A constituent of the unsaponifiable portion of animal tissue lipids (λmax. 272mμ.)

Abstract

A substance (SA) with an absorption peak at 272 m[mu] (in cyclohexane), an inflexion near 330 mu and a plateau near 410 mu. (e}^. 180, 13 and 8 approx. respectively) was obtained by chromatography on alumina of various animal tissue unsaponifiable fractions. SA is present in pig intestine, horse stomach and intestine, rat liver, kidney, intestine, and submaxillary gland whether from vitamin A-deficient or normal rats. SA was not found in unsaponifiable fractions from ox or sheep intestine or from bladder, testis and vagine of vitamin A-deficient rats. SA is not very strongly adsorbed on alumina, it contains 2 O2 atoms (no hydroxyl) and a possible formula is C28 H42 O2 (molecular weight observed 430); it is alkali-labile, particularly so in the purer state. From the polarity, infrared and UV absorption and probable empirical formula, SA could be a steroid with a chromophoric grouping 8(9)-ene-7: 11-dione. Horse intestine unsaponifiable matter contained small quantities of material slightly less polar than SA with 266 m[mu], (possibly cholesta-3:5-dien-7-one) a carotenoid (probably 10-apocarotenal) and a higher paraffin (m.p. 57[degree], mol. wt. 503).