Title: Ficin
CAS Registry Number: 9001-33-6
Additional Names: Ficus proteinase; Ficus protease
Trademarks: Debricin (J & J); Higueroxyl Delabarre
Literature References: A proteolytic enzyme of est. mol wt 23,800-25,500 which requires a free sulfhydryl group for activity and as such is a member of a group which includes papain and bromelain, q.q.v. Occurs in the latex of tropical trees of the genus Ficus subgenus Pharmacosyce, Moraceae (Oje trees). The commercial product is a concentrate prepd by filtering and drying the latex of Ficus glabrata H. B. & K., Moraceae. First crystallized from fresh fig latex: Walti, J. Am. Chem. Soc. 60, 493 (1938). Characterization: Cohen, Nature 182, 659 (1958); Englund et al., Biochemistry 7, 163 (1968). Purification: Gibian, Bratfisch, US 2950227 (1960 to Schering AG). Amino acid composition: Wong, Liener, Biochem. Biophys. Res. Commun. 17, 470 (1964); Metrione et al., Arch. Biochem. Biophys. 122, 137 (1967); Husain, Lowe, Biochem. J. 117, 333 (1970). Pharmacodynamics: H. Heisto, M. K. Fagerhol, Transfusion 19, 545 (1979); A. Perkash et al., ibid. 20, 301 (1980). Toxicology: H. Molitor et al., J. Pharmacol. Exp. Ther. 71, 20 (1941). Reviews: Liener, Friedenson, Methods Enzymol. 19, 260-273 (1970); Glazer, Smith, The Enzymes vol. III, P. D. Boyer, Ed. (Academic Press, New York, 3rd ed., 1971) pp 538-542.
Properties: Buff to cream-colored hygroscopic powder. Acrid odor, growing stronger with age. Bulky, approx 3 ml/g, not free-flowing. Appears dry, even with 15% H2O present. Not completely sol in water, 2-10% insol material. The sol portion of 1 g dissolves in 3 ml H2O. pH (2% soln): 4.1. Insol in usual organic solvents. Loses about 10-20% activity when stored 1-3 yrs at ordinary temp and atm conditions. Aq solns inactivated at 100°, solid partially inactivated within a few hours. Solns relatively stable between pH 4-8.5; incompatible with iron, copper, aluminum. Gelatin, coagulated egg white, casein, meat and most protein-like material hydrolyzed in aq ficin solns. Ficin is 10-20 times as active as papain in regard to milk clotting; 4-10 times as active, in general. LD50 orally in rats, mice: ~10 g/kg; in rabbits, guinea pigs: ~5 g/kg (Molitor).
Toxicity data: LD50 orally in rats, mice: ~10 g/kg; in rabbits, guinea pigs: ~5 g/kg (Molitor)
NOTE: The name ficin is currently used to describe both the crude dried latex from different species of the genus Ficus, as well as the enzyme itself.
CAUTION: Handle ficin carefully because of its tissue-dissolving properties. Can cause irritation to skin, eyes, mucous membranes. Large doses by mouth cause purging.
Use: Protein digestant. In the brewing industry as a chill proofing agent in beer. In the cheese industry as a substitute for rennet in the coagulation of milk. In the meat industry as a meat tenderizer and as an agent for removing casings from formed sausage. In the leather industry for the bating of leather. In the textile industry for shrinkproofing wool, for removing gelatin from sized thread, and mixed with amylases and maltases as a spot remover. In the prepn of peptones. For solubilizing protein material in spent grains. Also used in the determination of the Rh factor. Speeds 10 times the agglutination of human blood cells by the Rh factor when in contact with the anti-Rh serum.
Therap-Cat-Vet: Has been used as a trichuricide.
Fidarestat Filicinic Acid Filipin Filixic Acids Finasteride

EC number
CAS number 9001-33-6
IntEnz IntEnz view
ExPASy NiceZyme view
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum

Ficain (EC, ficin, debricin, higueroxyl delabarre) is an enzyme that is derived from figs latex.[1][2] It is of a family of proteases known as the cysteine endopeptidases, a group that also includes papain derived from papaya latex, bromelase (bromelain) extracted from pineapple stem, calpain, caspases, cathespisin B, and chymopapain. It is one of the most commonly used for differentiating many blood group antigens: For example, it destroys M, N, S, Duffy a, and Duffy b, and enhances some other antigens.

It is a common occurrence when eating the skins or the white pulp directly inside the skin of a fig to get a burning or itching sensation. This is due to the ficin in the latex (sap) of the fruit, particularly if it is unripened.