Showing papers by "Mohan S. M. Rawat published in 1988"

Structure elucidation of a spirostanol glycoside from Asparagus officinalis fruits by concerted use of two‐dimensional NMR techniques

Abstract: Complete 13C and 1H assignments for the oligosaccharide segment of a novel spirostanol glycoside were derived, and structural proof obtained, using a combination of DEPT, heteronuclear chemical shift correlation, homonuclear relayed coherence transfer, absolute value COSY, phase-sensitive double quantum filtered COSY, NOESY, INEPT and proton-detected long-range heteronuclear shift correlation via multiple quantum coherence.

Spermicidal Activity and Chemical Analysis of Pentapanax leschenaultii

Abstract: Triterpenic glycosides have been reported to have spermicidal potential furthermore "CONSAP" cream with these constituents as the active compounds has reached clinical trial as a male contraceptive. Panax and other araliacious plants are rich sources of triterpenic glycosides. We recorded 100% immobilization of human spermatozoa by the ethanolic extract of the fresh leaves of Pentapanax leschenaultii (DC). Seen at the 2% level when assayed by the methods reported. Since the plant has not been investigated chemical analyses of the light petroleum- and n-butanol-soluble portions of the extract were carried out. The compounds obtained were identified by the usual color tests physical data IR UV MS chemical degradation and comparison with the authentic samples. The activity was found to be associated with a triterpenic glycoside from the butanol fraction. The plant material collected from Tungnath U.P. was extracted with EtOH. The concentrated extract was partitioned into light petroleum: n-BuOH- and H20-soluble portions. Column chromatography (silica gel light petroleum-CHC13) gave the following compounds: hentriacontane m.p. 66-68 degrees Celsius (4) hentriacontanone m.p. 82-83 degrees Celsius (4) alpha-amyrin m.p. 183-185 degrees Celsius (4) beta-sitosterol m.p. 134-136 degrees Celsius (5) and oleanolic acid m.p. 304-306 degrees Celsius (6). The n-BuOH portion on CC (silica gel CHC13-MeOH) gave the following compounds: beta-sitosterol-beta-D-glucoside m.p. 134-136 degrees Celsius (5) quercetin m.p. 300 degrees Celsius (7) quercetin-3-0-rhamnoside m.p. 180-184 degrees Celsius (7) and a glycoside which on acidic hydrolysis gave a triterpenic aglycone and glucose and arbinose. Its further characterization is in progress. (full text)