with petroleum ether enriching the organic phase with indolpyruvate the aqueous phase is evaporated to remove solvent residues and is then recycled the organic phase is brought to dryness and taken up in methanol the crude products is placed on a semi preparative c 18 column 0 8 u00d7 30 cm waters company and eluted with a water alcohol mixture thus separating the indolpyruvate from the impurities present twenty sprague dawley male rats were divided into four groups of five animals each another five animals received no treatment and acted as controls the four treated groups received 10 mg kg of indolpyruvate orally each group was sacrificed in turn after 30 60 75 and 90 minutes plasma levels were determined for all animals and compared with those of the non treated control animals time 0 blood samples 4 ml from the sacrificed animals were treated with 0 4 ml of 10 edta and 0 1 ml of 20 vitamin c the resulting mixture was centrifuged at 4000 revolutions per minute at 5 u00b0 c for 10 minutes 0 7 ml of plasma were treated with 0 025 ml of 20 vitamin c and 0 3 ml of 12 trichloroacitic acid the mixture was left at 5 u00b0 c for 20 minutes and then centrifuged at 11 000 revolutions per minute at 5 u00b0 c for 10 minutes sorvall ss 34 rotor the supernatant was injected into a high pressure liquid chromotography apparatus equipped with a 5 micron rp 8 column merck company and eluted with aqueous alcohol solution at time 0 the indolpyruvate was not present in the plasma at least within the determination limits of the present method 0.