Monomethyl Phthalate Research Articles

Phthalate esters detected in various water samples and biodegradation of the phthalates by microbes isolated from river water.

Phthalate esters (PEs), especially di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) were detected in various water samples such as river water, well water and tap water. On degradation tests of PEs, Tempaku River water degraded almost 100% of diethyl phthalate (DEP), di-isobutyl phthalate and DBP, and approximately 70% of DEHP. All eight isolates from Tempaku River water (R1-R7, D1) did not degrade dimethyl phthalate (DMP), but showed biodegrading ability for the other PEs. The DBP-degrading ability was particularly high for the isolates R1-R3 and D1 of Acinetobacter iwoffii. Crude enzyme solutions prepared from bacterial cells of these isolates showed a higher degrading activity for DEHP compared with that for microbially-degradable DBP. Particularly high DEHP-degrading activity was found for crude enzyme solutions of the isolate D1. As metabolites from the river water and bacterial isolates, DMP and an unknown diester were produced from DEP. DMP, DEP, monomethyl phthalate, monobutyl phthalate (MBP) and an unknown diester were produced from DBP. DBP, DEP, DMP and an unknown diester were produced from DEHP. As metabolites by the crude enzyme solutions, DMP, MBP and an unknown diester derivative were produced from DBP. DBP, mono-(2-ethylhexyl) phthalate and an unknown diester derivative were produced from DEHP. Diesters with shortened alkyl carbon chains were also found as metabolites by the isolates and their crude enzyme solutions. The results suggest that the alkyl chains in the diesters are also decomposed in addition to monoester formation from DBP or DEHP at the first step reported for animals and some types of bacteria.

Biodegradation of diethyl phthalate in soil by a novel pathway.

Biodegradation of diethyl phthalate (DEP) has been shown to occur as a series of sequential steps common to the degradation of all phthalates. Primary degradation of DEP to phthalic acid (PA) has been reported to involve the hydrolysis of each of the two diethyl chains of the phthalate to produce the monoester monoethyl phthalate (MEP) and then PA. However, in soil co-contaminated with DEP and MeOH, biodegradation of the phthalate to PA resulted in the formation of three compounds, in addition to MEP. These were characterised by gas chromatography-electron ionisation mass spectrometry and nuclear magnetic resonance as ethyl methyl phthalate, dimethyl phthalate and monomethyl phthalate, and indicated the existence of an alternative pathway for the degradation of DEP in soil co-contaminated with MeOH. Transesterification or demethylation were proposed as the mechanisms for the formation of the three compounds, although the 7:1 ratio of H(2)O to MeOH means that transesterification is unlikely.

Biodegradation of diethyl phthalate in soil by a novel pathway

Biodegradation of diethyl phthalate (DEP) has been shown to occur as a series of sequential steps common to the degradation of all phthalates. Primary degradation of DEP to phthalic acid (PA) has been reported to involve the hydrolysis of each of the two diethyl chains of the phthalate to produce the monoester monoethyl phthalate (MEP) and then PA. However, in soil co-contaminated with DEP and MeOH, biodegradation of the phthalate to PA resulted in the formation of three compounds, in addition to MEP. These were characterised by gas chromatography-electron ionisation mass spectrometry and nuclear magnetic resonance as ethyl methyl phthalate, dimethyl phthalate and monomethyl phthalate, and indicated the existence of an alternative pathway for the degradation of DEP in soil co-contaminated with MeOH. Transesterification or demethylation were proposed as the mechanisms for the formation of the three compounds, although the 7:1 ratio of H 2O to MeOH means that transesterification is unlikely.

Mutagenicity and metabolism of dimethyl phthalate and its binding to epidermal and hepatic macromolecules

As an active ingredient in insect repellents, dimethyl phthalate (DMP) had previously been shown to produce chromosomal aberrations in the livers of rats following subchronic application of the phthalate to skin. When we tested DMP in the Ames mutagenesis assay, it produced in bacterial tester strain TA100 (but not TA98) a dose-related mutagenic response that was abolished by NAD- and NADP-independent metabolism associated with rat liver microsomal preparations (S9). In a host-mediated mutagenesis assay, rats were injected ip with DMP (2 g/kg body weight); urine was collected for 24 h, extracted, and analyzed for mutagenic activity and phthalic acid-containing derivatives. The extracted urine was not mutagenic to TA100 and contained an equivalent of 1.96 mg phthalate/ml urine. More than 97% of the phthalic acid-containing derivatives present in the extracted urine consisted of the nonmutagenic metabolite of DMP, monomethyl phthalate (MMP). In vitro experiments showed that rat liver homogenates hydrolyzed 93% of carbonyl-labeled 14C-DMP (7.7 mM) to MMP in 2 h and bound 0.07 nmol of [14C]phthalate/mg liver macromolecules. By contrast, rat epidermal homogenates metabolized only 5% and bound 38-fold higher levels of carbonyl-labeled 14C-DMP (2.66 nmol/mg of macromolecules), with no detectable binding to nucleic acids. Compared to epidermis and plasma, liver had a fivefold higher rate of DMP monoesterase activity (1240 nmol/h/mg protein), which, when inhibited by 67%, resulted in a 4.4-fold increase in phthalate-bound hepatic macromolecules (0.31 vs. 0.07 nmol of carbonyl-labeled 14C-DMP/mg macromolecules). In addition to MMP, formaldehyde was produced during the metabolism of DMP by liver. When ethanol was used to inhibit the oxidation of DMP-derived methanol by hepatic homogenates, there resulted a 74% reduction in the accumulation of formaldehyde and similar reductions of 71 and 73% in the binding of methyl-labeled 14C-DMP to nucleic acids and macromolecules. (Methyl-labeled, unlike carbonyl-labeled, 14C-DMP yields a 14C-labeled methanol when hydrolyzed.) These results indicate that the DMP diester is a weak bacterial mutagen, which binds to epidermal and hepatic macromolecules other than nucleic acids, and that although the rapid hepatic metabolism of DMP to its monoester (MMP) and methanol affords protection against higher levels of phthalate binding as well as against DMP-induced bacterial mutagenesis, it also oxidizes DMP-derived methanol to formaldehyde, a metabolite that binds macromolecules, including nucleic acids.

