Inositol, a Major Constituent of the Seminal Vesicle Secretion of the Boar

Abstract

IN the course of the recent isolation of ergo-thioneine from boar's vesicular secretion¹, an alcohol-precipitable fraction was separated which did not contain nitrogen or sulphur ; upon further purification of this fraction, crystalline material was obtained which tasted distinctly sweet, was optically inactive and non-reducing, and which gave a strongly positive Scherer reaction^2,3 characteristic of inositol. After recrystallization, first from ethanol and next from water, 18 gm. of pure meso-inositol was obtained from 1 litre of the vesicular secretion. The substance had a melting point of 225° C, and was found to contain 40.28 per cent C and 6.79 per cent H as against 40.11 per cent C and 6.66 per cent H expected theoretically ; on oxidation with periodic acid⁴ it showed a titration curve identical with that of pure meso-inositol. The concentration of inositol in the boar's seminal vesicle secretion exceeds considerably the amounts hitherto recorded for material of either plant or animal origin. The dry matter of 1 litre of vesicular secretion is about 150 gm., one-third of which is dialysable ; of this no less than 18 gm. or 40 per cent is free inositol.