in ch loroform (5 m l) an d after addition
of active Mn O2 (5 g, 57.5 m m ol) was sh aken for 1 h . Mn O2 was filtered off an d wash ed with
ch loroform . PLC (d, 3 ×) gave 26 (360 m g, 72%). Th ick n eedles (aceton e–h exan e), m .p.
270–273 °C (decom p.: about 50% of a m ore polar com poun d). TLC (e, 2 ×): R17 240, R15 87
(y-or, n eg., NH: pos.). IR: 3 510 (st, s), 1 710 (vst, br), 1 615 (m ), 1 440 < 1 375 (st), 1 245
(vst), 1 080, 1 015 (st), 880, 685; N–H: 3 150 (st, br), 3 045 (m ). MS (190 °C): 487 (M), 427
(M – AcOH), 409 (M – AcOH – H2O), 367 (M – 2 AcOH), 263 (203 + AcOH), 241
(C15H15NO2: rin gs C + ∆14,16-D + m aleim ide rin g + 7-CH2 + 13β-CH3), 203 BP (C15H23), 191
(C10H9NO3: ∆16-rin g D + 14-OH +13β-CH3 + m aleim ide rin g).
14-Hydroxy-17β-(N-m eth ylm alein im idoyl)-5β,14β-an drostan e-3β,16β-diyl Diacetate (27)
Com poun d 18 (500 m g, 0.99 m m ol) was oxidised with Mn O2 for 4 h (5 g, 57.5 m m ol) as
above. PLC (d, 3 ×) yields 27 (351 m g, 70%). M.p. 172–177 °C (ch loroform –eth an ol 9 : 1).
TLC (e, 2 ×): R18 145, R15 107 (or, n eg., NH: n eg.). IR: 3 450 (sh ), 1 730 (vst), 1 700 (vst),
1 620 w, 1 445, 1 375 (st), 1 245 (vst), 1 080, 1 015 (st), 880, 685; N–H: 3 150 (st, br), 3 045
(m ). MS (175 °C): 501 st (M), 441 vst (M – AcOH), 381 (M – 2 AcOH), 363 (M – 2 AcOH –
H2O), 348 (M – 2 AcOH – H2O – CH3), 314 st (M – AcOH – H2O – N-m eth ylm aleim ide rin g),
263 (203 + AcOH), 205 (C11H11NO3: ∆16-rin g D + 14-OH + N-m eth ylm aleim ide rin g +
13β-CH3) 203 BP (C15H23).
Reaction of 26/27 with H2S
Com poun d 26 (10 m g, 0.02 m m ol) was dissolved in pyridin e (2 m l) an d saturated with H2S
at 0 °C. TLC (d, 2 ×) sh ows th at after 24 h 26 was tran sform ed m ain ly (90%) to a m ore polar
product wh ich con tain s S2+: R26 77 (H3PO4: y, iodin e–azide–starch reagen t28 for S2+: pos.).
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

Cardenamides
351
Com poun d 27 reacts an alogously but som ewh at faster: after 15 h 100% tran sform ation .
R27 14 (y, S2+: pos.).
