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Koshi Saito - One of the best experts on this subject based on the ideXlab platform.
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Purification and some characteristics of preCarthamin, a precursor of Carthamin, isolated from the florets of Carthamus tinctorius L.
Acta Societatis Botanicorum Poloniae, 2014Co-Authors: Yoshiyuki Takahashi, Mizu Wada, Koshi SaitoAbstract:An unstable flame-coloured pigment, tentatively named preCarthamin, was isolated as orange-yellow microneedles with 0.12% yield from the yellow florets of Carthamus tinctorius L. through many purifying steps. The preCarthamin could be enzymically converted to a red pigment, which was identified as Carthamin by its chromatographic and spectral properties. The content of preCarthamin was examined at the various growth stages of the Carthamus flowers.
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the sensitivity of Carthamin and safflor yellow b colours towards redox substances
Acta Societatis Botanicorum Poloniae, 2014Co-Authors: Koshi Saito, Makiko Matsumura, Mihoko TakahashiAbstract:The sensitivities of Carthamin and safflor yellow B towards oxidants and antioxidants were compared in bufferized solutions at various given concentrations. The test chemicals affected variously on the pigment colourations: (1) externally charged 0 2 had less effect on the colour change of Carthamin, (2) organe-yellow coloured safflor yellow B was bleached by the gas flush, (3) Carthamin showed little or no affinitive property for H 2 0 2 at 0.001-230 µM level, (4) safflor yellow B reacted positively with the oxidant and was changed readily to faint yellow unknown compounds, (5) double-faced responses could be found in Carthamin solution with L-ascorbic acid or with D-isoascorbic acid, namely the former antioxidant intensified the colour of Carthamin and the latter reduced the red colouration, (6) hydroquinone emphasized the red colour of Carthamin in solution, (7) safflor yellow B shifted bathochromically in hydroquinone containing solution, however, it showed no shift in L-ascorbic acid and D-isoascorbic acid solutions. The data are discussed from the standpoint of oxidative dissimilation of the quinochalconoids in the floral tissues of dyer's saffron capitula.
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Apparent expression of flower colours and internal variation of enzyme activities in some typical phenotypes of dyer's saffron cultivars
Polish Botanical Society, 2014Co-Authors: Koshi Saito, Akiyoshi FukushimaAbstract:Phytochemical screening of four Carthamus pigments in phenotypically different cultivars of dyer's saffron was carried out by means of chromatographic techniques. The pigment composition in the floral part correlated well with the flower colour, supporting these components as idoneous chemotaxonomic markers. Among seven cultivars examined, three were orange-yellow and contained Carthamin (red) and preCarthamin, safflor yellow A and safflor yellow B (orange-yellow) (type 0). There were bright-yellow and also had the above four pigments (type Y). The seventh cultivar was ivory-white and produced no quinoidal chalcones in the florets (type W). Relative activities of three different enzymes were examined in soluble protein extracts from etiolated seedlings of the garden varieties. Monophenol monooxygenase (EC 1.14.18.1) and peroxidase (EC 1.11.1.7.) were distributed over all cultivars tested. The relative level of the enzyme activities could be ordered as follows: type 0, type W and type Y. The activity of a Carthamin-synthesizing enzyme was found in the protein extracts from all garden forms examined. Its activity was most prominent in type O. The activity level in type W was inferior to that of type O. The catalytic intensity in type Y was found to even lower. The results were discussed as to the composition of the phenotypic markers and the distribution of the enzyme activities in three different garden forms of dyer's saffron cultivars
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alginic acid and hyaluronic acid effective stabilizers of Carthamin red colour in aqueous solutions
Acta Societatis Botanicorum Poloniae, 2014Co-Authors: Koshi Saito, Keiichi MiyamatoAbstract:Sodium salts and free forms of two heterosaccharides, alginic and hyaluronic acids were mixed with Carthamin in a buffer at pH 5.5 and their preservation effects of Carthamin red colour were screened after incubation for 24 h at 3-5 o C in the dark. The effects observed were (alginic acid/hyaluronic acid, % on average): 69.3/60.3, for which the values are higher by 40.9 and 29.1%, respectively, compared with those of the control which was conducted with no addition of heterosaccharides. Alginic acid is a more promising stabilizer than haluronic acid, indicating that active groups such as hydroxyls, carboxyls and amino groups on the building units of the macromolecules are associated closely with the Carthamin red colour preservation. The empirical outcomes are referred to the practical application of Carthamin as a colourant of food products.
