- Thermal glycosylations: Reactions of β-cellobiosyl fluoride heptaacetate with tigogenin and its trimethylsilyl ether
-
Thermal reaction of β-cellobiosyl fluoride heptaacetate with ticogenin in toluene or o-xylene at 112-142°C gave ticogenyl β-cellobioside heptaacetate in 69-75% yields with good stereoselectivity. The procedure avoids the use of Lewis acid or traditional glycosidation promoters. The deacetylated product is a hypocholesterolemic and anti-atherosclerosis agent.
- Goggin, Kathleen D.,Lambert, Jack F.,Walinsky, Stanley W.
-
-
Read Online
- Jatropham derivatives and steroidal saponins from the bulbs of Lilium hansonii.
-
Two new jatropham derivatives and three new steroidal saponins were isolated from the fresh bulbs of Lilium hansonii, along with previously known compounds. The structures of the new compounds were elucidated, on the basis of spectroscopic data and chemical evidence, and by comparing them with those of known compounds, as (-)-5-hydroxy-3-methyl-3-pyrrolin-2-one (jatropham) 5-O-beta-D-glucopyranosyl-(1----3)-beta-D-glucopyranoside, (2S*,4R*)-1-(3-methyl-2-oxo-3-pyrrolinyl)-4-methyl-5-oxo-2-pyrr olidinecarboxyli c acid, 26-O-beta-D-glucopyranosyl-(25R)-5 alpha-furostan-3 beta,22 zeta-diol 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-[beta-D-glucopyranosyl-(1----4)]- beta-D-glucopyranoside, (25R)-5 alpha-spirostan-3 beta,12 alpha-diol 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-[beta-D-glucopyranosyl-(1----4)]- beta-D-glucopyranoside and (25R)-spirost-5-en-3 beta,12 alpha-diol 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-[beta-D-glucopyranosyl-(1----4)]- beta-D-glucopyranoside, respectively. The stereostructure of jatropham dimer, the plain structure of which was presented previously, was confirmed by X-ray crystallographic analysis. The inhibitory activity on cyclic AMP phosphodiesterase of the steroidal saponins was evaluated.
- Ori,Mimaki,Mito,Sashida,Nikaido,Ohmoto,Masuko
-
-
Read Online
- Antifungal activity of 2α,3β-functionalized steroids stereoselectively increases with the addition of oligosaccharides
-
Invasive fungal infections pose a significant problem to the immune-compromised. Moreover, increased resistance to common antifungals requires development of novel compounds that can be used to treat invasive fungal infections. Naturally occurring steroid
- Cammarata, Amy,Upadhyay, Sunil Kumar,Jursic, Branko S.,Neumann, Donna M.
-
supporting information; experimental part
p. 7379 - 7386
(2012/02/13)
-