3β-[3,4-Di-O-acetyl-2,6-dideoxy-β-D-ribo-h exopyran osyl-(1→4)-3-O-acetyl-2,6-dideoxy-
β-D-ribo-h exopyran osyl-(1→4)-3-O-acetyl-2,6-dideoxy-β-D-ribo-h exopyran osyl)oxy]-
14-h ydroxy-17β-(N-m eth ylm aleim idoyl)-5β,14β-an drostan e-16β-yl Acetate (30)
Pen ta-O-acetylgitoxin 28 (2 g, 2.02 m m ol) in CCl4 (200 m l) was brom in ated with
N-brom osuccin im ide (1.44 g, 8.09 m m ol) accordin g to th e stan dard procedure (see prepara-
tion of 17). Th e reaction m ixture was filtered an d th e filtrate was wash ed successively with
Na2S2O3, KHCO3, water an d dried. Meth ylam in e (2 m l, 33% in eth an ol, 21.2 m m ol) was
added to th e solution of th e brom in ation product. After 20 h at room tem perature th e m ix-
ture was wash ed successively with 0.1 M HCl, KHCO3 an d water, dried an d evaporated in
vacuo. Th e oily residue obtain ed was ch rom atograph ed on silica gel (100 g). Elution with
ch loroform –eth an ol (98 : 2) gave th e 21-h ydroxy-N-m eth yllactam 29 (627 m g, 30.4%) wh ich
was dried over P2O5 in vacuo, dissolved in ch loroform (20 m l) an d sh aken with active Mn O2
(6.8 g, 78.2 m m ol) for 2 h . Th e reaction product was purified on silica gel (30 g). Elution
with ch loroform provided 30 (527 m g, 84.2% from 29) wh ich crystallized from eth er–
m eth an ol–pen tan e as n eedles, m .p. 156–159 °C. MS: 631 (C34H49NO10: M+ – 3′′,3′′′,4′′′-tri-O-
acetyl(digitoxosyl)2), 613 (631 – H2O), 571 (631 – CH3COOH), 553 (613 – CH3COOH), 511
(631 – 2 CH3COOH), 493 (613 – 2 CH3COOH), 459 (aglycon : M+ – 3′,3′′,3′′′,4′′′-tetra-O-acetyl-
(digitoxosyl)3), 442 (459 – OH), 399 (459 – CH3COOH), 387 (C18H27O9: 3′′,3′′′,4′′′-tri-
O-acetyl(digitoxosyl)2), 382 (442 – CH3COOH), 327 (387 – CH3COOH), 231 (C10H15O6:
3′′′,4′′′-di-O-acetyldigitoxosyloxy), 215 (C10H15O5: 3′′′,4′′′-di-O-acetyldigitoxosyl), 155 (215 –
CH3COOH), 95 (215 – 2 CH3COOH). MS (h igh resolution ): 459.2618 (calculated for
C
26H37NO6: 459.2621), 399.2397 (calculated for C24H33NO4: 399.2409).
14-Hydroxy-17β-(1,2-N-m eth ylcarbam oylvin yl)-5β,14β-an drostan e-3β,16β-diyl
Diacetate (20)
Com poun d 15 (250 m g, 0.53 m m ol) was brom in ated with NBS (281 m g, 1.58 m m ol) by th e
stan dard procedure. Th e crude reaction product (con tain in g besides th e 21-brom o derivative
16 th e 21,21-dibrom o derivative 19) was dissolved in ch loroform (27 m l), m eth ylam in e
(33% in H2O, 0.23 m l, 2.44 m m ol) was added an d th e m ixture was sh aken for 10 m in . PLC
(f) an d elution of th e zon e RF 0.21 yields 20 (25 m g, 23% from 15). Clusters of fin e n eedles
(ch loroform –dieth yl eth er), m .p. 217–222 °C. TLC (e, 2 ×): R15 19 (SbCl3: y, n eg., NH: pos.).
UV: 218 (4.087). IR: 3 400 (st, br), 3 300 (sh , N–H), 1 735 (vst), 1 635 (vst, am ide I), 1 535
(st, am ide II), 1 455 (w, N–Me), 1 380, 1 370 (m , C–N), 1 255–1 230 (vst, br), 1 155 (w), 1 025
(m , C–N). MS (160 °C): 532 w (M), 501 st (M – CH3NH2), 472 (M – AcOH), 441 vst (M –
AcOH – CH3NH2), 400 (M – 2 CONHCH3 – CH3 – H), 381 st (M – 2 AcOH – CH3 – NH2), 263
(203 + AcOH), 203 BP (C15H23). 1H NMR: 6.22 (s, 1 H, 22-H); 5.37 (tr, 1 H, 16α-H); 5.11 (s,
1 H, 3α-H); 3.02 (d, 1 H, 17α-H); 2.80 an d 2.85 (2 d, 2 × 3 H, 2 × N-CH3, + D2O: on e s); 2.52
(q, 1 H, 15α-H); 2.12 (s, 3 H, 3β-OAc); 1.88 (s, 3 H, 16β-OAc); 1.06 (s, 3 H, 18-H3); 0.98 (s,
3 H, 19-H3). For C29H44NO7 (532.7) calculated: 65.39% C, 8.29% H, 5.21% N; foun d:
65.37% C, 8.31% H, 5.23% N.
