Synthesis and antitumor activity of cyclopentane-fused anthraquinone derivatives.

In our pursuit of developing novel analogs of anthracyclines with enhanced antitumor efficacy and safety, we have designed a synthesis scheme for 4,11-dihydroxy-5,10-dioxocyclopenta[b]anthracene-2-carboxamides. These newly synthesized compounds exhibit remarkable antiproliferative potency against various mammalian tumor cell lines, including those expressing activated mechanisms of multidrug resistance. The structure of the diamine moiety in the carboxamide side chain emerges as a critical determinant for anticancer activity and interaction with key targets such as DNA, topoisomerase 1, and ROS induction.

Novel multi-targeting anthra[2,3-b]thiophene-5,10-diones with guanidine-containing side chains: interaction with telomeric G-quadruplex, inhibition of telomerase and topoisomerase I and cytotoxic properties.

Novel generations of antitumor anthraquinones are expected to be advantageous over the conventional chemotherapeutic agents. Previous structure-activity relationship studies demonstrated an importance of the positively charged side chains conjugated to anthra[2,3-b]thiophene-5,10-dione scaffolds. Exploring a role of individual side chain moieties in binding to the duplex and G-quadruplex DNA, modulation of telomerase and topoisomerase I activities, intracellular accumulation and cytostatic potency, we herein analyzed a series of reported and newly synthesized guanidine-containing derivatives of anthra[2,3-b]thiophene-5,10-dione.

Guanidino anthrathiophenediones as G-quadruplex binders: uptake, intracellular localization, and anti-Harvey-Ras gene activity in bladder cancer cells.

We prepared a series of anthrathiophenediones (ATPDs) with guanidino-alkyl side chains of different length (compounds 1, 10-13). The aim was to investigate their interaction with DNA and RNA G-quadruplexes, their uptake in malignant and nonmalignant cells, and their capacity to modulate gene expression and inhibit cell growth. Flow cytometry showed that the ATPDs enter more efficiently in malignant T24 bladder cells than in nonmalignant embryonic kidney 293 or fibroblast NIH 3T3 cells.

Disordering of human telomeric G-quadruplex with novel antiproliferative anthrathiophenedione.

Linear heteroareneanthracenediones have been shown to interfere with DNA functions, thereby causing death of human tumor cells and their drug resistant counterparts. Here we report the interaction of our novel antiproliferative agent 4,11-bis[(2-{[acetimido]amino}ethyl)amino]anthra[2,3-b]thiophene-5,10-dione with telomeric DNA structures studied by isothermal titration calorimetry, circular dichroism and UV absorption spectroscopy. New compound demonstrated a high affinity (K(ass)∼10⁶ M⁻¹) for human telomeric antiparallel quadruplex d(TTAGGG)₄ and duplex d(TTAGGG)₄∶d(CCCTAA)₄.

Synthesis and cytotoxic properties of 4,11-bis[(aminoethyl)amino]anthra[2,3-b]thiophene-5,10-diones, novel analogues of antitumor anthracene-9,10-diones.

We developed the synthesis of a series of thiophene-fused tetracyclic analogues of the antitumor drug ametantrone. The reactions included nucleophilic substitution of methoxy groups in 4,11-dimethoxyanthra[2,3-b]thiophene-5,10-diones with ethylenediamines, producing the derivatives of 4,11-diaminoanthra[2,3-b]thiophene-5,10-dione in good yields. Several compounds showed marked antiproliferative potency against doxorubicin-selected, P-glycoprotein-expressing tumor cells and p53(-/-) cells.

Naphthoindole-based analogues of tryptophan and tryptamine: synthesis and cytotoxic properties.

The efficacy of anthracycline based anticancer drugs is limited by pleiotropic drug resistance of tumor cells. Aiming at the design of anthracyclinone congeners capable of circumventing drug resistance, we synthesized naphthoindole containing derivatives of tryptophan and tryptamine. In doing so we adapted the traditional, gramine based approach for tryptophan and tryptamine synthesis.