scholarly journals Toxicokinetics of perfluoroalkyl carboxylic acids with different carbon chain lengths in mice and humans

2015 ◽  
Vol 57 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Yukiko Fujii ◽  
Tamon Niisoe ◽  
Kouji H. Harada ◽  
Shinji Uemoto ◽  
Yasuhiro Ogura ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Carbon Chain ◽  
Chain Lengths

Morphology, Ionic-Molecular Interaction and Ionic Conductivity Behavior of PMMA/ENR 50 Electrolytes Containing Carboxylic Acids Modified SiO2 Fillers

2019 ◽  
Vol 821 ◽  
pp. 419-425
Author(s):  
Mohamad Zamri Sharil Fadli ◽  
Abdul Latif Famiza ◽  
Mohd Azuan Siti Izzati Husna
Keyword(s):  
Ionic Conductivity ◽  
Carboxylic Acids ◽  
Octanoic Acid ◽  
Silanol Group ◽  
Carbon Chain ◽  
Dodecanoic Acid ◽  
Casting Method ◽  
Acid Modification ◽  
Lithium Tetrafluoroborate ◽  
Chain Lengths

Carboxylic acids of various carbon chain lengths (Cn); i.e. butanoic acid (C4), octanoic acid (C8), dodecanoic acid (C12) and hexadecanoic acid (C16) have been used to organically modify silicon dioxide (SiO2). The acid modification involve replacing the hydrogen atom of the silanol group (Si-OH) of SiO2 with the RnCOO-of the acid via esterification technique. SiO2 and acid modified SiO2 (MoCn-SiO2) were used as filler in preparation of polymethyl methacrylate/50% epoxidized natural rubber electrolytes containing SiO2 (PEL-SiO2) and MoCn-SiO2 (PEL-MoCn-SiO2) via solvent casting method with lithium tetrafluoroborate (LiBF4) as dopant salt. Field-emission scanning electron microscopy (FESEM) analysis of PEL-SiO2 and PEL-MoCn-SiO2 films show LiBF4 accumulated to the fillers. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed formation of hydrogen bonding between LiBF4 with fillers and polymers in the polymer electrolyte films. Interestingly, the ionic conductivity of PEL-MoCn-SiO2 films increases as the Cn of acids increased with the highest ionic conductivity of 5.56 x 10-7 Scm-1 was achieved in PEL-MoC12-SiO2 film.

scholarly journals Lactational Transfer of Long-Chain Perfluorinated Carboxylic Acids in Mice: A Method to Directly Collect Milk and Evaluate Chemical Transferability

Toxics ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 23
Author(s):  
Yukiko Fujii ◽  
Kouji H. Harada ◽  
Hatasu Kobayashi ◽  
Koichi Haraguchi ◽  
Akio Koizumi
Keyword(s):  
Carboxylic Acids ◽  
Daily Intake ◽  
Carbon Chain ◽  
Postnatal Period ◽  
Industrial Chemicals ◽  
P Concentration ◽  
Perfluorinated Carboxylic Acids ◽  
Lactational Transfer ◽  
Chain Lengths ◽  
Long Chain

Perfluoroalkyl carboxylic acids (PFCAs), such as perfluorooctanoic acid (PFOA, C8), are a group of industrial chemicals that are detected in the serum of people throughout the world. Long-chain PFCAs (C9 to C13) have high lipophilicity, therefore they may have a high transfer rate to breast milk. This study investigated the lactational transfer of PFCAs with carbon chain lengths of 8 to 13 in mice. Lactating dams were given a single intravenous administration of PFCAs (C8 to C13) during the postnatal period (8–13 days after delivery). Milk was collected from the dam 24 h after administration using a milking device built in-house. Plasma was obtained from the dam at the same time as milk collection. The observed milk/plasma (M/P) concentration ratios were 0.32 for C8, 0.30 for C9, 0.17 for C10, 0.21 for C11, 0.32 for C12, and 0.49 for C13. These results indicate that the M/P concentration ratio is not related to the lipophilicity of PFCAs. However, estimated relative daily intake, an indicator of how much PFCA is transferred from dams to pups per body weight, increased with chain length: 4.16 for C8, 8.98 for C9, 9.35 for C10, 9.51 for C11, 10.20 for C12, and 10.49 for C13, which may be related to the lower clearance of long-chain PFCAs. These results indicate the importance of future risk assessment of long-chain PFCAs.

