Spermine, Choline, Ergothioneine 175 



Ergot from which ergothioneine has been obtained in yields 

 varying from 65 to 260 mg./lOO g., remained the only natural source 

 of this base until Hunter and Eagles (1925, 1927) isolated from pig 

 blood a crystalline substance, named at first 'sympectothion', which 

 gave with phosphotungstic and arsenophosphotungstic acid reagents 

 the same blue colour as uric acid. Quite independently, a blood 

 constituent with similar properties, named 'thiasine', was obtained 

 by Benedict, Newton and Behre (1926). Somewhat later, both 

 sympectothion and thiasine were shown to be identical with ergo- 

 thioneine (Newton, Benedict and Dakin, 1926; Eagles and Johnson, 

 1927). Blood ergothioneine, or 'thioneine' as it is sometimes called, 

 occurs only in the erythrocytes and is not found in the plasma. In 

 human blood there is no more than about 2 mg./lOO ml., but in the 

 pig there may be as much as 26 mg./lOO ml. ergothioneine (Hunter, 

 1951). Of the existing methods for the determination of ergothioneine 

 that of Hunter (1928, 1949), based on the diazo reaction, is the most 

 sensitive, specific and accurate. 



Isolation of ergothioneine from the boar seminal vesicle secretion 



It has been known for quite a while that protein-free extracts 

 from semen exhibit a marked reducing power towards iodine, 

 silver nitrate, 2 : 6-dichlorophenol-indophenol, and potassium per- 

 manganate in the cold, and that this property is due to substances 

 secreted in the seminal vesicle fluid. It has been mostly taken for 

 granted however, that the reducing power of semen is due to ascorbic 

 acid, particularly in the case of bovine and human semen (see p. 23) 

 and no attempt was made to strengthen this assumption by a chemi- 

 cal identification. In 1951, Leone and Mann undertook to purify 

 the reducing substance from the boar seminal vesicle secretion, 

 which being available in relatively large quantities, appeared to 

 offer a convenient source of starting material. It was noticed in the 

 course of the purification procedure that the reducing power went 

 parallel with three other chemical properties of the boar vesicular 

 secretion, (i) ability to reduce phosphotungstic acid to a blue 

 reaction product, (ii) a strongly positive diazo reaction, and (iii) 

 the occurrence of organically-bound sulphur which, however, unlike 

 that present in glutathione, cysteine or methionine, could be oxidized 

 and readily split off" as inorganic sulphate, by the addition of mild 



