Mass spectra of spirostanol and furostanol glycosides

Abstract

The electron impact mass spectra of twenty acetates and methylates of spirostanol and related furostanol glycosides of high molecular weight (above 650) have been investigated, and the most probable fragmentation patterns of the glycoside derivatives are presented. High resolution mass spectrometry provides useful information concerning the structures of both aglycone and sugar moieties as well as the molecular size of the oligoglycosides.

Acylated Flavone Glycosides from the Roots of Saussurea lappa and Their Antifungal Activity

“…Moreover, the coupling constant (15.6 Hz) of the two doublets at δ H 5.59 and 7.30 (each 1H) indicated the trans configuration of the caffeoyl moiety (fission) in the 13 C-NMR spectrum of compound 3 the downfield shift of C-2a′′ δ C 82.2 together with the upfield shift of C-1a′′ δ C 101.5 (Table 3) proved the attachment of the terminal glucosyl unit to this position [29]. Furthermore, the signal at δ C 64.6 was assigned to the C-6a′ or C-6a′′ in these two glucosyl units to which the caffeoyl moiety is attached [30] this can be determine the attachment site of the caffeoyl moiety little amount of the KSR3 was acetylated and subjected to EI-MS spectral analysis according to the procedure established in reference [31] which revealed a characteristic peak at m/z 331 (18%) corresponding to tetraacetylated glucose as a cationic fragment with a molecular formula [C 14 H 19 O 9 ] + as shown in Figure 4. This significant peak proved the presence of an unsubstituted terminal glucosyl unit [31].…”

“…Furthermore, the signal at δ C 64.6 was assigned to the C-6a′ or C-6a′′ in these two glucosyl units to which the caffeoyl moiety is attached [30] this can be determine the attachment site of the caffeoyl moiety little amount of the KSR3 was acetylated and subjected to EI-MS spectral analysis according to the procedure established in reference [31] which revealed a characteristic peak at m/z 331 (18%) corresponding to tetraacetylated glucose as a cationic fragment with a molecular formula [C 14 H 19 O 9 ] + as shown in Figure 4. This significant peak proved the presence of an unsubstituted terminal glucosyl unit [31]. Consequently, the attachment site of the caffeoyl moiety must be at C-6a′ of the glucopyranosyl.…”

Acylated flavonoid glycosides from Bassia muricata

“…1. This significant peak proved the presence of an unsubstituted terminal glucosyl unit (Komori et al, 1975). Consequently, the attachment site of the caffeoyl moiety must be at C-6 of the internal bglucosyl unit (C-6) and the structure of compound 1 was assigned as shown.…”

“…Furthermore, the signal at 64.6 was assigned to the C-6 of one of the two glucosyl units to which the caffeoyl moiety is attached (Miyase et al, 1992). To determine the attachment site of the caffeoyl moiety, compound 1 was acetylated and subjected to EI-MS spectral analysis according to the procedure established by Komori et al (1975) which revealed a characteristic peak at m/z 331 (18%) corresponding to tetraacetylated glucose as a cationic fragment with a molecular formula (C 14 H 19 O 9 ) + as shown in Fig. 1.…”

Analysis of Spirostans, Spirosolanes, and Solanidanes

“…The fast-atom bombardment mass spectra of glycoalkaloids (Price et ah, 1985) and the electron-impact spectra of permethylated and peracetylated saponins (Komori et al, 1975) are helpful in compound characterization because molecular ions (ions corresponding to the molecular weight of the compound) and fragment ions related to cleavage at the glycosidic bonds are observed. -i +…”