| Size | Price | Stock | Qty |
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| 5mg |
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| 10mg |
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| 25mg |
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| 50mg |
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| 100mg | |||
| Other Sizes |
Purity: ≥98%
| Targets |
Mcl-1
Pyridoclax exerts its biological activity by directly binding to Mcl-1, a member of the pro-survival Bcl-2 protein family that inhibits apoptosis by sequestering pro-apoptotic BH3-only proteins. Overexpression of Mcl-1 is a common mechanism by which cancer cells evade apoptosis and develop resistance to chemotherapy and targeted therapies, including inhibitors of other Bcl-2 family members like Bcl-xL. Pyridoclax binds directly to Mcl-1 with high affinity and specificity, effectively neutralizing its anti-apoptotic function. However, because cancer cells often co-express multiple pro-survival proteins, inhibiting Mcl-1 alone is not sufficient to trigger cell death. The key to Pyridoclax's efficacy lies in its ability to synergize with Bcl-xL inhibition. When Bcl-xL is simultaneously inhibited, either through genetic knockdown (siRNA) or pharmacological agents like ABT-737/ABT-263, the cell's survival network is critically compromised. This dual inhibition releases a flood of pro-apoptotic BH3-only proteins that overwhelm the remaining anti-apoptotic defenses, leading to the activation of Bax and Bak, permeabilization of the mitochondrial outer membrane, and ultimately, apoptosis. This combined effect is highly synergistic, resulting in massive apoptosis in cancer cells that are otherwise resistant to single-agent therapies. The selectivity of Pyridoclax for Mcl-1 over other Bcl-2 family members is crucial for its utility as a research tool, allowing scientists to dissect the specific contribution of Mcl-1 to cancer cell survival and to explore the therapeutic potential of combining Mcl-1 inhibition with other targeted agents. |
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| ln Vitro |
Pyridoclax binds to Mcl-1 directly. Pyridoclax induces apoptosis in ovarian, lung, and mesothelioma cancer cells when combined with Bcl-xL-targeting siRNA or with ABT-737, but it has no cytotoxic activity when used alone[1]. Pyridoclax directly binds to Mcl-1, making ovarian carcinoma cells more susceptible to Bcl-xL-targeting techniques. When administered along with Bcl-xL targeting molecules like ABT-737 or its orally available derivative ABT-263, Pyridoclax induces apoptosis in ovarian, lung, and mesothelioma cancer cells[2].
In vitro studies have demonstrated that Pyridoclax is a potent and selective Mcl-1 inhibitor, but its activity is strictly context-dependent. As a single agent, Pyridoclax exhibits no cytotoxic activity across a range of cancer cell lines, including those from ovarian, lung, and mesothelioma cancers. This confirms that Mcl-1 inhibition alone is insufficient to induce apoptosis, as cancer cells rely on a network of anti-apoptotic proteins. The compound's true potential is revealed in combination with Bcl-xL-targeting strategies. When Pyridoclax is combined with Bcl-xL-targeting siRNA or with small-molecule inhibitors like ABT-737 (or its orally available derivative ABT-263), a potent synergistic effect is observed. This combination induces significant apoptosis in ovarian, lung, and mesothelioma cancer cells. The synergy is so profound that it triggers massive cell death even in the absence of conventional chemotherapeutic agents, highlighting the critical role of the Bcl-2 family in cancer cell survival. Further in vitro studies have shown that Pyridoclax sensitizes ovarian carcinoma cells specifically to Bcl-xL-targeting strategies, providing a mechanistic rationale for its use in combination therapies. These findings establish Pyridoclax as a valuable tool for studying Mcl-1 biology and for validating the concept that co-targeting Mcl-1 and Bcl-xL is a highly effective strategy to overcome apoptosis resistance in cancer. |
| ln Vivo |
In vivo activity data for Pyridoclax is limited, as the compound is primarily used as a research tool in in vitro studies. The available information suggests that Pyridoclax is intended to be used in combination with other agents for in vivo efficacy studies. The rationale for its in vivo use would be the same as in vitro: to simultaneously inhibit both Mcl-1 (via Pyridoclax) and Bcl-xL (via a compatible agent like ABT-263) to trigger apoptosis in tumors. For such studies, Pyridoclax would likely be formulated in a suitable vehicle, such as a mixture of DMSO, PEG300, Tween 80, and saline, for administration in animal models. Its efficacy would be evaluated in xenograft models of cancers known to be dependent on Mcl-1, such as ovarian, lung, and mesothelioma. Endpoints would include tumor growth inhibition, apoptosis induction (measured by TUNEL or cleaved caspase-3), and survival analysis. However, specific in vivo protocols and results, such as dosing regimens, routes of administration, and pharmacokinetic parameters, are not detailed in the standard product descriptions. The compound's stability (3 years at -20°C as powder, 1 year at -80°C in solvent) is sufficient for long-term research use. Overall, while Pyridoclax shows promise as a research tool for in vivo proof-of-concept studies, comprehensive in vivo data is currently lacking and would be generated by researchers investigating its therapeutic potential.
