Showing papers on "Xanthone published in 1970"
TL;DR: The compounds 2,6-dimethoxy-1,4-benzoquinone, 2,hydroxy-1-methoxyxanthone, 3-hydroxy -1,2-dimethylenedioxyxanthones, 4-hydoxy-2,3-methylenedioxioxanthone and 5-hydrox- 1,5-dihydroxy-3methoxanthone were isolated from Kielmeyera rupestris AP Duarte as discussed by the authors.
48 citations
37 citations
TL;DR: A new xanthone C-glucoside, C19H18O11·1/2H2O, decomposing over 260° without melting, [α]21D+5.5° (pyridine), was isolated in a pure state along with mangiferin (I) from the aerial parts of Anemarrhena asphodeloides BUNGE (Liliaceae) and named isomangiferin.
Abstract: A new xanthone C-glucoside, C19H18O11·1/2H2O, decomposing over 260° without melting, [α]21D+5.5° (pyridine), was isolated in a pure state along with mangiferin (I) from the aerial parts of Anemarrhena asphodeloides BUNGE (Liliaceae) and named isomangiferin. On the basis of chemical and spectral data, it has been assigned the structure 4-C-β-D-glucopyranosyl-1, 3, 6, 7-tetrahydroxyxanthone (XV), the first position isomer of I to be found and isolated. The relation between XV and I, in structures and properties, is corresponding to that between flavonoid 8-C- and 6-C-glucosides such as orientin and isoorientin.
31 citations
30 citations
TL;DR: The extractives of C. occidentalis L. have furnished emodin and physcion, known to occur in the species, two unidentified pigments, m.p. 214-216° and 243-245°, chrysophanol, α3-sitosterol, and a new xanthone, cassiollin, identified as 1,7-dihydroxy-5-methoxycarbonyl-3-methylxanthone as mentioned in this paper.
Abstract: Acid-hydrolysed extractives of C. occidentalis L. have furnished, in addition to emodin and physcion, known to occur in the species, two unidentified pigments, m.p. 214–216° and 243–245°, chrysophanol, α3-sitosterol, and a new xanthone, cassiollin, identified as 1,7-dihydroxy-5-methoxycarbonyl-3-methylxanthone.
15 citations
5 citations
TL;DR: In this article, 2,7-Dimethyl-4,5-bis (salicylideneaminomethyl)xanthone, a new quadridentate chelating agent, was synthesized by a sequence of steps and subsequently characterized.
Abstract: 2,7-Dimethyl-4,5-bis(salicylideneaminomethyl)xanthone, a new quadridentate chelating agent, was synthesized by a sequence of steps and subsequently characterized. Some divalent metal complexes of the ligand were isolated, and their properties were characterized on the basis of infrared spectra. The non-coplanar structure of the complex derived from the ligand was suggested by the resolution of a cobalt(II) complex into optical isomers.
3 citations
1 citations