Structural characterization, by two-dimensional NMR spectroscopy and fast-atom-bombardment mass spectrometry, of a highly acylated trirhamnoside from Mezzettialeptopoda (Annonaceae)

Abstract

Can. J. Chem. 68, 1044 (1990). The structure of Mezzettiaside 3, a highly acylated trisaccharide obtained from the stem bark of Mezzettia leptopoda, was determined by a combination of double-quantum-filtered {'H,'H) correlation spectroscopy, two-dimensional homonuclear Hartmann-Hahn, and 'H-detected {'H,'~c) one-bond and multiple-bond shift correlation nuclear magnetic resonance experiments, in conjunction with fast-atom-bombardment mass spectrometry. Mezzettiaside 3 was found to be the a- 1044 (1990).La structure du Mezzettiaside 3, un trisaccharide trks acylC, obtenu a partir de 1'Ccorce du tronc de Mezzettia leptopoda, a Ct C elucidCe en faisant appel a la spectromCtrie de masse par bombardement avec des atomes rapides (SM-FAB) en combinaison avec les methodes de rCsonance magnitique nuclCaire (RMN) suivantes : spectroscopie de corrClation {'H,'H) doublement filtrC d'un point de vue quantique, spectroscopie Hartmann-Hahn homonuclCaire bidimensionelle et spectroscopie de corrClation des dCplacements {'H,'~c) par liaisons simples et multiples avec dCtection de 'H. On a trouvt? que la Mezzettiaside 3 est l'a-(n-octy1)glycoside du 3,4-di-O-ac~tyl-~-rhamnopyranosyl-a(1+3)-2,4-di-0-ac~tyl-~-rhamnopyranosyl-a(1~3)-4-0-hexanoyl-L-rhamnopyranose. La technique de corrClation hCtCronucltaire des liaisons multiples par RMN s'est avCrCe trks utile pour determiner la position des groupements 0-acylCs de ce carbohydrate complexe.

Nuclear Magnetic Resonance Spectroscopic Approaches for the Determination of Interglycosidic Linkage and Sequence in Oligosaccharides

“…, 1991Lu e t a / . , , 1992aOdake et al, 1992;Saito et al, 1994;Toki et al, 1994a, b;Trehara et al, 1989Trehara et al, , 1990a, flavonol glycosides (Bashir et al, 1991;Pearce et al, 1992;Satake et al, 1993), pregnane glycosides (Schneider et al, 1993), diterpenoid glycosides (Duc et al, 1994), triterpenoid saponins (Qulad-Ali et ul., 1994; Warashina et ul., 1991, Yamamoto et al, 199 1, 1993a and oligosaccharide multiesters (Miyase et al, , 1992Powell 1990;Saitoh et ul., 1993aSaitoh et ul., , b, 1994.…”

“…Discrimination between intra-and inter-sacchride correlation (Abeygunawardana et al, 1990;Reddy et al, 1993) is made by reference to the established 'H resonance assignments and by an iterative comparison of the one-and multiple-bond ]H-"C correlation maps which provide information in a sequential manner for the establishment of the IGL as well as monosaccharide sequence. This procedure has been widely employed by various workers (Ahmad et al, 1993;Ayer and Miao, 1993;Bader et ai., 1994a,b;Callis et al, 1994;Cui et al, 1990;Dirsch et al, 1994;Finger et al, 1991;Himmelsbach et al, 1994;Ikeshino et al, 1994;Jia et al, 1994;Jiang et al, 1991a,b;Kadota et al, 1990;Kakuno et al, 1992;Kanmoto et al, 1994;Katsuzaki et al, 1994;Kondo et al, 1992;Lacaille-Dubois et al, 1993;Lavaud et al, 1992;Lin et al, 1994;Lou et al, 1993;Massiot et al, 1991aMassiot et al, ,b, 1992aMimaki et al, 1992Mimaki et al, , 1993aMiyase et al, 1991Nakamura et al, 1994a,b;Noda et al, 1992a,b;Pal et al, 1994;Pant et al, 1994;Powell et al, 1990;Ridout et al, 1994;Ripperger and Porzel, 1994;Saito et al, 1990;Saitoh et al, 1993aSaitoh et al, ,b, 1994Schneider et al, 1993;…”

1H and13C NMR study of copteroside E derivatives

“…6 The calculated H-C-C-H dihedral angles of this model allowed us to obtain a set of calculated 1 H-1 H vicinal coupling constants for the glucuronolactone unit by means of a generalized Karplus-type relationship. 7,8 The couplings were in close correspondence with those observed in the experimental spectrum, as can be seen in Table 3.…”

Denovo asymmetric synthesis of the mezzettiaside family of natural products via the iterative use of a dual B-/Pd-catalyzed glycosylation

“…1 These anticancer natural products were shown to consist of α-1,3-linked L- rhamno -di-, tri- and tetra-saccharides with differing patterns of acetylation (Fig. 1).…”