Biosynthesis of vitamin B sub 12 : Structure of precorrin-6x octamethyl ester

Journal Article · Thu Nov 01 00:00:00 EST 1990 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

DOI:https://doi.org/10.1073/pnas.87.22.8800· OSTI ID:5702200

Thibaut, D; Blanche, F; Debussche, L ^[1]; Leeper, F J; Battersby, A R ^[2]

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1. Centre de Recherche de Vitry, Vitry-sur-Seine (France)
2. Univ. Chemical Lab., Cambridge (England)

{sup 13}C-labeled precorrin-6x is biosynthesized by cell-free protein preparations from Pseudomonas denitrificans in separate experiments using {delta}-amino (4-{sup 13}C)- and {delta}-amino (3-{sup 13}C) levulinic acid-labeled forms in conjunction with S-(methyl-{sup 13}C) adenosylmethionine for the latter two experiments. These labeled precorrin-6x samples, as their octamethyl esters, are studied by a range of NMR techniques. In addition, nuclear Overhauser effect difference measurements are made on unlabeled precorrin-6x ester to determine connectivities. The structure 6a so established for precorrin-6x ester (i) confirms the results reported in the preceding paper that precorrin-6x has a ring-contracted macrocycle, still carries the C-12 acetate residue, and stands at the oxidation level of a dehydrocorrin; (ii) reveals the unexpected methylation at C-11 not C-12, leading to a structure with separated chromophores; and (iii) implies that methyl migration from C-11 to C-12 occurs when precorrin-6x is converted into hydrogenobyrinic acid. Proposals for the biosynthesis of the corrin macrocycle of hydrogenobyrinic acid and vitamin B{sub 12} are made.

• OSTI ID: 5702200
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Vol. 87:22; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PIGMENTS
MOLECULAR STRUCTURE
VITAMIN B-12
BIOSYNTHESIS
AMINOLEVULINIC ACID
BIOLOGICAL PATHWAYS
CARBON 13
ESTERS
NUCLEAR MAGNETIC RESONANCE
PSEUDOMONAS
AMINO ACIDS
BACTERIA
CARBON ISOTOPES
CARBOXYLIC ACIDS
DRUGS
EVEN-ODD NUCLEI
HEMATINICS
HEMATOLOGIC AGENTS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MICROORGANISMS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
RESONANCE
STABLE ISOTOPES
SYNTHESIS
VITAMIN B GROUP
VITAMINS
550201* - Biochemistry- Tracer Techniques