TBPH does not have a specific biological target; it is an environmental toxicant. Its toxic mechanism involves disrupting endoplasmic reticulum-mitochondria (ER-Mito) contact sites, leading to mitochondrial dysfunction. It induces phospholipid metabolism disorders, reducing cardiolipin (CL) and phosphatidylserine (PS) levels. TBPH also promotes inflammation and fibrosis via mitochondrial double-stranded DNA (mtDNA) release and activation of the cGAS-STING pathway. It also induces oxidative stress and disrupts MFN2-mediated ER-Mito contacts.

TBPH (5-50 μM, 48 h) promotes NASH progression by disrupting MFN2-regulated ER-Mito contact in the NASH LO model [1]. TBPH (0-20 μg/mL, 48 h) reduces cell proliferation in TC-1 and BEAS-2B cells, induces oxidative stress, increases lung fibrosis, and leads to the release of ds-DNA from lung mitochondria, thereby activating c-GAS-STING [2].

---

In vitro, TBPH exhibits toxic effects. In NASH liver organoid (LO) models, TBPH (5-50 uM, 48 h) promotes NASH progression by disrupting MFN2-regulated ER-Mito contacts. It upregulates oxidative stress-related genes (CYP2E1, CYP1A2), fibrosis-related genes (COL3A1, COL4A1, LOXL2, TIMP1, VIM), and inflammatory genes (TNF-alpha, IL-8). In TC-1 and BEAS-2B cells, TBPH (0-20 ug/mL, 48 h) reduces cell proliferation, induces oxidative stress, increases lung fibrosis, and causes mitochondrial double-stranded DNA release, activating the c-GAS-STING pathway. In an MTT assay, TBPH reduces viability with an IC₅0 of 10-50 uM.

TBPH (20–200 mg/kg once daily for 4 weeks) enhanced Plasmodium accumulation and dysfunction in a micaceous choline deficiency (MCD) diet-induced NASH model, leading to cardiac response and fibrosis progression, disrupting hepatocyte endoplasmic reticulum-mitochondrial contact, fire channel disruption, and endoplasmic reticulum disruption[1]. TBPH (20–200 mg/kg once daily for 4 weeks) did not alter liver morphology or liver body index in a normal diet (ND) mouse model, but impaired hepatocyte endoplasmic reticulum-mitochondrial contact, inducing mitochondrial dysfunction and endoplasmic reticulum disruption[1]. TBPH (0–100 μg/mL once daily for 4 weeks) caused oxidative damage to lung cells in C57 mice and induced inflammatory responses in the lungs and tissues[2].

---

In vivo, TBPH promotes NASH progression in mice. In the methionine-choline-deficient (MCD) diet-induced NASH model, TBPH (20-200 mg/kg, oral gavage, daily for 4 weeks) exacerbates hepatic steatosis, inflammation, and fibrosis. It induces ER-Mito contact disruption, mitochondrial dysfunction, and phospholipid metabolism disorders. In a normal diet (ND) mouse model, TBPH (20-200 mg/kg, 4 weeks) does not change liver morphology but still damages ER-Mito contacts and induces mitochondrial dysfunction. In a lung model, TBPH (0-100 ug/mL, oral gavage, 4 weeks) induces oxidative damage and inflammation in mouse lungs.

RT-PCR[1]
Cell Types: NASH LOs model
Tested Concentrations: 5 μM, 50 μM
Incubation Duration: 48 h
Experimental Results: Upregulated the transcriptional levels of oxidative stress-related genes (CYP2E1 and CYP1A2), fibrosis-related genes (COL3A1, COL4A1, LOXL2, TIMP1, VIM), and inflammation-related genes (TNF-α, IL-8).

---

Immunofluorescence[1]
Cell Types: NASH LOs model
Tested Concentrations: 5 μM, 50 μM
Incubation Duration: 48 h
Experimental Results: Decreased colocalization of mitochondria (HSP60) and ER (GRP78), indicating reduced ER-Mito contacts.

---

Western Blot Analysis[1]
Cell Types: NASH LOs model
Tested Concentrations: 5 μM, 50 μM
Incubation Duration: 48 h
Experimental Results: Decreased MFN2 level, increased UPRmt markers (HSP60, SOD2) and ER stress markers (GRP78, ATF6).

---

Western Blot Analysis[1]
Cell Types: TC-1 and BEAS-2B cells
Tested Concentrations: 0 μg/mL, 0.2 μg/mL, 2 μg/mL, 10 μg/mL
Incubation Duration: 48 h
Experimental Results: Inhibited the expression of CyclinD1 and promoted the phosphorylation of Rb, increased the expression levels of CDK2/4 and P53. Increased the levels of IL-6, IL-1β, p-IκB and p-P65. Up-regulated the expression of FN and α-SMA, Down-regulated the expression of E-cadherin.

