Esters of chlorambucil with 2-substituted 1,4-dihydroxy-9,10-anthraquinones as multifunctional anticancer agents

Design and synthesis of novel hydroxyanthraquinone nitrogen mustard derivatives as potential anticancer agents via a bioisostere approach

A series of hydroxyanthraquinones having an alkylating N-mustard pharmacophore at 1'-position were synthesized via a bioisostere approach to evaluate their cytotoxicity against four tumor cell lines (MDA-MB-231, HeLa, MCF-7 and A549). These compounds displayed significant in vitro cytotoxicity against MDA-MB-231 and MCF-7 cells, reflecting the excellent selectivity for the human breast cancer. Among them, compound 5k was the most cytotoxic with IC50 value of 0.263 nM and is more potent than DXR (IC50 = 0.294 nM) in inhibiting the growth of MCF-7 cells. The excellent cytotoxicity and good selectivity of compound 5k suggest that it could be a promising lead for further design and development of anticancer agents, especially for breast cancer.

Synthesis and antiproliferative activity of 1,4-bis(dimethylamino)-9,10-anthraquinone derivatives against P388 mouse leukemic tumor cells

A series of 2-substituted-1,4-bis(dimethylamino)-9,10-anthraquinone derivatives were synthesized and their in vitro antiproliferative activities against p388 mouse leukemic tumor cells were evaluated. In addition, the effect of substituents on the phenyl ring was investigated. Among the derivatives tested, seven showed a high antiproliferative effect and three showed a moderate effect. In addition, introduction of a series of substituted phenyl groups into 1,4-bis(dimethylamino)-9,10-anthraquinone at 2-position were shown to enhance its antiproliferative activity. The antiproliferative activity also increased upon substitution of the benzene ring by an electron donating group such as an amine or methoxyl group.

Two novel nucleoside ester derivatives of chlorambucil as potential antileukemic prodrugs: a preliminary study

2-Chloro-2'-deoxyadenosine (cladribine) and chlorambucil are two drugs used in the treatment of lymphoid malignancies. We have synthesized 5'-O-esters of cladribine and its parental nucleoside 2'-deoxyadenosine with chlorambucil (2-chloro-2'-deoxyadenosine-chlorambucil and 2'-deoxyadenosine-chlorambucil, respectively) and compared some properties of the esters with regard to their potential use as antileukemic prodrugs. The 5'-O-ester bond showed no spontaneous hydrolysis at pH 7.4, but was susceptible to hydrolysis by porcine liver esterase and enzymes present in human lymphocyte lysate and blood plasma. Both 2-chloro-2'-deoxyadenosine-chlorambucil and 2'-deoxyadenosine-chlorambucil were taken up more avidly than their parental nucleosides by normal and malignant human lymphoid cells. 2-Chloro-2'-deoxyadenosine-chlorambucil was by an order of magnitude more toxic than 2'-deoxyadenosine-chlorambucil to human leukemic MOLT4 cells in culture. On the other hand, 2-chloro-2'-deoxyadenosine-chlorambucil cytotoxicity did not exceed that of its parental 2-chloro-2'-deoxyadenosine in MOLT4 cells, whereas 2'-deoxyadenosine-chlorambucil was considerably more cytotoxic than free chlorambucil in a variety of myeloid and lymphoid human malignant cell lines. Moreover, acute toxicity of 2'-deoxyadenosine-chlorambucil was lower than that of chlorambucil in mice. In summary, 2'-deoxyadenosine-chlorambucil, but not 2-chloro-2'-deoxyadenosine-chlorambucil, shows promise for clinical utility as a chlorambucil prodrug and thus warrants a more detailed study in vivo.