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Table 1 Sample list of a subset of well-established obesogens with their partitioning coefficients, half-life, and molecular weight (g/mol). The octanol/water partitioning coefficient is measured using the log Kow value, which indicates the partitioning of a chemical between octanol and water. In these experiments, octanol is used to mimic fat and other hydrophobic components in biological systems. A partitioning coefficient level greater than 1 indicates low solubility in water

From: Mechanisms of action, chemical characteristics, and model systems of obesogens

Obesogen Source

Obesogensa

Chemical Characteristics*

Partitioning (Log Kow) b

Half-life (hours)c

Size (g/mol)

Industrial Chemicals

Bisphenol A (BPA)

3.32

5.3d [10, 11]

228.291

Bisphenol A diglycidyl ether (BADGE)

~ 3.84

120e [12]

340.419

Bisphenol S (BPS)

~ 1.65

6.93 [13]

250.268

Firemaster 550 (FM550)

8.80–11.95f

Unknown [14]

549.923

2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47)

6.81 ± 0.08 [15]

664 daysg

485.795

3,3′,4,4′-Tetrachlorobiphenyl (PCB-77)

6.72

152–186 [16]

291.980

Mono-(2-ethylhexyl) phthalate (MEHP)

4.92h

4.4–6.6i

278.348

bis(2-ethylhexyl) phthalate (DEHP)

7.60

5j

390.564

Biocides

Dichlorodiphenyl-trichloroethane (DDT)

6.91

10.6k

354.476

Tributyltin (TBT)

3.90–4.90 [17]

23–30 days [18]

290.058

Triphenyltin (TPT)

4.19l

3 days

385.478

Pharmaceuticals

Diethylstilbestrol (DES)

5.07

2–3 days [19]

268.350

Estradiol (Estrogen steroid Hormone)

4.01

3 days

272.388

Pollutant

Dioxin

6.80

5–8 years

321.970

Smoking

Nicotine

1.17

1–4m

162.236

  1. Sources
  2. *Values of partition coefficients and half-lives might differ from those in this table because of variations in the study such as the location the study was conducted, type of tissue, biphasic pattern, initial dosage, temperature, salinity and pH.
  3. aThe obesogens discussed are well-established obesogens that have been used in various studies.
  4. bAll values of log Kow were reported at 25°C and at a pH of 7 unless stated otherwise.
  5. cAll estimated half-life values reported were conducted on studies in human based models unless stated otherwise.
  6. dBPA data are not consistent with the current consensus that BPA exposures are both rapidly cleared and almost entirely related to food intake. Instead, it appears plausible that there is substantial nonfood exposure, accumulation in body compartments with long elimination times, or both [3].
  7. eBisphenol A diglycidyl ether based on Hydrolysis in Water.
  8. f2-ethyl-1-hexyl-2,3,4,5-tetrabromobenzoate (TBB) and bis (2-ethylhexyl) tetrabromophthalate (TBPH) are the two major additive Brominated flame retardants (BFRs) in Firemaster 550. [16].
  9. gTetrabromodiphenyl ether (BDE-47) has two phases of elimination. The first phase of elimination is where the majority of the BDE-47 is eliminated from the body (67%), and the remaining BDE-47 is eliminated during the terminal phase. Additionally, elimination, both whole-body and from individual tissues, is biphasic due to varying initial and terminal phase lengths in different tissues. Since BDE-47 is highly lipophilic its terminal phase was primarily dictated by adipose tissue and skin [21].
  10. hMEHP was estimated from n-octanol: water coefficient (Kow) by the algorithm from Poulin and Krishnan (1993). A log Kow of 4.92 was estimated based on the chemical structure for nonionized MEHP.
  11. iSingle administration of MEHP in a rat (0.4 g/kg) resulted in plasma concentrations of 84.1 +/− 14.9 micrograms/ml 3 h after dosing; the half-life of MEHP was 5.5 +/− 1.1 h. [22].
  12. jAfter an absorption and distribution phase of 4 to 8 h, half-life times of excretion in the first elimination phase were approximately 2 h; Half-life times in the second phase—beginning 14 to 18 h post dose—were 5 h for MEHP [23].
  13. kFemale rats were dosed orally with (14) C-ring-labeled p,p’-DDT during pregnancy or lactation. Average half-life was 10.6 h in tissues and in the fetus.
  14. lTriphentylin Chloride was used to find the log Kow.
  15. mNicotine’s half-life in the initial phase is reportedly about 2–3 min and the half-life in the terminal phase averages about 2 h.
  16. Note: All partitioning coefficient values > 1 indicate lipophilic properties (bold). Half-life with strong indication of biphasic pattern (bold). Non-asterisk and cited chemical characteristics were obtained from the U.S. National Library of Medicine Open Chemistry Database and the International Programme on Chemical Safety.