The bisphenol A (BPA) metabolite, 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP) is possibly more estrogenic than its parent compound, finds a new scientific study. Published in the open access journal PLOS1, the study compared the 3D chemical structures of BPA, estradiol and MBP for their fit into the ligand pockets of both the human estrogen receptor α and β. MBP was a much closer fit than BPA, almost resembling the natural ligand estradiol, requiring a 1000-fold lower concentration than BPA to produce estrogenic effects.From first in vitro assays the researchers conclude that MBP is a better estrogen receptor ligand than BPA. So far it is not known how high MBP levels are in the general population and whether the substance would also be estrogen active in people.
Michael E. Baker, ME and Chandsawangbhuwana, C (2012). 3D Models of MBP, a Biologically Active Metabolite of Bisphenol A, in Human Estrogen Receptor α and Estrogen Receptor β. PLoS ONE 7(10): e46078. doi:10.1371/journal.pone.0046078