78950-23-9Relevant academic research and scientific papers
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
, 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.
Ectyoplasides A-b - Unique triterpene oligoglycosides from the Caribbean sponge Ectyoplasia ferox
Cafieri, Francesco,Fattorusso, Ernesto,Taglialatela-Scafati, Orazio
, p. 231 - 238 (2007/10/03)
Two novel norlanostane triglycosides, ectyoplasides A (1) and B (2), have been isolated from the methanolic extracts of the Caribbean sponge Ectyoplasia ferox (Raspaliidae, Axinellida). Their structures have been established by extensive application of high-resolution FABMS and two- dimensional NMR techniques, supported by chemical and enzymatic degradation methods. Ectyoplasides A and B have been shown to possess identical sugar chains (composed of two β-galactose units and one α-arabinose unit), but to differ in their aglycone moieties, which possess nortriterpene skeletons with an unprecedented substitution pattern on ring A. Ectyoplasides A and B show moderate cytotoxic activity when tested in vitro towards various cell lines.
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.
CHARACTERIZATION OF METHYL GLYCOSIDES AT THE PICO- TO NANO-GRAM LEVEL
Golik, Jerzy,Liu, Hung-Wen,Dinovi, Michael,Furukawa, Jun,Nakanishi, Koji
, p. 135 - 146 (2007/10/02)
We describe a general method that permits characterization of 100-pg to 1-ng quantities of sugars.Thus, oligosaccharides are subjected to methanolysis, followed by per-p-bromobenzoylation or pernaphthoylation, and the methyl glycoside peresters are separated by high-pressure liquid chromatography.The method is also applicable to amino and acetamido sugars.If required, the separated sugar derivatives may be unequivocally identified by the characteristic quasi-M+ peaks of bromobenzoates and extrema of excitation-split circular-dichroism (c.d.) curves.Furthermore, as the c.d. extrema of polybenzoates are predictable from extrema of component dibenzoate units, the c.d. data yield information on the unknown spatial disposition of -OH, -NH2, and -NHAc groups of glycopyranoses.Application of the method is demonstrated with viridopentaose C, a pentasaccharide obtained from the antibiotic sporaviridin.
