Barry M. Bloom

The Epoxidation of Unsaturated Steroids

Data for several additional instances of epoxidation by biological systems at isolated unsaturated sites on steroid structures are presented.These systems include the bovine adrenal, Curvularia lunata and a Curvularia species. This reaction predictably occurred only in the presence of enzymes capable of introducing “axial” hydroxyl functions at saturated carbons of corresponding analogous structures. A discussion of the implication of these findings in terms of the mechanism of the enzymatic hydfoxylation reaction is given.

C(14)-substituted corticosteroids; some D ring transformations in the compound S series.

Eine Anzahl am D-Ring substituierter Derivate von Reichsteins Verbindung S wurde als Modellverbindungen in der Synthese neuer Corticosteroide hergestellt. Die beschriebenen Strukturtypen schliessen Dehydroverbindungen, Epoxyde, Halogenhydrine und ein Glykol ein.

The synthesis of corticosteroids methylated at C21

Die Darstellung der beiden epimeren C21-Methylderivate des 9α-Fluorprednisolons wird beschrieben. 9α-Fluor-21-methyl-1, 4-pregnadien-11β, 17α, 21B-triol-3, 20-dion-21-azetat ist ein hochwirksames entzündungshemmendes Steroid, vollkommen frei von Nebenwirkungen der Natrium- und Wasserretention des C21-unsubstituierten 9α-Fluorprednisolons.

Chapter 22. Molecular Aspects of Drug-Receptor Interactions

Publisher Summary This chapter discusses the summary of the repeating unit concept because of the potentially outstanding heuristic value of knowledge about membrane structure, as it appears most relevant to the study of receptor systems. The molecular nature of the repeating units, the types of cohesive and repulsive forces that appear to be important in membrane systems, and discernible relationships between form and function are also mentioned. The probable mode of membrane biosynthesis is reviewed as a likely source of fundamental insights. The repeating units that have been detected in various types of cell membranes appear to be made up of so called base pieces, which are the sub-units essential to membrane formation, and detachable portions (headpieces and stalks) that contain enzymatic activity, but are not essential to the membrane continuum per se. The headpiece and stalk can be detached through procedures such as sonication or detergent action, without disruption of the membrane. The repeating units themselves can also be disassociated by detergent action. Upon removal of the disassociating influence, the units spontaneously reaggregate to form vesicular membranes. Going one step further, solvent extraction of lipid from repeating units removes their ability to form membranes, but this can be restored by reintroduction of the extracted lipid. The tendency to form membranes would, therefore, seem to be an expression of the intrinsic chemical properties of these lipoprotein repeating units.