Poly-L-lactates as antitumour agents

摘要

The anti-malignant tumor agent of the present invention comprises a mixture of poly L-lactates that are cyclic and linear oligomers having degrees of condensation of 3 to 23, which is prepared by dehydration condensation of L-lactic acid in a nitrogen atmosphere under stepwise reduced pressure and at an increasing temperature, drying ethanol- and methanol-soluble components in the resulting reaction solution under reduced pressure, subjecting the product to chromatography on a reverse phase ODS column, and after elution with 25 to 50 % aqueous acetonitrile at pH 2.0, eluting said mixture of poly L-lactates with 100 % acetonitrile at pH 2.0.