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Effect of external conditions on the stability of enzymically synthesized Carthamin
Acta Societatis Botanicorum Poloniae, 2014Co-Authors: Koshi Saito, Akiyoshi FukushimaAbstract:Enzymically synthesized Carthamin was subjected to testing of its stability under various conditions. It easily turned to unknown reddish-yellow or orange-yellow substances in water. This instability was further accelerated by the presence of a sulfhydryl reagent and or at higher temperature. In a typical result, the rate of the discolouration was calculated to be 21 nmol Carthamin h -1 at 20 °C in water and rose to 44.0 nmol Carthamin h -1 at 60 °C in water containing 1.0 mM 2-mercaptoethanol. Organic solvents such as methanol, ethanol and acetone showed little effect on Carthamin discolouration, while the stability of Carthamin in these solvents was gradually decreased by rising temperature. In various buffers, in the acidic range. Carthamin was relatively stable, whereas, it turned unstable on the basic side. All of the thiol reagents tested were unfavourable for retaining stability of Carthamin in solutions. 2-Mercaptoethanol, reduced glutathione and thioglycollic acid exhibited the strongest degrading effect on the pigment. At the 1.0 mM level, 2-mercaptoethanol reduced the absorption peak at 517 nm by 0.02 min -1 , which corresponded to 0.12 nmol Carthamin cm -3 min -1 L-Methionine, L-ascorbic and D-araboascorbic acids were found to be strong bathochromic effectors For example, L-methionine rised AA 517 nm up to 0.01 min -1 , whose value equaled to 0-1 nmol Carthamin cm -3 min -1 at 30 °C Carthamin was absorbed and adsorbed and stabilized by many macro-molecular Substances. Among the compounds tested, cellulose was found to be the most effective stabilizer. The stabilization effect of cellulose was specific for Carthamin and the term "SAITO EFFECT" is proposed for it. This effect was reduced by hydrolysis of the Carthamin-adsorbed cellulose with Asperqillus cellulase in an incubation system
Keisuke Suzuki - One of the best experts on this subject based on the ideXlab platform.
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synthetic study on Carthamin part 4 improved synthesis of a c glycosyl quinochalcone by installation of a side chain through regioselective de o methylation and acyl rearrangement
Synlett, 2021Co-Authors: Seiya Matsuoka, Ken Ohmori, Kohei Azami, Yusuke Fujiki, Reina Dohi, Tomokazu Yasuike, Keisuke SuzukiAbstract:We report an improved synthesis of a C-Glycosyl quinochalcone that is a key intermediate in our total synthesis of Carthamin, a natural red pigment of traditional heritage. The C-glycosyl quinochalcone is prepared by regioselective de-O-methylation of a C-glycosyl bromodienone, and installation of a p-coumaroyl side chain through an O→C acyl rearrangement.
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total synthesis of Carthamin a traditional natural red pigment
Angewandte Chemie, 2019Co-Authors: Kohei Azami, Taiki Hayashi, Ken Ohmori, Takenori Kusumi, Keisuke SuzukiAbstract:The first total synthesis of Carthamin (3), a historic natural red pigment, has been achieved. The molecular structure was efficiently constructed by assembling two equivalents of the in situ generated lithiated monomers and triisopropyl orthoformate. This synthesis confirms the structure proposed in 1996.
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synthetic study on Carthamin 2 stereoselective approach to c glycosyl quinochalcone via desymmetrization
Organic Letters, 2017Co-Authors: Taiki Hayashi, Ken Ohmori, Keisuke SuzukiAbstract:Toward the total synthesis of Carthamin, a stereoselective approach to the C-glycosyl quinochalcone intermediate is reported via the desymmetrization of a pseudo-Cs-symmetric C-glycosyl cyclohexadienone.