---

Animal/Disease Models: MCD diet-induced NASH mouse (Male C57BL/6, 8-9 weeks old, 22-25 g) model[1]
Doses: 20 mg/kg, 200 mg/kg
Route of Administration: i.g., once a day, 4 weeks
Experimental Results: Exacerbated hepatic pathology, increased the hepatosomatic index, enhanced lipid accumulation, decreased serum HDL and CHO levels, alongside elevated hepatic TG and serum LDL levels. Augmented hepatic steatosis and inflammatory cell infiltration, enhanced fibrotic deposition, increased steatosis, inflammatory infiltration, fibrosis and NASH scores, elevated serum levels of AST and ALT. Reduced the abundance of cardiolipin (CL), phosphatidylserine (PS), and phosphatidylethanolamine (PE), while increasing phosphatidic acid (PA) levels. Disrupted lipid metabolism associated with the endoplasmic reticulum and mitochondria, altered the negative intrinsic curvature of membranes. Reduced colocalization of ER and mitochondria in liver tissues, increased the physical distance between ER and mitochondria and reduced contact sites. Caused a marked reduction in mitochondrial cristae, disrupted cristae junctions (CJs), and disorganization of cristae membranes in hepatocytes, reduced overall oxygen consumption and ATP content. Increased HSP60, SOD2, mitochondrial proteases (LONP1, ClpP), GRP78, Atf6, eIF2α, and Chop levels, decreased the MFN2 protein level.

---

Animal/Disease Models: ND mice (Male C57BL/6, 8-9 weeks old, 22-25 g) model[1]
Doses: 20 mg/kg, 200 mg/kg
Route of Administration: i.g., once a day, 4 weeks
Experimental Results: Did not significantly alter liver morphology, did not change the hepatosomatic index. Affected C14:0 metabolism, fatty acids with 13-15 carbon chains, and mitochondrial metabolic processes, altered the negative intrinsic curvature of membranes. Reduced colocalization of ER and mitochondria in liver tissues, increased the physical distance between ER and mitochondria and reduced contact sites. Elevated the protein levels of mitochondrial chaperone HSP60, SOD2, GRP78, Atf6, eIF2α, and Chop, decreased the MFN2 protein level.

---

Animal/Disease Models: C57 mice model[2]
Doses: 0 μg/mL, 0.5 μg/mL, 1 μg/mL, 5 μg/mL, 10 μg/mL, 30 μg/mL L, 60 μg/mL, 100 μg/mL
Route of Administration: i.g., once a day, 4 weeks
Experimental Results: Induced capillary congestion in the alveolar wall and obvious inflammatory cell infiltration. Increased the expression levels of TNFα, IL-1β, IL-6, IL-8, IFNγ, eotaxin, MCP-1, MIP-2, RANTES, p16, p21, P65, and p-IκB proteins, and decreased the expression level of cell proliferation marker (Ki67). Up-regulated the expression of FN, α-SMA, and TGF-β, down-regulated the expression of E-cadherin, and increases the content of collagen fibers in the lungs. Increased ROS and MDA levels, and decreased GSH, SOD, and CAT expression levels.

---

TBPH is a lipophilic persistent organic pollutant. It accumulates in adipose tissue and has a long elimination half-life (years in humans). It is not readily metabolized and is excreted slowly. For research use, TBPH is supplied as a thick pale yellow oil, stored at 2-8degC, and is soluble in organic solvents.

TBPH is a moderate environmental hazard. The EPA classifies it as a moderate hazard for reproductive, developmental, neurological, and repeated-dose toxicities based on rodent studies. It is also an endocrine disruptor. It is not genotoxic. For impurity qualification in a drug substance, it is not a standard impurity; it is an environmental pollutant. If present, limits should be set based on toxicological data and ICH guidelines.

[1]. Zhou Y, Li B, Zhao J, Ren X, Guo Y, Yang L, Han J, Wu L, Zhou B. Bis(2-Ethylhexyl)-2,3,4,5-Tetrabromophthalate Promotes NASH Progression through Disrupting Endoplasmic Reticulum-Mitochondria Contacts. Environ Sci Technol. 2025 Jul 22;59(28):14302-14313.

[2]. TBPH-induced lung injury is induced by mitochondrial-derived ds-DNA-mediated inflammatory response. Ecotoxicol Environ Saf. 2024 Nov 1;286:117200.

Background: TBPH is a brominated phthalate derivative used as a flame retardant in polyvinyl chloride (PVC) and other polymers. It is an alternative to the phased-out polybrominated diphenyl ethers (PBDEs). It is found in household dust and is a contaminant of concern. The compound is used in research to study the health effects of flame retardants. It is for research use only.

705.915

26040-51-7

TBPH-13C6,d34

117291

Light yellow to yellow liquid（Density: 1.529±0.06 g/cm3）

0

16

32

514

0

UUEDINPOVKWVAZ-UHFFFAOYSA-N

InChI=1S/C24H34Br4O4/c1-5-9-11-15(7-3)13-31-23(29)17-18(20(26)22(28)21(27)19(17)25)24(30)32-14-16(8-4)12-10-6-2/h15-16H,5-14H2,1-4H3

bis(2-ethylhexyl) 3,4,5,6-tetrabromobenzene-1,2-dicarboxylate

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ≥ 175 mg/mL (~247.83 mM)

Solubility in Formulation 1: ≥ 5 mg/mL (7.08 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 50.0 mg/mL clarified DMSO stock solution to 900 μL of corn oil and mix well.

---

 (Please use freshly prepared in vivo formulations for optimal results.)