Diethylaminopropionamido-hydroxy-anthraquinones as potential anticancer agents: synthesis and characterization

Development of Anthraquinone Analogues as Phosphoglycerate Mutase 1 Inhibitors

Phosphoglycerate mutase 1 (PGAM1) coordinates glycolysis and biosynthesis to promote cancer cell proliferation, and is believed to be a promising target for cancer therapy. Herein, based on the anthraquinone scaffold, we synthesized 31 anthraquinone derivatives and investigated the structure−activity relationship (SAR). The 3-substitient of sulfonamide on the anthraquinone scaffold was essential for maintaining potency and the modifications of the hydroxyl of alizarin would cause a sharp decrease in potency. In the meantime, we determined the co-crystal structure of PGAM1 and one of the anthraquinone inhibitors 9i with IC₅₀ value of 0.27 μM. The co-crystal structure revealed that F22, K100 and R116 of PGAM1 were critical residues for the binding of inhibitors which further validated the SAR. Consistent with the crystal structure, a competitive assay illustrated that compound 9i was a noncompetitive inhibitor. In addition, compound 9i effectively restrained different lung cancer cells proliferation in vitro. Taken together, this work provides reliable guide for future development of PGAM1 inhibitors and compound 9i may act as a new leading compound for further optimization.

Synthesis and biological evaluation of anthraquinone derivatives as allosteric phosphoglycerate mutase 1 inhibitors for cancer treatment

Phosphoglycerate mutase 1 (PGAM1) coordinates glycolysis, pentose phosphate pathway, and serine synthesis to promote tumor growth through the regulation of its substrate 3-phosphoglycerate (3 PG) and product 2-phosphoglycerate (2 PG). Herein, based on our previously reported PGAM1 inhibitor PGMI-004A, we have developed anthraquinone derivatives as novel allosteric PGAM1 inhibitors and the structure-activity relationship (SAR) was investigated. In addition, we determined the co-crystal structure of PGAM1 and the inhibitor 8g, demonstrating that the inhibitor was located at a novel allosteric site. Among the derivatives, compound 8t was selected for further study, with IC₅₀ values of 0.25 and approximately 5 μM in enzymatic and cell-based assays, respectively. Mechanistically, compound 8t reduced the glycolysis and oxygen consumption rate in cancer cells, which led to decreased adenosine 5'-triphosphate (ATP) production and subsequent 5' adenosine monophosphate-activated protein kinase (AMPK) activation. The inhibitor 8t also exhibited good efficacy in delaying tumor growth in H1299 xenograft model without obvious toxicity. Taken together, this proof-of-principle work further validates PGAM1 as a potential target for cancer therapy and provides useful information on anti-tumor drug discovery targeting PGAM1.

Synthesis of an orange anthrathiophene pigment isolated from a Japanese bryozoan

A short, regiospecific synthesis of the naturally occurring anthrathiophene 1 from naphthazarin (7) is described.

Peptidyl anthraquinones as potential antineoplastic drugs: synthesis, DNA binding, redox cycling, and biological activity

A series of new compounds containing a 9,10-anthracenedione moiety and one or two peptide chains at position 1 and/or 4 have been synthesized. The amino acid residues introduced are glycine (Gly), lysine (Lys), and tryptophan (Trp), the latter two in both the L- and D-configurations. The peptidyl anthraquinones maintain the ability of intercalating efficiently into DNA, even though the orientation within the base-pair pocket may change somewhat with reference to the parent drugs mitoxantrone (MX) and ametantrone (AM). The interaction constants of the mono-, di-, and triglycyl derivatives are well comparable to those found for AM but 5-10 times lower than the value reported for MX. On the other hand, the glycyl-lysyl compounds bind DNA to the same extent as (L-isomer) or even better than (D-isomer) MX. As for the parent drugs without peptidyl chains, the new compounds prefer alternating CG binding sites, although to different extents. The bis-Gly-Lys derivatives are the least sensitive to base composition, which may be due to extensive aspecific charged interactions with the polynucleotide backbone. As far as redox properties are concerned, all peptidyl anthraquinones show a reduction potential very close to that of AM and 60-80 mV less negative than that of MX; hence, they can produce free-radical-damaging species to an extent similar to the parent drugs. The biological activity has been tested in human tumor and murine leukemia cell lines. Most of the test anthraquinones exhibit cytotoxic properties close to those of AM and considerably lower than those of MX. Stimulation of topoisomerase-mediated DNA cleavage is moderately present in representatives of the glycylanthraquinone family, whereas inhibition of the background cleavage occurs when Lys is present in the peptide chain. For most of the test anthraquinones, the toxicity data are in line with the DNA affinity scale and the topoisomerase II stimulation activity. However, in the lysyl derivatives, for which lack of cytotoxicity cannot be related to poor binding to DNA, the steric and electronic properties of the side-chain substituent must impair an effective recognition of the cleavable complex.

Inhibition of Growth, Morphological and Morphometrical Changes Induced by Amido-anthraquinone Derivatives in NCTC 2544 and HeLa Cells

In this work, we have studied cytotoxicity induced in NCTC 2544 and HeLa cell lines by two newly-synthesised potential anticancer drugs, the amido-anthraquinone derivatives 8-diethylaminopropionamido-1,4,5-trihydroxy-9,10-anthracenedione bromide (A888) and 5,8-bisdiethylaminopropionamido-1,4-dihydroxy-9,10-anthracenedione dibromide (A890). The results have been compared to the results obtained with mitoxantrone, a well-known anticancer agent. Using the neutral red uptake assay, A888 showed less cytotoxic action compared to mitoxantrone and A890. According to the results of morphological analysis after exposure for five hours, anthraquinone derivatives induced the formation of cytoplasmic vacuoles and changes in the arrangement of nucleus in both cell lines. On the basis of morphometrical analysis, we have observed an increase in total cellular area with a decrease in the nuclear/cytoplasmic ratio. We have found that the increase in total cellular area was higher in NCTC 2544 cells than in HeLa cells. From these data, we can conclude that NCTC cells are more sensitive to the compounds tested than HeLa cells. However, the growth inhibition assay and morphological analysis did not confirm these results.

Biochemical pharmacology of anthracenediones and anthrapyrazoles

DNA intercalating antitumor agents represent one of the more widely used classes of therapeutic agents in clinical oncology. Although a decisive mechanism to explain their ability to kill tumor cells has not been fully defined, the past decade has shown vast progress toward identifying key possibilities. The anthracenediones and anthrapyrazoles represent two latter generation classes of DNA intercalators that show great clinical promise as antitumor drugs. This article will review the currently known biochemical pharmacology for these agents and integrate these data into a broader picture touching on mechanisms of tumor cell kill.