Method for precipitating natural advermectins
AssigneePfizer Inc.
InventorAbdullah R. Ali
Life of this patent
Estimating the term…
Abstract
A process for separating a natural B avermectin from a natural avermectin containing fermentation broth by using an aqueous precipitation. The process comprises extracting natural avermectins from the fermentation broth with a water miscible solvent and adding sufficient water to precipitate the natural B avermectins. Preferably, the water miscible solvent is a C.sub.1 -C.sub.3 alcohol, acetone, or acetonitrile. In addition, an acid, base, salt or surfactant may be added to facilitate the precipitation. This invention provides an isolation technique that substitutes the use of an aqueous precipitation for nonaqueous solvent precipitations. The reduction in use of nonaqueous solvents provides economic, environmental and safety benefits.
Claims15
A process for separating a natural B avermectin from a natural avermectin containing fermentation broth comprising:
- a. extracting avermectins from said natural avermectin containing fermentation broth, wherein said natural B avermectin containing fermentation broth contains said natural B avermectin in a concentration greater than 0.2 grams/liter, with a C1-C3 alcohol, acetone, or acetonitrile, to produce a natural B avermectin-containing extract;
- b. adding sufficient water to said natural B avermectin-containing extract to precipitate said natural B avermectin wherein the water content is about 45% to about 75% by weight of the mixture and wherein said base or salt is added to said water wherein said base has a sodium, potassium, calcium, ammonium or hydrogen cation, said acid has a chloride, phosphate, sulfate, nitrate, bicarbonate, carbonate or hydroxide anion and said salt has a sodium, potassium, calcium, ammonium or hydrogen cation or a chloride, phosphate, sulfate, nitrate, bicarbonate, carbonate or hydroxide anion;
- and
- c. recovering the precipitate.
Dependencies are inferred from the claim text.