Cryptoxanthin epoxide

An enzyme system from the yeast Saccharomyces cerevisiae is able to incorporate isoprenoid precursors into the C30 phytoene analogue (200) only in the presence of Mn and absence of NADPH. If NAD PH is present and Mn is replaced by Mg, the sterol precursor squalene (201) is produced.The substrate specificity of the chloroplast enzyme violaxanthin deepoxidase has been examined.In addition to the normal substrate violaxanthin [(35,5/ ,65,3 5,5 i ,6 5)- 5,6,5, 6 -diepoxy-5,6,5, 6 -tetrahydro-/3,j8-carotene-3,3-diol, (196)] several all-trans-monoepoxy-carotenoids, such as anthera-xanthin [5,6-epoxy-5,6-dihydro-/3,/3-carotene-3,3 -diol (197)], diadinoxanthin [5,6-epoxy-7, 8 -didehydro-5,6-dihydro-j8, 8-carotene-3,3 -diol (198)], and /3-cryptoxanthin epoxide [5,6-epoxy-5,6-dihydro-/3,/3-caroten-3-ol (199)], all with the 38,5R,6S) configuration, were utilized. Violeoxanthin (9-cis-violaxanthin) and other 9-cis-isomers were not affected. A carrot Daucus carota) tissue culture has been shown to incorporate [ C]acetate into carotenoids. ... 

It is assumed that in order to have vitamin A activity a molecule must have essentially one-half of its structure similar to that of (i-carotene with an added molecule of water at the end of the lateral polyene chain. Thus, P-carotene is a potent provitamin A to which 100% activity is assigned. An unsubstituted p ring with a Cii polyene chain is the minimum requirement for vitamin A activity. y-Car-otene, a-carotene, P-cryptoxanthin, a-cryptoxanthin, and P-carotene-5,6-epoxide aU have single unsubstimted rings. Recently it has been shown that astaxanthin can be converted to zeaxanthin in trout if the fish has sufficient vitamin A. Vitiated astaxanthin was converted to retinol in strips of duodenum or inverted sacks of trout intestines. Astaxanthin, canthaxanthin, and zeaxanthin can be converted to vitamin A and A2 in guppies. ... 

The speed of autoxidation was compared for different carotenoids in an aqueous model system in which the carotenoids were adsorbed onto a C-18 solid phase and exposed to a continnons flow of water saturated with oxygen at 30°C. Major products of P-carotene were identified as (Z)-isomers, 13-(Z), 9-(Z), and a di-(Z) isomer cleavage prodncts were P-apo-13-carotenone and p-apo-14 -carotenal, and also P-carotene 5,8-epoxide and P-carotene 5,8-endoperoxide. The degradation of all the carotenoids followed zero-order reaction kinetics with the following relative rates lycopene > P-cryptoxanthin > (E)-P-carotene > 9-(Z)-p-carotene. 

Fig. 2.3. Characteristic chromatogram of paprika paste. Detection at 450 nm. Peak identification 1 = Capsorubin 2 = 5,6-Diepikarpoxanthin 3 = Capsanthin-5,6-epoxide 4 = Capsanthin-3,6-epox-ide 5 = Violaxanthin 6 = Luteoxanthin 2 7 = Luteoxanthin 1 8 = Capsanthin 9 = Antheraxanthin 10 = Mutatoxanthin 11 = Cucurbitaxanthin A 12 = (9/9 Z)-Capsanthins 13 = (13/13 Z)-Capsanthins 14 = Zeaxanthin 15 = Nigroxanthin 16 = (9Z)-Zeaxanthin 17 = (13Z)-Zeaxanthin 18 = Cryptocapsin 19 = a-Cryptoxanthin 20 = /TCryptoxanthin 21 = (Z)-Cryptoxanthin 22 = /1-Carotene 23 = (Z)-jS-Carotene. Reprinted with permission from J. Deli et al. [27].

In addition to (3-carotene there are a variety of other C j pro-vitamin A carotenes that differ from (3-c.arotene in the nature of the terminal cyclic moieties. Thus, representing the right cyclic moiety as X, we can represent (3-carotene as X—(IP)2—(PI)2—X that yields two molecules of vitamin A or X—(IP)2—OH. Carotenes can have different cyclic moieties X (where X X) or no cyclic isoprene dimer moieties. Other C () pro-vitamin A carotenes that yield only one vitamin A molecule on oxidation include a-carotene, (3-cryptoxanthin, (3-c.arotene epoxide, echinenone and mutachrome (generalized structure X—(IP)2—(PI)2—X ) and y-carotene and torulene (X-(IP)2-(PI)4). 

