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Methyl bixin

Derivation Methyl ester (methyl bixin) C26H3204 blue crystals, mp 203C. Ethyl ester (ethyl bixin), C27H3404 Red crystals, mp 138C. [Pg.167]

The two major carotenoids in Shepherdia canadensis were lycopene (16) and methyl apo-6 -lycopenoate (21). The latter was synthesised from apo-8 -lycopenal (22) by the appropriate Wittig condensation. The synthesis of methyl-bixin (24) with the natural cis double bond derived from the lactol (23) is outlined in Scheme 1. ... [Pg.203]

The syntheses of methyl bixin (24) and other natural carotenoids were mentioned above. A biogenetically inspired synthesis of e-carotene used the titanium tetrachloride complex of lycopene (16). Dehydrolycopene was also isolated. Two more syntheses of ) -carotene (2) have been reported which use intermediates in the synthesis of vitamin A (see Scheme 2). Although ll-cis-j5-carotene was produced it is rapidly isomerised to the all-frons form. The cross-conjugated system (72) has a previously unknown chromophore. Another example of this system, but with an additional 4 -oxo-group, was synthesised by Surmatis et al. in a study of the synthesis of keto carotenoids. They prepared echinenone (73) and the two protected 3,3 -dioxo-j8-carotene compounds (74) and (75). Treatment of the ketal with sulphuric acid gave mainly 3,3 -dioxo- -carotene (76) while hydrochloric acid gave 3,3 -dioxo-c-carotene (77). Under both conditions the enol ether gave the latter product. [Pg.211]

Methyl ester C26H3104, methyl bixin Broad, blue ro purple needles from benzene mp 203°. Absorption max (benzene) 475 nm (e 125 000). Synthesis Isler et al. Helv. Chim. Acta 40, 1242 (19S7) Buchta, An dree, Ber. 92, 3111 (1959). [Pg.201]

Bixin, a diapocarotenoid with a cis configuration at the carbon 9 and two carboxylic groups (one methylated), accounts for more than 80% of the total carotenoid content in annatto seeds, and has only been encountered to date in these seeds. The amount of red pigments in annatto seeds varies from 1.5 to 4%, depending on the variety. Bixin is the main pigment in commercial annatto powder... [Pg.224]

Bixin is an oil soluble, highly stable coloring ingredient. The saponification of the methyl ester group to form the dicarboxylic acid yields the water-soluble form of bixin, sometimes called norbixin. Annatto colorants date back into antiquity. The colorant has been used for centuries in connection with various textiles, medicinals, cosmetics, and foods. Annatto colors have also been used to color cheese, butter, and other dairy products for over a century. See also Carotenoids. [Pg.102]

Reaction of the ylide, generated from the phosphonium salt 578 (from the alcohol 577 and phosphine hydrobromide 504), with the polyene aldehyde 542 gives aleuria-xanthin acetate 579218). The methyl ester of the naturally occurring bixin 586 is formed by a combination of some carbonyl olefinations 279). The acetoxyaldehyde 580 is olefinated with methoxycarbonylmethylene-triphenylphosphorane 67 to the ( )-unsaturated ester 581. The latter is converted into the phosphonium salt 582 upon treatment with triphenylphosphine hydrobromide 504. The corresponding ylide of 582 is reacted with the dialdehyde 539 to the polyene aldehyde ester 583. The latter is reduced and converted into phosphonium salt 584. The corresponding ylide is now reacted in a third carbonyl olefination with 585 to give the methyl ester 586 279> (Scheme 98). [Pg.154]

Two amphiphiles with a reactive dye system as head groups, namely p-phenylenediamine and 4,4 -bipyridinium salts, have already been mentioned. Other such membrane-forming amphiphiles were modelled following natural photosynthetic membrane systems. Carotenoid amphiphiles are accessible from the cheap natural bolaamphiphile bixin, which carries a carboxylic acid on one end and a methyl ester on the other. A variety of orange-coloured bolaamphi-... [Pg.15]

The Cio-phosphonium acetals 27 and 28 (Scheme 4) proved their utility in the synthesis of 7,8-didehydroastaxanthin (402) [16] and various diapo- and apocarotenoids [17]. Selective reduction of Cio-dialdehyde 8 with NaBH4 furnished the hydroxyaldehyde 29, which was also used as an intermediate in the synthesis of the methyl ester of natural bixin (533) [18]. [Pg.119]

The synthesis of bixin (533) requires the regiospecific introduction of a Z double bond. Attention was first focused on the total synthesis of (all- )-methylbixin (534) [35]. (3-Methylepichlorohydrin (180) was treated with sodium acetylide (68) to give the alcohol 181 which was transformed with dihydropyran and phosphorus oxychloride to the acetylenic compound 182. Condensation of two moles of 182 with oct-4-ene-2,7-dione (5) in the presence of PhLi resulted in the C2o-diol 183. Treatment with p-toluenesulphonic acid first in toluene gave the diether 184 and afterwards in ethanol led to the diol 185, which was oxidized with Mn02 to the dial 186. The Knoevenagel condensation with malonic acid (187) and methylation with diazomethane gave the diester 188, which was hydrogenated in the presence of Lindlar catalyst and isomerized with iodine to (all- )-methylbixin (534) in an overall yield of 0.04% referred to 180 (Scheme 41). [Pg.157]

