Pyroglutamic acid (also known as PCA, 5-oxoproline, pidolic acid, or pyroglutamate for its basic form) is an uncommon and little studied amino acid derivative in which the free amino group of glutamic acid or glutamine cyclizes to form a lactam. It is a metabolite in the glutathione cycle that is converted to glutamate by 5-oxoprolinase. Pyroglutamate is found in many proteins including bacteriorhodopsin. N-terminal glutamic acid and glutamine residues can spontaneously cyclize to become pyroglutamate. This is one of several forms of blocked N-terminals which present a problem for N-terminal sequencing using Edman chemistry, which requires a free primary amino group not present in pyroglutamic acid. The enzyme pyroglutamate aminopeptidase can restore a free N-terminus by cleaving off the pyroglutamate residue.

CAS：149-87-1
中文别名：吡咯烷酮羧酸;DL-谷氨酸-Y-内酰胺;DL-2-吡咯烷酮-5-羧酸;5-氧代吡咯烷-2-羧酸;2-吡咯烷酮-5-甲酸;(±)-2-吡咯烷酮-5-羧酸;DL-焦性胶氨酸;2-吡咯烷酮-5-羧酸;
英文别名：DL-Pyroglutamic acid;5-Oxopyrrolidine-2-carboxylic Acid;D,l-2-Pyrrolidone-5-Carboxylic Acid;2-Pyrrolidone-5-carboxylic acid;DL-2-Pyrrolidone-5-carboxylic acid;H-DL-Pyr-OH;DL-Glutamic Acid Lactam;DL-Pyroglutamic Acid;
分子式：C5H7NO3
分子量：129.114
精确质量：129.043
Psa：66.4
Logp：-0.3216

MDL号：MFCD00064322
BRN号：82131
PubChem号：24857617
EINECS号：205-748-3

外观与性状：白色粉末
密度：1.38 g/cm3
沸点：453.1ºC at 760 mmHg
熔点：180-185ºC
闪点：227.8ºC
折射率：1.511
稳定性：Stable under normal temperatures and pressures.
储存条件：Keep container closed when not in use. Store in a cool, dry, well-ventilated area away from incompatible substances. Keep containers tightly closed.
蒸汽压：1.79E-09mmHg at 25°C

安全说明：S26-S37/39
危险类别码：R36/37/38
海关编码：29337900
危险品标志：Xi
危险标志：GHS07
危险性描述：H302; H315; H319; H335
危险性防范说明：P261; P305 + P351 + P338
信号词：Warning

用途
医药中间体；化妆品原料；用作生化试剂。