Distinction of Absolute Configuration at C-22 of C-23-Hydroxyspirostane and C-23-Hydroxyspirosolane Glycosides

Chem. Pharm. Bull. 55(7) 1079—1081 (2007)

and their glycosides are normally 22R configuration. On the other hand, spirosolanes such as tomatidine, solasodine and their glycosides take both 22R and 22S configurations (Chart 1). To determine the configuration at C-22 is very important, because the difference in C-22 configuration relates to the chemical reactions and bio-activity, for example, as shown in the following reaction of spiros...

Physicochemical and biological properties of natural and synthetic C-22 and C-23 hydroxylated bile acids.

In order to define the effect of a side chain hydroxy group on bile acid (BA) physicochemical and biological properties, 23-hydroxylated bile acids were synthesized following a new efficient route involving the alpha-oxygenation of silylalkenes. 22-Hydroxylated bile acids were also studied. The synthesized bile acids included R and S epimers of 3 alpha,7 alpha,23-trihydroxy-5 beta-cholan-24-oic...

Absolute configuration of isovouacapenol C

The title compound, C(27)H(34)O(5) {systematic name: (4aR,5R,6R,6aS,7R,11aS,11bR)-4a,6-dihy-droxy-4,4,7,11b-tetra-methyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodeca-hydro-phenanthro[3,2-b]furan-5-yl benzoate}, is a cassane furan-oditerpene, which was isolated from the roots of Caesalpinia pulcherrima. The three cyclo-hexane rings are trans fused: two of these are in chair conformations with the third...

The introduction of the C-22-C-23 ethylenic linkage in ergosterol biosynthesis.

Methods for the chemical synthesis of [23-(3)H(2)]lanosterol, [23,25-(3)H(3)]24-methyldihydrolanosterol and [24,28-(3)H(2)]24-methyldihydrolanosterol are described. It is shown that, in the biosynthesis of ergosterol from [26,27-(14)C(2),23-(3)H(2)]lanosterol by the whole cells of Saccharomyces cerevisiae, one of the original C-23 hydrogen atoms is lost and the other is retained at C-23 of ergo...

Stability of cell suspensions of Pasteurella pestis at 5 C and at -23 C.