Chapter 6, Notes 9. Twin Formation

The odd number of carbons in a cyclic molecule represents one of the conditions which always would result in the appearance of a twin formation, since the alternation between positive and negative signs gives the same electrical charge to two nearby carbons. (Fig. 254) The correlation of the positive and negative charges of nearby carbons to the fact that acetic acid molecules have been utilized in the synthesis of the molecule represents an additional factor for inducing twin formations even in cycles with an even number of carbons.

Gas chromatographic analysis of a sample of cod liver oil fatty acids showing some of the different constituents

Fig. 250. Gas chromatographic analysis of a sample of cod liver oil fatty acids showing some of the different constituents.

Gas chromatographic analysis of a sample of the fatty acids of cod liver oil after chemical conjugation

Fig. 251. Gas chromatographic analysis of a sample of the fatty acids of cod liver oil after chemical conjugation. No differences are seen between the curve of Fig. 250 and this curve, indicating that in the conditions under which the analysis was made, the conjugated members are not detected.

Spectral analysis of the sample used for gas chromatography

Fig. 252. Spectral analysis of the sample used for gas chromatography, shown in Fig. 251, indicating the presence of di-, tri-, tetra-, penta- and hexaenic conjugated members.

Fig. 254. A twin formation appears in cyclopentane as a result of the alternate sign of adjacent carbons.

A twin formation appears in cyclopentane as a result of the alternate sign of adjacent carbons

Chapter 6, Note 10. Arachidonic Acid-Sterol Relationship

The relationship between arachidonic acid and sterols, both of which are present in the adrenals, has been followed through the changes which occur in the amount of these substances in the adrenals during certain pathological processes. Rabbits were slowly injected intravenously with a suspension of microbes until symptoms of deep acute shock appeared. The animals were sacrificed immediately by bleeding them and the adrenals and blood analyzed. The amount of polyunsaturated fatty acids of the adrenals had markedly decreased, and, in some animals, had almost disappeared from these organs. At the same time, the amount of the same fatty acids of the circulating blood had manifestly increased. The amount of insaponifiable fractions and sterols in the adrenals was unchanged as compared with controls. It seems that fatty acids have passed from the adrenals into the general circulation as a first response to the noxious intervention.