Acid-soluble nucleotides in milk of ewe, cow, goat and sow

Abstract

The acid-soluble uucleotides are separated by partition at 0-2° on Dowex 1 column. Identification of different peaks is based on usual techniques of the chemistry of nucléotides. The nucléotide linked carbohydrates are identified after acid hydro- lysis, paper chromatography, and ionophoresis.

Ewe’s, goat’s and sow’s milks give a total ultra-violet ab­ sorption at 260 mu from 1.500 to 4.000 of weighted optical den- sity per 1.000 cm3 of milk. The ultra-violet spectrum of cow’s milk is different from the spectra of milks of other studied species and its total absorption amounts only to 700 of weighted optical density at 260 mu per 100 cm3.

Milks from the ewe (38 th day of lactation) from the goat (end of lactation) and from the sow (30th 45 th day of lactation) contain mostly uridine-pyrophosphates linked to carbohydrate- derivatives (77 %, 66 %, 77,3 % of total micromolécules). Milk from the cow on the contrary is very poor in uridine nucléotides (4,5 %) ; but, inversely, orotic acid and its some non-identified dérivatives represent 81,2 % of the total micromolecules.