Fig. 9.7 Separation of carotenoids from red pepper with gradient. (Reproduced with permission from L. Almela, J. M. Lopez-Roca, M. E. Candela and M. D. Alcazar, J. Chromatogr., 502, 95 (1990).) Conditions sample, saponificated extract from red pepper fruit column, 25cm x 4.6mm i.d. stationary phase, Spherisorb 5 am mobile phase, 1mlmin petroleum ether-acetone, linear gradient from 5 to 25% acetone in 30 min visible-range detector 460 nm. Peaks 1 = j5-carotene 2 = cryptocapsin 3 = cryptoflavin 4 = j5-cryptoxanthin 5 = antheraxanthin 6 = capsolutein 7 = luteoxanthin 8 = zeaxanthin 9 = mutatoxanthin 10 = capsanthin 11 =capsanthin-5,6-epoxide ...

The photosynthetic pigments of higher plants comprise not only the chlorophylls (a and b) but also a range of carotenoids. The main ones of these are B-carotene (usually 25-30% of the total carotenoids) and the xanthophylls lutein (45-50%), violaxanthin (ca. 15%) and neoxanthin (ca. 15%), though small amounts of others, e.g. a-carotene, zeaxanthin, antheraxanthin, lutein-5,6-epoxide and a-cryptoxanthin, may also be detected. The... 

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)... 

Anthocyanins and flavonoids (Lima et al. 2002) and also a complex carotenoid profile were identified for pitanga fruit. Several carotenoids were already identified, including lycopene and rubixanthin, cis-m-bixanthin, p-cryptoxanthin, cis-lycopene, P-carotene, y-carotene, zea-xanthin, lutein, violaxanthin, and p-carotene-5,6-epoxide (Filho et al. 2008 Azevedo-Meleiro and Rodriguez-Amaya 2004). The flavonoids quercetin, kaempferol, and myricetin were positively identified for pitanga fruits of undefined varieties with values ranging from 5.1-7.3, 2.7-4.2, and 0.3-0.6 mg/lOOg FW, respectively. 

Z Matus, J Deh, J Szaholcs. Carotenoid composition of yellow pepper during ripening isolation of heta-cryptoxanthin 5,6-epoxide. J Agric Food Chem 39 1907-1914, 1991. 

Xanthophylls are the main carotenoids of plants. They primarily arise as products of biochemical oxidation (hydroxylation and epoxidation) of carotenes. Xanthophylls derived from acyclic carotenes occur in foods in small quantities. For example, tomatoes contain as minor pigments 1,2-epoxylycopene, 5,6-epoxylycopene, 1,2-epoxyphytoene and some other compounds. Much more common are monohydroxysubstituted alicyclic derivatives of carotenes called cryptoxanthins. Most plant materials contain small amounts of a-cryptoxanthin also called zeinoxanthin, derived from a-carotene (9-182) and P-cryptoxanthin, derived from... 

Seeds contain steroidal s onins (proto-dioscin, oligofurostanosides) large amounts of NaOH-soluble polysaccharides " carotenoids (mutatoxanthin epimers, antheraxanthin, P-carotene, P-cryptoxanthin, lutein, cap-santhin, capsanthin 5,6-epoxide, eapsorubin, neoxanthin, violaxanthin, zeaxanthin) and 15.3% oil composed of 43.47% arachidie, 22.16% oleic, 11.52% palmitic, 11.34% lino-leic, 5.78% behenic, 3.59% stearic, 2.14% linolenic acids, and 1.43% unsaponifiable matter consisted mostly of P-sitosterol. ... 

Antheraxanthin, capsanthin, capsanthin-5, 6-epoxide, capsorubin, fj-carotene, fJ-carotene-S, 6-epoxide, hydroxy-a-carotene, cryptocapsin, fj-cryptoxanthin, lutein, neoxanthin, violaxanthin, and zeaxanthin (3-Carotene, (3-cryptoxanthin, lutein, neoxanthin, violaxanthin, neocrome, auroxanthin, zeaxanthin, capsanthin, capsorubin, and cucurbitaxanthin A (3-Carotene, (3-cryptoxanthin, zeaxanthin, capsanthin, and capsorubin Lycopene, prolycopene, violaxanthin, neoxanthin, c -mutatoxanthin, and lutein... 

Capsorubin, violaxanthin, capsanthin-5,6-epoxide, capsanthin, 9-cw-capsanthin, 13-c -capsanthin, antheraxanthin, mutatoxanthin, cucurbitaxanthin A (capsolutein), zeaxanthin, 9-cis-zeaxanthin, 13-cis-zeaxanthin, p-apo-8 -carotenal, cryptoeapsin, P-cryptoxanthin, p-earotene, and cw-p-carotene Neoxanthin, violaxanthin, lutein, antheraxanthin, mutatoxanthin, P-carotene, neochrome, auioxanthin, luteoxanthin, and chltuophylls... 

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