Chemo-enzymatic synthesis of optically pure l-leucovorin, an augmentor of 5-fluorouracil cytotoxicity against cancer.
Optically pure l-leucovorin was synthesized on a large scale by the combination of chemical and enzymatic processes. After reduction of folate with zinc, dihydrofolate was reduced asymmetrically to (6)-tetra-hydrofolate by use of dihydrofolate reductase from E. coli C600/pTP600, with simultaneous NADPH cofactor recycling using glucose dehydrogenase from Gluconobacter scleroideus KY3613. Calcium l-leucovorin.4H2O (113 g) was obtained from (6S)-tetrahydrofolate via 5,10-methyenyltetrahydrofolate by formylation, reflux, addition of calcium ions and floricil column chromatography, with an overall yield of 50% based on folate. The l-leucovorin showed optical purity of 99.9% de as (6S)-form.
Uwajima
T
T
Tokyo Research Laboratories, Kyowa Hakko Co., Ltd., Japan.
Oshiro
T
T
Eguchi
T
T
Kuge
Y
Y
Horiguchi
A
A
Igarashi
A
A
Mochida
K
K
Iwakura
M
M
D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005472:Fluorouracil / Q000627:therapeutic use / Q000633:toxicity*; D007536:Isomerism; D002955:Leucovorin / Q000138:chemical synthesis* / Q000627:therapeutic use; D009243:NAD / Q000378:metabolism; D009369:Neoplasms / Q000188:drug therapy; D010084:Oxidation-Reduction; D010957:Plasmids; D011401:Promoter Regions, Genetic; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism
D009243:NAD; D013762:Tetrahydrofolate Dehydrogenase; D002955:Leucovorin; D005472:Fluorouracil