Wenxi Fan

Synthesis and structure–activity relationships of harmine derivatives as potential antitumor agents

Harmine, a naturally occurring β-carboline alkaloid, showed good antitumor activities together with remarkable neurotoxic effects in animal models. In order to search for novel leading compounds endowed with better antitumor activities and less neurotoxicities, a series of harmine derivatives were designed and synthesized by modification of position-2, 7 and 9 of β-carboline nucleus, and their cytotoxic activities against human tumor cell lines were investigated. Acute toxicities and antitumor activities of the selected compounds in mice were also evaluated. Structure-activity relationships studies confirmed that (1) the 7-methoxy structural moiety was the pharmacophore responsible for the neurotoxic effects of this class of compounds; (2) the substituents in position-2 and 9 played a vital role in modulation of their antitumor activities.

Synthesis and biological evaluation of 1,9-disubstituted β-carbolines as potent DNA intercalating and cytotoxic agents

A series of novel 1,9-disubstituted β-carbolines was designed, synthesized and evaluated as cytotoxic and DNA intercalating agents. Compounds 7b, 7c, 8b and 8c exhibited the most potent cytotoxic activities with IC(50) values of lower than 20 μM against ten human tumor cell lines. The results indicated that (1) the 3-chlorobenzyl and 3-phenylpropyl substituents in position-9 of β-carboline nucleus were the suitable pharmacophoric group giving rise to significant antitumor agents; (2) the length of the alkylamino side chain moiety affected their cytotoxic potencies, and three CH(2) units were more favorable. In addition, these compounds were found to exhibit remarkable DNA intercalating effects.

Design, synthesis and in vitro and in vivo antitumor activities of novel bivalent β-carbolines

A series of bivalent β-carbolines with a spacer of three to ten methylene units between the indole nitrogen was synthesized and evaluated as antitumor agents. The results demonstrated that compounds 18c, 21b, 25a and 31b exhibited strong cytotoxic activities with IC(50) value of lower than 20 μM against four tumor cell lines. Acute toxicities and antitumor efficacies of the selected compounds in mice were also evaluated, compounds 18b, 21b, 26a and 31b exhibited potent antitumor activities with tumor inhibition rate of over 40% in animal models. Preliminary structure-activity relationships analysis indicated that (1) the spacer length affected antitumor potencies, and four to six methylene units were more favorable; (2) the introduction of appropriate substituent into position-1 of β-carboline facilitated antitumor potencies.

Synthesis and structure–activity relationships of N2-alkylated quaternary β-carbolines as novel antitumor agents

A series of novel N(2)-alkylated quaternary β-carbolines was synthesized by modification of position-1, 2, 7 and 9 of β-carboline nucleus with various alkyl and arylated alkyl substituents, and their cytotoxic activities in vitro and antitumor potencies in mice were evaluated. Compound 3m was found to be the most potent antitumor agent. SARs analysis revealed that (1) the substituents in position-2 and 9 of β-carboline nucleus played a vital role in modulation of antitumor activity; (2) the benzyl and 3-phenylpropyl substituents in position-2 and 9 of β-carboline ring were the optimal substituents giving rise to significant antitumor agent. These compounds might be a novel promising class of antitumor agents with clinical development potential.

Synthesis and biological evaluation of novel bivalent β-carbolines as potential antitumor agents

A series of novel bivalent β-carbolines with a spacer of three to ten methylene units between the 3-carboxyl oxygens was synthesized and evaluated as antitumor agents. The results demonstrated that most compounds displayed good and selective cytotoxic activities against 769-P and KB cell lines. Acute toxicities and antitumor efficacies of the selected compounds in mice were also evaluated. Compound 22 exhibited potent antitumor activity against Lewis lung cancer in mice with a tumor inhibition rate of 64.2%. Preliminary structure–activity relationship analysis indicated that (1) the length of the spacer affected cytotoxic activities in vitro and six methylene units were more favorable; (2) the introduction of substituents into position-1 of the β-carboline ring might be detrimental to antitumor potency in vivo models.

Synthesis and biological evaluation of piperazine group-linked bivalent β-carbolines as potential antitumor agents

A series of novel bivalent β-carbolines with a piperazine group spacer between 3-methylene units were synthesized and evaluated as antitumor agents. The results demonstrated that compounds 7e and 7g exhibited the most potent cytotoxic activities against ten tumor cell lines. Structure–activity relationships analysis indicated that (1) the substituents in positions 1 and 9 of the β-carboline ring played a significant role in modulating the antitumor activity; (2) the introduction of alkyl groups into position-9 of the β-carboline nucleus enhanced their cytotoxic potencies and the butyl substituent was the optimal group. Investigation of the preliminary mechanism of action demonstrated that compound 7g showed obvious anti-angiogenic activity in the in vivo CAM assay, and the potency was similar to that of CA4P (200 μM).

Synthesis and preliminary evaluation of novel alkyl diamine linked bivalent β-carbolines as angiogenesis inhibitors

A series of novel bivalent β-carbolines linked with an alkyl diamine spacer at the C-3 position were synthesized and evaluated as potent angiogenesis inhibitors. The results demonstrated that most bivalent β-carbolines displayed significant anti-proliferative effects against EA.HY926 human umbilical vein cell lines. Compound 8z was found to be the most potent anti-proliferative agent with an IC50 value of 1.10 μM against EA.HY926 cell lines. Preliminary investigations on the mechanisms of action revealed that compound 8z could dramatically inhibit EA.HY926 cell migration and tube formation in a dose-dependent manner. Moreover, compound 8z exhibited significant angiogenesis inhibitory effects in CAM assay, and the anti-angiogenic potency was comparable with that of the reference drug Endostar. These molecules might serve as candidates for further development into vascular-targeting antitumor drugs.

Design, synthesis and biological evaluation of novel alkyl diamine linked bivalent β-carbolines as angiogenesis inhibitors

A series of novel alkyl diamine linked bivalent β-carbolines was synthesized and evaluated for antiproliferative activity, inhibition of cell migration and tube formation, and anti-angiogenic activity in vivo. The results showed that most bivalent β-carbolines displayed significant antiproliferative effect against human umbilical vein cell lines EA.HY926. Compound 2s was found to be the most potent antiproliferative agent with IC50 value of 1.06μM against EA.HY926 cell lines. Further investigations on mechanisms of action revealed that compound 2s significantly inhibited EA.HY926 cells migration and tube formation in a dose-dependent manner. Moreover compound 2s exhibited significant angiogenesis inhibitory effects in CAM assay, and the antiangiogenetic potency was comparable with the reference drug Endostar (30μM).