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 00:00:00 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-; TRN: 87-010805
• Journal Information: J. Nucl. Med.; (United States), Vol. 25:5; Conference: 31. annual meeting of the Society of Nuclear Medicine, Los Angeles, CA, USA, 5 Jun 1984
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CARBON 11
RADIOCHEMISTRY
LACTIC ACID
CHEMICAL PREPARATION
LABELLING
PYRUVIC ACID
RADIOPHARMACEUTICALS
ALANINE-L
AUTOMATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
CYCLOTRONS
IMMOBILIZED ENZYMES
ION EXCHANGE CHROMATOGRAPHY
LIQUID COLUMN CHROMATOGRAPHY
OXIDOREDUCTASES
REMOTE HANDLING
TRACER TECHNIQUES
ACCELERATORS
ALANINE-ALPHA
ALANINES
AMINO ACIDS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
CARBON ISOTOPES
CARBOXYLIC ACIDS
CHEMISTRY
CHROMATOGRAPHY
CYCLIC ACCELERATORS
DRUGS
ENZYMES
EVEN-ODD NUCLEI
HYDROXY ACIDS
ISOTOPE APPLICATIONS
ISOTOPES
KETO ACIDS
KINETICS
LABELLED COMPOUNDS
LIGHT NUCLEI
MINUTES LIVING RADIOISOTOPES
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
RADIOISOTOPES
REACTION KINETICS
SEPARATION PROCESSES
SYNTHESIS
YIELDS
550601* - Medicine- Unsealed Radionuclides in Diagnostics
400202 - Isotope Effects
Isotope Exchange
& Isotope Separation