[article]
Titre : |
Color forming property of derivatives and modification products of natural iridoids with methylamine |
Type de document : |
texte imprimé |
Auteurs : |
Xue Shao, Auteur ; Keyi Ding, Auteur ; Jun Liu, Auteur |
Année de publication : |
2015 |
Article en page(s) : |
p. 1-6 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Catégories : |
Couleur Iridoïdes Méthylamine Pigments -- Analyse Pigments -- Synthèse
|
Index. décimale : |
667.2 Colorants et pigments |
Résumé : |
Derivatives and modified products of five natural iridoids (geniposide, gentiopicroside, swertiamarin, loganin and morroniside) were obtained by derivatization or modification. Compounds before and after derivatization or modification were adopted to react with methylamine to investigate their color-forming property. The relationship between the color of the pigments and the structure was analyzed using ultraviolet-visible (UV-vis) spectroscopy. The results indicated that: (1) when the backbone of the iridoids was the same, the position of the modified substituent groups had the greatest effect on the color of the pigments formed. For example, methygentiopicroside aglycone and methylswertimarin aglycone have a similar skeleton structure, differing only at positions C-5 and C-6, and the pigments obtained from their reaction with methylamine were also similar i.e. bright yellow. However, geniposidic acid aglycone and genipin, which also have a similar skeleton structure, differing only in the substituent at position C-4, produce pigments of different color upon reaction with methylamine, one being dark blue and the other purple red. (2) In different buffer systems, i.e., phosphate buffered saline (PBS, pH=8.0) and acetate buffer (ACE, pH=5.0), the same iridoid formed pigments with different colors. (3) After the ?-? conjugation of benzoyl was introduced to the skeleton of loganin, genipin and morronin as a substituent group, the characteristic absorption wavelength of pigments changed. Taking loganin as an example, the characteristic absorption wavelength of pigments changed from 430 nm and 650, to 465 nm and 670 nm when reacted in PBS, and from 560 nm to 610 nm when reacted in ACE. The reason might be that the conjugation system became longer and the molecular structure became more stable. |
Note de contenu : |
- EXPERIMENTAL : Materials - Preparation of derivative of geniposide and its reaction with methylamine principal
- METHODS : Preparation of geniposidic acid - Hydrolysis of geniposidic acid - The reaction of geniposidic acid aglycon with methylamine - Preparation of derivatives of gentiopicroside and swertiamarin and their reaction with methylamine principal - Method - Structural modification for natural iridoids the process for preparing benzoyl chloride - The reaction of natural iridoids with benzoyl chloride (taking geniposide as an example - Hydrolysis of iridoid glucosides - Color forming reaction of six iridoid aglycones with methylamine
- RESULTS AND DISCUSSION : The color forming reaction of geniposidic acid aglycon with methylamine - The color-forming reaction of methygentiopicroside aglycone and methylswertimarin aglycone with methylamine - Comparing experiment for the color forming of three aglycones and their modification products color-forming result of loganin aglycon and its modification product (compound II) - Color-forming results of genipin, morroniside aglycone and their modification products (compounds I and III) |
En ligne : |
https://drive.google.com/file/d/1gUrJfpY8rqZKElx_riZHmxBdop7aRonT/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=22790 |
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CX, N° 1 (01/2015) . - p. 1-6
[article]
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