Enzymatic syntheses of (1-(C-11))pyruvic acid and L-(1-(C-11))lactic acid via DL-(1-(C-11))alanine

Conference · Sun Jan 01 04:00:00 EST 1984 · J. Nucl. Med.; (United States)

OSTI ID:6758931

Ropchan, J R; Barrio, J R

L-(1-(C-11)) Lactic acid was prepared in three steps using a remote, semi-automated procedure: (1) production of DL-(1-(C-11)) alanine (2) enzymatic conversion of DL (1-(C-11)) alanine to (1-(C-11)) pyruvate and (3) enzymatic transformation of (1-(C-11)) pyruvate to L-(1-(C-11)) lactic acid. DL-(1-(C-11)) Alanine was synthesized from NCA C-11 HCN using a modification of the Bucherer-Strecker reaction. The DL-isomers were converted to (1-(C-11)) pyruvate by passage through (1) immobilized D-amino acid oxidase enzyme column followed by (2) immobilized L-alanine dehydrogenase (l-ADH) enzyme column. (1-(C-11)) Pyruvate was then transformed to L-(1-(C-11)) lactic acid by elution through a L-lactic dehydrogenase enzyme column. These enzyme columns are reusable beyond three months, give high radiochemical purity (>98%), eliminate the possibility of protein contamination, assure sterile, pyrogen-free products and allow rapid separation and quantitative conversion of DL-isomers to the desired products. Typically the synthesis required 30-40 min after cyclotron production of NCA C-11 HCN with radiochemical yields of 15-25 mCi (23%) of L-(1-(C-11)) lactic acid and 20-35 mCi (33%) of (l-(C-11)) pyruvic acid starting with 250-400 mCi of C-11 HCN. Also 10-20 mCi (19%) of L-(1-(C-11)) alanine was produced by resin separation (AG50W-X8), H/sup +/ form of (1-(C-11)) pyruvate and L-(1-(C-11)) alanine following elution through D-AAO enzyme column. The radiochemical purities of (1-(C-11)) pyruvic acid, L-(1-(C-11)) lactic acid and L-(1-(C-11)) alanine were verified routinely by reversed-phase HPLC.

• Research Organization: UCLA School of Medicine, Los Angeles, CA
• OSTI ID: 6758931
• Report Number(s): CONF-840619-
• Conference Information: Journal Name: J. Nucl. Med.; (United States) Journal Volume: 25:5
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400202 -- Isotope Effects
Isotope Exchange
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62 RADIOLOGY AND NUCLEAR MEDICINE
ACCELERATORS
ALANINE-ALPHA
ALANINE-L
ALANINES
AMINO ACIDS
AUTOMATION
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
CARBON 11
CARBON ISOTOPES
CARBOXYLIC ACIDS
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
CHEMISTRY
CHROMATOGRAPHY
CYCLIC ACCELERATORS
CYCLOTRONS
DRUGS
ENZYMES
EVEN-ODD NUCLEI
HYDROXY ACIDS
IMMOBILIZED ENZYMES
ION EXCHANGE CHROMATOGRAPHY
ISOTOPE APPLICATIONS
ISOTOPES
KETO ACIDS
KINETICS
LABELLED COMPOUNDS
LABELLING
LACTIC ACID
LIGHT NUCLEI
LIQUID COLUMN CHROMATOGRAPHY
MINUTES LIVING RADIOISOTOPES
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDOREDUCTASES
PYRUVIC ACID
RADIOCHEMISTRY
RADIOISOTOPES
RADIOPHARMACEUTICALS
REACTION KINETICS
REMOTE HANDLING
SEPARATION PROCESSES
SYNTHESIS
TRACER TECHNIQUES
YIELDS