1‐Amino‐2‐phthalimido‐diazen‐1‐oxide: Bildung, Eigenschaften und Fragmentierungen in Imido‐ und Amino‐nitrene

1‐Amino‐2‐phthalimido‐diazene‐1‐oxides: Formation, Properties and Fragmentation Reactions into Imido‐ and Amino‐nitrenes1)Oxidatively generated phthalimido‐nitrene (1) reacts with the nitrosoamines 2a‐d (see Scheme 1) to give the corresponding (Z)‐1‐amino‐2‐phthalimido‐diazene‐1‐oxides 3a‐d in good yields. With the O‐nitroso compound 2e, no addition of the nitrene 1 took place.The constitution the adducts 3 (R = NR′2) is deduced from their spectroscopic properties (UV., IR., 1H‐NMR. and MS.) as compared to those of (Z)‐1‐aryl‐ and (Z)‐1‐alkyl‐2‐phthalimido‐diazene‐1‐oxides 3 (R = aryl and alkyl, resp.). The (Z)‐configuration of 3 (R = NR′2) follows from an X‐ray analysis which is reported separately.Compounds 3 (R = NR′2) are cleaved photolytically as well as by acid to the corresponding nitrosoamines 2 (R = NR′2) and the nitrene 1, which could be trapped by cyclohexene to give 40% of 7‐phthalimido‐7‐azabicyclo [4.1.0]heptane (8) and by dimethylsulfoxide to yield 96% of S, S‐dimethyl‐N‐phthalimido‐sulfoximide (13).Nucleophilic attack leads to fragmentation of 3 (R = NR′2) into derivatives of phthalic acid and degradation products of intermediate aminonitrenes 24 corresponding to the respective nitrosoamines 2 (R = NR′2) with loss of oxygen. A general rationalization for the formation of 24 includes as a key step of N‐ to C‐migration of the O‐atom (see Scheme 6). The final fate of 24 is depending on the type of the nucleophile used. Thus, hydrazinolysis of 3b and of 3c generates besides N, N′‐phthaloylhydrazine (15), morpholine (14) from 3b and 1, 3‐dihydroisoindole (16) together with 6′‐methylidene‐1, 2, 3, 4‐tetrahydronaphthalene‐2‐spiro‐1′‐cyclohexa‐2′, 4′‐diene (17) from 3c (see Scheme 5). Treatment of 3b and of 3c with sodium methylate leads in both reactions to monomethyl phthalate (33) and, with 3b, to 1, 2‐dimorpholinodiazene (31) and, with 3c, to 17 (see Scheme 7). Finally, the reaction of 3b with diethylamine generates N, N‐diethylphthalamic acid (36), morpholine (14), 1,1,4,4‐tetraethyl‐2‐tetrazene(34) and l,l‐diethyl‐4,4‐(3‐oxapentamethylene)‐2‐tetrazene (35) (see Scheme 8).

ChemInform Abstract: EFFECT OF IONIC STRENGTH AND DIELECTRIC CONSTANT ON BASE HYDROLYSIS OF MONOMETHYL PHTHALATE

Chemischer InformationsdienstVolume 9, Issue 38 Preparative Organic Chemistry ChemInform Abstract: EFFECT OF IONIC STRENGTH AND DIELECTRIC CONSTANT ON BASE HYDROLYSIS OF MONOMETHYL PHTHALATE V. HOLBA, V. HOLBASearch for more papers by this authorJ. BENKO, J. BENKOSearch for more papers by this authorK. OKALOVA, K. OKALOVASearch for more papers by this author V. HOLBA, V. HOLBASearch for more papers by this authorJ. BENKO, J. BENKOSearch for more papers by this authorK. OKALOVA, K. OKALOVASearch for more papers by this author First published: September 19, 1978 https://doi.org/10.1002/chin.197838089AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume9, Issue38September 19, 1978 RelatedInformation