C/s-Carotenes

Gollnick, H.P.M. and Siebenwirth, C., /S-Carotene plasma levels and content in oral mucosal epithelium is skin type associated, Skin Pharmacol. Appl. Skin Physiol., 15, 360, 2002. 

Table IV. Differential inhibition of sterol accumulation and of the light-induced prenyllipid accumulation at high mevinolin concentration in excised 9-day-old etiolated primary wheat leaves during 18 h of continuous white light. Prenyllipids in U8 per 40 leaf segments. Mean of 2 runs with SD < 10%. X = Xanthopylls c = S-carotene x-i-c = sum of carotenoids. Chlorophylls and carotenoids were separated by TLC (1) and determined photometrically.

In a novel approach to the separation of carotenoids, Tai and Chen [340], used a C30 column (A = 450 nm) and an 89/1/10 methanol/dicUoromethane/IPA mobile phase. Daylily (Hememcallis disticha) extracts were characterized. Sixteen compounds (e.g., neoxanthin, lutein-5,6-epoxide, j8-cryptoxanthin, 9-c/s- -carotene)... 

FIGURE 17.11 Imine formation between the aldehyde function of 11-c/s-retinal and an amino group of a protein (opsin) is involved in the chemistry of vision. The numbering scheme in retinal is specifically developed for carotenes and related compounds. 

Contrary to the carotenoid behavior during orange juice pasteurization, losses of 46%-54% in the all-trans-a- and all-trans-fi-carotene contents and the formation of m-isomers were also verified for the pasteurization of carrot juice at 110°C and at 120°C, both for 30 s (Chen et al. 1995). In addition, all cis- isomer levels increased, with 13-c -P-carotene and 15-d.v-a-carotene formed in the largest amount. Heating at 121°C for 30min caused further losses of 61% in al I-tran.v-a-carotene and 55% in all-trans-P-carotene (Chen et al. 1995). However, minor effects on the amounts of trans- and cis- isomers of a- and P-carotenes were observed after the acidification and the heating of carrot juice at 105°C for 25 s (Chen et al. 1995). 

Comparison of Photosensitized and Direct Photolysis Isomerization Quantum Yields (iso) of AH-trans and several c/s-lsomers of (3-Carotene in n-Hexane... 

C.-S. You, R. S. Parker, and J. E. Swanson, Bio availability and vitamin A value of carotenes from red palm oil assessed by an extrinsic isotope reference method, Asia Pac. J. Clin. Nutr. 11 (2002) S348-S442. 

Kessova, I.G., Leo, M.A., and Lieber, C.S. 2001. Effect of beta-carotene on hepatic cytochrome P-450 in ethanol-fed rats. Alcohol Clin Exp Res 25 1368-1372. 

Dietary /1-carotene, a nutritionally important source of vitamin A, exhibits a protective effect against cancer risk31,32. The deuteriated compound, 10,10, 19,19,19,19, 19, 19 -2H8-/S-carotene, 32, has been obtained33 by double condensation of the C-15 Wittig salt 33 with the symmetrical C10 dial 2,7-dimethyl-2,4,6-octatrienedial, 34 (equation 13) for the study of /J-carotene metabolism in humans. 

The a-, (3- and y-carotenes, which are found in most plants, are vitamin A provitamins and are converted to vitamin A alcohol (all- ran,v-retinol), which is usually called vitamin Aj (Figure 12.8) by oxidative mid-point cleavage. Retinol and its fatty acid esters are the main forms in which vitamin A is stored in animals and humans, and its oxidation product, 1 1-c/s-retinal (vitamin A, aldehyde), is required for the visual process. 

Fig. 2.17. Saponified carotenoids in orange juice. Chromatographic conditions are given in text. Chromatograms from absorbance monitoring at 430, 486 and 350 nm, respectively, are shown, all at identical attenuation. Peak identification 1, 3, 5, 8, 26 and 29 = unidentified peaks 4 = valen-ciaxanthin 6 = neochrome 7 = trollichrome 9 = antherxanthin 11 = c/s-anthexanthin 12 = neoxanthin 19 = auoxanthin B 20 = c/s-violaxanthin 22 = leutoxanthin 23 = mutatoxan-thin A 24 = mutatoxanthin B 25 = lutein 27 = zeaxanthin 28 = isolutein 31 = a-cryptoxanthin 33 = /J-cryptoxanthin 34 = phytofluene 35 = a-carotene 36 = ae-carotene 37 = / -carotene. Reprinted with permission from R. Rouseff et al. [41].

