Synthesis of 6-deoxy-6-fluoro-L-ascorbic acid

Summary 6-Deoxy-6-fluoro-L-ascorbic acid has been synthesized in 5 steps starting from 2,3-4,6-di-O-isopropylidene-2-keto-L-gulonic acid.Dedicated to Professor Albert Szent-Györgyi, National Foundation for Cancer Research, Marine Biological Laboratory, Woods Hole, Massachusetts, on the occasion of his 85th birthday.     

G-6PD loading of G-6PD-deficient erythrocytes

G-6PD-deficient erythrocytes were loaded during hypotonic hemolysis with G-6PD extracted from yeast. It was shown that enzyme was really trapped into red blood cells and remained functionally active.     

G-6PD loading of G-6PD-deficient erythrocytes

Summary G-6PD-deficient erythrocytes were loaded during hypotonic hemolysis with G-6PD extracted from yeast. It was shown that enzyme was really trapped into red blood cells and remained functionally active.     

Hydroxylation of demethoxy-Q6 constitutes a control point in yeast coenzyme Q6 biosynthesis

Coenzyme Q is a lipid molecule required for respiration and antioxidant protection. Q biosynthesis in Saccharomyces cerevisiae requires nine proteins (Coq1p–Coq9p). We demonstrate in this study that Q levels are modulated during growth by its conversion from demethoxy-Q (DMQ), a late intermediate. Similar conversion was produced when cells were subjected to oxidative stress conditions. Changes in Q₆/DMQ₆ ratio were accompanied by changes in COQ7 gene mRNA levels encoding the protein responsible for the DMQ hydroxylation, the penultimate step in Q biosynthesis pathway. Yeast coq null mutant failed to accumulate any Q late biosynthetic intermediate. However, in coq7 mutants the addition of exogenous Q produces the DMQ synthesis. Similar effect was produced by over-expressing ABC1/COQ8. These results support the existence of a biosynthetic complex that allows the DMQ₆ accumulation and suggest that Coq7p is a control point for the Q biosynthesis regulation in yeast. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Received 04 September 2008; received after revision 22 October 2008; accepted 23 October 2008     

6-Methoxymellein as a phytoalexin

Résumé Le dihydroisocoumarin (I) était considéré comme un « phytoalexin » produit par des carottes infectées deCeratocystis fimbriata. Mais l'isocoumarin (II), de structure apparentée ayant été dégagé d'une culture de ce champignon sur bouillon synthétique, on peut douter que (I) tire son origine des carottes.     

Regulation of Lrp6 phosphorylation

The Wnt/β-catenin signaling pathway plays important roles in embryonic development and tissue homeostasis, and is implicated in human disease. Wnts transduce signals via transmembrane receptors of the Frizzled (Fzd/Fz) family and the low density lipoprotein receptor-related protein 5/6 (Lrp5/6). A key mechanism in their signal transduction is that Wnts induce Lrp6 signalosomes, which become phosphorylated at multiple conserved sites, notably at PPSPXS motifs. Lrp6 phosphorylation is crucial to β-catenin stabilization and pathway activation by promoting Axin and Gsk3 recruitment to phosphorylated sites. Here, we summarize how proline-directed kinases (Gsk3, PKA, Pftk1, Grk5/6) and non-proline-directed kinases (CK1 family) act upon Lrp6, how the phosphorylation is regulated by ligand binding and mitosis, and how Lrp6 phosphorylation leads to β-catenin stabilization.     

The biosynthesis of 6-azauracil riboside byEscherichia coli growing in the presence of 6-azauracil

Zusammenfassung Bei der Kultivierung vonE. coli in 6-azaurazilhaltigem Medium wird ein neuer Stoff akkumuliert, der als 6-Azaurazilribosid identifiziert wurde.     

