Distribution of Cardenolides in Digitalis lanata

By means of a digoxin-RIA it has been shown that all organs and tissues of DIGITALIS LANATA contain Cardenolides.     

Cryopreservation of Digitalis lanata cell cultures

Suspension cultures of Digitalis lanata strain I were grown in a medium containing 3% mannitol. For cryopreservation cell suspensions were treated with a mixture of sucrose-glycerol (20%/20 V%), cooled slowly (about 1 degrees C/min) till -100 degrees C and then were transferred to liquid nitrogen. After storage in liquid nitrogen the cells were thawed rapidly in a water bath of 40 degrees C and spread on the surface of a solidified nutrient medium. After 7 days of regrowth the cells were suspended in liquid nutrient medium for further cultivation. About 50% of the cells survived freezing and thawing. However, also the apparently surviving cells showed signs of injury (membrane vesicles outside the plasmalemma, dilated ER cisternae and separation of the nuclear membranes). The cultures derived from the surviving cells had the same growth rate and biochemical activity relative to the transformation of cardenolides, e.g., digitoxin, as the parent cultures. The frequency distribution of the nuclear DNA content in the cell cultures was the same before and after cryopreservation. These results indicate that there is no selection of a special cell type during freezing and thawing.     

Cryopreservation of Digitalis lanata Shoot Tips

A method for the preservation in liquid nitrogen of shoot tips (meristems) of D. LANATA is described. It includes the following steps: (a) hardening of shoots by cultivation at 4 degrees C for 8 weeks, (b) treatment of the explanted shoot tips with cryoprotectors, e.g., 2 mol DMSO l (-1) for 2 h, (c) either ultrarapid cooling (ca. 4000 K min (-1)) of the shoot tips by submerging in liquid nitrogen or slow cooling (ca. 0.5 K min (-1)) of the shoot tips to -40 degrees C using a suitable freezer, (d) storage of the shoot tips at -196 degrees C in liquid nitrogen, (e) ultrarapid rewarming of the ultrarapidly cooled shoot tips by placing them directly into nutrient medium or rapid rewarming of the ampoules containing the slowly cooled shoot tips with water at 40 degrees C, and (f) recultivation of the shoot tips at the surface of a solidified nutrient medium containing 2.5 micromol BA 1 (-1). About 70% of the shoot tips survived this procedure and about 30% of the shoot tips regenerated shoots.     

New Cardiac Glycosides from Digitalis lanata

From the leaves of DIGITALIS LANATA Ehrh. two new Cardenolides have been found and structurally elucidated as Digoxigenin-3-O-beta- D-digitoxosido-beta- D-digitoxosido-beta- D-xyloside bei TLC and spectroscopic methods.     

New Cardiac Glycosides from Digitalis lanata.

From the leaves of DIGITALIS LANATA E HRH. three as yet unknown cardenolides were isolated and structurally elucidated as Digoxigenin-3-O-beta-D-digitoxosido-beta-D-digitoxosido-beta-D-glucomethylosid, Digoxigenin-3-O-beta-D-digitoxosido-beta-D-glucomethylosid and Diginatigenin-3-O-beta-D-digitalosid by TLC and mainly spectroscopic methods.     

New Cardiac Glucosides from Digitalis lanata1

From the leaves of DIGITALIS LANATA Ehrh. two as yet unknown cardenolides have been found. They were structurally elucidated as Digoxigenin-3-O-beta- D-digitoxosido-beta- D-2,6-dideoxyglucoside and Digoxigenin-3-O-beta- D-digitaloside by TLC and mainly spectroscopic methods.     

Cryopreservation of Digitalis lanata Cell Cultures.

Suspension cultures of DIGITALIS LANATA strain I were grown in a medium containing 3% mannitol. For cryopreservation cell suspensions were treated with a mixture of sucrose-glycerol (20%/20 V%), cooled slowly (about 1 degrees C/min) till -100 degrees C and then were transferred to liquid nitrogen. After storage in liquid nitrogen the cells were thawed rapidly in a water bath of 40 degrees C and spread on the surface of a solidified nutrient medium. After 7 days of regrowth the cells were suspended in liquid nutrient medium for further cultivation. About 50% of the cells survived freezing and thawing. However, also the apparently surviving cells showed signs of injury (membrane vesicles outside the plasmalemma, dilated ER cisternae and separation of the nuclear membranes). The cultures derived from the surviving cells had the same growth rate and biochemical activity relative to the transformation of cardenolides, e.g., digitoxin, as the parent cultures. The frequency distribution of the nuclear DNA content in the cell cultures was the same before and after cryopreservation. These results indicate that there is no selection of a special cell type during freezing and thawing.