Structural elucidation of a novel transglycosylated compound α-glucosyl rhoifolin and of α-glucosyl rutin by NMR spectroscopy. (18th April 2017)

• Record Type: Journal Article
• Authors: Aoki, Chisa; Takeuchi, Yoshihiro; Higashi, Kenjirou; Okamoto, Yuta; Nakanishi, Akihito; Tandia, Mahamadou; Uzawa, Jun; Ueda, Keisuke; Moribe, Kunikazu
• Is Part Of: Carbohydrate research. Volume 443/444(2017)
• Page Start: 37
• Page End: 41
• Publication Date: 2017-04-18
• Subjects: Transglycosylated compound -- Rhoifolin -- Rutin -- NMR -- Signal assignment -- Intramolecular interaction; Carbohydrates -- Periodicals; Chemistry, Organic -- Periodicals; Biochemistry -- Periodicals; Carbohydrates -- Periodicals; Chimie organique -- Périodiques; Glucides -- Périodiques; Biochemistry; Carbohydrates; Chemistry, Organic; Periodicals; Electronic journals; 507.78
• DOI: 10.1016/j.carres.2017.03.011
• Languages: English
• ISSNs: 0008-6215

Abstract

Abstract: We report the full assignment of 1 H and 13 C NMR signals belonging to α-glucosyl rhoifolin (Rhf-G), a novel transglycosylated compound synthesized from a flavone glycoside, rhoifolin, as well as its chemical structure. Furthermore, we report the complete NMR signal assignment for another transglycosylated compound, α-glucosyl rutin (Rutin-G), as the signals corresponding to its sugar moieties had not been identified. Electrospray ionization-mass spectrometry along with multiple NMR methods revealed that Rhf-G possesses three sugar moieties in its chemical structure. The additional glucose was bound directly via a transglycosylation to rhoifolin at position 3a of the sugar moiety. Interestingly, intramolecular hydrogen bonds in the basic Rhf-G and Rutin-G skeletons were confirmed by HMBC experiments. These findings will be helpful for comprehensive NMR studies on transglycosylated compounds in food, cosmetic, and pharmaceutical fields. Graphical abstract: Highlights: The structure of a novel transglycosylated compound, Rhf-G, was identified. 1 H and 13 C NMR peaks including sugar moieties of Rhf-G and Rutin-G were assigned. HMBC correlations showed intramolecular hydrogen bonds in the flavonoid skeletons.