R.P. Rastogi

Triterpenoid saponins and sapogenins: 1973–1978

The triterpenoid saponins identified in plants during the period 1973 to 1978 inclusive are reviewed. Their natural occurrence, chemistry and biological activities are discussed. A compilation of all saponins, the structures of which have been fully elucidated, is included.

A reinvestigation of the triterpenes of Centella asiatica

Abstract Apart from the constituents reported earlier, the isolation of asiatic acid, asiaticoside, meso -inositol and a new oligosaccharide, “centellose”, is described from the Indian variety and their relative proportions determined in the plant material. The periodate oxidation product of asiatic acid has been reinvestigated and its structure has been assigned as a hemiacetal derivative.

Two lignans from Cedrus deodara

Abstract Two new lignans were isolated from the lead acetate-purified butanol-soluble fraction obtained from the wood of Cedrus deodara . They were identifie

Aquillochin, a coumarinolignan from Aquilaria agallocha

Aquillochin, isolated from the whole plant of Aquilaria agallocha, has been shown to be a coumarinolignan, and a structure has been proposed on the basis of chemical and physical studies.

Bacogenin-A1: a novel dammarane triterpene sapogenin from Bacopa monniera

The constitution of bacogenin-A1, obtained from the acid hydrolysate of bacoside-A, has been established as 3,18-dihydroxy-20 → 25-epoxy-22(or 23)-methyl-24-nor-dammar-22-en-16-one. The treatment of di-O-acetylbacogenin-A1 with RuO4 led to a diol instead of the usual dioxo product.

Dihydroflavonols from Cedrus deodara

The identification of taxifolin and structure elucidation of cedeodarin (6-methyltaxifolin), dihydromyricetin, cedrin (6-methyldihydromyricetin) and cedrinoside from cedar wood are described.

Bacogenin-A3: A new sapogenin from Bacopa monniera

Abstract The structure of bacogenin A 3 , one of the sapogenins of the bacosides has been established by various chemical and spectral methods.

Structure of asclepin and some observations on the NMR spectra of Calotropis glycosides

Asclepin has been shown to be 3′-O-acetylcalotropin using various chemical and physical methods. The NMR data of all the Calotropis glycosides have been analysed in conjunction with that of asclepin, certain anomalies have been pointed out and revised structures have been proposed for the acetylated glycosides.

Auriculoside, a new flavan glycoside from Acacia auriculiformis

The structural elucidation of auriculoside, a new flavan glucoside from Acacia auriculiformis, is described. This is the third report of a flavan glycoside unsubstituted in the heterocyclic ring.

Agarol, a new sesquiterpene from Aquilaria agallocha

The isolation of two sesquiterpenes, gmelofuran and agarol, from Aquilaria agallocha is described Gmelofuran has not been previously reported from this genus and the structure of agarol has been elucidated by physical methods and chemical reactions.