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The Collaborative International Dictionary

Glycocoll \Gly"co*coll\, n. [Gr. glyky`s sweet + ko`lla glue.] (Physiol. Chem.) A crystalline, nitrogenous substance, with a sweet taste, formed from hippuric acid by boiling with hydrochloric acid, and present in bile united with cholic acid. It is also formed from gelatin by decomposition with acids. Chemically, it is amido-acetic acid. Called also glycin, and glycocin.


n. 1 (context organic compound English) A phenolic derivative of glycine, ''N-(4-hydroxyphenyl)glycine'', used as a photographic developer. 2 (misspelling of: glycine)


Glycin, or N-(4-hydroxyphenyl)glycine, is N-substituted p-aminophenol. It is a photographic developing agent used in classic black-and-white developer solutions. It is unrelated to the amino acid glycine. When fresh, it is typically characterized as thin plates of white or silvery powder, turning brown with age. It is sparingly soluble in water and most organic solvents; it is readily soluble in alkalies and acids.

Glycin is related to 4-aminophenol and Metol. Compared to Metol, glycin has a carboxyl group attached to the methyl group of the Metol. This weakens the reduction potential of the compound and the two developers have markedly different character. Glycin is slower acting, but much longer lasting in solution. Glycin is rarely used as a developing agent today, primarily because it is expensive and manufactured for specialty applications only. In its dry form, it also has limited shelf life compared to Metol and Phenidone.

Glycin can be synthesized by reacting p-aminophenol with chloracetic acid in a solvent.

Other uses of glycin can be found in some procedures of analytical chemistry.

Usage examples of "glycin".

The University of Miami found two free protein-building amino-acids, glycin and alanin, in lunar rocks brought back by the crew of Apollo XI.