Eleutherobin

Protein target name:

Tubulin

Mechanism of action:

Stabilization of microtubules

Recommended Concentration for use in cells:

~~5 uM~~

Reviewer suggested Concentration for use in cells:

250-500 nM

Probe Information

Target and Probe Information

Target Details

Target class:

Structural protein

Subclass:

Cytoskeleton

Probe Details

Chemical Probes Portal ID:

CPP1630

PubChem CID:

6918335

ChEMBL ID:

CHEMBL504387

SMILES string:

CC1=CC[C@@H]([C@@H]/2[C@H]1C[C@@H]([C@@]3(C=C[C@@](O3)(/C(=C2)/CO[C@H]4[C@H]([C@@H]([C@@H](CO4)O)O)OC(=O)C)OC)C)OC(=O)/C=C/C5=CN(C=N5)C)C(C)C

InChi Key:

XOPYFXBZMVTEJF-PDACKIITSA-N

Validation in Cells and Model Organisms

In vitro validation

On target activity

Potency:

EC50

6.2 uM

Potency assay:

In vitro calf brain tubulin polymerization assays,

Structure-activity relationship:

Yes, pharmacore reported (PMID: 10200249); see also PMID: 10412947.

In cell validation

On target activity in cells

Potency in cells:

IC50

2 uM

Potency assay (cells):

Displacement of 3H-taxol

Target engagement assay (cells):

Yes, displacement of taxol

Toxicity

Cytoxicity assay:

Yes

Notes on cytotoxicity:

In XTT assays, Eleutherobin was cytotoxic to HCT116 cells (IC50=10.7 uM); overexpression of P-glycoprotein efflux pump renders cells resistant. Cytotoxicity is due to an on-target induction of mitotic arrest.

Primary Reference

Reference (doi):

Cancer Res 10.1073/pnas.96.8.4256 10.1021/bi983023n Cancer Chemother Pharmacol 10.1021/ja9717828

Reference (PMID):

9515790 10200249 10220336 10412947

Endorsed probe

The Chemical Probes Portal endorses this compound as chemical probe for use in cells.

SAB Rating

Rating for use in Cells

3 review(s)

Rating for use in Model Organisms

no rating

SAB Members

SAB Comments

Eleutherobin is the prototypical member of the eleutherobin class of tubulin inhibitors, consisting of 7 unique agents each isolated from several species of marine sponges. Its structure is well defined by NMR and the active enantiomer of the compound (based heavily on the orientation of the carbohydrate R-group motif) has been described. A synthetic pathway for its synthesis is published and freely available. Utilising direct binding experiments for tubulin stabilisation in a variety of approaches including reactions in free solution and in cellular models, eleutherobin demonstrates strong binding to tubulin which is consistently 5-10 fold less potent than the commonly utilised taxol, paclitaxel. Direct binding of eleutherobin to tubulin has been confirmed and it directly competes with paclitaxel for binding, suggesting that these drugs share a common binding site and mechanism. The inhibitory dose 50 (IC50) anti-prolferaitve range for this drug in multiple cancer cell lines is approximately10-140 nM. Use of a low concentration (50nM) of eleutherobin in cellular models induces microtubule stabilisation, cell cycle arrest at the G2/M phase and phenotypic nuclear morphology changes associated with mitotic catastrophe and mitotic slippage. Eleutherobin is also a substrate for the drug efflux pump, P-glycoprotein, which must be taken into account when selecting the cellular model to test the drug in. Additionally, eleutherobin can still bind and stabilise tubulin mutants which predispose to paclitaxel resistance which highlights the usefulness of eleutherobin in acting as an alternative tubulin probe in the context of this genetic background. Elutherobin is, therefore, a potent probe of tubulin biology in cellular models, including those bearing paclitaxel-nullifying tubulin mutations. Although SAR has been performed, the precise mode of binding to tubulin is not defined. Moreover, the potential for incidental ‘off targets’ with relevance to cell biology is incompletely mapped. Commercial supply of elutherobin is limited, with no vendors currently listed to purchase the drug, limiting its wider spread use as a commonly utilised probe.

Jun 7 2020 - 6:06pm

Even if the direct activity of eleutherobin on tubulin has been demonstrated in vitro, some structural components are potentially reactive (such as the Michael acceptor) and reversible and/or irreversible interactions with other targets may contribute to its activity in cells.

Nov 4 2020 - 11:36am

Eleutherobin

Probe Information

Target Details

Probe Details

In vitro validation

In cell validation

Toxicity

Primary Reference

Supporting Organizations

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Eleutherobin

Probe Information

Target Details

Probe Details

In vitro validation

In cell validation

Toxicity

Primary Reference

Supporting Organizations

Interested in supporting the portal?