Mepazine HCl (Pecazine HCl) is a potent and specific MALT1 protease inhibitor. Mepazine HCl inhibits full-length GSTMALT1 and the 325-760 segment of GSTMALT1 with IC50s of 0.83 and 0.42 μM, respectively. Mepazine HCl affects the viability of ABC-DLBCL cells by enhancing apoptosis.

Physicochemical Properties

Molecular Formula	C19H23CLN2S
Molecular Weight	346.92
Exact Mass	346.127
CAS #	2975-36-2
Related CAS #	Mepazine;60-89-9
PubChem CID	102907
Appearance	White to off-white solid powder
Boiling Point	444.4ºC at 760 mmHg
Flash Point	222.6ºC
Vapour Pressure	4.29E-08mmHg at 25°C
LogP	5.436
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	3
Rotatable Bond Count	2
Heavy Atom Count	23
Complexity	352
Defined Atom Stereocenter Count	0
InChi Key	RLCFKYRNUBRPIK-UHFFFAOYSA-N
InChi Code	InChI=1S/C19H22N2S.ClH/c1-20-12-6-7-15(13-20)14-21-16-8-2-4-10-18(16)22-19-11-5-3-9-17(19)21;/h2-5,8-11,15H,6-7,12-14H2,1H3;1H
Chemical Name	10-[(1-methylpiperidin-3-yl)methyl]phenothiazine;hydrochloride
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: Please store this product in a sealed and protected environment, avoid exposure to moisture.
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	MALT1[1]
ln Vitro	In activated B-cell subtypes of diffuse large B-cell lymphoma (ABCDLBCL) cells, mepazine (5–20 μM; 4 days) reduces cell survival; however, it has no discernible effect on GCB-DLBCL cells [1].
ln Vivo	Mepazine (16 mg/kg; i.p.) inhibits the development of the ABC-DLBCL cell line OCI-Ly10 in NOD/scid IL-2RgnuLl (NSG) mice and causes apoptosis. Mepazine given daily significantly inhibits the ABC-DLBCL cell line OCI-Ly10's ability to proliferate [1].
Cell Assay	Cell Viability Assay[1] Cell Types: ABC-DLBCL cell lines (HBL1, OCI-Ly3, U2932, TMD8, OCI-Ly10 ) and GCB-DLBCL cell lines (BJAB, Su-DHL-6, Su-DHL-4) Tested Concentrations: 5, 10, and 20 μM Incubation Duration: 4 days Experimental Results: Caused a decrease of cell viability in the ABC-DLBCL cells HBL1, OCI-Ly3, U2932, and TMD8, without Dramatically affecting GCB-DLBCL cells.
Animal Protocol	Animal/Disease Models: 6- to 8weeks old female NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice with a murine DLBCL xenogeneic tumor model[1] Doses: 400 μg per animal (25 g), corresponding to approximately 16 mg/kg Route of Administration: intraperitoneal (ip)administration; started 1 or 12 days after transplantation and given continuously every 24 hr; daily application Experimental Results: Daily administration strongly impaired the expansion of the ABC-DLBCL cell line OCI-Ly10.
References	[1]. Pharmacologic inhibition of MALT1 protease by phenothiazines as a therapeutic approach for the treatment of aggressive ABC-DLBCL. Cancer Cell. 2012 Dec 11;22(6):825-37.

Solubility Data

Solubility (In Vitro)

DMSO : 50 mg/mL (144.13 mM) H2O : 2.22 mg/mL (6.40 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.21 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% 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 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.5 mg/mL (7.21 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 25.0 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 3: ≥ 2.5 mg/mL (7.21 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (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 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly. Solubility in Formulation 4: 1.25 mg/mL (3.60 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication (<60°C).  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.8825 mL	14.4125 mL	28.8251 mL
	5 mM	0.5765 mL	2.8825 mL	5.7650 mL
	10 mM	0.2883 mL	1.4413 mL	2.8825 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.