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Synthetic Study on Carthamin. 2. Stereoselective Approach to C‑Glycosyl Quinochalcone via Desymmetrization
2017Co-Authors: Taiki Hayashi, Ken Ohmori, Keisuke SuzukiAbstract:Toward the total synthesis of Carthamin, a stereoselective approach to the C-glycosyl quinochalcone intermediate is reported via the desymmetrization of a pseudo-Cs-symmetric C-glycosyl cyclohexadienone
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synthetic study on Carthamin problem and solution for oxidative dearomatization approach to quinol c glycoside
Synlett, 2016Co-Authors: Taiki Hayashi, Ken Ohmori, Keisuke SuzukiAbstract:Synthetic study on Carthamin, a natural red pigment, is described. Attempts at the construction of the key quinol C-glycoside structure by oxidative dearomatization of C-glycosyl phenols were hampered by the competing cleavage of the C1–C2 bond in the sugar moiety. By employing the 2-O-acetyl protection, the projected reaction proceeded smoothly, giving the desired products in good to excellent yields. An interesting photochemical stability/instability of the chalcone geometry in the synthetic compounds was observed.
Ken Ohmori - One of the best experts on this subject based on the ideXlab platform.
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synthetic study on Carthamin part 4 improved synthesis of a c glycosyl quinochalcone by installation of a side chain through regioselective de o methylation and acyl rearrangement
Synlett, 2021Co-Authors: Seiya Matsuoka, Ken Ohmori, Kohei Azami, Yusuke Fujiki, Reina Dohi, Tomokazu Yasuike, Keisuke SuzukiAbstract:We report an improved synthesis of a C-Glycosyl quinochalcone that is a key intermediate in our total synthesis of Carthamin, a natural red pigment of traditional heritage. The C-glycosyl quinochalcone is prepared by regioselective de-O-methylation of a C-glycosyl bromodienone, and installation of a p-coumaroyl side chain through an O→C acyl rearrangement.
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total synthesis of Carthamin a traditional natural red pigment
Angewandte Chemie, 2019Co-Authors: Kohei Azami, Taiki Hayashi, Ken Ohmori, Takenori Kusumi, Keisuke SuzukiAbstract:The first total synthesis of Carthamin (3), a historic natural red pigment, has been achieved. The molecular structure was efficiently constructed by assembling two equivalents of the in situ generated lithiated monomers and triisopropyl orthoformate. This synthesis confirms the structure proposed in 1996.
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synthetic study on Carthamin 2 stereoselective approach to c glycosyl quinochalcone via desymmetrization
Organic Letters, 2017Co-Authors: Taiki Hayashi, Ken Ohmori, Keisuke SuzukiAbstract:Toward the total synthesis of Carthamin, a stereoselective approach to the C-glycosyl quinochalcone intermediate is reported via the desymmetrization of a pseudo-Cs-symmetric C-glycosyl cyclohexadienone.
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Synthetic Study on Carthamin. 2. Stereoselective Approach to C‑Glycosyl Quinochalcone via Desymmetrization
2017Co-Authors: Taiki Hayashi, Ken Ohmori, Keisuke SuzukiAbstract:Toward the total synthesis of Carthamin, a stereoselective approach to the C-glycosyl quinochalcone intermediate is reported via the desymmetrization of a pseudo-Cs-symmetric C-glycosyl cyclohexadienone
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synthetic study on Carthamin problem and solution for oxidative dearomatization approach to quinol c glycoside
Synlett, 2016Co-Authors: Taiki Hayashi, Ken Ohmori, Keisuke SuzukiAbstract:Synthetic study on Carthamin, a natural red pigment, is described. Attempts at the construction of the key quinol C-glycoside structure by oxidative dearomatization of C-glycosyl phenols were hampered by the competing cleavage of the C1–C2 bond in the sugar moiety. By employing the 2-O-acetyl protection, the projected reaction proceeded smoothly, giving the desired products in good to excellent yields. An interesting photochemical stability/instability of the chalcone geometry in the synthetic compounds was observed.
