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β-Cyclodextrin (CD) derivatives containing an aromatic triazole ring were studied as potential carriers of the following drugs containing an anthraquinone moiety: anthraquinone-2-sulfonic acid (AQ2S); anthraquinone-2-carboxylic acid (AQ2CA); and a common anthracycline, daunorubicin (DNR). UV-Vis and voltammetry measurements were carried out to determine the solubilities and association constants of the complexes formed, and the results revealed the unique properties of the chosen CDs as effective pH-dependent drug complexing agents. The association constants of the drug complexes with the CDs containing a triazole and lipoic acid (βCDLip) or galactosamine (βCDGAL), were significantly larger than that of the native βCD. The AQ2CA and AQ2S drugs were poorly soluble, and their solubilities increased as a result of complex formation with βCDLip and βCDGAL ligands. AQ2CA and AQ2S are negatively charged at pH 7.4. Therefore, they were less prone to form an inclusion complex with the hydrophobic CD cavity than at pH 3 (characteristic of gastric juices) when protonated. The βCDTriazole and βCDGAL ligands were found to form weaker inclusion complexes with the positively charged drug DNR at an acidic pH (pH 5.5) than in a neutral medium (pH 7.4) in which the drug dissociates to its neutral, uncharged form. This pH dependence is favorable for antitumor applications.

We developed the aerobic photooxidative bromination of aromatic compounds using carbon tetrabromide in the presence of anthraquinone-2-carboxylic acid under visible light irradiation.

A convenient metal-free oxidation protocol of various cyclic acetals with molecular oxygen and anthraquinone-2-carboxylic acid under visible light irradiation by a fluorescent lamp afforded their corresponding hydroxyalkyl esters.

We developed an efficient method for the generation of hydrogen peroxide by aerobic photooxidation of 2-propanol using anthraquinone-2-carboxylic acid and molecular oxygen in air and visible light from fluorescent lamps. One-pot epoxidation of α,β-unsaturated ketones using the generated hydrogen peroxide is also reported.

2-Aryl and 2-alkyl substituted 1,3-dioxolanes and dioxanes are successfully transformed to the correspondingly substituted hydroxyethyl or hydroxypropyl esters, respectively.

Hydrogen peroxide, generated in situ from 2-propanol in the presence of air and anthraquinone-2-carboxylic acid as the catalyst under irradiation with fluorescent lamp, is successfully employed for the epoxidation of α,β-unsaturated ketones.

1-Nitro-9,10-anthraquinone-2-carboxylic acid reacts with 2-aminoethanol to give 1-(2-hydroxy- ethylamino)-9,10-anthraquinone-2-carboxylic acid which undergoes intramolecular cyclization to 1,2,3,5,8,13- hexahydroanthra[1,2-e][1,4]oxazepine-5,8,13-trione on heating in acetic acid. Reactions of the cyclization product with amines result in cleavage of the seven-membered heteroring.

1-Nitro-9,10-anthraquinone-2-carboxylic acid reacts with 2-aminoethanol to give 1-(2-hydroxy- ethylamino)-9,10-anthraquinone-2-carboxylic acid which undergoes intramolecular cyclization to 1,2,3,5,8,13- hexahydroanthra[1,2-e][1,4]oxazepine-5,8,13-trione on heating in acetic acid. Reactions of the cyclization product with amines result in cleavage of the seven-membered heteroring.