We gratefully acknowledge the skillful assistance of Mrs H. Timm.
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

352
Megges et al.:
REFERENCES
1. Repke K. R. H., Megges R., Weiland J., Schön R.: Angew. Chem., Int. Ed. Engl. 1995, 34,
282.
2. Katzung G., Munoz J. A., Shirachi D. Y., Trevor A. J., Chang H. H., Wolff M. E.:
Experientia 1970, 26, 1189.
3. Ferland J. M., Lefebvre Y., Dinoi R., Deghenghi R.: Can. J. Chem. 1971, 49, 2676.
4. Megges R., Timm H., Portius H.-J., Franke P., Hintsche R., Repke K.: Ger. (GDR) 126 092
(1977); Chem. Abstr. 1978, 88, 152681.
5. Megges R., Timm H., Dittrich F., Portius H.-J., Repke K.: Ger. (GDR) 109 869 (1974);
Chem. Abstr. 1975, 83, 179414.
6. Megges R., Timm H., Portius H.-J., Franke P., Hintsche R., Repke K.: Ger. (GDR) 126 093
(1977); Chem. Abstr. 1978, 88, 170 392.
7. Megges R., Timm H., Franke P.: Ger. (GDR) 148 222 (1981); Chem. Abstr. 1982, 96,
35645 .
8. Repke K. R. H., Schön R., Megges R., Weiland J., Nissen E., Matthes E.: Anti-Cancer Drug
Des. 1995, 10, 177.
9. Megges R., Rollka W., Timm H. Franke P., Hintsche R., Repke K. R. H.: Ger. (GDR)
228 814 (1985); Chem. Abstr. 1987, 106, 18940.
10. Megges R., Rollka W., Weiland J., Franke P., Hintsche R.: Ger. (GDR) 218 370 (1985);
Chem. Abstr. 1986, 104, 186717.
11. Schindler O., Reichstein T.: Helv. Chim. Acta 1951, 34, 108.
12. Reindel F., Hoppe W.: Chem. Ber. 1954, 87, 1103.
13. Repke K. R. H., Schönfeld W., Weiland J., Megges R., Hache A. in: Design of Enzyme
Inhibitors as Drugs (M. Sandler and H. J. Smith, Eds), p. 435. Oxford University Press,
Oxford, New York, Tokyo 1989.
14. Repke K. R. H., Weiland J., Megges R., Schön R.: Prog. Med. Chem. 1993, 30, 135.
15. Haustein K.-O.: Pharmacology 1974, 11, 117.
16. Glusa E.: Personal communication.
17. Günthert T. W., Linde H. H. A., Ragab M. S., Spengel S.: Helv. Chim. Acta 1978, 61, 977.
18. Guzmann A., Muchowski J. M., Strossberg A. M., Sims J. M.: Can. J. Chem. 1981, 59,
3241.
19. Ferland J. M., Lefebvre Y., Deghenghi R., Wiesner K.: Tetrahedron Lett. 1966, 3617.
20. Reck G., Messerschmidt A., Megges R.: Cryst. Struct. Commun. 1981, 10, 637.
21. Messerschmidt A., Megges R., Höhne E.: Unpublished results.
22. Vasquez D.: Inhibitors of Proteinbiosynthesis, p. 21. Springer Verlag, Berlin 1979.
23. Neher R., Wettstein A.: Helv. Chim. Acta 1951, 34, 2278.
24. Weichsel H.: Microchim. Acta 1965, 325.
25. Lawday D.: Nature (London) 1952, 170, 415.
26. Kaiser F.: Chem. Ber. 1955, 88, 556.
27. Runge F., Jumar A., Köhler F.: J. Prakt. Chem. 1963, 21, 39.
28. Chargaff E., Levine C., Green C.: J. Biol. Chem. 1948, 175, 67.
Collect. Czech. Chem. Commun. (Vol. 67) (2002)