Dorita A. Norton

β-Side catalytic hydrogenation and the molecular structure of 17β-Hydroxy-1,4-Androstadien-3-One: p-bromophenol (1:1)

Abstract β-Side hydrogenation of the C(1)-C(2) double bond in 17β-hydroxy-1,4-androstadign-3-one by heterogeneous catalysis is explained in terms of precise Molecular conformation of the steroid obtained fron X-ray crystallographlc determination of the steroid:p-bromophenol (1:1) complex structure. This explanation serves as an example of how conformatlonal details can be correlated with molecular function. The steroid self-association interactions in the solid indicate that great care must be exerted in specifying the total α- or β-side of steroid molecules as the primary determinants of molecular function. The nature of this complex and its implications concerning other complexes of steroid molecules with molecules of biological importance is summarized.

Molecular interactions of hormonal steroids: The participation of the steroid 17β side chain in binding

Abstract The participation of the 17β side chain in the binding of steroids has been investigated. The C 20 carbonyl of the pregnane side chain is basically a proton acceptor, the binding of which is suppressed by substitution of an electronegative group in the C 21 position. This finding rules out the possibility of intramolecular hydrogen binding between the C 20 carbonyl and the C 17α , C 21 hydroxyl groups in adrenocortical steroids. It is suggested, however, that the C 20 -C 21 α-ketol group functions mainly as a proton donor in intermolecular binding. The possible participation of the steroid 17β side chain in steroid-protein interactions is discussed in view of our findings, with particular reference to steroid binding strength to certain proteins and hormonal activity.

Molecular interactions of hormonal steroids: The participation of the 17β side chain of corticosteroids in the formation of complexes with Co (II). Part I

Abstract Studies were carried out on a model system of Co++ and deoxycorticosterone. The C20-C21 α-ketol group of the 17β side chain of corticosteroids was observed to form metal complexes possibly of a chelate type structure. While the 1:1 steroid-cobalt complex is stable in anhydrous solvents as well as in water-solvent mixtures, the 2:1 complex is stable only in a nonaqueous medium.

Introduction to steroid molecular stacking

Abstract A set of molecular stacking postulates for steroids in the solid state has been formulated from a study of the stacking arrangements observed in single crystals. Since only six crystalline steroids have been studied, the molecular stacking postulates are to be considered as a working hypothesis. They are: (1) when present, heavy atoms play a leading role in steroid stacking; (2) the angular methyl groups seem to be the major stacking determinants in molecules lacking side chains or heavy atoms; (3) one of the most frequently observed stackings thus far consists of molecules arranged longitudinally in chains in which adjacent molecules may or may not be connected by hydrogen bonding; and (4) when the molecule has a complex system of side chains, these are primarily responsible for the stacking.

Molecular Geometry of Androsterone

THE structure of androsterone, C19H30O2 (Fig. 1), the first male sex hormone to be discovered, was determined recently by High1 by vector coincidence methods. The space group of this compound is P21; the unit cell constants are a = 9.56 Å, b = 7.90 Å, c = 11.78 Å, = 111.36°, Z = 2, and the measured density equals 1.164 g cm−3. Highs atomic positional parameters have been used to calculate the quantitative geometry of the androsterone molecule as follows. The final monoclinic fractional co-ordinates (x, y, z) were converted to Cartesian coordinates in Å (p, q, r) using the expressions p = a0x + c0z cos β, q = b0y, and r = c0z sin β, where a0, b0 and c0 are taken in the Donnay setting (a0 = 11.78 Å, b0 = 7.90 Å, c0 = 9.56 Å). The Cartesian Å co-ordinates were used, in turn, to compute a series of ‘best’ planes (Table 1) to which various geometrical features of the molecule could be referred, namely, the root mean square distances of atoms from the ‘best’ planes (Table 2), the perpendicular distance of individual atoms from the ‘best’ planes (Table 3), and the angles between the ‘best’ planes and various sub-portions thereof (Table 4). The ‘best’ plane calculations were performed on an IBM 1620 computer using the ‘best’ plane ‘Fortran’ programme of Harris and Harker2.

X-Ray Diffraction Powder Data for Some 5α-Pregnanes

X-ray diffraction data for seventeen 5α-pregnanes were collected using a General Electric XRD-5 diffractometer with a nickel-filtered CA-7 copper target tube operated at 40 kv and 20 ma in conjunction with a scintillation counter and a No. 2 SPG preamplifier. The linear scale of a Leeds and Northrup Speedomax G recorder was used to record the X-ray powder spectra. Samples were run at a speed of 0.2°/min using a take-off angle of 2.0°, a 3.0° beam slit, a medium resolution Soller slit, and a 0.1° detector slit. The number of cps was recorded by a digital printer that was synchronized with the 2θ scan. The digital tape readings and Speedomax charts were compared to determine maximum peak heights and locations in accordance with the accepted methods outlined by Klug and Alexander (2) and by Clark (1).

“Teflon”1 - A Matrix for Infrared Absorption Spectroscopy

Abstract It is a well-known observation in infrared absorption spectroscopy that certain bands of a spectrum when measured in solution differ considerably from the same bands obtained in solid state by the usual potassium bromide pellet technique2. Since these solid phase spectra are critically affected by the preparation procedures of grinding, mixing, pressure, etc, solution spectra are routinely perferred due to their relatively good reproducibility.