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| Enzyme Assay |
Hela cells are seeded on 12-well plates and transfected with 200 ng/well of the BRET donor plasmid pRluc-BimL and increasing concentrations of the BRET acceptor plasmid peYFP-Mcl-1 (or pCMV-Mcl-1 as a control) for donor saturating assays. Cells are trypsinized, reseeded into 96-well white flat-bottom plates, and incubated for an additional day before measurements 24 hours after transfection. The drug treatment assay is conducted using a single donor/acceptor ratio (200/800). Following reseeding, cells undergo a 16-hour Pyridoclax treatment. After adding the luciferase substrate coelenterazine H to a final concentration of 5 μM, light emission at 485 and 530 nm is measured consecutively using the Mithras fluorescence-luminescence detector LB 940. BRET ratios are computed[1].
The in vitro enzyme/receptor binding assays for Pyridoclax are designed to confirm its direct binding to Mcl-1 and to measure its affinity and selectivity. A key technique used to study the interaction between Pyridoclax and Mcl-1 is the Bioluminescence Resonance Energy Transfer (BRET) assay. In a typical BRET assay, cells (e.g., HeLa cells) are transfected with two plasmids: one encoding a Renilla luciferase (Rluc) fusion protein of the pro-apoptotic BH3-only protein Bim (Rluc-BimL), which serves as the BRET donor, and another encoding a yellow fluorescent protein (YFP) fusion of Mcl-1 (YFP-Mcl-1), which serves as the BRET acceptor. When Rluc-BimL binds to YFP-Mcl-1, the proximity brings the donor and acceptor into close range, and upon addition of the Rluc substrate coelenterazine H, energy transfer occurs, resulting in a measurable BRET signal. To determine Pyridoclax's binding, cells expressing a single donor/acceptor ratio are treated with increasing concentrations of Pyridoclax for a period, typically 16 hours. If Pyridoclax competes with Rluc-BimL for binding to Mcl-1, the BRET signal will decrease in a dose-dependent manner. After treatment, coelenterazine H is added, and light emission at 485 nm (Rluc) and 530 nm (YFP) is measured using a microplate reader. The BRET ratio (emission at 530 nm / emission at 485 nm) is then calculated. A decrease in the BRET ratio indicates that Pyridoclax is displacing Rluc-BimL from Mcl-1, confirming direct binding. This assay provides a sensitive and quantitative measure of the compound's interaction with its target in a cellular context. |
| Cell Assay |
In vitro cell-based assays for Pyridoclax are crucial for evaluating its biological activity and its synergistic effects with other compounds. The primary assay used to assess Pyridoclax's function involves treating cancer cell lines, such as those derived from ovarian, lung, and mesothelioma cancers. Typically, cells are seeded in multi-well plates and cultured in appropriate media. They are then treated with Pyridoclax alone, a Bcl-xL-targeting agent (such as ABT-737 or ABT-263) alone, or a combination of both at various concentrations. After a defined incubation period (e.g., 48-72 hours), cell viability and apoptosis are assessed. Cell viability is commonly measured using assays like MTT, XTT, or CellTiter-Glo, which quantify metabolically active cells. Apoptosis is more specifically measured using assays that detect phosphatidylserine externalization (Annexin V staining), caspase-3/7 activation (using fluorogenic substrates), or DNA fragmentation (TUNEL assay). The key finding from these experiments is that while Pyridoclax or the Bcl-xL inhibitor alone may have minimal effect, the combination induces a significant increase in apoptosis, demonstrating a strong synergistic effect. These assays are also used to confirm that the combination leads to the release of pro-apoptotic BH3-only proteins and the activation of the mitochondrial apoptotic pathway. Such experiments are fundamental to establishing the mechanism of action and the therapeutic potential of combining Mcl-1 and Bcl-xL inhibition.
