78950-23-9Relevant articles and documents
Quinofuracins A-E, produced by the fungus staphylotrichum boninense PF1444, show p53-dependent growth suppression
Tatsuda, Daisuke,Momose, Isao,Someno, Tetsuya,Sawa, Ryuichi,Kubota, Yumiko,Iijima, Masatomi,Kunisada, Takao,Watanabe, Takumi,Shibasaki, Masakatsu,Nomoto, Akio
supporting information, p. 188 - 195 (2015/03/18)
Quinofuracins A-E, novel anthraquinone derivatives containing β-d-galactofuranose that were isolated from the fungus Staphylotrichum boninense PF1444, induced p53-dependent cell death in human tumor cells. The structures of quinofuracins A-E, including absolute configurations, were elucidated by extensive spectroscopic analysis and chemical transformation studies. Quinofuracins were classified into three groups according to the aglycone moieties. 5'-Oxoaverantin was present in quinofuracins A-C, whereas averantin and versicolorin B were identified in quinofuracins D and E, respectively. These quinofuracins induced p53-dependent growth suppression in human glioblastoma LNZTA3 cells.
Alkyl galactopyranosides: Rotational population dependence of the hydroxymethyl group on the aglycon and its absolute configuration and on the anomeric configuration
Padron, Juan I.,Morales, Ezequiel Q.,Vazquez, Jesus T.
, p. 8247 - 8258 (2007/10/03)
The rotational populations of the hydroxymethyl group in chiral and nonchiral alkyl α- and β-galactopyranosides proved, on the basis of circular dichroism (CD) and 1H NMR data, to be dependent on the structure of the aglycon: the population of the gt and tg rotamers increased and decreased, respectively, as the pK(a) of the bonded alcohol (aglycon) increased, while the population of the gg rotamer remained practically constant. Furthermore, low-temperature CD measurements proved that the most stable rotamer is the gt, and not the tg. In addition, a clear correlation between the rotational populations and the absolute configuration of the chiral aglycon was observed; namely, higher and smaller gt and tg populations were observed for the (S)-alkyl β-D-galactopyranosides than for their (R)- alkyl β-D-galactopyranoside counterparts, the opposite behavior being observed for the α-anomers. The results point to the exo anomeric effect as being responsible for these rotational dependencies, as well as to nonbonding interactions between the aglycon and the chromophore at C6 for those stereoisomers having in their aglycon a bulky substituent syn to the endocyclic oxygen (O5). In addition, the chemical shift differences (Δδ) of the aglyconic protons of galactosylated chiral alcohols proved to be characteristic of the absolute configuration of the bonded chiral alcohol.
