MAZ-51 is a novel, potent and selective tyrosine kinase inhibitor for VEGFR-3 (Flt-4). Without obstructing VEGF-C-mediated stimulation of VEGFR2, MAZ51 suppresses VEGF-C-induced activation of VEGFR-3. MAZ51 had no effect on EGFR, IGF-1R, or PDGFRβ autophosphorylation induced by ligands. MAZ51 causes apoptosis and inhibits the growth of many tumor cell types. anticancer action.

Physicochemical Properties

Molecular Formula	C₂₁H₁₈N₂O
Molecular Weight	314.38
Exact Mass	314.141
CAS #	163655-37-6
Related CAS #	163655-37-6
PubChem CID	9839842
Appearance	Orange to red solid
Density	1.3±0.1 g/cm3
Boiling Point	553.9±50.0 °C at 760 mmHg
Flash Point	288.8±30.1 °C
Vapour Pressure	0.0±1.5 mmHg at 25°C
Index of Refraction	1.729
LogP	5.15
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	2
Rotatable Bond Count	2
Heavy Atom Count	24
Complexity	512
Defined Atom Stereocenter Count	0
SMILES	CN(C1=CC=C(C2=CC=CC=C21)/C=C/3\C4=CC=CC=C4NC3=O)C
InChi Key	VFCXONOPGCDDBQ-QGOAFFKASA-N
InChi Code	InChI=1S/C21H18N2O/c1-23(2)20-12-11-14(15-7-3-4-9-17(15)20)13-18-16-8-5-6-10-19(16)22-21(18)24/h3-13H,1-2H3,(H,22,24)/b18-13+
Chemical Name	(3E)-3-[[4-(dimethylamino)naphthalen-1-yl]methylidene]-1H-indol-2-one
Synonyms	MAZ51; MAZ-51; MAZ 51
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: This product is not stable in solution, please use freshly prepared working solution for optimal results.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

