G.C. Uniyal

Saponin production in callus and cell suspension cultures of Panax quinquefolium

Abstract Callus and cell suspension cultures of American ginseng (Panax quinquefolium) were compared for growth and in vitro ginsenoside production over a 35-day culture cycle on modified Murashige and Skoogs medium. A time course study at five day intervals revealed that biomass yield in suspension and callus cultures was maximal on the 25th and 30th day of growth, respectively. Both types of cultures were able to produce ginsenosides in amounts and quality comparable to the cultivated plants. TLC-densitometry and HPLC analyses of the crude ginsenosides revealed that yield and relative distribution of different fractions belonging to the Rb and Rg groups of ginsenosides were greatly influenced by culture age. For the Rb group components, 25-day-old callus or suspension cultures were the best source of these compounds, while for the Rg group fractions 30–35-day-old cell cultures gave the maximum yield. Appreciable amounts of ginsenosides, particularly Rg1, were found to leach out in the culture medium of 30–35-day-old suspension cultures.

Differential morphogenetic responses, ginsenoside metabolism and RAPD patterns of three Panax species

Genetic and metabolomic demarcations between two Indian and one American congeners of Genus Panax have been discerned. Genomic DNA was isolated from the root derived callus cultures of these species and amplified by AP-PCR. RAPD analyses of the DNA with six most responding arbitrary oligonucleotide decamers provided a total of 70 reproducible bands for computation of the similarity matrix amongst the Panax species. Only 18 of these were monomorphic giving an estimate of about 74% polymorphism among the test species examined. The similarity coefficient values based on the amplification pattern support an equidistant position of the three test species. The molecular demarcations between the species are also manifested in terms of their characteristic cultural requirements, in vitro growth kinetics, regeneration competence and ginsenoside complement of their calli. The Indian congeners i.e. P. sikkimensis and P. pseudoginseng were distinguishable by higher proportions of ginsenoside Rf and Ro (40% and 20%, respectively) in the crude saponin fractions. Furthermore P. quinquefolium calli mainly accumulated ginsenoside Rb2 and Rg1, whilst P. sikkimensis callus was rich in Rd fraction. P. quinquefolium showed high similarity with P. sikkimensis with respect to plasticity and totipotency for somatic embryogeny whereas P. pseudoginseng callus was highly recalcitrant and lacked regenerative capacity. The chemical and genetic fingerprints alongwith morphogenetic responses of the three species under controlled in vitro environment strongly advance the case of P. sikkimensis as an independent species, rather than a conglomerate of location specific variety or sub-species of P. pseudoginseng. The findings are also of relevance to formulations and evaluation of ginseng-based health foods.

Steroidal glycosides from Agave cantala.

Two new steroidal glycosides, agaveside A and B, isolated from the fruits of Agave cantala were characterized as 3 beta-O-[beta-D-xylopyranosyl-(1----2),beta-D-xylopyranosyl-(1----3), beta-D-glucopyranosyl-(1----3)-[beta-D-xylopyranosyl-(1----3)-beta-D- galactopyranosyl-(1----2)]-beta-D-glucopyranosyl]-(25R)-5 alpha-spirostane and 3 beta-O-[beta-D-xylopyranosyl-(1----2), beta-D-xylopyranosyl-(1----3)-beta-D-glucopyranosyl-(1----3)- [beta-D-galactopyranosyl-(1----2)]-beta-D-glucopyranosyl]-(25R)-5 alpha-spirostane. The structures were elucidated by a combination of 13CNMR spectroscopy, chemical degradation and fast atom bombardment mass spectrometry.

Reverse-phase High Performance Liquid Chromatography of Sennosides in Cassia angustifolia

A rapid and simple reverse-phase high performance liquid chromatographic method has been developed for the quantitative estimation of the medicinally useful laxative principles sennoside A and sennoside B in senna. Using a Bondapak C,, column eluted with methano1:water:acetic acid:tetrahydrofuran (60:38:2:2) both compounds were well resolved with recoveries of 97 and 96% respectively.

Agaveside C, a steroidal glycoside from Agave cantala

Abstract A new steroidal glycoside, agaveside C, isolated from the fruits of Agave cantala was characterized as 3β-{α- l -rhamnopyranosyl-(1→2)-β- d -glucopyranosyl-(1→3)-β- d -glucopyranosyl-[β- d -xylopyranosyl-(1→4)-α- l -rhamnopyranosyl-(1→2)]-β- d -glucopyranosyl}-2α-hydroxy-25R-5α-spirostane on the basis of chemical degradation, 13C NMR spectroscopy and fast atom bombardment mass spectrometry.

A spirostane hexaglycoside from Agave cantala fruits

A new steroidal glycoside, agaveside D, isolated from the fruits of Agave cantala was characterized as 3 beta-(alpha-L-rhamnopyranosyl-(1----2),beta-D-glycopyranosyl- (1----3)-beta-D-glucopyranosyl[beta-D-xylopyransoyl-(1----4)-alpha -L-rhamnopyranosyl-(1----2)]-beta-D-glucopyranosyl)-25R-5 alpha-spirostane on the basis of chemical degradation and spectrometry.