Bis(2-ethylhexyl) phthalate: Sources, Biological Activity and Metabolism

Sources

Bis(2-ethylhexyl) phthalate (DEHP) is an organic compound isolated from a number of microorganisms (e.g., bacteria and fungi), including Penicillium, Lactiplantibacillus plantarum BCH-1, Aspergillus parasiticus and Fusarium subglutinans. DEHP can be used as a plasticiser for polyvinyl chloride (PVC) products, and can also be used to improve the plasticity and flexibility of materials such as food packaging, construction, toys and medical devices (e.g., blood storage bags, intravenous fluid bags).

Biological Activity

Bis(2-ethylhexyl) phthalate has good antimicrobial and larvicidal bioactivities and can effectively inhibit the growth of Gram-positive pathogens and Culex quinquefasciatus Say larvae.

In a study of the antimicrobial activity of DEHP against Escherichia coli, Streptococcus lactis B and Staphylococcus aureus, the results showed that the MIC value of DEHP was 32 mg/ml. DEHP exhibits antimicrobial activity against both Gram-positive and Gram-negative pathogens, and therefore can be used for the treatment of infections with these bacterial pathogens.

Another study also showed that the antibacterial potential of DEHP against E. coli and S. aureus was 12.33 ± 0.56 mm and 5.66 ± 1.00 mm, respectively. The larvicidal efficacy of DEHP against Culex quinquefasciatus Say larvae was 100 per cent mortality after 72 hours at 250 ppm, with a LC50 of 67.03 ppm. The LD50 was 67.03 ppm and the inhibition of acetylcholinesterase was 29.00, 40.33, 53.00, 64.00 and 75.33 (%) at 50, 100, 150, 200 and 250 ppm respectively after 72 h. DEHP had a significant acetylcholinesterase inhibitory effect on the larvae of Culex quinquefasciatus Say larvae. DEHP has a strong antibacterial and larvicidal activity against Culex quinquefasciatus Say larvae with significant acetylcholinesterase inhibition and DNA damage.

Metabolism

Most of the metabolites of DEHP in the body are excreted through urine and faeces (bile secretion). To study the human metabolism of bis (2-ethylhexyl)-phthalate (DEHP) urine samples were analyzed from non-uremic psoriatic patients, uremic patients undergoing hemodialysis treatments and patients undergoing cardiac bypass surgery using High Performance Liquid Chromatography (HPLC). The urine of dialyzed non-uremic patients contained phthalic acid, mono (2-ethylhexyl) phthalate and bis (2-ethylhexyl) phthalate. Other compounds identified were p-hydroxy benzoic acid, m-hydroxy benzoic acid, o-hydroxy hippuric acid, o-hydroxy benzoic acid and benzoic acid, which may be either diet dependent normal urinary constituents or metabolites of bis (2-ethylhexyl) phthalate. The levels of phthalic acid and bis (2-ethylhexyl) phthalate found in the urine of patients who were on total body oxygenators containing a membrane during cardiac bypass surgery were comparable to levels obtained from non-uremic psoriatic patients. Significant levels of phthalic acid were detected in the urine of the uremic patients studied while mono (2-ethylhexyl) phthalate and bis (2-ethylhexyl)-phthalate were present only in small amounts or were completely absent. In general, the urinary phthalate content of uremic patients increased with urinary volume.

References:

[1] ALI M A A, DARWEESH A O, MATAR M M. Isolation and characterization of an antibacterial compound Bis-(2-ethylhexyl) phthalate from the fungi Penicillium digitatum[J]. Biomedicine (India), 2023. DOI:10.51248/.v43i5.3264.

[2] MUHAMMAD RIZWAN JAVED. The Antibacterial and Larvicidal Potential of Bis-(2-Ethylhexyl) Phthalate from Lactiplantibacillus plantarum.[J]. Molecules, 2022. DOI:10.3390/molecules27217220.

[3] E. DRAVIAM; J. K; K H Pearson. Human Metabolism of Bis(2-ethylhexyl)phthalate[J]. Analytical Letters, 1982. DOI:10.1080/00032718208065150.

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