Mono-n-butyl phthalate

Methyl vinyl ketone, see 2-Methyl-l, 3-butadiene Molinate sulfoxide, see Molinate Monobutyl phosphate, see Tributyl phosphate Monobutyl phthalate, see Benzyl butyl phthalate Mono-n-butyl phthalate, see Di-n-butyl phthalate Monobutyl phthalate, see Di-n-butyl phthalate Monochlorobenzidine, see 3,3 -Dichlorobenzidine Monochlorobiphenyl, see Chlorobenzene, PCB-1221, PCB-1254... 

Di-n-butyl phthalate DnBP Mono-n-butyl phthalate MnBP... 

SYNS BUTYL HYDROGEN PHTHALATE MBP MONO-n-BUTYL PHTHALATE... 

Keys et al. (2000) describe a PBPK model of di- -butyl phthalate in rats that simulates the pharmacokinetics of both di-n-butyl phthalate and its major metabolite, mono-n-butyl phthalate. The model is intended for use in simulating doses of mono-n-butyl phthalate to the testes resulting from oral exposures to di-n-butyl phthalate. It is based on a earlier model developed for simulating the pharmacokinetics of di(2-ethylhexyl) phthalate and mono(2-ethylhexyl) phthalate (Keys et al. 1999). 

Description of the Model. The Keys et al. (2000) model simulates seven tissue compartments small intestine, blood, liver, fat, testis, slowly perfused tissues, and rapidly perfused tissues. The model simulates the absorption of mono-n-butyl phthalate formed from di-n-butyl phthalate in the small intestine absorption of intact di-n-butyl phthalate is assumed not to occur. Conversion of di-n-butyl phthalate to mono- -butyl phthalate in the small intestine is simulated with a first order rate constant. Absorption of mono- -butyl phthalate from the small intestine is simulated with a first order rate constant for uptake into the liver. Elimination of absorbed mono-n-butyl phthalate is assumed to be entirely by metabolism in the liver. Metabolism of mono- -butyl phthalate is simulated with a single Michaelis-Menten-type function (i.e., k and which represents all pathways combined. 

Keys et al. (2000) explored five approaches to modeling the pharmacokinetics of di- -butyl phthalate and mono- -butyl phthalate. In a flow-limited version of the model, transfers between blood and tissues are simulated as functions of blood flow, tissue concentrations of di- -butyl phthalate or mono-n-butyl phthalate, and tissue blood partition coefficients, assuming instantaneous partitioning of the compounds between tissue and blood (Ramsey and Anderson 1984). In an enterohepatic circulation version of the model, the transfer of mono-n-butyl phthalate from the liver to the small intestine is represented with a first order rate constant (diffusion-limited) and a time delay constant for the subsequent reabsorption of mono- -butyl phthalate from the small intestine. In a diffusion-limited version of the model, the tissue transfers include a first order rate term (referred to as the permeation constant) that relates the intracellular-to-extracellular concentration gradient to the rates of transfer. This model requires estimates of extracellular tissue volume (ECV) and intracellular volume (ICV) ECV is assumed to be equal to tissue blood volume and ICV is assumed to be equal to the difference between tissue blood volume and... 

Tissue Nonionized mono-n-butyl phthalate (estimated) Total mono-n-butyl phthalate (experimental) " Total mono-n-butyl phthalate (estimated) ... 

Keys DA, Wallace DG, Kepler TB, et al. 2000. Quantitative evaluation of alternative mechanisms of blood disposition of di(n-butyl) phthalate and mono(n-butyl) phthalate in rats. Toxicol Sci 53 173-184. 

SE.7 Dibutyl phthalate (DBP) is produced from mono-n-butyl phthalate (MBP) with butanol in liquid phase and catalyzed with F32S04 in a CSTR reactor, according to the following reaction ... 

Most epoxy formulations contain diluents, fillers or reinforcement materials, and toughening agents. Diluents may be reactive (mono- and diepoxides) or nonreactive (di-n-butyl phthalate). Toughening (flexibilizing) agents such as low-molecular-weight polyesters or... 

D BP Di-n-butyl phthalate, MnBP Mono-n-hutyl phthalate, BBP Benzyl butyl phthalate, MBnP Monobenzyl phthalate, DEHP Di-(2-ethylhexyl) phthalate, MEHP Mono-2-ethylhexyl phthalate, DnOP Di-n-octyl phthalate, MnOP Mono-n-octyl phthalate, DiNP Di-iso-nonyl phthalate, MiNP Mono-iso-nonyl phthalate, DiDP Di-iso-deeyl phthalate, MiDP Mono-iso-decyl phthalate expressed as the number of carbon atoms in the alkyl side ehain... 

Tissue blood partition coefficients for total and nonionized mono- -butyl phthalate were estimated from their n-octanol water partition coefficients (Kq,), using the approach reported by Poulin and Krishnan (1995). Tissue blood partition coefficients for total mono- -butyl phthalate (ionized and nonionized) were determined experimentally using a vial-equilibration method with correction for pH (Table 3-4). 

Additionally, the bound fraction of numerous further anthropogenic contaminants were investigated by quantitation of the extractable and nonextractable matter. The selection of the contaminants (including chlorinated and brominated naphthalenes, 2,4,6-tribromoaniline, mono-and dibrominated phenols, phthalates, tri-n-butylphosphate, 2,4,4-trimethylpentane-l,3-dioldi-Ao-butyrate, bisphenol A, butylated nitrophenols, 4-nitrobenzoic acid, galaxolide and tonalide) was based on the results of extended GC-MS-screening analyses applied to the extracts of the sediment samples as well to the extracts derived from selective chemical degradation procedures. 

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