- Low Triphenylphosphate, High Phosphorous Content Isopropyl Phenyl Phosphates With High Ortho Alkylation
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The present invention relates to low triphenyl phosphate, high phosphorous content aryl phosphates with high ortho alkylation that are suitable for use as flame retardant compositions, processes for their preparation, and their use as flame retardants.
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- Effects of triaryl phosphates on mouse and human nuclear receptors
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The constitutively active receptor (CAR) is a crucial regulator of genes encoding for enzymes active in drug/steroid oxidation, conjugation, and transport. In our attempt to isolate the endogenous inhibitory ligand(s) for the mouse CAR, we found surprisingly that the inhibitory activity was associated with di- and tri-isopropylated phenyl phosphates that were present in livers of untreated mice. Trans-activation experiments in mammalian cells with synthetic compounds verified that mouse CAR was inhibited by various isopropylated phenyl phosphates (40-80%). Such triaryl phosphates are widely used as fire retardants, lubricants, and plasticizers, and some of them are known to disturb reproduction by currently unknown mechanisms. Equipped with the finding that these compounds could interact with mouse CAR, we proceeded to determine their functional effects on other nuclear receptors. Human CAR and pregnane X receptor (PXR) were variably activated (2-5-fold) by triaryl phosphates while mouse PXR, peroxisome proliferator-activated receptor-α, and vitamin D receptor were refractory. Among steroid hormone receptors, the human androgen receptor was inhibited by triphenyl phosphate and di-ortho-isopropylated phenyl phosphate (40-50%) and activated by di- and tri-para-substituted phenyl phosphates (2-fold). Our results add to the list of CAR and PXR activators and suggest steroid-dependent biological pathways that may contribute to the reproductive effects of triaryl phosphates.
- Honkakoski, Paavo,Palvimo, Jorma J.,Penttilae, Leena,Vepsaelaeinen, Jouko,Auriola, Seppo
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- KINETICS OF ESTERIFICATION OF MONOISOPROPYLPHENOLS WITH PHOSPHORYL TRICHLORIDE
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The kinetics of liquid-phase isothermal esterification of POCl3 with 2-isopropylphenol and 4-isopropylphenol have been studied within the temperature intervals of 110 to 130 and 90 to 110 deg C, respectively.The rate constants and activation energies of the individual steps of this three-step reaction have been calculated from the values measured.The reaction rates of the two isomers markedly differ: at 110 deg C 4-isopropylphenol reacts faster by the factors of about 7 and 20 for k1 and k3 respectively.This finding can be utilized in preparation of mixed triarylphosphates, since the alkylation mixture after reaction of phenol with propene contains an excess of 2-isopropylphenol over 4-isopropylphenol.
- Magura, Miroslav,Vojtko, Jan,Ilavsky, Jan
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p. 1311 - 1317
(2007/10/02)
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