MetaboLights
A neoxanthin in which all of the double bonds have trans geometry.
Identification
(3S,3'S,5R,5'R,6R,6'S,8R)-6,7-didehydro-5,5',6,6'-tetrahydro-5',6'-epoxy-beta,beta-carotene-3,3',5-triol ,
(3S,5R,6R,3'S,5'R,6'S)-6,7-didehydro-5',6'-epoxy-5,6,5',6'-tetrahydro-beta,beta-carotene-3,5,3'-triol
all-trans-Neoxanthin
all-trans-neoxanthin
Neoxanthin
Species
Europe PubMed Central results
Identification of neoxanthin synthase as a carotenoid cyclase paralog.
Author: Bouvier F, D'harlingue A, Backhaus RA, Kumagai MH, Camara B.
Abstract: Neoxanthin, a precursor of the plant hormone abscisic acid, is an allenic xanthophyll recognized as the last product of carotenoid synthesis in green plants. A cDNA for neoxanthin synthase (NSY) was isolated from tomato using a molecular approach based on the mechanistic and structural similarities of NSY to two other closely related carotenogenic enzymes, lycopene cyclase (LCY) and capsanthin-capsorubin synthase (CCS). The identified tomato NSY cDNA (T.NSY) encodes a 56-kDa plastid-targeted protein that when expressed in Escherichia coli, catalyzes the conversion of violaxanthin to neoxanthin. In tobacco leaves that transiently express T.NSY, an increase in neoxanthin content with a concomitant decrease in violaxanthin is observed. NSY is structurally similar to LCY and CCS. However, in Cyanobacteria, the generally accepted progenitor of plastids, both CCS and NSY are absent while LCY is present. LCY catalyzes a simplified version of the reaction catalyzed by NSY and CCS suggesting that these two enzymes were remodeled from LCY during higher plant evolution to create new forms of oxidized carotenoids.
The epoxide nature of the carotenoid, neoxanthin.
An epoxide-furanoid rearrangement of spinach neoxanthin occurs in the gastrointestinal tract of mice and in vitro: formation and cytostatic activity of neochrome stereoisomers.
Author: Asai A, Terasaki M, Nagao A.
Abstract: Neoxanthin, a major carotenoid in green leafy vegetables, was reported to exhibit potent antiproliferative effect via apoptosis induction on human prostate cancer cells. However, the metabolic fate of dietary neoxanthin in mammals remains unknown. In the present study, we investigated the gastrointestinal metabolism of neoxanthin in mice and the in vitro digestion of spinach, and estimated the antiproliferative effect of neoxanthin metabolites on PC-3 human prostate cancer cells. Two hours after the oral administration to mice of purified neoxanthin, unchanged neoxanthin and stereoisomers of neochrome (8'-R/S) were detected in the plasma, liver, and small intestinal contents. To estimate the effect of intragastric acidity on the conversion of dietary neoxanthin into neochrome (epoxide-furanoid rearrangement), spinach was digested in vitro by incubating it with a pepsin-HCl solution at pH 2.0 or 3.0 (gastric phase) followed by a pancreatin-bile salt solution (intestinal phase). Spinach neoxanthin was largely converted into (R/S)-neochrome during the digestion when the gastric phase was set at pH 2.0, whereas the rearrangement was observed to a lesser extent at pH 3.0. (R/S)-neochrome dose-dependently inhibited the proliferation of PC-3 cells as well as neoxanthin at concentrations < or = 20 micromol/L. Although neoxanthin induced evident apoptotic cell death, (R/S)-neochrome inhibited the cell proliferation without obvious apoptosis induction. These results indicate that dietary neoxanthin is partially converted into (R/S)-neochrome by intragastric acidity before intestinal absorption and that (R/S)-neochrome exhibits an antiproliferative effect on PC-3 cells by the induction of cytostasis.
Determination of carotenoids in Taraxacum formosanum by HPLC-DAD-APCI-MS and preparation by column chromatography.
Author: Kao TH, Loh CH, Inbaraj BS, Chen BH.
Abstract: The objectives of this study were to determine the variety and content of carotenoids in Taraxacum formosanum, a traditional Chinese herb possessing vital biological activities, by developing an HPLC-DAD-APCI-MS method and a preparative column chromatographic method for carotenoid isolation. A total of 25 carotenoids were resolved within 66 min by employing a YMC C30 column and a gradient mobile phase of methanol-acetonitrile-water (79:14:7, v/v/v) and methylene chloride (100%) with flow rate at 1.0 mL/min and detection at 450 nm. All-trans-canthaxanthin was shown to be an appropriate internal standard for quantitation, with all-trans-β-carotene and its cis isomers present in largest amount (413.6 μg/g), followed by all-trans-violoxanthin and its cis isomers (209.5 μg/g), all-trans-lutein and its cis isomers (212.4 μg/g), all-trans-neoxanthin and its cis isomers (134.6 μg/g), antheraxanthin (16.5 μg/g), all-trans-β-cryptoxanthin and its cis isomers (5.8 μg/g), all-trans-zeaxanthin (3.6 μg/g) and neochrome (0.1 μg/g). For preparative chromatography, with a glass column containing 52 g of magnesium oxide-diatomaceous earth (1:3, w/w) as adsorbent, the carotenoid fraction was eluted with 300 mL of ethyl acetate with flow rate at 10 mL/min. Some more epoxides and cis isomers of carotenoids were generated during preparative column chromatography. Nevertheless, the carotenoids isolated from T. formosanum may be used as raw material for possible production of health food in the future.
Calcipotriene/betamethasone dipropionate foam: primary evidence supporting its use in patients with psoriasis vulgaris. A narrative review.
Author: Narbutt J, Czajkowski R, Lesiak A, Owczarek W, Reich A, Szepietowski JC.
Abstract: Psoriasis vulgaris is a chronic, immune-mediated disorder, which has a substantial impact on all aspects of patients' quality of life. In most patients, the disease is mild to moderate and is successfully treated with topical agents. The most common therapy involves a vitamin D<sub>3</sub> analogue (calcipotriene) in combination with a synthetic corticosteroid (betamethasone dipropionate). The aerosol vehicle (foam) with softening properties is another formulation of this combination drug, apart from ointment and gel, expanding the therapeutic options available to patients with psoriasis. The article describes the pharmacokinetic and pharmacodynamic properties of calcipotriene/betamethasone dipropionate foam. The results of the key randomised clinical studies investigating the efficacy, including patients' quality of life and safety of the foam versus ointment, gel and either active ingredient in foam vehicle are presented. In addition, the results of a study on maintenance treatment with calcipotriene/betamethasone dipropionate foam as well as reports on real-world use of this medicine in patients with psoriasis, are discussed.