Degrees of order of solubilized alkanes, alcohols, carboxylates, and carboxylic acids in oriented lyomesophases

1977 ◽  
Vol 55 (12) ◽  
pp. 2404-2410 ◽  
Author(s):  
Douglas M. Chen ◽  
Fred Y. Fujiwara ◽  
Leonard W. Reeves
Keyword(s):  
Carboxylic Acids ◽  
Chain Length ◽  
Linear Increase ◽  
Short Chain ◽  
Appreciable Amount ◽  
Linear Region ◽  
Short Chain Length ◽  
Chain Lengths ◽  
Degree Of Order ◽  
Limiting Value

The degree of order of solubilized molecules and ions in oriented lyomesophases has been determined at specifically deuterated C—D bond axes from the quadrupole splitting of the deuterium magnetic resonance. Mixtures at low concentration of specifically deuterated alkanes, alcohols, carboxylic acids, and carboxylates of different chain length have been observed in host cationic and anionic lyomesophases. The degree of order of a given C—D position in alcohols increases strongly with chain length up to a length comparable with the host detergent. A broad series of carboxylic acids and carboxylate ions from C2 to C16 have been deuterated in the α position. The α-C—D bond axis in the solubilisate increases in order with chain length, the anion having lower order than the parent acid. An accurately linear increase in the degree of order of the α position is observed for intermediate chain lengths. At chain lengths approximately equal to the host chain lengths the α position reaches a limiting value in the degree of order and further segments do not influence the order. At short chain lengths the degree of order is less than that predicted from extrapolation of order in the linear region. This has been interpreted in terms of distribution into the aqueous compartment by the solubilisates of short chain length. Acetic acid and the acetate, propionate, butanoate, and pentanoate ions spend an appreciable amount of time in the aqueous region. An estimate has been made of these distributions based on reasonable assumptions.

The Use of N-alkanes for Estimating Intake and Passage Rate in Horses

1996 ◽  
Vol 1996 ◽  
pp. 98-98
Author(s):  
B M L McLean ◽  
R W Mayes ◽  
F D DeB Hovell
Keyword(s):  
Recent Work ◽  
Chain Length ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Passage Rate ◽  
Forage Crops ◽  
Carbon Chains ◽  
Naturally Occurring ◽  
Chain Lengths ◽  
Long Chain

Alkanes occur naturally in all plants, although forage crops tend to have higher alkane contents than cereals. N-alkanes have odd-numbered carbon chains. They are ideal for use as markers in feed trials, because, they are inert, indigestible and naturally occurring, and can be recovered in animal faeces. Synthetic alkanes (even-numbered carbon chains) are available commercially and can also used as external markers. Dove and Mayes (1991) cite evidence indicating that faecal recovery of alkanes in ruminants increases with increasing carbon-chain length. Thus the alkane “pairs” (e.g. C35 & C36, and C32 & C33) are used in calculating intake and digestibility because they are long chain and adjacent to each other. However, recent work by Cuddeford and Mayes (unpublished) has found that in horses the faecal recovery rates are similar regardless of chain lengths.

scholarly journals Terminal Olefin Profiles and Phylogenetic Analyses of Olefin Synthases of Diverse Cyanobacterial Species

2018 ◽  
Vol 84 (13) ◽  
Author(s):  
Tao Zhu ◽  
Thibault Scalvenzi ◽  
Nathalie Sassoon ◽  
Xuefeng Lu ◽  
Muriel Gugger
Keyword(s):  
Fatty Acid ◽  
Genetic Basis ◽  
Carbon Chain ◽  
Fatty Acyl ◽  
Carbon Chain Length ◽  
Substrate Activation ◽  
Chain Length Specificity ◽  
Modular Architectures ◽  
Terminal Olefins ◽  
Chain Lengths

