| 摘要 |
A one-step microbial process for producing 13 beta -hydroxy- or 14,15-epoxy-milbemycins of the following formulae I and II <IMAGE> in which R1 and Ri represent methyl, ethyl, isopropyl or sec-butyl or represent the group <IMAGE> in which X denotes methyl, ethyl or isopropyl and A and A' represent the group <IMAGE> in which R2 denotes hydrogen, -C(O)-CH2O-C(O)-CH2CH2-COOH or -C(O)-CH2CH2-COOH, or of mixtures of compounds of the formulae I and II, which is characterised in that a milbemycin dissolved in a liquid phase, of the formula III <IMAGE> in which R3 represents R1 or Ri and R4 represents A or A' and R1, Ri, A and A' have the meanings indicated under the formulae I and II, is brought into contact with a microorganism or active constituents thereof capable of 13 beta -hydroxylation or 14,15-epoxidation or of both reactions. The microorganism or its active constituents in this case can be present either in free or in immobilised form. |
