Two-dimensional NMR studies of native coenzyme F430

Abstract

The infrared and Raman spectra of bicyclo[ 1.1 .O] butane and of its 2,3-d2 and 2,2,4,4-d4 isotopomers were redetermined, and the intensities of the infrared bands were measured. A new vibrational assignment was made with the help of the spectrum

Derivatives of Coenzyme F430 with a Covalently Attached α‐Axial Ligand. Part II

“…) That coenzyme F430 (1) is diamagnetic in 2,2,2-trifluoroethanol was reported for the first time by Won et al[16].…”

Ein NiII‐haltiges Vitamin‐B12‐Derivat mit einem Kofaktor‐F430‐artigen π‐System

“…Die Signale fürdas C10-Proton sowie die C1A-Methylgruppe wurden jeweils bei 6.02 und 1.69 ppm detektiert, d. h. mit einer signifikanten Tieffeldverschiebung gegenüber H 2 OCbl (1-OH 2 + ;A bbildung S1 und Tabelle S2). [31] Um die Frage der Konfiguration an den Positionen C5 und C6 des rekonstituierten Makrozyklus zu klären, wurde zunächst die 1 H-1 H-ROESY-Spektroskopie zu Rate gezogen (Abbildung 5). Im 1 H-13 C-HMBC-Spektrum wurde eine Korrelation zwischen der Methylgruppe C51 (2.69 ppm) und C6 (176.5) gefunden, welche die Rekonstitution der C5-C6-Bindung zwischen den Ringen Aund Bin4,die während der reduktiven Demetallierung des Secocorrins 2 À etabliert wurde,b estätigt (Schema 1u nd Abbildung 5).…”

Photoactivation of the 2-(methylthio)ethanesulfonic acid reductase from Methanobacterium.

“…The Ammu = 1.1, and the composition was determined to be C12H2507NPS. Native coenzyme F430 and 12,13-diepimer F430 and 12,13-didehydro-F430 (F560) were purified by anion-exchange chromatography and RP-HPLC as described (24). Concentrations of these cofactors were determined by using the molar absorptivities of the structurally related methyl ester derivatives (25,26).…”

“…The temperature directly in front of the filter (with an air stream to cool it) was =500C. (24,29,30). When Ti(III)Cit (3.6 ,umol) was added to the cuvette containing the purple 12,13-didehydro-F430 (F560; 45 nmol), the solution immediately turned yellow independent of light.…”

“…When Ti(III)Cit (3.6 ,umol) was added to the cuvette containing the purple 12,13-didehydro-F430 (F560; 45 nmol), the solution immediately turned yellow independent of light. After light exposure, analysis of a sample of this solution by RP-HPLC, which is capable of separating the various stereoisomers (24), indicated that the bulk of the product (>80%) was native F430. This was not surprising, since Eschenmoser and coworkers (26) had shown that the purple dehydrogenation product can be Addition of HS-HTP Is Required for Photoactivation and Methanogenesis.…”