Dynole 34-2

Synthesis of Dynole 34-2, Dynole 2-24 and Dyngo 4a for investigating dynamin GTPase.[Pubmed:24651498]

Nat Protoc. 2014 Apr;9(4):851-70.

Dynamin is a large GTPase with roles in membrane fission during clathrin-mediated endocytosis, in actin dynamics and in cytokinesis. Defects in dynamin have been linked to human diseases. The synthesis of a dynamin modulator toolkit comprising two different inhibitor classes is described. The first series comprises Dynole 34-2, Dynole 2-24 and the inactive control Dynole 31-2. The Dynole compounds act on the dynamin G domain, are not GTP competitive and can be synthesized in 2-3 d. Knoevenagel condensation of 1-(3-(dimethylamino)propyl)-1H-indole-3-carbaldehyde (1) with cyanoamides (2 and 3) affords Dynole 31-2 and Dynole 34-2, respectively. Reductive amination of 1 with decylamine gives Dynole 2-24. The second series acts at an allosteric site in the G domain of dynamin and comprises Dyngo 4a and Dyngo O (inactive control). Both are synthesized in an overnight reaction via condensation of 3-hydroxy-2-naphthoic hydrazide with 2,4,5-trihydroxybenzaldehyde to afford Dyngo 4a, or with benzaldehyde to afford Dyngo O.

Inhibition of dynamin by dynole 34-2 induces cell death following cytokinesis failure in cancer cells.[Pubmed:21750222]

Mol Cancer Ther. 2011 Sep;10(9):1553-62.

Inhibitors of mitotic proteins such as Aurora kinase and polo-like kinase have shown promise in preclinical or early clinical development for cancer treatment. We have reported that the MiTMAB class of dynamin small molecule inhibitors are new antimitotic agents with a novel mechanism of action, blocking cytokinesis. Here, we examined 5 of the most potent of a new series of dynamin GTPase inhibitors called dynoles. They all induced cytokinesis failure at the point of abscission, consistent with inhibition of dynamin while not affecting other cell cycle stages. All 5 dynoles inhibited cell proliferation (MTT and colony formation assays) in 11 cancer cell lines. The most potent GTPase inhibitor, Dynole 34-2, also induced apoptosis, as revealed by cell blebbing, DNA fragmentation, and PARP cleavage. Cell death was induced specifically following cytokinesis failure, suggesting that Dynole 34-2 selectively targets dividing cells. Dividing HeLa cells were more sensitive to the antiproliferative properties of all 5 dynoles compared with nondividing cells, and nontumorigenic fibroblasts were less sensitive to cell death induced by Dynole 34-2. Thus, the dynoles are a second class of dynamin GTPase inhibitors, with Dynole 34-2 as the lead compound, that are novel antimitotic compounds acting specifically at the abscission stage.

Iminochromene inhibitors of dynamins I and II GTPase activity and endocytosis.[Pubmed:20426422]

J Med Chem. 2010 May 27;53(10):4094-102.

Herein we report the synthesis of discrete iminochromene ("iminodyn") libraries (14-38) as potential inhibitors of dynamin GTPase. Thirteen iminodyns were active (IC(50) values of 260 nM to 100 microM), with N,N-(ethane-1,2-diyl)bis(7,8-dihydroxy-2-iminochromene-3-carboxamide) (17), N,N-(ethane-1,2-diyl)bis(7,8-dihydroxy-2-iminochromene-3-carboxamide) (22), and N,N-(ethane-1,2-diyl)bis(7,8-dihydroxy-2-iminochromene-3-carboxamide) (23) (IC(50) values of 330 +/- 70, 450 +/- 50, and 260 +/- 80 nM, respectively) being the most potent. Five of the most potent iminodyns all inhibited dynamins I and II approximately equally. Iminodyn-22 displayed uncompetitive inhibition with respect to GTP. Selected iminodyns were evaluated for their ability to block receptor mediated endocytosis (RME, mediated by dynamin II) and synaptic vesicle endocytosis (SVE, mediated by dynamin I), with 17 showing no activity while 22 returned RME and SVE IC(50) values of 10.7 +/- 4.5 and 99.5 +/- 1.7 microM, respectively. The iminodyns reported herein represent a new chemical class of the first nanomolar potent dynamin inhibitors that are also effective endocytosis inhibitors.

Inhibition of dynamin mediated endocytosis by the dynoles--synthesis and functional activity of a family of indoles.[Pubmed:19459681]

J Med Chem. 2009 Jun 25;52(12):3762-73.

Screening identified two bisindolylmaleimides as 100 microM inhibitors of the GTPase activity of dynamin I. Focused library approaches allowed development of indole-based dynamin inhibitors called dynoles. 100-Fold in vitro enhancement of potency was noted with the best inhibitor, 2-cyano-3-(1-(2-(dimethylamino)ethyl)-1H-indol-3-yl)-N-octylacrylamide (Dynole 34-2), a 1.3 +/- 0.3 microM dynamin I inhibitor. Dynole 34-2 potently inhibited receptor mediated endocytosis (RME) internalization of Texas red-transferrin. The rank order of potency for a variety of dynole analogues on RME in U2OS cells matched their rank order for dynamin inhibition, suggesting that the mechanism of inhibition is via dynamin. Dynoles are the most active dynamin I inhibitors reported for in vitro or RME evaluations. Dynole 34-2 is 15-fold more active than dynasore against dynamin I and 6-fold more active against dynamin mediated RME (IC(50) approximately 15 microM; RME IC(50) approximately 80 microM). The dynoles represent a new series of tools to better probe endocytosis and dynamin-mediated trafficking events in a variety of cells.