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Humectants

L-Pyroglutamic acid

Also known as Pyroglutamic acid, Pidolic acid, 5-oxo-L-proline

CAS 98-79-3Formula C5H7NO3Molar mass 129.12 g/molEC 202-700-3
GHS signal word: Danger. Pictograms: Corrosive, Harmful or irritant 117 suppliers listed
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L-Pyroglutamic acid chemical structure, C5H7NO3, CAS 98-79-3
2D chemical structure

Key facts

What buyers check first

All properties
CAS number
98-79-3
Formula
C5H7NO3
Molar mass
129.12 g/mol
EC number
202-700-3
HS code
293379
Category
Humectants

What is L-Pyroglutamic acid?

Plain description, key identifiers and synonyms

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.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
(2S)-5-oxopyrrolidine-2-carboxylic acid
CAS number
98-79-3 CAS number cross-checked
EC number
202-700-3
Molecular formula
C5H7NO3
UNII
SZB83O1W42
MDL number
MFCD00005272
INCI name
PCA
InChIKey
ODHCTXKNWHHXJC-VKHMYHEASA-N
InChI
InChI=1S/C5H7NO3/c7-4-2-1-3(6-4)5(8)9/h3H,1-2H2,(H,6,7)(H,8,9)/t3-/m0/s1
Canonical SMILES
O=C1CCC(C(=O)O)N1
Isomeric SMILES
C1CC(=O)N[C@@H]1C(=O)O

Synonyms

  • 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
Show all 38 synonyms
  • 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
  • (5S)-2-Oxopyrrolidine-5-carboxylic acid
  • 5-Oxo-2-pyrrolidinecarboxylic acid
  • 2-Pyrrolidone-5-Carboxylic Acid
  • H-Pyr-OH
  • (S)-5-Oxopyrrolidine-2-carboxylic Acid

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

No measured properties are recorded for this substance yet. Ask suppliers for a technical data sheet.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
129.12 g/molcalc.
Exact mass
129.0426 Dacalc.
LogP (octanol/water)
-0.65calc.
Topological polar surface area
66.4 Ųcalc.
Hydrogen bond donors
2calc.
Hydrogen bond acceptors
2calc.
Rotatable bonds
1calc.
Heavy atoms
9calc.
Rings
1calc.
Aromatic rings
0calc.
Fraction sp3 carbons
0.6calc.
Formal charge
0calc.
Stereocentres
1calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Murcko scaffold

The ring system that remains when every side chain is removed

Murcko scaffold of this chemical, O=C1CCCN1

O=C1CCCN1

1 ring, 6 atoms, the 2-Pyrrolidone ring system.

3,308 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Danger
GHS05: Corrosive
Corrosive
GHS07: Harmful or irritant
Harmful or irritant

Hazard statements

  • H315Causes skin irritation.
  • H318Causes serious eye damage.
  • H319Causes serious eye irritation.
  • H335May cause respiratory irritation.
Precautionary statements (18)
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P271Use only outdoors or in a well-ventilated area.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P302 + P352If on skin: Wash with plenty of water.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P351 + P338If in eyes: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P305 + P354 + P338If in eyes: Immediately rinse with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P317Get medical help.
  • P319Get medical help if you feel unwell.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • P332 + P317If skin irritation occurs: Get medical help.
  • P337 + P317If eye irritation persists: Get medical help.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • P403 + P233Store in a well-ventilated place. Keep container tightly closed.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Full safety data and first aid

L-Pyroglutamic acid suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 117 suppliers
30 of 30 offers

Suppliers marked Unclaimed profile have not claimed their profile yet. They are not verified by CompoundList, their offers are price on request and details may have changed, so please confirm them with the supplier. Company representatives can claim a profile with a business email on the company's own website domain. Our team verifies each claim and sends the result by email.

Where suppliers are based

117 suppliers in 21 countries

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L-Pyroglutamic acid price

Indicative price range per kg from live supplier offers

No published prices right now

Suppliers quote this chemical on request. Send one free request and compare quotes side by side.

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Uses and applications

What the substance is used for, by industry and function

Industrial uses: Antioxidant.

Consumer uses: Antioxidant.

Use classes: Cosmetics.

Cosmetic ingredient, INCI name PCA(humectant, moisturising)

Roles

  • algal metabolite
  • eukaryotic metabolite
  • metabolite

Functional uses

  • Flavouring and nutrient
  • Humectant

Cosmetic functions

  • Humectant
  • Moisturising

Pharmacology

Pidolic Acid is a keto derivative of the amino acid proline.

Regulatory status

Inventories, regulations and trade controls that list this substance

Health and food

  • EU cosmetic ingredient inventory

United States

  • TSCA inventory (USA)
    Status: Active in US commerce

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code L-Pyroglutamic acid is traded under.

HS 2933.79Indicative HS code

Lactams, other lactams

World exports in 2024
$16.2B
−64.4% vs 2023, imports $15.4B
2019 to 2024
Top exporters
  1. Ireland37.0%
  2. France * partner reported15.6%
  3. Spain11.3%
Top importers
  1. Germany27.8%
  2. Ireland18.9%
  3. Panama * partner reported12.9%

* Partner reported figures, a lower bound.

Reported customs values in USD, not prices.Full trade data

The HS code shown for L-Pyroglutamic acid is indicative (it was assigned by structure rules). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about L-Pyroglutamic acid, based on the data on this page

What is L-Pyroglutamic acid?

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.

What is the CAS number of L-Pyroglutamic acid?

The CAS registry number of L-Pyroglutamic acid is 98-79-3.

What is the molecular formula and weight of L-Pyroglutamic acid?

The molecular formula of L-Pyroglutamic acid is C5H7NO3 and its molar mass is 129.12 g/mol.

What is L-Pyroglutamic acid used for?

Industrial uses: Antioxidant. Consumer uses: Antioxidant. Use classes: Cosmetics.

Is L-Pyroglutamic acid hazardous?

L-Pyroglutamic acid carries the GHS signal word "Danger". Main hazards: causes skin irritation, causes serious eye damage, causes serious eye irritation. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of L-Pyroglutamic acid?

L-Pyroglutamic acid is usually classified under HS code 293379 (Lactams, other lactams). This is indicative, confirm it with your customs broker before shipping.

Where can I buy L-Pyroglutamic acid?

CompoundList lists 117 suppliers of L-Pyroglutamic acid in China, United States, Germany, United Kingdom and 17 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy L-Pyroglutamic acid in India?

1 supplier in India list L-Pyroglutamic acid on CompoundList. Filter the suppliers list by country and send a request to compare prices, grades and delivery times.

What is the price of L-Pyroglutamic acid?

Suppliers quote L-Pyroglutamic acid on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle L-Pyroglutamic acid

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Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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