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Peptides

Leupeptin

Also known as acetyl-l-leucyl-l-leucyl-l-argininal, (2S)-2-acetamido-N-[(2S)-1-[[(2S)-5-(diaminomethylideneamino)-1-oxopentan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]-4-methylpentanamide, N-Acetyl-L-leucyl-L-leucyl-L-argininal

CAS 55123-66-5Formula C20H38N6O4Molar mass 426.56 g/molEC 600-443-5
GHS signal word: Warning. Pictograms: Harmful or irritant 15 suppliers listed
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Leupeptin chemical structure, C20H38N6O4, CAS 55123-66-5
2D chemical structure

Key facts

What buyers check first

All properties
CAS number
55123-66-5
Formula
C20H38N6O4
Molar mass
426.56 g/mol
EC number
600-443-5
HS code
292529
Category
Peptides

What is Leupeptin?

Plain description, key identifiers and synonyms

Leupeptin is a tripeptide composed of N-acetylleucyl, leucyl and argininal residues joined in sequenceby peptide linkages. It is an inhibitor of the calpains, a family of calcium-activated proteases which promote cell death. It has a role as a serine protease inhibitor, a cathepsin B inhibitor, an EC 3.4.21.4 (trypsin) inhibitor, a bacterial metabolite and a calpain inhibitor. It is an aldehyde and a tripeptide. It is a conjugate base of a leupeptin(1+).

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
(2S)-2-acetamido-N-[(2S)-1-[[(2S)-5-(diaminomethylideneamino)-1-oxopentan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]-4-methylpentanamide
CAS number
55123-66-5Other or deprecated CAS: 103476-89-7, 24365-47-7
EC numbers
600-443-5, 640-991-2, 686-481-3
Molecular formula
C20H38N6O4
UNII
J97339NR3V
InChIKey
GDBQQVLCIARPGH-ULQDDVLXSA-N
InChI
InChI=1S/C20H38N6O4/c1-12(2)9-16(24-14(5)28)19(30)26-17(10-13(3)4)18(29)25-15(11-27)7-6-8-23-20(21)22/h11-13,15-17H,6-10H2,1-5H3,(H,24,28)(H,25,29)(H,26,30)(H4,21,22,23)/t15-,16-,17-/m0/s1
Canonical SMILES
CC(=O)NC(CC(C)C)C(=O)NC(CC(C)C)C(=O)NC(C=O)CCCN=C(N)N
Isomeric SMILES
CC(C)C[C@@H](C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCN=C(N)N)C=O)NC(=O)C

Synonyms

  • acetyl-l-leucyl-l-leucyl-l-argininal
  • (2S)-2-acetamido-N-[(2S)-1-[[(2S)-5-(diaminomethylideneamino)-1-oxopentan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]-4-methylpentanamide
  • N-Acetyl-L-leucyl-L-leucyl-L-argininal
  • L-Leucinamide, N-acetyl-l-leucyl-N-((1S)-4-((aminoiminomethyl)amino)-1-formylbutyl)-
  • L-Leucinamide, N-acetyl-l-leucyl-N-(4-((aminoiminomethyl)amino)-1-formylbutyl)-, (S)-
  • L-Leucinamide, N-acetyl-L-leucyl-N-[(1S)-4-[(aminoiminomethyl)amino]-1-formylbutyl]-
  • (2S)-2-acetamido-N-((2S)-1-(((2S)-5-(diaminomethylideneamino)-1-oxopentan-2-yl)amino)-4-methyl-1-oxopentan-2-yl)-4-methylpentanamide
  • Ac-Leu-Leu-Arg-H
  • Acetyl-L-leucyl-L-leucylargininal
  • Leupeptin (hemisulfate)
  • Ac-LLR-H
  • Leupeptins
  • N-acetyl-leucylleucylargininal
  • Ac-L-Leu-L-Leu-L-Arg-H
  • L-Leucinamide, N-acetyl-L-leucyl-N-[4-[(aminoiminomethyl)amino]-1-formylbutyl]-
  • N-acetyl-L-leucyl-N-[(2S)-5-carbamimidamido-1-oxopentan-2-yl]-L-leucinamide
  • Bio2_000428
  • Bio2_000908
  • (S)-2-(2-Acetamido-4-methylvaleramido)-N-(1-formyl-4-guanidinobutyl)-4-methyl-valeramide
  • N-acetyl-L-leucyl-N-[(1S)-4-{[amino(imino)methyl]amino}-1-formylbutyl]-L-leucinamide
  • Valeramide, 2-(2-acetamido-4-methylvaleramido)-N-(1-formyl-4-guanidinobutyl)-4-methyl- (S)-
  • (2S)-2-acetamido-N-[(1S)-1-[[(1S)-1-formyl-4-guanidino-butyl]carbamoyl]-3-methyl-butyl]-4-methyl-pentanamide
  • N-Acetyl-L-leucyl-L-leucyl-L-arginine, aldehyde deriv.
  • Ac-Leu-Leu-Arg-H, N-Acetyl-L-leucyl-L-leucyl-L-arginine, aldehyde deriv
  • (S)-2-Acetamido-N-((S)-1-((S)-5-guanidino-1-oxopentan-2-ylamino)-4-methyl-1-oxopentan-2-yl)-4-methylpentanamide
Show all 26 synonyms
  • L-Leucinamide, N-acetyl-L-leucyl-N-[(1S)-4-[(aminoiminomethyl)amino]-1-formylbutyl]-, sulfate

