Structure of β-Acylacrylic Acids
IN previous publications1–5 the β-formyl-, β-acetyl- and β-pivaloyl-acrylic acids were investigated by means of their spectra in the ultra-violet and infra-red. This work has been extended to comprise the α-methyl-β-acrylic acid6,7. In regard to cis–trans isomerism and open or cyclic structure for the preparations used, the infra-red spectra (in the case of acid (5) also by means of the nuclear magnetic resonance) have confirmed the following structures : (1) β-Formylacrylic acid, m.p. 53–56° C.: cyclic, cis (2) β-Acetylacrylic acid, m.p. 122–125° C.: trans (probably with a smaller amount cis-open acid) (3) β-Pivaloylacrylic acid, m.p. 84–85° C.: cyclic, cis (4) β-Pivaloylacrylic acid, m.p. 94–95° C.: trans (5) α-Methyl-β-acetylacrylic acid, m.p. 98–101° C.: cyclic, cis
Acylacrylic Acids and Biological Activity
IT has recently been reported1 that β-acetylacrylic acid and its (ethyl) ester are rather poisonous to mice, about 1 mgm. given subcutaneously to a 25-gm. mouse being lethal. There was also an increase in leucocytes, which in the case of the ester appear after about three weeks and in the case of the acid after a few hours. In the latter case the effect disappeared after about a day and this increase was assumed to be due to acidosis. This has now been found to be almost certain, because injection of a neutralized solution caused no clear rapid increase followed by a rapid decrease in leucocytes. However, the poisonous effect with neutralized acid remained almost unchanged, 2 mgm. being lethal.
Effect of a new inhibitor of cholesterol biosynthesis (AY 9944) on serum and tissue sterols in the rat.
AY 9944 is a novel inhibitor of cholesterol biosynthesis which appears to act on the Delta 7-reductase enzyme, interfering with the conversion of 7-dehydrocholesterol to cholesterol. In all tissues studied, with the exception of the lens, there was a reduction in cholesterol and a marked accumulation of 7-dehydrocholesterol. Isotope studies showed a reduced uptake of acetate into cholesterol, and an increased uptake into 7-dehydrocholesterol, in various tissues in vivo and by skin samples in vitro. There was no apparent accumulation of lanosterol or of the methostenols in the rat skin.