Fig. 2.24. C30 chromatograms of carotenoids extracted from human serum (a) xanthophylls fraction, 7 93 (v/v) MTBE-methanol mobile phase (b) a- and / -carotenes fraction, 11 89 (v/v) MTBE-methanol mobile phase (c) lycopene fraction, 38 62 (v/v) MTBE-methanol mobile phase. Tentative peak identifications (a) 1, 13-c/s-lu- lutein 2, 13 r/.vlutein 3, a//-/ra s-lutein 4, zeaan-thin 5-7, unidentified P,e-carotenoids and 8, / -cyrptoanthin (b) 1-2, unidentified ae-carotene isomers 3, 15-eH -/f-carotenc 4, 13-cw-/ -carotene 5, all-trans-a-carotene 6, all-trans-P-carotene and 7, 9-ci.v-/3-carotene and (c) 1-11 and 13, c/s-lycopene isomers and 12, all-trans-lycopene. Reprinted with permission from C. Emenhiser el al. [51].

Edes, T. E., Gysbers, D. G., Buckley, C. S., and Thornton, W. H., Jr. (1991). Exposure to the carcinogen benzopyrene depletes tissue vitamin A Beta-carotene prevents depletion. 

The main effect of efferent action of Hepamal preparation is inhibition of LPO processes, increase of antioxidative abiUty of the organism and stimulation of enzymes of the organism s detoxication system. These activities are stipulated by natural vitamin complexes (A, E, PP, C, 6-carotenes, foUc acid) present in Hepamal, which have high antioxidative potential, whereas flavonoids and terpenoids, also present in the preparation, stimulate both detoxication phases. 

The cyclization was also successful with natural unsaturated aldehydes such as /J-carotene, c/s-retinal (95%), and trans-retinal (50%).183,1842 Compounds like 142 are potential intermediates in the syntheses of /J-carotene derivatives and polymeric alkenes.184,185,186... 

Figure F2.2.1 The spectral characteristics of all-trans (3-carotene (solid line), 9-els (3-carotene (dashed and dotted line) and 15-c/ s (3-carotene (dashed line).

Figure F2.4.1 Liquid chromatography/mass spectrometry (LC/MS) analysis of isomeric carotenes in a hexane extract from 0.5 ml human serum. Positive ion electrospray ionization MS was used on a quadrupole mass spectrometer with selected ion monitoring to record the molecular ions of lycopene, p-carotene, and a-carotene at m/z (mass-to-charge ratio) 536. A C30 HPLC column was used for separation with a gradient from methanol to methyl-ferf-butyl ether. The a -trans isomer of lycopene was detected at a retention time of 38.1 min and various c/ s isomers of lycopene eluted between 27 and 39 min. The all-frans isomers of a-carotene and P-carotene were detected at 17.3 and 19.3 min, respectively.

Fig. 3 Structures of cis isomers of /3-carotene that occur in foods, (a) 15-cz.v-/3-carotene (b) l3-cis-/3-carotene (c) 9-c s-/3-carotene.

Raw and cooked vegetables, salads, fruits Extract with MeOH, reextract with THF. Partition into petroleum ether and water. Vydac 201 TP54 C,s 5 /xm 250 X 4.6 mm MeOH/THF, 95 5 Lutein, zeaxanthin, /3-cry ptoxan thin, a-carotene, /3-carotene, lycopene Vis 445 nm 167... 

A useful atlas of chiral molecules has appeared the major monoterpenoids of known absolute configuration are illustrated, with a literature coverage to the end of 1971.3 The reader should beware of printing errors e.g. (+)-/ -irone lacks a methyl group at C-2, (—)-(R)-a-cyclogeraniol lacks a double bond between C-2 and C-3, and (+)-S-carotene has only 39 carbon atoms (p. 131) carvotanacetone is incorrectly indexed and the nomenclature and presentation of thujane monoterpenoids is different from that used in these Reports. 

RBP is relatively rich in aromatic amino acids, which create a deep hydrophobic pocket that is specific for the 8-ionone ring, polyene side chain, and polar end group. In addition to all- trans-retinol, RBP binds retinaldehyde, retinoic acid, and 13-c/s-retinol, but not retinyl esters or carotene. RBP shows considerable structural homology with 8-lactoglobulin from milk and other... 

The steric stability of acetylenic carotenoids has been investigated. " Stereoisomerization of a -trans- and 9,9 -di-cw-alloxanthin [7,8,7, 8 -tetra-dehydro-jS,/S-carotene-3,3 -diol (94)] and all-tran5-7,8,7, 8 -tetradehydro-astaxanthin (49) in the presence of I2 gave mainly the 9,9 -di-cw- and 9-mono-c/s-isomers, with none of the all-trans-form present in the pseudo-equilibrium mixture. All-trans-7,8-didehydroastaxanthin (48), however, gave a mixture of the 9-mono-c/s- and all-trans-isomers. 

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