Changes in the G6PDH/6PGDH ratio in the chick brain during development

Summary The profile of the G6PDH/6PGDH ratio at various stages of development was drawn on the basis of the specific activities of glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconic dehydrogenase (6PGDH) found in the embryonic brain of the chick. The ratio value lower than 1, found in the adult chick brain, is a special biochemical feature which emerges at a certain time-point of development, occurring around the middle of the prehatching age.Acknowledgment. This work was supported by grants from M.P.I. and C.N.R.     

Isolation of 6-hydroxymethyl-eugenin fromChaetomium minutum

Zusammenfassung 6-Hydroxymethyl-eugenin (1) wurde als Nebenprodukt von Chaetocin aus dem PilzstammChaetomium minutum isoliert. Eugenin und Eugenitin, die Inhaltsstoffe der NelkeEugenia caryophyllata, Leprariasäure aus verschiedenen Flechten, sowie der Pilzmetabolit1 unterscheiden sich nur in Stellung 6 des Chromongerüstes.     

Potentiation of the inhibition of xanthine oxidase by a combination of 6-mercaptopurine and 6-thioguanine

Summary Carcinostatic agents, 6-mercaptopurine and 6-thioguanine inhibited the in vitro and in vivo activity of the enzyme xanthine oxidase (xanthine-oxygen oxidoreductase E.C. 1.2.3.2.). Simultaneous, addition of a mixture of the 2 antimetabolites produced a synergistic effect on the inhibition of the enzyme activity.We thank the University Grants Commission, New Delhi, for their financial assistance and the Dean, M.G.M. Medical College Indore, for providing necessary facilities.     

Plastid differentiation on 6-azauracil media

Résumé Les mutants au locusm de l'Arabidopsis ne réussissent pas à former de chloroplastes normaux dans certaines conditions et montrent des activités plus hautes en synthèse de pyrimidines que le témoin. La nutrition aseptique par 6-azauracile, inhibiteur spécifique de cette voie métabolique, restaure la différenciatin de structure lamellaire dans la plupart de ces organites, mais aux concentrations élevées, apparaissent des chloroplastes morphologiquement déviants, quoique de fonction efficace.     

Umlagerung von Pinen-nitrosochlorid in 6-Chlor-Campheroxim

Summary The nitrosochloride of pinene dissolved in benzene will be transformed quantitatively by adsorbing to SiO₂ to the not yet described 6-chlor-campheroxim. This compound is also a by-product in the reaction of -pinene with nitrosylchloride.

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Teil der DissertationW. Russow, Univ. Würzburg 1967.     

Difficulties in vitamin B6 nomenclature

Zusammenfassung Der Name Vitamin B₆ hat Nachteile. Ein Ausdruck, der das Wort Vitamin enthält, ist nicht in allen Fällen zutreffend, und ein zweiwörtiger Ausdruck passt schlecht in gewissen Zusammenhängen. Da wenigstens 5 verwandte, aber verschiedene Verbindungen Vitamin-B₆-Aktivität besitzen, ist ein einziger, gewöhnlicher chemischer Name unzulänglich. Frühere Vorschläge weisen mehrere Mängel auf. Wir schlagen Pyridox vor.     

Δ6-Tetrahydrocannabinol-7-oic acid,a urinary Δ6-THC metabolite: Isolation and synthesis

Zusammenfassung 7-Hydroxy- ⁶-tetrahydrocannabinol (7-Hydroxy- ⁶-THC), ein psychotomimetisch aktiver Metabolit des ⁶-THC, wird von Kaninchen in inaktive ⁶-THC-7 Säure metabolisiert. Die Synthese dieser Säure wird beschrieben.

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The work in Jerusalem was supported by the US National Institute of Mental Health and in Stockholm by the Swedish Medical Research Council.     

The effects of dopaminergic blocking agents on the glucose tolerance test in 6 humans and 6 dogs.

Pre-treatment with low doses of sulpiride, an atypical dopaminergic blocking agent, but not haloperidol, a classical dopaminergic blocking agent, decreased tolerance to glucose and increased blood serotonin levels in 6 normal humans and 6 normal dogs investigated.