Taiki Hayashi - One of the best experts on this subject based on the ideXlab platform.
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total synthesis of Carthamin a traditional natural red pigment
Angewandte Chemie, 2019Co-Authors: Kohei Azami, Taiki Hayashi, Ken Ohmori, Takenori Kusumi, Keisuke SuzukiAbstract:The first total synthesis of Carthamin (3), a historic natural red pigment, has been achieved. The molecular structure was efficiently constructed by assembling two equivalents of the in situ generated lithiated monomers and triisopropyl orthoformate. This synthesis confirms the structure proposed in 1996.
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synthetic study on Carthamin 2 stereoselective approach to c glycosyl quinochalcone via desymmetrization
Organic Letters, 2017Co-Authors: Taiki Hayashi, Ken Ohmori, Keisuke SuzukiAbstract:Toward the total synthesis of Carthamin, a stereoselective approach to the C-glycosyl quinochalcone intermediate is reported via the desymmetrization of a pseudo-Cs-symmetric C-glycosyl cyclohexadienone.
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Synthetic Study on Carthamin. 2. Stereoselective Approach to C‑Glycosyl Quinochalcone via Desymmetrization
2017Co-Authors: Taiki Hayashi, Ken Ohmori, Keisuke SuzukiAbstract:Toward the total synthesis of Carthamin, a stereoselective approach to the C-glycosyl quinochalcone intermediate is reported via the desymmetrization of a pseudo-Cs-symmetric C-glycosyl cyclohexadienone
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synthetic study on Carthamin problem and solution for oxidative dearomatization approach to quinol c glycoside
Synlett, 2016Co-Authors: Taiki Hayashi, Ken Ohmori, Keisuke SuzukiAbstract:Synthetic study on Carthamin, a natural red pigment, is described. Attempts at the construction of the key quinol C-glycoside structure by oxidative dearomatization of C-glycosyl phenols were hampered by the competing cleavage of the C1–C2 bond in the sugar moiety. By employing the 2-O-acetyl protection, the projected reaction proceeded smoothly, giving the desired products in good to excellent yields. An interesting photochemical stability/instability of the chalcone geometry in the synthetic compounds was observed.
Zhiyong Liu - One of the best experts on this subject based on the ideXlab platform.
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the mechanism of Carthamin yellow injection promote acute myocardial infarction infarct border zone angiogenesis
International Conference on Biomedical and Biological Engineering, 2016Co-Authors: Xiaomin Wang, Zhiyu Zhou, Yaokun Xiong, Jiangtao Wei, Yanting Wan, Zhiyong LiuAbstract:We observed the impact of Carthamin yellow injection on revascularization in rats with acute myocardial infarction and discuss its mechanism. The left anterior descending branches of the coronary arteries of Wistar rats were ligatured, and the animal model with acute myocardial infarction was duplicated. The animals with successful modeling were randomly divided into the model group and treatment group. The rats in the treatment group were injected with Carthamin yellow (2.5 mg/Kgd) for 3, 7 and 14 days. Their weights were measured 24 h after the last drug administration, and their hearts were removed for weighing and blood collection. The Cardiac indices were then measured, and electrocardiograms (ECGs) were recorded. Masson staining was used to determine the microvessel count of the infarct border zone of the myocardium. Immunohistochemistry was used to detect the expression of vascular endothelial growth factor (VEGF). Compared with the model group, the cardiac indices of the rats treated with Carthamin yellow for 7 and 14 days were decreased (P < 0.05). The ECGs of these treated rats returned to normal. In the drug administration groups, the number of capillaries at the marginal zone of the myocardial infarction clearly increased (P < 0.05). The immunohistochemical results showed that the expressions of VEGF at the marginal zone of acute myocardial infarction increased (P < 0.05). The injection of Carthamin yellow has therapeutical effects on rats with acute myocardial infarction. It can promote the revascularization of the myocardium at the marginal zone of myocardial infarction. This effect could be related to the increase in VEGF expression at the marginal zone of acute myocardial infarction.