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
426.56 g/molcalc.
Exact mass
426.2955 Dacalc.
LogP (octanol/water)
-0.19calc.
Topological polar surface area
168.8 Ųcalc.
Hydrogen bond donors
5calc.
Hydrogen bond acceptors
5calc.
Rotatable bonds
14calc.
Heavy atoms
30calc.
Rings
0calc.
Aromatic rings
0calc.
Fraction sp3 carbons
0.75calc.
Formal charge
0calc.
Stereocentres
3calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Warning
GHS07: Harmful or irritant
Harmful or irritant

Hazard statements

  • H302Harmful if swallowed.
  • H332Harmful if inhaled.
Precautionary statements (9)
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P270Do not eat, drink or smoke when using this product.
  • P271Use only outdoors or in a well-ventilated area.
  • P301 + P317If swallowed: Get medical help.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P317Get medical help.
  • P330Rinse mouth.
  • 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

Leupeptin suppliers

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

All 15 suppliers
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Where suppliers are based

15 suppliers in 7 countries

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Leupeptin 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

Pharmacological actions

  • Cysteine Proteinase Inhibitors

Roles

  • bacterial metabolite
  • calpain inhibitor
  • cathepsin B inhibitor
  • cysteine protease inhibitor
  • enzyme inhibitor
  • metabolite
  • prokaryotic metabolite
  • protease inhibitor
  • serine protease inhibitor

Regulatory status

Inventories, regulations and trade controls that list this substance

No regulatory list memberships are recorded for this substance yet. Always check the rules of the importing and exporting country before trade.

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Leupeptin is traded under.

HS 2925.29Indicative HS code

Imines and their derivatives, salts thereof, other

World exports in 2024
$1.8B
+12.4% vs 2023, imports $1.84B
2019 to 2024
Top exporters
  1. China35.9%
  2. France * partner reported15.5%
  3. Germany9.1%
Top importers
  1. United States13.3%
  2. China13.0%
  3. Brazil9.7%

* Partner reported figures, a lower bound.

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

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

Frequently asked questions

Quick answers about Leupeptin, based on the data on this page

What is Leupeptin?

Leupeptin is a tripeptide composed of N-acetylleucyl, leucyl and argininal residues joined in sequenceby peptide linkages. It is an inhibitor of the calpains, a family of calcium-activated proteases which promote cell death.

What is the CAS number of Leupeptin?

The CAS registry number of Leupeptin is 55123-66-5. Other or deprecated CAS numbers: 103476-89-7, 24365-47-7.

What is the molecular formula and weight of Leupeptin?

The molecular formula of Leupeptin is C20H38N6O4 and its molar mass is 426.56 g/mol.

What is Leupeptin used for?

Known uses and roles of Leupeptin include bacterial metabolite, calpain inhibitor, cathepsin b inhibitor, cysteine protease inhibitor, enzyme inhibitor and 5 more.

Is Leupeptin hazardous?

Leupeptin carries the GHS signal word "Warning". Main hazards: harmful if swallowed, harmful if inhaled. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Leupeptin?

Leupeptin is usually classified under HS code 292529 (Imines and their derivatives, salts thereof, other). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Leupeptin?

CompoundList lists 15 suppliers of Leupeptin in China, United States, Australia, Hong Kong and 3 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

What is the price of Leupeptin?

Suppliers quote Leupeptin 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 Leupeptin

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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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