Heterocyclic Analogs of 5,12-Naphthacenequinone 14*. Synthesis of naphtho[2,3-f]indole-3-carboxylic Acid Derivatives

Heteroarene-fused anthraquinone derivatives as potential modulators for human aurora kinase B

The quest for effective anticancer therapeutics continues to be extensively pursued. Over the past century, several drugs have been developed, however, a majority of these drugs have a poor therapeutic index and increased toxicity profile. Hence, there still exists ample opportunity to discover safe and effective anticancer drugs. Aurora Kinase B (AurB), a member of the Aurora kinase family and a key regulator of mitotic cell division, is found to be frequently overexpressed in a variety of human cancers and has thus emerged as an attractive target for the design of anticancer therapeutics. In the present study, a structure-based scaffold hopping approach was utilized to modify the heterocyclic moiety of (S)-3-(3-aminopyrrolidine-1-carbonyl)-4,11-dihydroxy-2-methylanthra [2,3-b]furan-5,10-dione (anthrafuran 1) to generate a series of heteroarene-fused anthraquinone derivatives, which were then subjected to virtual screening for the identification of potential AurB inhibitors. The obtained hits were subsequently synthesized and evaluated by using a combination of in silico and biophysical techniques for elucidating their in vitro binding and inhibition activity with recombinantly expressed AurB. Four identified hits presented an improved binding profile as compared to their parent analog anthrafuran 1. One derivative, anthrathiophene 2 demonstrated excellent in vitro inhibition of AurB (7.3 μM).

Introduction of Carbon Substituents into Nitroarenes via Nucleophilic Substitution of Hydrogen: New Developments

Nucleophilic substitution of hydrogen in nitroarenes has become a powerful synthetic tool for functionalization of these important organic substrates, complementary to other modern methods. In this review we present new developments in the area of introduction of alkyl and functionalized alkyl substituents into nitroarene rings via nucleo­philic substitution of hydrogen, followed by application of these processes in the construction of carbo- and heterocyclic rings. Finally, new developments in the investigation of the mechanism of SNArH are summarized.

1 Introduction

2 Alkylation and Haloalkylation

3 Functionalized Carbon Substituents

4 Formation of Carbo- and Heterocyclic Rings

5 Mechanistic Aspects of SNArH

6 Conclusion

Amides of pyrrole- and thiophene-fused anthraquinone derivatives: A role of the heterocyclic core in antitumor properties

Heteroarene-fused anthraquinone derivatives represent a class of perspective anticancer drug candidates capable of targeting multiple vital processes including drug resistance. Taking advantage of previously demonstrated potential of amide derivatives of heteroarene-fused anthraquinones, we herein dissected the role of the heterocyclic core in antitumor properties. A new series of naphtho[2,3-f]indole-3- and anthra[2,3-b]thiophene-3-carboxamides was synthesized via coupling the respective acids with cyclic diamines. New compounds demonstrated a submicromolar antiproliferative potency close to doxorubicin (Dox) against five tumor cell lines of various tissue origin. In contrast to Dox, the new compounds were similarly cytotoxic for HCT116 colon carcinoma cells (wild type p53) and their isogenic p53 knockout counterparts. Modification of the heterocyclic core changed the targeting properties: the best-in-series naphtho[2,3-f]indole-3-carboxamide 8 formed more affine complexes with DNA duplex than furan and thiophene analogs, a property that can be translated into a stronger inhibition of topoisomerase 1 mediated DNA unwinding. At tolerable doses the water soluble derivative 8 significantly inhibited tumor growth (up to 79%) and increased the lifespan (153%) of mice bearing P388 lymphoma transplants. Together with better solubility for parenteral administration and well tolerance by animals of the indole derivative 8 indicates prospects for further search of new antitumor drug candidates among the heteroarene-fused anthraquinones.