CAS No 2321-07-5 , 3',6'-dihydroxyspiro[2-benzofuran-3,9'-xanthene]-1-one

Title: Fluorescein
CAS Registry Number: 2321-07-5
CAS Name: 3￠,6￠-Dihydroxyspiro[isobenzofuran-1(3H),9￠-[9H]xanthen]-3-one
Synonyms: 9-(o-carboxyphenyl)-6-hydroxy-3H-xanthen-3-one; 3￠,6￠-dihydroxyfluoran; 3￠,6￠-fluorandiol; 9-(o-carboxyphenyl)-6-hydroxy-3-isoxanthenone; resorcinolphthalein; D & C Yellow no. 7; C.I. Solvent Yellow 94; C.I. 45350:1
Molecular Formula: C20H12O5
Molecular Weight: 332.31
Percent Composition: C 72.29%, H 3.64%, O 24.07%
Literature References: Prepd by heating phthalic anhydride with resorcinol: Fischer, Bollmann, J. Prakt. Chem. 104, 123 (1922); McKenna, Sowa, J. Am. Chem. Soc. 60, 124 (1938). Structure: Ramart-Lucas, Compt. Rend. 205, 864 (1937); Nagase et al., J. Pharm. Soc. Jpn. 73, 1033, 1039 (1953). Review of synthesis, properties and histological use: R. F. Steiner, H. Edelhoch, Chem. Rev. 62, 457 (1962). Use as label in immunoassays: E. F. Ullman et al., J. Biol. Chem. 251, 4172 (1976); Y. Suzuki et al., Jpn. J. Exp. Med. 49, 179 (1979). Toxicity studies in fish: L. L. Marking, Prog. Fish Cult. 31, 139 (1969). Toxicity data: S. L. Yankell, J. J. Loux, J. Periodontol. 48, 228 (1977). See also: Colour Index vol. 4 (3rd ed., 1971) p 4424; H. J. Conn's Biological Stains, R. D. Lillie, Ed. (Williams & Wilkins, Baltimore, 9th ed., 1977) p 337.
Properties: Yellowish-red to red powder. mp 314-316° in sealed tube, with decompn. Insol in water, benzene, chloroform, ether. Sol in hot alcohol or glacial acetic acid; also sol in alkali hydroxides or carbonates with a bright green fluorescence appearing red by transmitted light. Absorption max: 493.5, 460 nm.
Melting point: mp 314-316° in sealed tube
Absorption maximum: Absorption max: 493.5, 460 nm
 
Derivative Type: Disodium salt
CAS Registry Number: 518-47-8
Synonyms: Soluble fluorescein; resorcinol phthalein sodium; uranin(e); uranine yellow; D & C yellow No. 8; C.I. Acid Yellow 73; C.I. 45350
Trademarks: Ak-Fluor (Akorn); Fluorescite (Alcon); Fluorets (Chauvin); Fluor-i-strip (Ayerst); Ful-Glo (Sola-Barnes-Hinds); Funduscein (IOLAB); Irescein (Americal)
Molecular Formula: C20H10Na2O5
Molecular Weight: 376.27
Percent Composition: C 63.84%, H 2.68%, Na 12.22%, O 21.26%
Properties: Hygroscopic orange-red powder. Freely sol in water with yellowish-red color and intense yellowish-green fluorescence perceptible down to a dil of 0.02 ppm under uv light. The fluorescence disappears when the soln is made acid, and reappears when the soln is again made neutral or alkaline. Absorption max (water): 493.5 nm. Slightly sol in alc. LD50 in mice, rats (mg/kg): 4738, 6721 orally (Yankel, Loux).
Absorption maximum: Absorption max (water): 493.5 nm
Toxicity data: LD50 in mice, rats (mg/kg): 4738, 6721 orally (Yankel, Loux)
 
Use: In examining subterranean waters. Serves to ascertain source of springs, connections between streams and sea, determining approx vol of water delivered by a spring, detecting source of contamination of drinking water, infiltration of soil with waste waters of factories. In externally applied drugs and cosmetics. Analytical reagent (protein label). Clinical reagent (immuno-histological stain, immuno-fluorescent label).
Therap-Cat: Diagnostic aid (corneal trauma indicator), ophthalmic angiography, contact lens fitting.
Therap-Cat-Vet: Diagnostic aid (corneal lesions, intra-ocular inflammation).
Keywords: Diagnostic Aid.