A unique immuno-stimulant steroidal sapogenin acid from the roots of Asparagus racemosus

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 (1S,2R,3S.8S,9S,10S,13S,14S,16S,17R,22R,25R)-21-nor-18 beta,27 alpha-dimethyl-1 beta.2 beta,3 beta-trihydroxy-25-spirost-4-en-19 beta-oic acid. 1 crystallizes in monoclinic space group P2(1) with a=9.295(2), b = 11.238(2), c = 11.376(2)angstrom; beta = 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. (C) 2010 Elsevier Inc. All rights reserved.