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Cholesterol oxidase has been used in the qualitative analysis of model mixtures of hydroxylic steroids. Selective oxidation of Δ 5 -3β-ols and 5α-3β-ols of the sterol series has been accomplished: the resulting ketones were completely separable by gas-liquid chromatography. Steroids with the cholane and pregnane types of side-chain were oxidised more slowly than cholesterol and those of the androstane group were almost unattacked. Steroids with modified sterol side-chains (C-24 alkylated sterols, hydroxycholesterols, sapogenins) were satisfactory substrates.

The use of the tert. -butyl chromate reagent on paper chromatograms has been shown (i) to detect 3-hydroxy- or 3-keto-, 4- or 5-unsaturated steroids in the androstane, pregnane, cholane, cholestane, and spirostane series if followed by heating with alkali and examination for fluorescnce emission under a 360 mμ U.V. light, and (ii) to detect 17-hydroxy-20-hydroxy- or 17-hydroxy-20-ketopregnane derivatives if followed by Zimmermann's reagent for the 17-ketosteroids produced. Oestrogens gave a red colour on tert. -butyl chromate oxidation and blue fluorescence on alkali treatment.

A series of basic derivatives of cholane and norcholane has been examined for bacteriostatic activity against the Gram-positive Staphylococcus aureus and Lactobacillus helveticus and the Gram-negative Bacillus lactis aerogenes . The basic derivatives, in general, were more highly bacteriostatic against the Gram-positive organisms than against the Gram-negative. Of the compounds studied, the highest antibacterial activity was shown by 3:7:12-trihydroxy-23-guanido-norcholane hydrochloride. No relationship was apparent between the lowering of the surface tension of the medium induced by the compounds and their bacteriostatic activity.

Some methanesulfonate esters of cholane alcohols derived from desoxycholic acid have been prepared and submitted for screening as antitumor agents. Infrared spectra of the dimesylates have distinctive patterns in the 870 to 1000 cm. −1 region, each of which is shown to be virtually superimposable on a composite spectrum of a pair of corresponding mono-mesylates. Antitumor screening test results indicate that the 3α,12α-, and 12α,24-compounds are inactive and harmless to test animals, but the 3α,24-isomer is quite toxic.

Publisher Summary This chapter discusses microbiological transformation of bile acids. There is an intimate relationship between bile acid metabolism in vivo and intestinal microorganisms. The conjugated primary bile acids are attacked by intestinal microorganisms in the lower small intestine and cecum and transformed into various metabolites that are absorbed and further transformed by liver enzymes prior to re-excretion into the bile. The liver enzymes mainly catalyze the following reactions: (1) conjugation of free bile acids with taurine or glycine, (2) reduction of keto groups to alcohols, and (3) hydroxylation of the cholane nucleus. Thus, the final composition of the bile acids in normal bile is the result of an intimate interaction between the liver and intestinal microorganisms. The bile-acid transformations in the intestine can be classified as follows: (1) hydrolysis of the conjugated bile acids; (2) elimination of hydroxyl groups, mainly at the C-7 position of the cholane nucleus; (3) oxidation of the hydroxyl groups at C-3, C-7, and C-12 to oxo groups; (4) reduction of oxo groups to both α- and β-hydroxyl groups; and (5) other miscellaneous reactions.

Four bisquaternary ammonium salts derived from 3α,12α-diamino-5β-cholane and 3α,12α-diamino-24-nor-5β-cholane and possessing an interonium distance of ca 5.8 A were found to lower blood pressure in cats, to inhibit the responses of the nictitating membrane to preganglionic stimulation and to inhibit the pressor response to DMPP. The responses of the nictitating membrane to postganglionic stimulation and to noradrenaline were not inhibited. The only effect of the steroids on single-shock stimulation of the cat tibialis anterior muscle-sciatic nerve preparation was a slight augmentation of maximal twitches. Using different stimulation parameters, the steroids were shown to have an effect at the neuromuscular junction but this was no more pronounced than that produced by standard ganglion-blocking agents. It was concluded that these drugs exerted their main action at autonomic ganglia and hence they represent a successful application of theoretical concepts in the design of ganglion-blocking agents by the use of the rigid steroid nucleus substituted with quarternary ammonium groups.

The allo bile acids are the 5α-cholanoic acids, i.e., derivatives of cholanoic acid in which the hydrogen at C5 is alpha-oriented rather than beta-oriented as in the large number of naturally occurring bile acids. The sequence of numbering in the cholane nucleus is the same as in the normal series. The prefix allo (Greek allos, other) has been defined by Chemical Abstracts to designate the more stable of two geometrical isomers. The trans relationship of rings A and B existing in these derivatives is the more stable conformation [see Fieser and Fieser (1) for discussion of this matter]. The allo-acids presently known, in addition to the unsubstituted allocholanoic acid, are oxygenated at positions 3, 6, 7, and/or 12. Where the structure of the allo-acid is otherwise identical to a known 5β acid, the acid is frequently named by the trivial name of the 5β acid with the prefix allo; e.g., allocholic acid (t) (3α, 7α, 12α-trihydroxy-5α-cholanoic acid) is the 5α-derivative of cholic acid.

After demonstrating that the female bitterling test was not a test for pregnancy,1 we have stated2 that the fraction of male urine containing the male hormones is responsible for the ovipositor elongating reaction. A positive reaction was taken as a lengthening of the ovipositor from a quiescent stage to a length equal to that of the anterior edge of the anal fin, i. e., the ovipositor must reach the end of the fin.Crystalline theelin and theelol were also tested and although they did not give positive reactions, they sometimes caused a slight lengthening of the ovipositor. We therefore felt it important to determine whether any other substance containing the cholane nucleus would produce this reaction in greater or lesser degree.We have tested ergosterol† and cholesterol emulsions and solutions of sodium taurocholate according to our method.2 Small doses of all these compounds produced no reactions. These doses were equivalent to, or several times greater than the doses of male hormone which produced pro...