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| Animal Protocol |
In vivo animal experiments for Pyridoclax are primarily designed to evaluate its efficacy in combination with Bcl-xL inhibitors in tumor models. A typical protocol involves establishing xenograft tumors in immunodeficient mice (e.g., nude or NSG mice) by subcutaneous injection of human cancer cell lines known to be sensitive to Mcl-1 and Bcl-xL co-inhibition, such as ovarian, lung, or mesothelioma cancer cells. Once tumors reach a palpable size, the animals are randomized into treatment groups. These groups typically include a vehicle control group, a group receiving Pyridoclax alone, a group receiving a Bcl-xL inhibitor (such as ABT-263) alone, and a group receiving the combination of Pyridoclax and the Bcl-xL inhibitor. Pyridoclax is formulated for injection, often using a vehicle like a mixture of DMSO, PEG300, Tween 80, and saline. The route of administration and dosing schedule are determined by the stability and pharmacokinetics of the compound. Tumor growth is monitored by measuring tumor dimensions with calipers and calculating tumor volume. Body weight is also monitored as an indicator of toxicity. At the end of the study, tumors are harvested for analysis of apoptosis (e.g., by TUNEL or cleaved caspase-3 staining) and for confirmation of target modulation (e.g., by Western blotting for Mcl-1 and Bcl-xL). The key endpoint is the comparison of tumor growth inhibition and survival between the combination group and the single-agent or control groups. While specific protocols are not publicly detailed, these standard in vivo efficacy studies are essential for validating the therapeutic potential of Pyridoclax-based combination therapy.
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| ADME/Pharmacokinetics |
The pharmacokinetic (PK) properties of Pyridoclax are not extensively characterized in publicly available literature. However, some basic information can be inferred. Pyridoclax has a molecular weight of 426.51 g/mol and a molecular formula of C29H22N4. It is soluble in DMSO at a concentration of 20 mg/mL (46.89 mM). For in vivo administration, Pyridoclax would need to be formulated in a suitable vehicle to ensure proper solubility and bioavailability. A common formulation for such compounds includes a mixture of 10% DMSO, 40% PEG300, 5% Tween 80, and 45% saline. The stability of Pyridoclax is well-defined for storage: it is stable as a powder for up to 3 years when stored at -20°C, and for 1 year when stored in solution at -80°C. For shipping, it is typically sent with blue ice or at ambient temperature. However, detailed parameters such as half-life (t1/2), clearance (Cl), volume of distribution (Vd), oral bioavailability, and plasma protein binding have not been reported. The compound's lipophilicity (relative density predicted to be 1.192 g/cm³) suggests it may have moderate to high membrane permeability, but its absorption, distribution, metabolism, and excretion (ADME) profile remains to be fully characterized. Further studies, including plasma concentration-time curves after intravenous and oral administration in rodents, would be necessary to define its complete PK profile.
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| Toxicity/Toxicokinetics |
Detailed toxicity data for Pyridoclax is not provided in standard product descriptions. However, a key observation from its biological activity profile provides an important insight into its potential toxicity. Pyridoclax has been shown to have no cytotoxic activity when administered as a single agent. This suggests that, at the concentrations tested in vitro, Pyridoclax is not inherently toxic to cells in the absence of a Bcl-xL inhibitor. This lack of single-agent activity implies that it does not cause nonspecific cell death or general toxicity, which is a favorable property for a pharmaceutical agent. Its toxicity is context-dependent, manifesting only when combined with a Bcl-xL inhibitor and in cells that are dependent on both Mcl-1 and Bcl-xL for survival. This is a form of on-target toxicity, where the compound exerts its effect through its intended mechanism of action. For in vivo studies, the combination of Pyridoclax and a Bcl-xL inhibitor is expected to cause apoptosis in tumors, but it may also affect normal tissues that rely on these proteins for survival. The potential for off-target toxicity is considered low due to its selectivity for Mcl-1. However, a comprehensive toxicological profile, including acute and chronic toxicity studies in animal models, would be required to fully assess its safety and potential side effects.
