Compound: L-Pyroglutamic acid
SMILES: O=C1N[C@H](C(=O)O)CC1
InChIKey: ODHCTXKNWHHXJC-VKHMYHEASA-N
Synonyms: L-Pyroglutamic acid, 98-79-3, Pyroglutamic acid, Pidolic acid, 5-oxo-L-proline, (2S)-5-oxopyrrolidine-2-carboxylic acid, pyroglu, GLUTIMIC ACID, (S)-(-)-2-Pyrrolidone-5-carboxylic acid, 5-L-Oxoproline, L-Proline, 5-oxo-, L-5-Oxoproline, Pidolidone, (S)-PYROGLUTAMIC ACID, AJIDEW A-100, (-)-2-Pyrrolidone-5-carboxylic acid, Acide pidolique, Acido pidolico, 5-Carboxy-2-pyrrolidinone, L-pca, 2-Pyrrolidinone-5-carboxylic acid, L-5-Carboxy-2-pyrrolidinone, (S)-5-Oxo-2-pyrrolidinecarboxylic acid, L-5-Oxo-2-pyrrolidinecarboxylic acid, GLUTIMINIC ACID, L-Pyroglutamate, 5-Pyrrolidinone-2-carboxylic acid, Acidum pidolicum, l-pyrrolidone carboxylic acid, Pyroglutamic acid, l-, 2-L-Pyrrolidone-5-carboxylic acid, 5-Pyrrolidone-2-carboxylic acid, 2-Pyrrolidone-5-carboxylate, L-5-Pyrrolidone-2-carboxylic acid, L-Glutamic acid gamma-lactam, NSC9966, (5S)-2-Oxopyrrolidine-5-carboxylic acid, 5-OXO-2-PYRROLIDINECARBOXYLIC ACID, NSC-143034, NSC-760414, SZB83O1W42, DTXSID6046260, DTXCID4026260, CHEBI:18183, NSC143034, RefChem:1088266, 202-700-3, 2-Pyrrolidone-5-Carboxylic Acid, H-Pyr-OH, (S)-5-Oxopyrrolidine-2-carboxylic Acid, Proline, 5-oxo-, 5-OXOPROLINE, Pidolate, Pyrrolidonecarboxylic acid, L-GLUTIMINIC ACID, L-2-PYRROLIDONE-5-CARBOXYLIC ACID, OXOPROLINE, NSC 143034, MFCD00005272, Pyr-OH, (S)-2-Pyrrolidone-5-carboxylic acid, NCGC00160613-01, L-GLUTIMIC ACID, M03204, Pidolic acid [INN], oxo-proline, CAS-98-79-3, pGlu-OH, SMR000857158, Acide pidolique [INN-French], Acido pidolico [INN-Spanish], Acidum pidolicum [INN-Latin], Ajidew A 100, (-)-Pyroglutamic acid, L-Glutamic Acid Lactam, PYRROLIDINONECARBOXYLIC ACID, L-PYRROLIDONECARBOXYLIC ACID, 2-Oxopyrrolidine-5-carboxylic acid, NSC 9966, EINECS 202-700-3, L-PYRROLIDINONECARBOXYLIC ACID, PYRROLIDONE-5-CARBOXYLIC ACID, Proline, 5-oxo-, L-, Pidolic acid [INN:BAN], 2-Benzothiazolesulfenic acid morpholide, UNII-SZB83O1W42, Glutiminate, Glutimate, pidolic-acid, pGlu, L-Glutiminate, L-Glutimate, Pidolic acid CRS, (S)-Pyroglutamate, (-)-Pyroglutamate, L-pyro-glutamic acid, Pyrrolidinonecarboxylate, (L)-pyroglutamic acid, L-Pyrrolidonecarboxylate, Oxopyrrolidinecarboxylate, L-Pyrrolidinonecarboxylate, Pyrrolidone-5-carboxylate, L-Glutamic acid g-lactam, Rec-PGA 273K, pyrrolidone car-boxylic acid, L-Pyroglutamic acid, 97%, Oxopyrrolidinecarboxylic acid, SCHEMBL15790, (S)-(-)-pyroglutamic acid, L-Pyroglutamic acid, BioXtra, MLS001332421, MLS001332422, 2-Pyrrolidinone-5-carboxylate, 5-Pyrrolidinone-2-carboxylate, 2-L-Pyrrolidone-5-carboxylate, L-2-Pyrrolidone-5-carboxylate, PIDOLIC ACID [WHO-DD], CHEMBL397976, L-Pyroglutamic acid (Standard), orb1310545, orb3139803, L-Glutamic acid .gamma.