Über das Vitamin E

Abstract

ie ersten Beobachtungen uber die Existenz eines I. Vitamin-E-Mangelerscheinungen an der Ratte D Nahrungsfaktors, der von Ratten zur Erhaltung ihrer und Testverfahren. normalen Fortpflanzungsfahigkeit benotigt wird, -gehen zuriick auf Evans u. Mitarb. (1) im Jahre 1922. In jahrelanger Arbeit mit Versuchen an uber 10000 Ratten haben Evans u. Burr die Erscheinungsformen des Vitamin-I3-Mangels an mannlichen und weiblichen Tieren sowie die Eigenschaften und das Vorkommen dieses neuen Nahrungsfaktors eingehend studiert und ihre Beobachtungen in einem ausgezeichneten Werke, ,,The antisterility vitamine E" (2) Angewandte Chamic 62.Jahrg.l#d#. Nr.24 Yo1 CH, CH, A n g~w n n d f e Chrmie 5 2 . J a h r g . 193% 9 r . P I F . v. Werder u. Th.

Vitamin E Activity of -Tocopherol Side Chain Analogs in Selenium-Deficient Chicks

“…Chicks reared for 2 weeks using the selenium-deficient diet showed significant (P < 0.05) increases in gain, efficiency of feed utilization (feed/ gain), prevention of ED, survival, and total fat-soluble reducing substances in plasma in response to dietary supplementation with all-rac-a-T (Table 11). These results are consistent with previous reports of diminished activities of 2RS-a-T-C6, 2RS, 4'RS-a-T-C1, and 2 RS-a-T-nC,, in rat fetal resorption tests (14,15,17), and of 2RS-a-T-C6 and 2RS, 4'RS-a-T-CI1 in erythrocyte hemolysis tests (28). If this is true, then a-T analogs with shorter or unbranched side chains would be expected to have less vitamin E activity than all-rac-a-T.…”

“…Early studies (with rats) of modified side chain analogs of all-rac-a-T in which the hydrocarbon side chain lacked one (14) or two (15) isopentyl units, had one additional isopentyl unit (16), or was unbranched and contained only 12 carbon atoms (17), showed that changes in the length and branching of the side chain of all-rac-a-T markedly affect its biological activity. Although some investigators have reported no significant differences between the biological activities of 2-arnbo-a-T and all-rac-a-T (7,8,18,19), suggesting that the configurations of the 4' and 8' carbon atoms are not important for vitamin activity, this conclusion has been questioned (20) and a recent study found a small but significant difference between these two forms (21).…”

The Early Years of 2,2′-Bipyridine—A Ligand in Its Own Lifetime

“…An early review of iron coordination chemistry dating from 1928 appears to be the first recognition of Blau’s observation of the redox couple [330]. With a subsequent colorimetric determination of iron(II) as [Fe(bpy) 3 ] 2+ , methods for the determination of vitamin C (ascorbic acid) [331], vitamin E (tocopherol) [332,333,334,335,336,337] were developed based upon the quantitative reduction of Fe 3+ by the analytes. Most of these methods utilize mixtures of bpy and iron(III) compounds, which in the presence of reducing agents that can reduce the iron(III) to iron(II) develop the characteristic red [Fe(bpy) 3 ] 2+ colour which can be quantified colorimetrically.…”

125 Jahre Chemie im Spiegel der “Angewandten”

“…[113] Die Vitaminforschung war von besonderer Bedeutung in Deutschland, [114] und so wurden deren Fortschritte im Heft 30 des Jahres 1934 und auch später ausführlich referiert. [115] Im Jahr 1938 erhielt Richard Kuhn den Chemie-Nobelpreis für seine Arbeiten zu den Carotinoiden und den Vitaminen. [116] Er blieb bis Kriegsende und darüber hinaus einer der aktivsten Autoren der Zeitschrift.…”