LV-320 is a potent and noncompetitive ATG4B inhibitor (antagonist) with IC50 of 24.5 μM and a Kd of 16 μM. LV-320 inhibits the enzymatic activity of ATG4B, blocks autophagy, and is stable, non-toxic and active in the body.

Physicochemical Properties

Molecular Formula	C29H26CLNO2S2
Molecular Weight	520.11
Exact Mass	519.109
CAS #	2449093-46-1
PubChem CID	134817239
Appearance	Light yellow to yellow solid powder
Density	1.317±0.06 g/cm3(Predicted)
Boiling Point	718.4±60.0 °C(Predicted)
LogP	7.8
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	11
Heavy Atom Count	35
Complexity	663
Defined Atom Stereocenter Count	0
SMILES	C1=CC=C(C=C1)CCSC(C2=CC=C(C=C2)/C=C/C3=C4C=CC(=CC4=NC=C3)Cl)SCCC(=O)O
InChi Key	PHENTWJNXGESKT-RMKNXTFCSA-N
InChi Code	InChI=1S/C29H26ClNO2S2/c30-25-12-13-26-23(14-17-31-27(26)20-25)9-6-22-7-10-24(11-8-22)29(35-19-16-28(32)33)34-18-15-21-4-2-1-3-5-21/h1-14,17,20,29H,15-16,18-19H2,(H,32,33)/b9-6+
Chemical Name	3-[[4-[(E)-2-(7-chloroquinolin-4-yl)ethenyl]phenyl]-(2-phenylethylsulfanyl)methyl]sulfanylpropanoic acid
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
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	IC50: 24.5 µM (ATG4B); Kd: 16 μM (ATG4B)[1]
ln Vitro	In all four cell lines, endogenous LC3B-II and protein p62 levels increase in a dose-dependent manner upon treatment with LV-320 (0-120 µM; SKBR3, MCF7, JIMT1, and MDA-MB-231 cells)[1]. Treatment with -320 (120 µM; 48 hours; MDA-MB-231 cells) causes an increase in LC3B-II, suggesting that LV-320 inhibits autophagic flux[1].
ln Vivo	Treatment with LV-320 (100-200 mg/kg; oral gavage; three times over two days; GFP-LC3 mice) causes a 104 µM liver level and a 169 µM terminal blood level. Compared to controls, mice treated with LV-320 exhibited a considerably higher accumulation of GFP-LC3 puncta expression. Animals treated with LV-320 also exhibit an increase in LC3B-II protein. At any dosage, the therapy does not significantly harm mice[1].
Cell Assay	Western Blot Analysis[1] Cell Types: SKBR3, MCF7, JIMT1, and MDA-MB-231 cells Tested Concentrations: 0 µM, 25 µM, 50 µM, 75 µM, 100 µM, or 120 µM Incubation Duration: Experimental Results: Resulted in a dose-dependent increase in endogenous LC3B-II and protein p62 levels in all four cell lines. Cell Autophagy Assay[1] Cell Types: MDA-MB-231 cells Tested Concentrations: 120 µM Incubation Duration: 48 hrs (hours) Experimental Results: Blocked autophagic flux.
Animal Protocol	Animal/Disease Models: GFP-LC3 mice (females, 9-14 weeks)[1] Doses: 100 mg/kg or 200 mg/kg Route of Administration: po (oral gavage); three times over two days (pharmacokinetic/PK study) Experimental Results: Terminal blood levels were 169 µM and liver levels were 104 µM. LC3B-II protein level was also increased.
References	[1]. A new quinoline-based chemical probe inhibits the autophagy-related cysteine protease ATG4B. Sci Rep. 2018 Aug 3;8(1):11653. doi: 10.1038/s41598-018-29900-x.

Solubility Data

Solubility (In Vitro)

DMSO : 135 mg/mL (259.56 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.25 mg/mL (4.33 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 22.5 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: ≥ 2.25 mg/mL (4.33 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 22.5 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.9227 mL	9.6134 mL	19.2267 mL
	5 mM	0.3845 mL	1.9227 mL	3.8453 mL
	10 mM	0.1923 mL	0.9613 mL	1.9227 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.