Glycosides from Muscaricomosum. 4. Structure of muscaroside A

Abstract

The less polar component of the glycoside mixture extracted from the bulbs of Muscaricomosum has been completely characterized. This glycoside, 5, possesses an α-L-rhamnopyranosyl(1→2)-β-D-glucopyranosyl(1→2)-α-L-arabinopyranosyl(1→6)-β-D-glucopyranosyl chain linked at the C-3 position of eucosterol 1.

Glycosides from Muscaricomosum. 6. Use of homo- and heteronuclear two-dimensional nuclear magnetic resonance spectroscopy for the structure determination of the novel glycoside muscaroside C

“…In connection with our studies (1)(2)(3)(4)(5) on the glycoside fraction of Muscari comosum we recently reported the isolation and structure determination of muscarosides A (4) and B (5). In this paper we describe the structure elucidation of a minor glycoside, muscaroside C, 1, which possesses a P-D-apio-Dfuranosyl( 142)-P-D-glucopyranosyl-(1-2)-a-L-arabinopyranosyl(l+6)-P-D-glucopyranosyl chain linked at the 3-position of (23S)-17,23-epoxy-3~,30,31-trihydroxy-27-nor5a-lanost-8-ene 2 (2).…”

“…No direct evidence for the a-configuration of the L-arabinopyranosyl unit was found, owing to its high conformational mobility (4,5,17). However, an a-configuration was inferred from the striking similarity between the I " data of the L-arabinopyranosyl unit of 1 and those found for the a-L-arabinopyranosyl residues identically located in muscarosides A and B (4, 5).…”

Glycosides from Muscaricomosum. 5. Structure of muscaroside B

“…This safely established that one branch of the chain consisted of two, and only two, arabinopyranose units. (27); B, methyl a-L-arabinopyranoside (27); C, methyl a-L-rhamnopyranoside (27); D, methyl a-L-arabinofuranoside (13); E, eucosterol (4).…”

Mineral Content, Chemical Analysis, In Vitro Antidiabetic and Antioxidant Activities, and Antibacterial Power of Aqueous and Organic Extracts of Moroccan Leopoldia comosa (L.) Parl. Bulbs

“…Indeed, Parrilli et al [35] reported that the bulb of L. comosa is an important source of triterpene and glycoside, of which eucosterol 4a, a terpene of the nor-27 lanostane family, is the major compound. e same team was able to characterize the structure of glycosides from L. comosa [36]. In 1984, Adinolfi et al were able to determine the structure of new triterpenes from L. comosa bulbs harvested in Italy [37,38].…”