a spectrophotometric method is used to determine the acidity constants of some derivatives of 9,10-anthraquinone in binary methanol-water mixtures at 25 °c. there is a linear inverse relationship between pka of all acids and the mole fraction of methanol in the mixed solvent. the influence of substituents in the molecular structure on the ionization constants is discussed.

Five new 1-hydroxy-2-(1-alkyloxymethyl)-9,10-Anthraquinones (9a-e) have been prepared. Selective nitration of 2-methyl-9,10-anthraquinone, reduction to the corresponding amine, diazotization and treatment by sulfuric acid solution afforded the 1-hydroxy-2-methyl-9,10-anthraquinone in good yield as the key intermediate. Reaction with dimethylsulphate/K2CO3 and subsequen...

The mutagenicity of anthracene, anthraquinone, and four structurally similar compounds of each was evaluated in the Ames/Salmonella microsome assay. Anthraquinone was shown to be mutagenic for strains TA1537, TA1538, and TA98 in the absence of rat liver homogenate. The four anthraquinone derivatives tested were mutagenic for TA1537 exclusively. None of the anthracenes exhibited mutagenic activity.

five new 1-hydroxy-2-(1-alkyloxymethyl)-9,10-anthraquinones (9a-e) have been prepared. selective nitration of 2-methyl-9,10-anthraquinone, reduction to the corresponding amine, diazotization and treatment by sulfuric acid solution afforded the 1-hydroxy-2-methyl-9,10-anthraquinone in good yield as the key intermediate. reaction with dimethylsulphate/k2co3 and subsequent monobromination with nbs...

Rheum species are medicinally important herbs, posses several type of biological activities due to the presence of anthraquinone derivatives. Several HPLC methods have been used for sepeatation of anthraquinone of Rheum Species. In most cases anthraquinones were separated using C18 column as a stationary phase, acetonitrile, water and methanol with or without acid as mobile phase at 1.0 ml/min ...

Two anthraquinone derivatives, named anthrasesamones D and E, were isolated from the roots of Sesamum indicum. Their respective structures were determined to be 1,2,4-trihydroxy-3-(4-methylpent-3-enyl)anthraquinone and 1,2-dihydroxy-3-(4-methylpent-3-enyl)anthraquinone on the basis of spectroscopic evidence.

Three new anthraquinone derivatives (1-3) and one new artifact (4) were isolated, along with six known anthraquinone derivatives (5-10) and three xanthones (11-13), from a culture of an endolichenic fungus, Aspergillus versicolor, that was isolated from the lichen Lobaria retigera. The structures of these substances were determined on the basis of 1D and 2D (COSY, HMQC, and HMBC) NMR and MS ana...