Abstract
▶ A new sapogenin 1, having 21-nor and C19 carboxylic acid characteristics,isolated from A. racemosus. ▶
1 was identified as 21-nor-18β,27α-dimethyl-1β,2β,3β-trihydroxy-25-spirost-4-en-19β-oic acid. ▶ Crystallography of 1 confirmed conformation of rings (B,C,F) as chair, A as half chair and E as envelop. ▶ Compound 1 showed promising immunostimulatory activity in experimental animals.
A new steroidal sapogenin molecule
1 having unique characteristics, 21-nor and unusual C19 carboxylic acid has been isolated from the roots of
Asparagus racemosus. On the basis of chemical evidence, extensive spectroscopic analysis including two dimensional (2D) NMR and X-ray studies of single crystal, the structure of
1 was determined as (1
S,2
R,3
S,8
S,9
S,10
S,13
S,14
S,16
S,17
R,22
R,25
R)-21-nor-18β,27α-dimethyl-1β,2β,3β-trihydroxy-25-spirost-4-en-19β-oic acid.
1 crystallizes in monoclinic space group
P2
1 with
a
=
9.295(2),
b
=
11.238(2),
c
=
11.376(2)
Å;
β
=
91.993(4)°,
Z
=
2,
D
cal
=
1.344
Mg/m
3. The structure was solved by direct methods and refined by full-matrix least-squares procedure to a final
R-value of 0.0561 for 4064 observed reflections.
1 was tested against the type of immune responses generated during treatment in normal and immune-suppressed animals and detailed biological activity evaluation suggests it to be a potent immunostimulator.