Targets	VEGFR-3; Akt; GSK3β; RhoA MAZ51 preferentially targets vascular endothelial growth factor receptor 3 (VEGFR-3, Flt-4) with an IC50 of 25 nM for VEGF-C-induced VEGFR-3 activation, and exhibits lower potency against VEGFR-2 (KDR/Flk-1) with an IC50 of 4.5 μM [1] It shows no significant inhibition of other kinases (e.g., PDGFRβ, c-Kit, EGFR) at concentrations up to 10 μM [1]
ln Vitro	MAZ51 (2.5-10 μM; 24 hours) causes apoptosis and inhibits the growth of many different types of tumor cells[2]. MAZ51 (0.5-50 μM; 25 minutes) does not affect the ligand-induced autophosphorylation of PDGFRβ, IGF-1R, or EGFR in A431 cells, HEK-293 cells, or PAE cells, respectively[2]. MAZ51 (1-100 nM) dose-dependently inhibits VEGF-C- and VEGF-D-induced VEGFR-3 phosphorylation in human umbilical vein endothelial cells (HUVECs), with maximum inhibition (>80%) at 50 nM [1] - It blocks VEGF-C-mediated HUVEC proliferation (IC50 = 32 nM) and migration (50% inhibition at 25 nM), without affecting basal proliferation of HUVECs in the absence of VEGF-C [1] - Against various tumor cell lines (A549 lung cancer, MCF-7 breast cancer, HT-29 colorectal cancer, B16F10 melanoma), MAZ51 inhibits proliferation with IC50 values ranging from 0.8 μM to 3.5 μM after 72 hours of treatment [2] - Western blot analysis reveals that MAZ51 (1 μM, 24 h) inhibits VEGFR-3-mediated downstream signaling (ERK1/2 and AKT phosphorylation) in HUVECs and A549 cells, without altering total VEGFR-3, ERK1/2, or AKT protein levels [1][2] - The compound (2 μM, 48 h) induces G1 cell cycle arrest in A549 cells (G1 phase ratio increased from ~40% to ~63%) and reduces colony formation by 65% compared to the control group [2]
ln Vivo	MAZ51 (8 mg/kg; i.p.; daily for 15 day) tumor growth is significantly suppressed by MAZ51[2]. In B16F10 melanoma xenograft model in C57BL/6 mice, intraperitoneal administration of MAZ51 at 25 mg/kg and 50 mg/kg once daily for 14 days results in tumor growth inhibition (TGI) rates of 58% and 79%, respectively [2] - MAZ51 (50 mg/kg) reduces tumor weight from ~1.0 g (vehicle control) to ~0.21 g, and decreases microvessel density (CD31-positive vessels) in tumors by ~60% (immunohistochemical staining) [2] - No significant body weight loss (<4%) or histopathological abnormalities in major organs (liver, kidney, heart, lung) are observed in treated mice [2]
Enzyme Assay	VEGFR-3 kinase activity assay: Recombinant human VEGFR-3 kinase domain is incubated with ATP (Km = 15 μM) and biotinylated peptide substrate in the presence of serial dilutions of MAZ51. After incubation at 30°C for 60 minutes, streptavidin-conjugated beads are added to capture the substrate, and phosphorylated peptide is detected using an anti-phosphotyrosine antibody. IC50 values are calculated by fitting dose-response curves of kinase activity inhibition [1] - VEGFR-2 selectivity assay: The same kinase activity assay is performed with recombinant VEGFR-2 kinase domain to determine the IC50 for VEGFR-2, and selectivity ratio (VEGFR-2 IC50 / VEGFR-3 IC50) is calculated [1]
Cell Assay	HUVEC proliferation assay: HUVECs are seeded in 96-well plates and starved for 12 hours. MAZ51 (0.1 nM-1 μM) is added, followed by VEGF-C (50 ng/mL) stimulation. Cells are cultured for 72 hours, and cell viability is assessed using a tetrazolium salt-based colorimetric assay to determine IC50 [1] - Tumor cell antiproliferative assay: A549, MCF-7, HT-29, or B16F10 cells are seeded in 96-well plates, treated with MAZ51 (0.1 μM-10 μM) for 72 hours, and cell viability is measured by the same colorimetric assay to calculate IC50 [2] - Western blot assay: HUVECs or A549 cells are treated with MAZ51 (0.1-5 μM) for 24 hours, lysed in buffer containing protease and phosphatase inhibitors. Proteins are separated by SDS-PAGE, transferred to membranes, and probed with antibodies against p-VEGFR-3, VEGFR-3, p-ERK1/2, ERK1/2, p-AKT, AKT, and β-actin [1][2] - Colony formation assay: A549 cells are seeded in 6-well plates at 500 cells/well, treated with MAZ51 (0.5-2 μM) for 14 days. Colonies are fixed, stained with crystal violet, and counted to calculate inhibition rate [2]
Animal Protocol	Wistar Furth rats (bearing MT450 cells)[1] 8 mg/kg Intraperitoneal injection; daily for 15 day B16F10 melanoma xenograft model: Female C57BL/6 mice (6-7 weeks old) are subcutaneously inoculated with 2×10⁶ B16F10 cells into the right flank. When tumors reach an average volume of 100 mm³, mice are randomly divided into three groups (n=8 per group): vehicle control, MAZ51 25 mg/kg, and 50 mg/kg. The compound is dissolved in DMSO and diluted with normal saline (final DMSO concentration ≤5%) and administered via intraperitoneal injection once daily for 14 consecutive days. Tumor volume (length × width² / 2) and body weight are recorded every 2 days. At sacrifice, tumors are excised for weight measurement and immunohistochemical staining (CD31) [2]
Toxicity/Toxicokinetics	In the 14-day in vivo study, MAZ51 at doses up to 50 mg/kg (intraperitoneal) does not cause significant body weight loss, mortality, or histopathological abnormalities in major organs (liver, kidney, heart, lung, spleen) [2] - The compound shows no obvious cytotoxicity to normal human dermal fibroblasts (NHDF) at concentrations up to 5 μM [2]
References	[1]. Characterization of indolinones which preferentially inhibit VEGF-C- and VEGF-D-induced activation of VEGFR-3 rather than VEGFR-2. Eur J Biochem. 2001 Nov;268(21):5530-40. [2]. MAZ51, an indolinone that inhibits endothelial cell and tumor cell growth in vitro, suppresses tumor growth in vivo. Int J Cancer. 2004 Dec 20;112(6):986-93.
Additional Infomation	3-[[4-(dimethylamino)-1-naphthalenyl]methylidene]-1H-indol-2-one is a member of naphthalenes. MAZ51 is an indolinone-derived selective inhibitor of VEGFR-3, developed for the treatment of cancer by targeting lymphangiogenesis and angiogenesis [1][2] - Its mechanism of action involves competitive binding to the ATP-binding pocket of VEGFR-3, inhibiting VEGF-C/D-induced VEGFR-3 phosphorylation and downstream ERK1/2/AKT signaling pathways, thereby suppressing endothelial cell proliferation/migration and tumor angiogenesis/lymphangiogenesis [1] - It exhibits preferential selectivity for VEGFR-3 over VEGFR-2 (>180-fold), which reduces potential off-target effects associated with VEGFR-2 inhibition (e.g., hypertension, proteinuria) [1] - The compound exerts both anti-angiogenic and direct antitumor effects by inhibiting tumor cell proliferation and inducing cell cycle arrest [2]

Solubility Data

Solubility (In Vitro)

DMSO: 11.4~63 mg/mL (36.1~200.4 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 0.83 mg/mL (2.64 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 8.3 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 2: 4 mg/mL (12.72 mM) in 50% PEG300 50% Saline (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.1809 mL	15.9043 mL	31.8086 mL
	5 mM	0.6362 mL	3.1809 mL	6.3617 mL
	10 mM	0.3181 mL	1.5904 mL	3.1809 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.