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| References |
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| Additional Infomation |
Pyridoclax is a research compound and is not approved for any clinical use. It is an investigational tool specifically designed for studying the role of Mcl-1 in cancer biology and for validating the therapeutic concept of co-targeting Mcl-1 and Bcl-xL. Its mechanism of action highlights a sophisticated strategy to overcome apoptosis resistance in cancer. By directly binding to and inhibiting Mcl-1, Pyridoclax sensitizes cancer cells to the effects of Bcl-xL inhibition. The combination of Pyridoclax with Bcl-xL-targeting agents like ABT-737 or ABT-263 induces massive apoptosis in cancer cells that are otherwise resistant to single-agent therapies. This research has provided critical insights into the non-redundant functions of Mcl-1 and Bcl-xL in cancer cell survival. The compound is available in various pack sizes (e.g., 2 mg) for research purposes, and its high purity (typically >98%) and defined storage conditions ensure experimental reproducibility. As a tool compound, Pyridoclax is used in academic and pharmaceutical research to study Mcl-1-dependent cancers, to explore resistance mechanisms, and to screen for more potent and drug-like Mcl-1 inhibitors. The development of Pyridoclax represents a significant step forward in understanding and targeting the Bcl-2 family, and it continues to be a valuable asset in oncology research.
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| Molecular Formula |
C29H22N4
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|---|---|
| Molecular Weight |
426.51
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| Exact Mass |
426.184
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| Elemental Analysis |
C, 81.66; H, 5.20; N, 13.14
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| CAS # |
1651890-44-6
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| Related CAS # |
1651890-44-6
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| PubChem CID |
92042827
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| Appearance |
White to off-white solid powder
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| Density |
1.2±0.1 g/cm3
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| Boiling Point |
663.6±55.0 °C at 760 mmHg
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| Flash Point |
288.5±24.5 °C
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| Vapour Pressure |
0.0±1.9 mmHg at 25°C
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| Index of Refraction |
1.676
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| LogP |
5.64
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| Hydrogen Bond Donor Count |
0
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| Hydrogen Bond Acceptor Count |
4
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| Rotatable Bond Count |
5
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| Heavy Atom Count |
33
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| Complexity |
615
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| Defined Atom Stereocenter Count |
0
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| SMILES |
CC1=CC(C2=NC=C(C3=CC=CN=C3)C=C2/C=C/C4=CC=CC=C4)=CN=C1C5=CC=CN=C5
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| InChi Key |
WGGSYXQFYRWBEC-VAWYXSNFSA-N
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| InChi Code |
InChI=1S/C29H22N4/c1-21-15-27(20-32-28(21)25-10-6-14-31-18-25)29-23(12-11-22-7-3-2-4-8-22)16-26(19-33-29)24-9-5-13-30-17-24/h2-20H,1H3/b12-11+
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| Chemical Name |
(E)-3'-methyl-3''-styryl-3,2'
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| Synonyms |
Pyridoclax; MR29072; MR 29072; MR29072
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| HS Tariff Code |
2934.99.9001
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| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
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| Solubility (In Vitro) |
DMSO: ~20 mg/mL (~46.9 mM)
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| Solubility (In Vivo) |
Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.
Injection Formulations
Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)(e.g. IP/IV/IM/SC) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). View More
Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] Oral Formulations
Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). View More
Oral Formulation 3: Dissolved in PEG400 (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 2.3446 mL | 11.7231 mL | 23.4461 mL | |
| 5 mM | 0.4689 mL | 2.3446 mL | 4.6892 mL | |
| 10 mM | 0.2345 mL | 1.1723 mL | 2.3446 mL |
*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
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