-lactam, PYROGLUTAMIC ACID, (L), SCHEMBL29479230, L-PYROGLUTAMIC ACID [MI], (S)-2-Pyrrolidone-5-carboxylate, L-5-Oxo-2-pyrrolidinecarboxylate, (-)-2-Pyrrolidone-5-carboxylate, HMS2231L11, HMS3264E20, Pharmakon1600-01506185, 2-Oxopyrrolidine-5(S)-carboxylate, PYROGLUTAMIC ACID [USP-RS], CS-M0659, NSC-9966, NSC11742, STR02331, (S)-5-Oxo-2-pyrrolidinecarboxylate, Tox21_111936, CCG-36432, EBC-04029, GEO-04256, HY-76082R, MSK9039-100W, NSC-11742, NSC760414, s5823, SBB004232, (5S)-2-Oxopyrrolidine-5-carboxylate, AKOS015855330, MSK9039-1000W, Tox21_111936_1, (2S)-5-pyrrolidone-2-carboxylic acid, (S)-(-)-g-Butyrolactam-g-carboxylate, (S)-5-oxopyrolidine-2-carboxylic acid, 2-Oxopyrrolidine-5(S)-carboxylic acid, DB03088, FP31392, (S)-(-)-2-Pyrrolidone-5-carboxylate, L-Pyroglutamic acid, >=99.0% (T), (5S)-2-xopyrrolidine-5-carboxylic acid, NCGC00160613-02, (S)-5-oxo-pyrrolidine-2-carboxylic acid, AC-15173, BP-12844, HY-76082, ST069342, (S)-(-)-g-Butyrolactam-g-carboxylic acid, DB-002779, (s)-(-)-2-pyrrolidinone-5-carboxylic acid, NS00006581, P0573, (S)-(-)-gamma-Butyrolactam-gamma-carboxylate, EN300-72896, C01879, P17107, SBI-0633635.0002, SBI-0633635.0003, AB00514366_07, (S)-(-)-gamma-Butyrolactam-gamma-carboxylic acid, L-Pyroglutamic acid Solution in Water, 100ug/mL, L-Pyroglutamic acid Solution in Water, 1000ug/mL, L-Pyroglutamic Acid(Discontinued,See C4X-20793), BRD-K57313110-001-06-8, Q60998677, F8889-8712, Z1154378309, Pidolic acid, European Pharmacopoeia (EP) Reference Standard, E478F48D-E369-43AE-8132-08D819242518, Pyroglutamic Acid, United States Pharmacopeia (USP) Reference Standard
Theoretical properties:
molecular_formula: C5H7NO3
molecular_weight: 129.11 g/mol
exact_mass: 129.042593085 g/mol
formal_charge: 0
hydrogen_bond_donor_count: 2
hydrogen_bond_acceptor_count: 3
rotatable_bond_count: 1
heavy_atom_count: 9
topological_polar_surface_area: 66.4 Å²
isotope_atom_count: 0
covalently_bonded_unit_count: 1
Physical properties:
Descriptions:
pubchem: 5-oxo-L-proline is an optically active form of 5-oxoproline having L-configuration. It has a role as an algal metabolite. It is a 5-oxoproline, a non-proteinogenic L-alpha-amino acid and a L-proline derivative. It is a conjugate acid of a 5-oxo-L-prolinate. It is an enantiomer of a 5-oxo-D-proline.
chebi: An optically active form of 5-oxoproline having <small>L</small>-configuration.
chembl: PIDOLIC ACID is a small molecule listed in the ChEMBL database and has reached clinical trial phase 2.0.
wikipedia: Pyroglutamic acid (also known as PCA, 5-oxoproline, pidolic acid) is a ubiquitous but understudied natural amino acid derivative in which the free amino group of glutamic acid or glutamine cyclizes to form a lactam. The names of pyroglutamic acid conjugate base, anion, salts, and esters are pyroglutamate, 5-oxoprolinate, or pidolate.

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, or enzymatically converted by glutaminyl cyclases. This is one of several forms of blocked N-termini 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.
Pyroglutamic acid exists as two distinct enantiomers:

(2R) or D which happens to be (+) or d
(2S) or L which happens to be (–) or l