A Supramolecular Enzyme Mimic That Catalyzes the 15,15′ Double Bond Scission of ,-Carotene

French, Richard R.; Holzer, Philipp; Leuenberger, Michele; Woggon, Wolf‐D.

doi:10.1002/(sici)1521-3773(20000403)39:7<1267::aid-anie1267>3.0.co;2-7

Cited by 97 publications

(48 citation statements)

References 8 publications

(13 reference statements)

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“…The ruthenium catalyst afforded cleavage at C15-C15', C12'-C11', and at C10'-C9' in an overall yield of 30 %. However, the selective cleavage of C15-C15' was observed when one of the cyclohexene end groups of β,β-carotene was replaced by an ortho-dimethylphenyl group [211] . Other catalytic investigations targeted the electrochemical oxidation of sugars for applications as fuel in fuel cells.…”

Section: Catalysismentioning

confidence: 99%

Chemical Synthesis and Medicinal Applications of Glycoporphyrins

Moylan¹,

Scanlan²,

Senge

2015

CMC

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Abstract:This review presents an in-depth overview of the modification of porphyrins with bioconjugates and their applications in medicine today. Porphyrin bioconjugates ranging from nucleotides to steroids are under active scrutiny. However, carbohydrates have been at the forefront of such research in recent years and offer significant potential. This is attributed to their own selectivity to lectins on the surface of cancer cells and their influence on the amphiphilicity of the porphyrin macrocycle. These characteristics and the tendency of porphyrin photosensitizers to accumulate in tumor tissues make glycoporphyrins promising candidates for use as photosensitizers. Thus, a detailed overview of the synthesis and biological evaluation of glycoporphyrins is given with a particular focus on their applications in photodynamic therapy and their future prospects as drug candidates have been reported.

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Section: Catalysismentioning

confidence: 99%

Chemical Synthesis and Medicinal Applications of Glycoporphyrins

Moylan¹,

Scanlan²,

Senge

2015

CMC

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“…However, it was recently shown that carotenoid hydroxylation is catalyzed by CYP 450 in bacteria [69] and in plants [70,71]. A well-developed and elegant porphyrin model of a catalytic system has been used to mimic the central cleavage of carotenoids [72]. The reaction was about 40 % regioselective for the oxidative cleavage of β-carotene on its central (15,15') carbon-carbon double bond.…”

Section: Carail and C Caris-veyratmentioning

confidence: 99%

Carotenoid oxidation products: From villain to saviour?

Carail¹,

Caris-Veyrat²

2006

Pure and Applied Chemistry

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Carotenoid oxidation products have various structures, among which epoxides and apo-or seco-carotenoids are the two main families. Although both these compound types are widely found in the natural world, the sensitivity of carotenoids to oxidation means they can also be an unwanted presence in in vitro assays. On the other hand, carotenoid oxidation products have also provided chemists with useful chemical tools for the structural identification of carotenoids, and in the natural world they are important biological mediators for plants and animals. In vitro, carotenoid oxidation products have been found to exert various effects which are either potentially beneficial or, on the contrary, detrimental to human health. However, to date, few carotenoid oxidation products have been found in humans.In order to isolate and characterize carotenoid oxidation products and identify their mechanism of formation, we set up two chemical oxidation systems. Lycopene was oxidized with potassium permanganate in a biphasic system to produce the fullest possible range of apo-lycopenals and some diapocarotene-dials. Biomimetic chemical systems of a heminic enzyme center were shown to oxidize lycopene and β-carotene into different families of molecules. Analysis by high-performance liquid chromatography coupled with a diode array-UV/vis detector and a mass spectrometry detector (HPLC-DAD-MS) was used to gain insight into the possible mechanisms of formation of the carotenoid oxidation products formed by these biomimetic systems.

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“…The filtrate was concentrated on a rotary evaporator and the residue distilled at 0. 15 (8) 6.04 6.12 6.12 HÀC(8') 6.04 6.12 6.12 HÀC(10) 6.08 6.6 6.6 HÀC(10') 6.08 6.10 6.6 HÀC(11) 6.62 6.31 6.31 HÀC (11') 6.62 6.62 6.31 HÀC (12) 6.29 6.04 6.05 HÀC(12') 6.29 6.29 6.05 HÀC (13) 6.34 6.85 6.85 HÀC(13') 6.34 6.34 6.85 HÀC (14) 6.30 6.31 6.31 HÀC(14') 6.30 6.31 6.31 HÀC (15) 6.30 6.37 6.37 HÀC(15') 6.30 6.30 6.37 (10) 6.10 6.53 6.53 HÀC(10') 6.10 6.11 6.53 HÀC (11) 6.61 6.35 6.37 HÀC (11') 6.61 6.61 6.37 HÀC (12) 6.31 6.09 6.10 HÀC(12') 6.31 6.31 6.10 HÀC(13) 6.32 6.78 6.79 HÀC(13') 6.32 6.32 6.79 HÀC (14) 6.32 6.32 6.37 HÀC(14') 6.32 6.32 6.37 HÀC (15) 6.32 6.32 6.38 HÀC(15') 6.32 6.32 6.38 was chromatographed on an Alox II N column (hexane/benzene 4 : 1) to give, after evaporation, 569 mg of an orange oil. It was rechromatographed on an Alox II N column (hexane/benzene 5 : 1) to yield, after evaporation, a yellow oil (377 mg, 44%) of a mixture of three isomers of 15 1 ).…”

Section: Experimental Partmentioning

confidence: 99%

“…Parallel to our efforts to purify the native protein [7] and to determine the reaction mechanism [10], we developed a synthetic supramolecular enzyme model that catalyzes carotenoid cleavage [11] [12], and we also investigated the substrate specificity of b,b-carotene 15,15'-monooxygenase from chicken intestinal mucosa using enriched enzyme fractions. We wish to report here the synthesis of several potential substrates and incubation experiments with 14 substrate analogues.…”

Section: Introduction ± Bb-carotenementioning

confidence: 99%

The Substrate Specificity ofβ,β-Carotene 15,15′-Monooxygenase

Wirtz

Bornemann

Giger

et al. 2001

HCA

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The synthesis of several substrate analogues of the enzyme b,b-carotene 15,15'-monooxygenase is reported. The substrate specificity of enriched enzyme fractions isolated from chicken intestinal mucosa was investigated. Regarding substrate binding/cleavage, these experiments demonstrate that i) any deviation from the rod-like b,b-carotene structure is not tolerated, ii) one natural, unsubstituted b-ionone ring is required, iii) the position and presence of the Me groups attached to the polyene chain is significant. These results suggest a hydrophobic barrel-like substrate binding site in which the proteins amino acid residues through interaction with the Me groups, direct the central CC bond in binding distance to the active sites metal-oxo center, supporting the unique regiospecificity of cleavage to retinal (provitamin A).

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A Supramolecular Enzyme Mimic That Catalyzes the 15,15′ Double Bond Scission of ,-Carotene

Cited by 97 publications

References 8 publications

Chemical Synthesis and Medicinal Applications of Glycoporphyrins

Chemical Synthesis and Medicinal Applications of Glycoporphyrins

Carotenoid oxidation products: From villain to saviour?

The Substrate Specificity ofβ,β-Carotene 15,15′-Monooxygenase

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