Metabolism of methanol in plant cells. Carbon-13 nuclear magnetic resonance studies

Using (13)C-NMR, we demonstrate that (13)C]methanol readily entered sycamore (Acer pseudoplatanus L.) cells to be slowly metabolized to 3-(13)C]serine, (13)CH(3)]methionine, and (13)CH(3)]phosphatidylcholine. We conclude that the assimilation of (13)C]methanol occurs through the formation of (13)CH(3)H(4)Pte-glutamate (Glu)(n) and S-adenosyl-methionine, because feeding plant cells with 3-(13)CH(3)]serine, the direct precursor of (13)CH(2)H(4)Pte-Glu(n), can perfectly mimic (13)CH(3)]methanol for folate-mediated single-carbon metabolism. On the other hand, the metabolism of (13)C]methanol in plant cells revealed assimilation of label into a new cellular product that was identified as (13)CH(3)]methyl-beta-D-glucopyranoside. The de novo synthesis of methyl-beta-D-glucopyranoside induced by methanol did not require the formation of (13)CH(3)H(4)Pte-Glu(n) and was very likely catalyzed by a "transglycosylation" process.