Oxidation of alcohols and reduction of aldehydes derived from methyl- and dimethylpyrenes by cDNA-expressed human alcohol dehydrogenases

Field Evaluation of a Potential Exposure Biomarker of Methylated Polycyclic Aromatic Hydrocarbons: Association between Urinary Phenanthrene-2-carboxylic Acid and Personal Exposure to 2-Methylphenanthrene

“…Interestingly, alcohol consumption was negatively associated with 2-PHECA but not ΣOH-PHEs. Alcohol is a major substrate of ADHs and ALDHs, which catalyze the transformation of hydroxymethylated PAHs to carboxylic acid. , Thus, the competition on ADHs and ALDHs from alcohol could reduce 2-PHECA level. Of note, we observed no difference in exposure to alcohol or secondhand smoke between the nonheating or heating seasons (Figure S1); thus, they are unlikely to contribute to the between-season differences in biomarker concentrations.…”

“…Laboratory blank samples were prepared for each batch of eight urine samples, and negligible contamination was observed. The recovery of 13 C-labeled 2-OH-PHE was 81 ± 14%. Urinary creatinine levels were measured based on the Jaffe reaction and were used to normalize the concentrations of PAHs metabolites.…”

“…While PAHs are metabolized by cytochrome P450 (CYPs) into OH-PAHs, in vitro studies found that the oxidation of MePAHs by human liver microsomes or Hep G2 cells may occur on the methyl side chain, resulting in the formation of hydroxymethylated intermediates , and subsequently carboxylic acids catalyzed by alcohol dehydrogenases (ADHs) and aldehyde dehydrogenases (ALDHs). , Previously, we have found the ubiquitous occurrence of phenanthrene-2-carboxylic acid (2-PHECA) in urine samples and proposed it as an exposure biomarker of 2-methylphenanthrene (2-MePHE) . Furthermore, we also hypothesized that the ratio of 2-PHECA to hydroxylated phenanthrenes (ΣOH-PHEs) may provide information in exposure sources given that the 2-MePHE/PHE ratio in environmental samples is a widely acknowledged diagnostic indicator for the relative abundance of petrogenic versus pyrogenic sources. − However, a direct linkage has not been established between urinary 2-PHECA and an individual’s exposure to 2-MePHE, as well as between urinary 2-MePHE/ΣOH-PHEs and environmental 2-MePHE/PHE ratios.…”

A comparison of octanol–water partitioning between organic chemicals and their metabolites in mammals

“…The oxidation reactions of alcohols and aldehydes did not lead to a significant lipophilicity change, having intercepts of about zero. While this may be at odds with the high metabolic rates usually noted for alcohols (Klaassen, 2008), one has to keep in mind that this hydrophobicity trend allows the reverse reduction of aldehydes to alcohols driven by the alcohol dehydrogenase (Kollock et al, 2008). Furthermore, the majority of acids deprotonate at cytosolic pH, the ionic form being more water-soluble, thus more easily excretable.…”

Synthesis, characterization, and anticancer potential of pyrene-appended Schiff base tin(iv) complexes: experimental and computational insights

“…Pyrene, a polycyclic aromatic hydrocarbon, holds significant biological importance and has garnered attention across scientific fields. 32,33 When incorporated into Schiff base organotin(IV) complexes, the pyrene moiety can greatly enhance their biological activities. 33,34 The unique properties of pyrene, such as its aromaticity and hydrophobicity, facilitate improved cellular uptake and interactions with target biomolecules, leading to enhanced therapeutic efficacy.…”