Different effects of α- and γ-polymorphs of glycine on behavior of GC rats predisposed to catalepsy

Glycine: The Gift that Keeps on Giving

“…It is being used by practical medical doctors as a neuroprotector in the acute period of ischemic stroke, [288][289][290] a protector in cisplatin nephrotoxicity, [293] a corrective medication against alcoholic intoxication, [294,295] and even to correct the functional states resulting from opium addiction. [296] Glycine can reduce the duration of cataleptic states, [297][298][299] enduring other negative symptoms of schizophrenia, [300][301][302][303][304] of bipolar disorders, [305] or different forms of dementia, including the Alzheimer's disease. [306] Its effect on the brain [307,308] is quite remarkable, considering that amino acids, including glycine, are abundant in the body as a result of food digestion, in quantities comparable with or exceeding the doses that are introduced as medication.…”

“…Remarkably, the efficiency of the administration of solid glycine depends on the polymorph, the γ-form being more active than the α-form. [298,299] Even more interesting is that the difference in the activity of the two polymorphs is preserved even if they are administered as freshly prepared solutions. [308,315] The difference between the biological activity of the solutions prepared from different polymorphs disappeared after the solutions were frozen and then heated again.…”

The effect of carboxylic acids on glycine polymorphism, salt and co-crystal formation. A comparison of different crystallisation techniques

“…[13][14][15][16][17] Recently, it was shown both in vitro and in vivo that the biological activity of g-glycine is higher than that of both the aand b-polymorphs. [18][19][20] Glycine is also known to form both organic and inorganic salts with a variety of acids, many of which are considered to be promising optical, ferroelectric and piezoelectric materials. [21][22][23][24][25][26][27][28][29][30][31][32][33][34] The pharmaceutical industry also makes use of glycine both as an excipient and an active pharmaceutical ingredient, 35 therefore its salts and co-crystals can be of interest for pharmaceutical applications.…”

Interfacial Effect of Water/Oleic Acid Emulsion on Polymorphic Selection in the Cooling Crystallization of Glycine

“…Also undetermined is which polymorphic form performs better commercially. In recent years, Markel et al reported that γ-glycine had higher biological activity than α-glycine in ameliorating behavioral disorders in genetically cataleptic rats. , Although the detailed pharmacological mechanism was not determined, these results may be related to solution structure when aqueous glycine solutions are prepared with raw α- or γ-glycine. The results highlight the importance of selective γ-glycine crystallization.…”