Studies on Vitamin B₁ and Related Compounds. CIII

Studies on Uric Acid and Related Compounds

The systematic study of the substrate specificity of mammalian xanthine oxidase has indicated a common mechanism by which various purines may be dehydrogenated (1). The results obtained also made it clear why methylated xanthines, with the exception of 1-methylxanthine (2), cannot be oxidized by xanthine oxidase to the corresponding substituted uric acids (3, 4). Therefore, another source had t...

Studies on the Cancerogenic Azo and Related Compounds *

Even in the earliest days of cancer research it was claimed that Scarlet Red and o-aminoazotoluene could accelerate epithelial proliferation, and that these chemicals, when orally administered, could cause an adenomatous proliferation in the liver. But no definite evidence was found to prove their carcinogenic effect, notwithstanding numerous experimental attempts, until, a few years ago, Sasak...

Some Recent Studies on Carotenoids and Related Compounds

Studies on models synthesized by stereochemically controlled routes show that the central triene chromophore in the common cis isomer of phytoene has the irans,cis,trans configuration, and that the phytoene from Flavobacterium dehydrogenans consists mainly of the all-trans isomer. Capsorubin, with the natural configuration at all four chiral centres, has been synthesized from (+)-camphor. Sever...

13C CP/MAS NMR studies of vitamin E model compounds.

13C cross-polarization magic angle spinning (CP/MAS) NMR data for 2,2,5,7,8-pentamethylchroman-6-ol (2), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox c) (3) and its acetate (4), 2-methoxy-2,2,5,7,8-pentamethylchroman-6-ol (5), 2-hydroxy-2,2,5,7,8-pentamethylchroman-6-ol (6) and 2,2,5,7,8-pentamethylchroman (7) are reported. A deshielding of 7.7 ppm for the carboxylic carbon wa...

Studies in vitamin A; reactions of retinene1 with amino compounds.