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：98-79-3
中文别名：(S)-5-氧-2-吡咯烷羧酸;(S)-(-)-2-吡咯烷酮-5-羧酸;(S)-(-)-2-吡咯烷酮-5-甲酸;5-羧基吡咯烷酮;
英文别名：L-Pyroglutamicacid;hydroxy-pyridin-3-yl-acetic acid;5 oxoproline;L-Proline, 5-oxo-;L-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：MFCD00005272

外观与性状：白色细晶体
密度：1.38 g/cm3
沸点：453.1ºC at 760 mmHg
熔点：160-163°C(lit.)
闪点：227.8ºC
折射率：-10 ° (C=5, H2O)
水溶解性：10-15 g/100 mL (20 ºC)
稳定性：Stable. Incompatible with bases, acids, strong oxidizing agents.
储存条件：Store at RT.

RTECS号：TW3710000
安全说明：S26-S36-S37/39
危险类别码：R36/37/38
WGK Germany：3
海关编码：2933790090
危险品标志：Xi

生产方法
有半合成法、酶转化法和全合成法。目前工业生产的主要方法是以谷氨酸为原料的半合成法。将42%谷氨酸水溶液在140℃加热3h,得到L-焦谷氨酸为主要成分的反应液。经减压浓缩、结晶、洗涤、干燥,即得L-焦谷氨酸,转化率为94%。 用于食品、医药、化妆品等行业。
用途
用于食品、医药、化妆品等行业。