Xanthophylls as precursors of retinoids

Matsuno, Takao

doi:10.1351/pac199163010081

Cited by 87 publications

(44 citation statements)

References 1 publication

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“…Proposed reaction mechanism for the oxidative cleavage of J3-carotene (or other provitamin A carotenoids) catalyzed by carotene 15,15'-dioxygenase. This mechanism for molecular O2 addition across the central 15-15' carbon-carbon double bond was proposed originally by and OLSON and HAYAISHI (1965) and/or metabolism; various species show markedly different characteristics and properties with respect to carotenoid absorption and metabolism (MATSUNO 1991; VAN VLIET 1996). In humans the majority of absorbed ~ carotene (60%-70%) is converted to retinal and the remainder is absorbed intact and deposited in adipose tissue (OLSON 1989(OLSON ,1990).…”

Section: Uptake and Metabolism Of Dietary Provitamin A Carotenoidsmentioning

confidence: 84%

Biosynthesis, Absorption, Metabolism and Transport of Retinoids

Vogel¹,

Gamble²,

Blaner³

1999

Retinoids

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All retinoids (vitamin A and its analogs) in the body originate in the diet either as preformed vitamin A, usually from animal food sources, or as provitamin A carotenoids, usually from plant food sources or as supplements or additives to processed foods. Both preformed vitamin A and provitamin A undergo metabolism within the intestine (BLANER and OLSON 1994), including a series of metabolic conversions, extracellularly in the lumen of the intestine and intracellularly in the intestinal mucosa, which result in the preponderance of the dietary vitamin A being converted to retinol (vitamin A alcohol). The retinol, along with other dietary lipids in the intestinal mucosa, is packaged as retinyl ester in nascent chylomicrons. The chylomicrons are secreted into the lymphatic system, and approximately 75% of chylomicron retinoid is eventually taken up as part of the chylomicron remnants by the liver, where the majority of the body's retinoid reserves are stored. Some retinoid is delivered to extrahepatic tissues where this retinoid is either stored as retinyl ester, released back into the circulation for delivery to the liver and other tissues, metabolized to active retinoid forms such as retinoic acid or metabolized to catabolic forms destined for excretion from the body.The predominant retinoid present in the fasting circulation is the retinoic acid precursor, retinol. Since retinol is not soluble in aqueous environments, all circulating retinol is bound to retinol-binding protein (RBP). Other retinoids are also present in blood, albeit at much lower concentrations than retinol. Both all-trans-and 13-cis-retinoic acid can be found in fasting plasma of both animals and humans. Some retinyl ester is present as a component of lipoproteins, especially in very low density lipoprotein (VLDL) and low density lipoprotein (LDL). Glucuronides of both retinol and retinoic acid can be found in the circulation along with low levels of retro-metabolites of retinol.This chapter focuses primarily on recent advances in our understanding of the uptake and metabolism of dietary retinoid and provitamin A carotenoids, retinoid storage and metabolism in the liver and the delivery of retinoid to target tissues. Thus this review is concerned primarily with the metabolism and transport of the precursor retinol and its storage form, retinyl ester. Later chapters review the formation and catabolism of active retinoid forms such as retinoic acid and retro-retinoids from retinol.

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Section: Uptake and Metabolism Of Dietary Provitamin A Carotenoidsmentioning

confidence: 84%

Biosynthesis, Absorption, Metabolism and Transport of Retinoids

Vogel¹,

Gamble²,

Blaner³

1999

Retinoids

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“…Recently, its diverse biological functions have been revealed as a vitaminA precursor [16], a scavenger and/or quencher against free radicals and active oxygen species [18], an anti-cancer agent [15,31], and an enhancer of the immune response [ 12]. Since animals cannot synthesize carotenoids de novo, carotenoids that are biosynthesized by microorganisms or plants must be transferred to animals as ingredients in feed or food [15,19].…”

Section: Introductionmentioning

confidence: 99%

Isolation and functional identification of a novel cDNA for astaxanthin biosynthesis from Haematococcus pluvialis, and astaxanthin synthesis in Escherichia coli

et al. 1995

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We succeeded in isolating a novel cDNA involved in astaxanthin biosynthesis from the green alga Haematococcus pluvialis, by an expression cloning method using an Escherichia coli transformant as a host that synthesizes beta-carotene due to the Erwinia uredovora carotenoid biosynthesis genes. The cloned cDNA was shown to encode a novel enzyme, beta-carotene ketolase (beta-carotene oxygenase), which converted beta-carotene to canthaxanthin via echinenone, through chromatographic and spectroscopic analysis of the pigments accumulated in an E. coli transformant. This indicates that the encoded enzyme is responsible for the direct conversion of methylene to keto groups, a mechanism that usually requires two different enzymatic reactions proceeding via a hydroxy intermediate. Northern blot analysis showed that the mRNA was synthesized only in the cyst cells of H. pluvialis. E. coli carrying the H. pluvialis cDNA and the E. uredovora genes required for zeaxanthin biosynthesis was also found to synthesize astaxanthin (3S, 3'S), which was identified after purification by a variety of spectroscopic methods.

