Silver (Ι)-assisted enantiomeric analysis of ginsenosides using electrospray ionization tandem mass spectrometry was written by Yu, Qing;Yu, Binbin;Yang, Hongmei;Li, Xue;Liu, Shuying. And the article was included in Journal of Mass Spectrometry in 2012.Category: tetrahydropyran This article mentions the following:
For identification of ginsenoside enantiomers, electrospray ionization mass spectrometry (ESI-MS) was used to generate silver complexes of the type [ginsenoside + Ag]+. Collision induced dissociation of the silver-ginsenoside complexes produced fragment ions by dehydration, allowing differentiation of ginsenoside enantiomers by the intensity of [M + Ag – H2O]+ ion. In the meanwhile, an approach based on the distinct profiles of enantiomer-selective fragment ion intensity varied with collision energy was introduced to refine the identification and quantitation of ginsenoside enantiomers. Five pairs of enantiomeric ginsenosides were distinguished and quantified on the basis of the distribution of fragment ion [M + Ag – H2O]+. This method was also extended to the identification of other type of ginsenoside isomers such as ginsenoside Rb2 and Rb3. For demonstrating the practicability of this novel approach, it was utilized to analyze the molar ratio of 20-(S) and 20-(R) type enantiomeric ginsenosides in enantiomer mixture in red ginseng extract The generation of characteristic fragment ion [M + Ag – H2O]+ likely results from the reduction of potential energy barrier of dehydration because of the catalysis of silver ion. The mechanism of enantiomer identification of ginsenosides was discussed from the aspects of computational modeling and internal energy. Copyright © 2012 John Wiley & Sons, Ltd. In the experiment, the researchers used many compounds, for example, 20(R)-Ginsenoside Rh2 (cas: 112246-15-8Category: tetrahydropyran).
20(R)-Ginsenoside Rh2 (cas: 112246-15-8) belongs to tetrahydropyran derivatives. Numerous natural products have tetrahydropyran skeleton as the building block for designing new natural products and their derivatives e.g. aplysiatoxins, avermectins, oscillatoxins, talaromycins, latrunculins and acutiphycins. There is large number of marine macrolide natural products that contain tetrahydropyran and tetrahydrofuran ring together. For instance, goniodomin A (actin targeting polyether), prorocentrolide (toxin halistatins), and percentotoxineCategory: tetrahydropyran
Referemce:
Tetrahydropyran – Wikipedia,
Tetrahydropyran – an overview | ScienceDirect Topics