Pfizer Corporation

Beecham Group Plc

Mark E Poulton

Geoffrey H Baker

Roderick J Dorgan

Rhona Mary Banks

Peter Robin Shelley

Simon Edward Blanchflower

David Owen Morgan

Compounds of formula (I): ##STR1## wherein R.sup.1 is hydrogen or methyl, R.sup.2 is hydrogen or (E)-2-methyl 2-butenoyloxy, and R.sup.3 is hydrogen or hydroxy, with the proviso that when R.sup.3 is hydrogen, R.sup.1 and R.sup.2 are both hydrogen, and when R.sup.2 is (E)-2-methyl 2-butenoyloxy, R.sup.1 is methyl; the compound of formula (II): ##STR2## and the compound of formula (III): ##STR3## are obtainable by the fermentation of Streptomyces E225 NCIB 12310 or Streptomyces E225B NCIB 12509. The compounds have anthelmintic utility.

Parasiticidal milbemycin derivatives

Compounds of formula (I): ##STR1## wherein R.sup.1 is hydrogen or methyl, R.sup.2 is hydrogen or (E)-2-methyl 2-butenoyloxy, and R.sup.3 is hydrogen or hydroxy, with the proviso that when R.sup.3 is hydrogen, R.sup.1 and R.sup.2 are both hydrogen, and when R.sup.2 is (E)-2-methyl 2-butenoyloxy, R.sup.1 is methyl; the compound of formula (II): ##STR2## and the compound of formula (III): ##STR3## are obtainable by the fermentation of Streptomyces E225 NCIB 12310 or Streptomyces E225B NCIB 12509. The compounds have antihelminthic utility.

Process for producing parasiticidal milbemycin derivatives by culturing

Compounds of formula (I): ##STR1## wherein R.sup.1 is hydrogen or optionally protected hydroxy; R.sup.2 is alkoxy, optionally protected hydroxy, oxo or optionally O-substituted oximino; R.sup.3 is hydrogen, optionally protected hydroxy, or a group 4'-(.alpha.-L-oleandrosyl)-.alpha.-L-oleandrosyloxy or .alpha.-L-oleandrosyloxy wherein the terminal hydroxy group is optionally protected; one or R.sup.4 and R.sup.5 is hydrogen and the other is methyl; and one of R.sup.6 and R.sup.7 is hydrogen and the other is methyl; with the proviso that (a) when R.sup.1 is optionally protected hydroxy, R.sup.3 is hydrogen, and (b) when R.sup.2 is not methoxy or optionally protected hydroxy, R.sup.1 and R.sup.3 are both hydrogen, are new and useful as anthelmintic agents.

Derivatives of avermectin and milbemycin

Growing community of inventors

Tadworth, United Kingdom

Mark E Poulton