One of the pressing needs of biochemistry and allied sciences is an adequate supply of pure amino acids. While methods for the isolation and purification of these substances are well known, nevertheless the labor and expense involved are in many instances prohibitive except for the production of relatively small quantities. With the exception of glutamic acid no use for amino acids other than for scientific purposes has been found and manufacturers have as yet been unable to apply the benefits of quantity production sufficiently to make these substances cheap enough for extensive investigations.

It was shown some years ago by Ikeda 1 that the taste of the constituents of the seaweed Laminaria japonica is due to the content of glutamic acid. This is to a certain extent also true of meat extract and allied preparations. The demand for condiments of this type has led to the production of the mono-sodium salt of glutamic acid on a scale large enough to make it relatively cheap.

Our experiments with Ajinomoto (a commercial preparation of sodium glutamate sold by S. Suzuki & Co., Tokio, Japan) were carried out with a view of using this substance as a cheap as well as a convenient source for pure glutamic acid. Our results show that this preparation consists largely of the mono-sodium salt of glutamic acid. To isolate glutamic acid, Ajinomoto is dissolved in a small quantity of water (600 c.c. for each 100 grams) and HCl is added in an amount equivalent to the amino nitrogen present. Purified charocal is then added, the mixture brought to the boiling point, filtered hot and the filtrate placed in the ice chest to crystallize. The crystals are drained, washed several times with small quantities of ice water until free from chlorides and dried.

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A cheap and convenient source for glutamic acid