ABSTRACT Cyanobacteria can synthesize alkanes and alkenes, which are considered to be infrastructure-compatible biofuels. In terms of physiological function, cyanobacterial hydrocarbons are thought to be essential for membrane flexibility for cell division, size, and growth. The genetic basis for the biosynthesis of terminal olefins (1-alkenes) is a modular type I polyketide synthase (PKS) termed olefin synthase (Ols). The modular architectures of Ols and structural characteristics of alkenes have been investigated only in a few species of the small percentage (approximately 10%) of cyanobacteria that harbor putative Ols pathways. In this study, investigations of the domains, modular architectures, and phylogenies of Ols in 28 cyanobacterial strains suggested distinctive pathway evolution. Structural feature analyses revealed 1-alkenes with three carbon chain lengths (C 15 , C 17 , and C 19 ). In addition, the total cellular fatty acid profile revealed the diversity of the carbon chain lengths, while the fatty acid feeding assay indicated substrate carbon chain length specificity of cyanobacterial Ols enzymes. Finally, in silico analyses suggested that the N terminus of the modular Ols enzyme exhibited characteristics typical of a fatty acyl-adenylate ligase (FAAL), suggesting a mechanism of fatty acid activation via the formation of acyl-adenylates. Our results shed new light on the diversity of cyanobacterial terminal olefins and a mechanism for substrate activation in the biosynthesis of these olefins. IMPORTANCE Cyanobacterial terminal olefins are hydrocarbons with promising applications as advanced biofuels. Despite the basic understanding of the genetic basis of olefin biosynthesis, the structural diversity and phylogeny of the key modular olefin synthase (Ols) have been poorly explored. An overview of the chemical structural traits of terminal olefins in cyanobacteria is provided in this study. In addition, we demonstrated by in vivo fatty acid feeding assays that cyanobacterial Ols enzymes might exhibit substrate carbon chain length specificity. Furthermore, by performing bioinformatic analyses, we observed that the substrate activation domain of Ols exhibited features typical of a fatty acyl-adenylate ligase (FAAL), which activates fatty acids by converting them to fatty acyl-adenylates. Our results provide further insight into the chemical structures of terminal olefins and further elucidate the mechanism of substrate activation for terminal olefin biosynthesis in cyanobacteria.

scholarly journals Biochemical Characterization of CYP505D6, a Self-Sufficient Cytochrome P450 from the White-Rot FungusPhanerochaete chrysosporium

2018 ◽  
Vol 84 (22) ◽  
Author(s):  
Kiyota Sakai ◽  
Fumiko Matsuzaki ◽  
Lisa Wise ◽  
Yu Sakai ◽  
Sadanari Jindou ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Cytochrome P450 ◽  
Phanerochaete Chrysosporium ◽  
Carbon Chain ◽  
Fatty Alcohols ◽  
White Rot ◽  
Wild Type ◽  
Content Type ◽  
Attractive Candidate ◽  
Chain Lengths

ABSTRACTThe activity of a self-sufficient cytochrome P450 enzyme, CYP505D6, from the lignin-degrading basidiomycetePhanerochaete chrysosporiumwas characterized. Recombinant CYP505D6 was produced inEscherichia coliand purified. In the presence of NADPH, CYP505D6 used a series of saturated fatty alcohols with C9–18carbon chain lengths as the substrates. Hydroxylation occurred at the ω-1 to ω-6 positions of such substrates with C9–15carbon chain lengths, except for 1-dodecanol, which was hydroxylated at the ω-1 to ω-7 positions. Fatty acids were also substrates of CYP505D6. Based on the sequence alignment, the corresponding amino acid of Tyr51, which is located at the entrance to the active-site pocket in CYP102A1, was Val51 in CYP505D6. To understand the diverse hydroxylation mechanism, wild-type CYP505D6 and its V51Y variant and wild-type CYP102A1 and its Y51V variant were generated, and the products of their reaction with dodecanoic acid were analyzed. Compared with wild-type CYP505D6, its V51Y variant generated few products hydroxylated at the ω-4 to ω-6 positions. The products generated by wild-type CYP102A1 were hydroxylated at the ω-1 to ω-4 positions, whereas its Y51V variant generated ω-1 to ω-7 hydroxydodecanoic acids. These observations indicated that Val51 plays an important role in determining the regiospecificity of fatty acid hydroxylation, at least that at the ω-4 to ω-6 positions. Aromatic compounds, such as naphthalene and 1-naphthol, were also hydroxylated by CYP505D6. These findings highlight a unique broad substrate spectrum of CYP505D6, rendering it an attractive candidate enzyme for the biotechnological industry.IMPORTANCEPhanerochaete chrysosporiumis a white-rot fungus whose metabolism of lignin, aromatic pollutants, and lipids has been most extensively studied. This fungus harbors 154 cytochrome P450-encoding genes in the genome. As evidenced in this study,P. chrysosporiumCYP505D6, a fused protein of P450 and its reductase, hydroxylates fatty alcohols (C9–15) and fatty acids (C9–15) at the ω-1 to ω-7 or ω-1 to ω-6 positions, respectively. Naphthalene and 1-naphthol were also hydroxylated, indicating that the substrate specificity of CYP505D6 is broader than those of the known fused proteins CYP102A1 and CYP505A1. The substrate versatility of CYP505D6 makes this enzyme an attractive candidate for biotechnological applications.

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