Beschreibung:
<jats:title>ABSTRACT</jats:title>
<jats:p>
Nearly
100% 5′-position selectivity of transglucosylation from
maltodextrin to pyridoxine (PN) by cells of
<jats:italic>Verticillium
dahliae</jats:italic>
TPU 4900 was observed when the reaction was carried out
with borate. The same effect of borate was observed not only during
synthesis of pyridoxine 5′-α-
<jats:sc>d</jats:sc>
-glucoside by
partially purified enzyme of this strain but also during synthesis of
this compound by other microorganisms and with other enzymes
(α-glucosidase and cyclomaltodextrin glucanotransferase). The
effect was thought to be caused by the formation of a borate complex
with 3- and 4′-position hydroxyl groups of PN. A decrease in
the formation of pyridoxine 5′-α-
<jats:sc>d</jats:sc>
-glucoside
was observed in the reaction with borate, but this decrease was
overcome by optimizing the pH and increasing the amount of cells in the
reaction
mixture.
</jats:p>