Title: Bixins
Literature References: Carotenoid carboxylic acids isolated from seeds of Bixa orellana L., Bixaceae; principal pigments of the crude coloring extract, annatto, q.v. The natural product is the cis-form. Isomerization to the more stable all-trans-form occurs upon heating or commercial extraction. Isoln: J. B. Boussingault, Ann. Chim. Phys. 28, 440 (1825). Isomerization studies: J. Herzig, F. Faltis, Ann. 431, 40 (1923); P. Karrer et al., Helv. Chim. Acta 12, 741 (1929). Structural studies: R. Kuhn et al., ibid. 11, 427 (1928); 12, 64, 904 (1929); Ber. 64, 1732 (1931); 65, 646, 1873 (1932). NMR determn of stereochemistry: M. S. Barber et al., J. Chem. Soc. 1961, 1625. Properties of bixin and norbixin: J. F. Reith, J. W. Gielen, J. Food Sci. 36, 861 (1971). 1H and 13C NMR, MS, and x-ray crystal structure determn: D. R. Kelly et al., J. Chem. Res. Miniprint 10, 2640 (1996). HPLC analysis of food coloring formulations: M. J. Scotter et al., J. Agric. Food Chem. 46, 1031 (1998). Biosynthesis and prodn in genetically engineered E. coli (stereo unspecified): F. Bouvier et al., Science 300, 2089 (2003). Review of cis-trans isomerization and stereochemistry: L. Zechmeister, Chem. Rev. 34, 267-344 (1944); of chemistry and extraction from annatto: H. D. Preston, M. D. Rickard, Food Chem. 5, 47-56 (1980).
Derivative Type: cis-Form
CAS Registry Number: 6983-79-5
CAS Name: (2E,4Z,6E,8E,10E,12E,14E,16E,18E)-4,8,13,17-Tetramethyl-2,4,6,8,10,12,14,16,18-eicosanonaenedioic acid monomethyl ester
Additional Names: 9-cis-6,6¢-diapo-y,y-carotenedioic acid monomethyl ester; 6¢-methyl hydrogen (9¢Z)-6,6¢-diapocarotene-6,6¢-dioate; a-bixin; labile bixin
Molecular Formula: C25H30O4
Molecular Weight: 394.50
Percent Composition: C 76.11%, H 7.66%, O 16.22%
Properties: Dark purple, lustrous crystals from ethanol + chloroform or dichloromethane + acetone, mp 190 ± 1°; dec 200.3 ± 0.6°. Absorption max (chloroform): 502, 471 nm (log e = 5.02, 5.07).
Melting point: mp 190 ± 1°
Absorption maximum: Absorption max (chloroform): 502, 471 nm (log e = 5.02, 5.07)
Derivative Type: trans-Form
CAS Registry Number: 39937-23-0
CAS Name: (2E,4E,6E,8E,10E,12E,14E,16E,18E)-4,8,13,17-Tetramethyl-2,4,6,8,10,12,14,16,18-eicosanonaenedioic acid monomethyl ester
Additional Names: all-trans bixin; b-bixin; isobixin; stable bixin
Molecular Formula: C25H30O4
Molecular Weight: 394.50
Percent Composition: C 76.11%, H 7.66%, O 16.22%
Properties: Orange to purple plates from acetone, mp 204-206° (dec). Absorption max (chloroform): 507, 476 nm (E1%1cm 2970 ±40, 3240 ±50). Sol in oil.
Melting point: mp 204-206°
Absorption maximum: Absorption max (chloroform): 507, 476 nm
Derivative Type: a-Norbixin
CAS Registry Number: 626-76-6
CAS Name: (2E,4E,6E,8E,10E,12E,14E,16Z,18E)-4,8,13,17-Tetramethyl-2,4,6,8,10,12,14,16,18-eicosanonaenedioic acid
Additional Names: 9-cis-6,6¢-diapo-y,y-carotenedioic acid
Molecular Formula: C24H28O4
Molecular Weight: 380.48
Percent Composition: C 75.76%, H 7.42%, O 16.82%
Properties: No melting observed £280°; yellow coloring observed at 240°; black coloring (carbonization) at ³280°. Absorption max (chloroform): 499, 468 nm (E1%1cm 2200 ±30, 2470 ±30).
Absorption maximum: Absorption max (chloroform): 499, 468 nm (E1%1cm 2200 ±30, 2470 ±30)
Derivative Type: b-Norbixin
CAS Registry Number: 542-40-5
CAS Name: (All-E)-4,8,13,17-tetramethyl-2,4,6,8,10,12,14,16,18-eicosanonaenedioic acid
Additional Names: 6,6¢-diapo-y,y-carotenedioic acid; all-trans norbixin
Molecular Formula: C24H28O4
Molecular Weight: 380.48
Percent Composition: C 75.76%, H 7.42%, O 16.82%
Properties: No melting observed £300°; red color darkens ³250°. Absorption max (chloroform): 506, 475 nm; (0.1 N NaOH): 486, 457 nm. Sol in H2O.
Absorption maximum: Absorption max (chloroform): 506, 475 nm; (0.1 N NaOH): 486, 457 nm
Use: Food coloring; imparts a golden yellow color to butter and cheese. |