Bis [4-(vinyloxy) methyl] cyclohexyQ methyl] terephthalate. See Bis [[[4-(ethenyloxy) methyl] cyclohexyl] methyl] terephthalate BIT. See 1,2-Benzisothiazolin-3-one Bixa Orellana. SeeAnnatto (Bixa orellana) extract Bixin. SeeAnnatto (Bixa orellana) Annatto (Bixa orellana) extract BKF. See2,2 -Methylenebis (6-t-butyl-4-methylphenol)... [Pg.1000]

Methyl natural bixin [(74), R=CH3] with a 9 -cis (by C-w-carotenoid numbering) double bond has been synthesized by a stereochemically controlled synthesis with (75), obtained from the appropriate lactone as key intermediate (145). The configuration of natural bixin [(74), R = H] rested on NMR assignments (19). [Pg.148]

Antheraxanthin Zeaxanthin Violaxanthin Capsanthin Capsorubin Bixin Azafrin Echinenone Rhodoxanthin Isozeaxanthin Methyl 8 -apo-j5-caro-tenoate... [Pg.268]

During extraction, 9 -ds-bixin is also partly decomposed to orange and pale yellow products. The main product is 14-methyl-hydrogen-4,8-dimethyltetradeca-2,4,6,8,10,12-hexaene-l,14-dioic acid (9-189). This compound exists in various stereoisomers such as the all-trans isomer, 15-cis, 13-cis and 9-ds isomer. Related compounds with 18 and 13 carbon atoms per molecule, m-xylene, toluene and other products also arise. Coloured degradation products of 9 -ds-bixin may constitute up to 40% of pigments in commercial products. [Pg.733]

In stored foods containing natural bixin (9 -ds isomer), in the presence of light, aU-trans-bixin may result and, by its hydrolysis, all-trfl s-norbixin. In cheeses containing bixin, these substances bind to phosphoproteins (e.g. to some caseins), causing pink discoloration of products. In addition to tra s-isomers, some degradation products of bixin may also arise, such as methyl ester of d -trans-4,8-dimethyltetradeca-2,4,6,8,10,12-hexaenoic acid and aromatic hydrocarbons (e.g. m-xylene). [Pg.736]

Bixin, 6 -methyl hydrogen 9 -cis-6,6 -diapocarotene-6,6 -dioate (lUPAC, 1974 also 6,6 -diapo-4/,4/-carotenedioitic acid monomethyl ester and carotenoid-carboxylic acid), is isolated from seedsof5wa orellana L. MerckIndex, 1996 Schweppe, 1992). Classed here as a carotenoid compound, it also has the Colour Index designation Cl 75120. [Pg.51]

The coloring principles are carotenoids, mostly bixin (oil-soluble) and norbixin (water-soluble), with bixin (especially the cis isomer) in major concentration (2.5% dry wt.). Norbixin is the principle component of the water-soluble dyes of annatto and is formed by the removal of the methyl esters of bixin. Both a- and P-forms of norbixin are found in water-soluble annatto dye. (—)-Bixin (syn. a-bixin) is unstable and during extraction is usually converted to trans-hixin (syn. P-bixin), the stable isomer, which is also known as isobixin. Bixin is a monomethyl ester of norbixin (a dicarboxylic acid) it is readily hydrolyzed by alkalis during alkali extraction of annatto to the dicarboxylic acid, norbixin (evans MERCK).Annatto also contains P-carotene (6.8-11.3 mg/lOOg), apocarotenoids, diapo-carotenoids, an essential oil (with the sesquiterpene ishwarane as the major component), pentosans, pectin, protein (13-17%), tannins, and others (evans). [Pg.40]

Kunkel examined oxidations of bixin and tocopherols coupled to lipoxidase-catalyzed oxidation of methyl lineoleate (461) and found that the rate of oxidation of the bixin-methyl linoleate system is proportional to the square root of lipoxidase concentration, and that the tocopherols cause a transitory inhibition only of lipoxidase. [Pg.100]


See other pages where Methyl bixin is mentioned: [Pg.309]    [Pg.316]    [Pg.334]    [Pg.335]    [Pg.336]    [Pg.171]    [Pg.309]    [Pg.316]    [Pg.334]    [Pg.335]    [Pg.336]    [Pg.171]    [Pg.370]    [Pg.243]    [Pg.398]    [Pg.181]    [Pg.379]    [Pg.75]    [Pg.126]    [Pg.200]    [Pg.210]    [Pg.480]    [Pg.201]    [Pg.460]    [Pg.423]    [Pg.499]    [Pg.171]   
See also in sourсe #XX -- [ Pg.20 , Pg.602 ]

See also in sourсe #XX -- [ Pg.20 , Pg.602 ]




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