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“…This pigment has been developed for industrial use mainly as an agent for pigmentation of cultured fish and shellfish (18,26). Recently, its diverse biological functions have been revealed as a vitamin A precursor (38), a scavenger and/or quencher of free radicals and active oxygen species (39,40), a preventative against cancer (30,59), and an enhancer of the immune response (27,28). In relation to the quenching effect of astaxanthin against singlet molecular oxygen, the activity is approximately 500 to 1,000 times greater than that of ␣-tocopherol (39).…”

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confidence: 99%

Structure and functional analysis of a marine bacterial carotenoid biosynthesis gene cluster and astaxanthin biosynthetic pathway proposed at the gene level

et al. 1995

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A carotenoid biosynthesis gene cluster for the production of astaxanthin was isolated from the marine bacterium Agrobacterium aurantiacum. This cluster contained five carotenogenic genes with the same orientation, which were designated crtW, crtZ, crtY, crtI, and crtB. The stop codons of individual crt genes except for crtB overlapped the start codons of the following crt genes. Escherichia coli transformants carrying the Erwinia uredovora carotenoid biosynthesis genes provide suitable substrates for carotenoid biosynthesis. The functions of the five crt genes of A. aurantiacum were determined through chromatographic and spectroscopic analyses of the pigments accumulated in some E. coli transformants carrying various combinations of the E. uredovora and A. aurantiacum carotenogenic genes. As a result, the astaxanthin biosynthetic pathway is proposed for the first time at the level of the biosynthesis genes. The crtW and crtZ gene products, which mediated the oxygenation reactions from ␤-carotene to astaxanthin, were found to have low substrate specificity. This allowed the production of many presumed intermediates of astaxanthin, i.e., adonixanthin, phoenicoxanthin (adonirubin), canthaxanthin, 3-hydroxyechinenone, and 3-hydroxyechinenone.During the last 6 years, significant advances have been made in our understanding of the genes coding for the enzymes involved in carotenoid biosynthesis. Many carotenoid biosynthesis genes have been cloned from various organisms, and their functions have been determined (3, 54, 62). Phytoene synthase genes, which mediate the formation of the first colorless carotenoid phytoene from geranylgeranyl PP i (GGPP) (11,46,55), have been isolated from the photosynthetic bacteria Rhodobacter species (5, 31), the nonphotosynthetic bacteria Erwinia species (4,45,60) and Thermus thermophilus (20), the cyanobacterium Synechococcus sp. strain PCC7942 (11), the fungus Neurospora crassa (57), and higher plants (7,50,51,58). Many genes involved in the desaturation (dehydrogenation) steps to convert phytoene to -carotene, neurosporene, or lycopene have also been obtained from the photosynthetic bacteria Rhodobacter species (5, 6, 31), the nonphotosynthetic bacteria Erwinia species (4, 45, 60) and Myxococcus xanthus (16), the cyanobacterium Synechococcus sp. strain PCC7942 (12), the fungi N. crassa (56) and Cercospora nicotianae (15), and higher plants (8,21,48). A second desaturase gene, which mediates the desaturation reaction from -carotene to lycopene, has been obtained from the cyanobacterium Anabaena sp. strain PCC7120 (33). The genes coding for lycopene cyclase, which catalyzes the formation of a cyclic carotenoid ␤-carotene from lycopene, have been isolated from the nonphotosynthetic bacteria Erwinia species (25, 45) and the cyanobacterium Synechococcus sp. strain PCC7942 (14).Among these organisms, the carotenoid biosynthesis genes of the yellow-pigmented nonphotosynthetic soil bacteria Erwinia uredovora (45) and Erwinia herbicola (4, 22, 60) have been used most frequently in the study o...

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Xanthophylls as precursors of retinoids

Abstract: Abstract

Cited by 87 publications

References 1 publication

Biosynthesis, Absorption, Metabolism and Transport of Retinoids

Biosynthesis, Absorption, Metabolism and Transport of Retinoids

Isolation and functional identification of a novel cDNA for astaxanthin biosynthesis from Haematococcus pluvialis, and astaxanthin synthesis in Escherichia coli

Structure and functional analysis of a marine bacterial carotenoid biosynthesis gene cluster and astaxanthin biosynthetic pathway proposed at the gene level

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