Title: Malachite Green
CAS Registry Number: 569-64-2; 510-13-4 (carbinol base)
CAS Name: N-[4-[[4-(Dimethylamino)phenyl]phenylmethylene]-2,5-cyclohexadien-1-ylidene]-N-methylmethanaminium chloride
Additional Names: bis[p-(dimethylamino)phenyl]phenylmethylium chloride; C.I. Basic Green 4; C.I. 42000; aniline green; benzal green; benzaldehyde green; china green; diamond green B; diamond green Bx; diamond green P extra; fast green; light green N; new victoria green extra O; new victoria green extra I; new victoria green extra II; solid green O; victoria green W; victoria green B
Molecular Formula: C23H25ClN2
Molecular Weight: 364.91
Percent Composition: C 75.70%, H 6.91%, Cl 9.72%, N 7.68%
Literature References: Triphenylmethane dye with fungicidal and limited antiseptic activity. Prepn: Colour Index Vol. 4 (3rd ed., 1971) p 4380. Conformational changes in excited state: S. Saikan, J. Sei, J. Chem. Phys. 79, 4154 (1983). Use in electron microscopy: R. G. Pourcho et al., Stain Technol. 53, 29 (1978); as stain in determn of prostaglandin E and F compounds: E. J. Singh et al., J. Chromatogr. 105, 195 (1975); in determn of inorganic phosphate: W. Hohenwallner, E. Wimmer, Clin. Chim. Acta 45, 169 (1973); S. G. Carter, D. W. Karl, J. Biochem. Biophys. Methods 7, 7 (1982). Antiseptic activity: J. E. Madden et al., Surg. Forum 22, 63 (1971). Toxicology: N. Brock, A. Erhardt, Arzneim.-Forsch. 1, 5 (1951); T. D. Bills, L. L. Marking, Invest. Fish Control 75, 6 (1977); S. Clemmensen et al., Arch. Toxicol. 56, 43 (1984). Reviews of use as fungicide in fish culture: N. C. Nelson, U.S. NTIS Report (PB-235450, 1974) 79 pp, C.A. 82, 150006p (1975), (PB-235451, 1974) 33 pp, C.A. 83, 1547j (1975); and as biological stain: Conn's Biological Stains, R. W. Horobin, J. A. Kiernan, Eds. (BIOS Scientific Publishers Ltd, Oxford, UK, 10th ed., 2002) 189-190. Review of toxicological effects: S. Srivastava et al., Aquat. Toxicol. 66, 310-329 (2004).
Properties: Green crystals with metallic luster. Very sol in water; sol in alcohol, methanol, amyl alcohol. Water solns are blue-green, absorption max 616.9 nm; yellow below pH 2. pK 6.90. LD50 in mice (mg/kg): 80 orally; 4.2 i.p. (Brock, Erhardt). LC50 (6 hr, 12°C) in bluegill sunfish, channel catfish, rainbow trout, coho salmon (mg/l): 2.19 (pH 7.5), 0.960 (pH 7.5), 6.8 (pH 8.0), 3.0 (pH 7.5) (Bills, Marking).
pKa: pK 6.90
Absorption maximum: absorption max 616.9 nm
Toxicity data: LD50 in mice (mg/kg): 80 orally; 4.2 i.p. (Brock, Erhardt); LC50 (6 hr, 12°C) in bluegill sunfish, channel catfish, rainbow trout, coho salmon (mg/l): 2.19 (pH 7.5), 0.960 (pH 7.5), 6.8 (pH 8.0), 3.0 (pH 7.5) (Bills, Marking)
Derivative Type: Oxalate salt
CAS Registry Number: 2437-29-8
Molecular Formula: C46H50N4.2HC2O4.C2H2O4
Molecular Weight: 927.00
Percent Composition: C 67.37%, H 5.87%, N 6.04%, O 20.71%
Properties: Sol to 4% in water, 5% in ethanol. Insol in xylene.
Derivative Type: Leucomalachite green
CAS Registry Number: 129-73-7
Additional Names: Bis(p-dimethylaminophenyl)phenylmethane
Molecular Formula: C23H26N2
Molecular Weight: 330.47
Percent Composition: C 83.59%, H 7.93%, N 8.48%
Properties: Colorless, reduced form of malachite green. Practically insol in water. Slightly sol in ethanol.
NOTE: The term malachite green applies to the oxalate as well as the chloride.
Use: For directly dyeing silk, wool, jute and leather; dyeing cotton after mordanting. Biological stain. Clinical reagent (inorganic phosphate assay). As spot test reagent for detecting sulfurous acid and cerium. As acid-base indicator: pH 0.0 yellow, 2.0 green; 11.6 green, 14 colorless.
Therap-Cat-Vet: Fungicide and parasiticide in fish.