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3 H-digoxigenin is metabolized by rat liver homogenates to 3 H-3-epidigoxigenin and 3 H-3-dehydrodigoxigenin. Maximum conversion occurs after approximately 80 min of incubation. The amount of each metabolite which accumulates depends on the amount of NADP + added to the incubation mixture. No formation of more polar metabolites was observed, indicating that a microsomal hydroxylating system may not be operative in the metabolism of digoxigenin.

Dioscorea deltoidea plant tissue suspension cultures are capable of metabolizing progesterone to 5α-pregnan-3-β-ol-20-one and 5α-pregnan-3β,20β-diol. The latter product has not previously been reported as a metabolic product of progesterone by plant systems. Both transformation products are present as conjugates in this plant tissue culture.

From the seeds of Yucca glauca Nutt., sarsasapogenin. markogenin. tigogenin. neo-tigogenin. neo-gitogenin, hecogenin and gloriogenin have been isolated and identified. Sarsasapogenin was the predominant sapogenin. Markogenin and gloriogenin have not been reported in leaves, roots or rhizomes of this species before. Small amounts of a sapogenin believed to be either diosgenin or yamogenin were also detected.

β-Sitosterol-4- 14 C is metabolized to Δ 4 -β-sitosten-3-one by Cheiranthus cheiri leaf homogenates. Greater than 60% conversion occurs within 2 hr. Under identical conditions, leaf homogenates of Strophanthus kombe fail to metabolize β-sitosterol, while Digitalis purpurea leaf homogenates yield only very small amounts of the metabolite.

Leaf homogenates of Cheiranthus cheiri and Digitalis purpurea rapidly metabolize pregnenolone to progesterone and 5α-pregnan-3,20-dione. Under identical conditions Strophanthus kombe yielded only small amounts of progesterone. Leaf homogenates of C. cheiri, D. purpurea, S. kombe and Corchorus olitorius metabolized progesterone to 5α-pregnan-3,20-dione, with small amounts of 5α-pregnan-3β-ol, 20-one. With both substrates, C. cheiri was most active. No 5β metabolites of either pregnenolone or progesterone could be detected.

The incubation of 20α-hydroxycholesterol-7- 3 H with leaf homogenates of Cheiranthus cheiri results in the formation of pregnenolone and progesterone. Preliminary results suggest that leaf homogenates of Nerium oleander , but not Digitalis purpurea or Strophanthus kombe , will yield the same two products under identical conditions.

Cheiranthus cheiri leaf and tissue culture homogenates readily metabolize [4-14C] cholesterol to 4-cholesten-3-one. The cytoplasmic fraction has the greatest metabolic activity, although other fractions are active as well. Homogenates from Nerium oleander leaves and Dioscorea deltoidea tissue cultures are devoid of metabolic activity under identical conditions. Digitalis leaf homogenates are only about 1 70 th as active as the Cheiranthus systems. The first step in cholesterol side chain cleavage by plants may be the formation of 4-cholesten-3-one.

A simple method is presented for the separation of cardiac glycosides from cardiac aglycones using highly cross-linked lipophilic dextran gel chromatography with 95% ethanol as the solvent.

Digitoxigenin is metabolized in vitro by rat liver homogenates and subcellular fractions. No metabolism by cardiac tissue homogenates was observed, with only limited conversion by kidney tissue homogenates. The primary product is 3-epidigitoxigenin, with smaller amounts of 3-dehydrodigitoxigenin and more polar metabolites being detected. The microsomal hydroxylation system can be induced by treatment of the animals with phenobarbital.

A method for the separation of 3β‐hydroxysterols from other sterols is presented. The method involves precipitating 3β‐hydroxysterols as the digitonides. The digitonide is then decomposed and separated into components using chromatography on highly cross‐linked lipophilic polysaccharide gels. The digitonin in the mother liquor is separated from other sterols using the same chromatographic procedure.