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Heterocyclic compounds

Fluorescin

Also known as resorcinolphthalin, 2-(3,6-dihydroxy-9H-xanthen-9-yl)benzoic acid, Leucofluorescein

CAS 518-44-5Formula C20H14O5Molar mass 334.33 g/molEC 208-252-5
GHS signal word: Warning. Pictograms: Harmful or irritant 1 supplier listed
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Fluorescin chemical structure, C20H14O5, CAS 518-44-5
2D chemical structure

Key facts

What buyers check first

All properties
CAS number
518-44-5
Formula
C20H14O5
Molar mass
334.33 g/mol
EC number
208-252-5
HS code
293299
Category
Heterocyclic compounds

What is Fluorescin?

Plain description, key identifiers and synonyms

Fluorescin is a member of xanthenes.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
2-(3,6-dihydroxy-9H-xanthen-9-yl)benzoic acid
CAS number
518-44-5 CAS number cross-checked
EC number
208-252-5
Molecular formula
C20H14O5
UNII
ES5WQ31089
MDL number
MFCD00046931
InChIKey
MURGITYSBWUQTI-UHFFFAOYSA-N
InChI
InChI=1S/C20H14O5/c21-11-5-7-15-17(9-11)25-18-10-12(22)6-8-16(18)19(15)13-3-1-2-4-14(13)20(23)24/h1-10,19,21-22H,(H,23,24)
SMILES (canonical and isomeric)
C1=CC=C(C(=C1)C2C3=C(C=C(C=C3)O)OC4=C2C=CC(=C4)O)C(=O)O

Synonyms

  • resorcinolphthalin
  • 2-(3,6-dihydroxy-9H-xanthen-9-yl)benzoic acid
  • Leucofluorescein
  • Benzoic acid, 2-(3,6-dihydroxy-9H-xanthen-9-yl)-
  • 2-(3,6-Dihydroxyxanthen-9-yl)benzoic acid
  • 2(3,6Dihydroxyxanthen9yl)benzoic acid
  • 2(3,6Dihydroxy9Hxanthen9yl)benzoic acid
  • Benzoic acid, 2(3,6dihydroxy9Hxanthen9yl)
  • Fluorescin [Reagent for Oxydases and Peroxydases]
  • 4fab
  • 2-(3,6-dihydroxy-9H-xanthen-9-yl)-benzoic acid
  • 2-(3,6-Dihydroxy-9H-xanthen-9yl)-benzoic 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
334.33 g/molcalc.
Exact mass
334.0841 Dacalc.
LogP (octanol/water)
4.08calc.
Topological polar surface area
86.99 Ųcalc.
Hydrogen bond donors
3calc.
Hydrogen bond acceptors
4calc.
Rotatable bonds
2calc.
Heavy atoms
25calc.
Rings
4calc.
Aromatic rings
3calc.
Fraction sp3 carbons
0.05calc.
Formal charge
0calc.
Stereocentres
0calc.
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, c1ccc(C2c3ccccc3Oc3ccccc32)cc1

c1ccc(C2c3ccccc3Oc3ccccc32)cc1

4 rings, 20 atoms.

74 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

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

Hazard statements

  • H315Causes skin irritation.
  • H319Causes serious eye irritation.
Precautionary statements (9)
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P302 + P352If on skin: Wash with plenty of water.
  • P305 + P351 + P338If in eyes: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • 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.

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

Fluorescin suppliers

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

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  • Chemodex Ltd.
    Switzerland, St. GallenUnclaimed profile
    FluorescinGrade, purity and minimum order on request
    Price on request
    View

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Where suppliers are based

1 supplier in 1 country

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Fluorescin 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

Applications are not documented for this substance yet. Suppliers often describe uses on their product pages, linked in the suppliers list above.

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 Fluorescin is traded under.

HS 2932.99Indicative HS code

Heterocyclic compounds with oxygen hetero-atom(s) only, other

World exports in 2024
$3.81B
+10.3% vs 2023, imports $7.05B
2019 to 2024
Top exporters
  1. China28.9%
  2. Switzerland * partner reported12.7%
  3. Germany7.8%
Top importers
  1. United States49.7%
  2. China11.9%
  3. India * partner reported3.3%

* Partner reported figures, a lower bound.

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

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

Frequently asked questions

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

What is Fluorescin?

Fluorescin is a member of xanthenes.

What is the CAS number of Fluorescin?

The CAS registry number of Fluorescin is 518-44-5.

What is the molecular formula and weight of Fluorescin?

The molecular formula of Fluorescin is C20H14O5 and its molar mass is 334.33 g/mol.

Is Fluorescin hazardous?

Fluorescin carries the GHS signal word "Warning". Main hazards: causes skin irritation, causes serious eye irritation. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Fluorescin?

Fluorescin is usually classified under HS code 293299 (Heterocyclic compounds with oxygen hetero-atom(s) only, other). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Fluorescin?

CompoundList lists 1 supplier of Fluorescin in Switzerland. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

What is the price of Fluorescin?

Suppliers quote Fluorescin 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 Fluorescin

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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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