2,4,5-Trichlorolichexanthone

In this study, triazol derivatives, 4,4'-(((1E, 1E')-1,2-phenylenebis (methanylyidene)) bis (azanylidene)) bis (5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (2), 4,4'-(((1E, 1E')-1,3-phenylenebis (methanylyidene)) bis (azanylidene)) bis (5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (3) and 4,4'-(((1E, 1E')-1,4-phenylene bis (methanyl yidene)) bis (azanylidene)) bis (5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (4) were synthesized from the reaction of 4-amino-5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one and phthalaldehyde/isophthalaldehyde/terephthalaldehyde, respectively. Compounds 2-4 were characterized by Fourier transform infrared (FTIR), proton and carbon-13 nuclear magnetic resonance (1H- and 13C- NMR) spectroscopic methods. Theoretical study for compounds 2-4 were carried out by DFT/B3LYP/6-311++G(d,p). Structural and spectroscopic parameters were determined theoreticaly and compared with experimental ones. Also, the molecular electrostatic potential (MEP) maps of compounds were obtained. Leishmanicidal activity of compounds 2-4 against to Leishmania infantum was determined by microdilution broth method containing alamar blue. As a result of the study, compounds 2-4 were found to be effective against the specie of Leishmania. Molecular docking analysis against Trypanothione Reductase (TRe) with compound 2 was carried out to see the necessary interactions responsible for antileishmanial activity. The docking calculations of compound 2 supported the antileishmanial activity exhibiting high inhibition constant.Communicated by Ramaswamy H. Sarma.

Previous studies have reported the feminizing effects of 2,4-dichlorophenol (2,4-DCP) on zebrafish (Danio rerio). However, the effect of 2,4-DCP on the number of primordial germ cells (PGCs), an indicator for early sex differentiation, remains elusive. In the present study, Tg (piwil1:egfp-UTR nanos3) zebrafish (GFP-labeled PGCs) were treated with 2,4-DCP (10, 20, and 40 μg/L) from 5 to 15 days postfertilization to explore the effect on PGC numbers and to elucidate associated molecular mechanisms. The results showed that 2,4-DCP exposure increased PGC numbers, as evidenced by larger GFP fluorescent areas, upregulated expressions of PGC marker genes (vasa and dnd), and raised the female ratio. Notably, the mRNA level of estrogen receptor 2a (esr2a) was also increased subsequently. Moreover, docking studies revealed stable 2,4-DCP interactions with ESR2a, speculating a role of ESR2a signaling pathway in 2,4-DCP toxicity. Furthermore, in esr2a knockout (esr2a-/-) zebrafish, the effects of 2,4-DCP were considerably minimized, proving the involvement of the ESR2a signaling pathway in the 2,4-DCP-mediated increase in PGC numbers. Dual-luciferase reporter gene assay and point mutation studies demonstrated that 2,4-DCP-stimulated promoter activity was mediated by estrogen response element (ERE) located in -686/-674 of the vasa promoter and -731/-719 of the dnd promoter. Overall, 2,4-DCP can potentially enhance the expression of vasa and dnd by binding to zebrafish ESR2a, thus leading to increased PGC numbers and subsequent female-biased sex differentiation.

2,4,6-Tribromophenol (2,4,6-TBP) is a brominated flame retardant that accumulates in human tissues and is a potential toxicant. Previous studies found 2,4,6-TBP levels in human tissues were significantly higher than those of brominated flame retardants measured in the same samples. In contrast, the levels of 2,4,6-TBP in the environment and foodstuff are not elevated, suggesting a low potential for direct intake through environmental exposure or diet. Here, we hypothesized that high levels of 2,4,6-TBP in human tissues are partially from the indirect exposure sources, such as biotransformation of highly brominated substances. We conducted in vitro assays utilizing human and rat liver microsomes to compare the biotransformation rates of four highly brominated flame retardants, which could potentially transform to 2,4,6-TBP, including decabromodiphenyl ethane (DBDPE), 2,4,6-tris-(2,4,6-tribromophenoxy)-1,3,5-triazine (TTBP-TAZ), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), and tetrabromobisphenol A (TBBPA). Our results show that TTBP-TAZ rapidly metabolizes in both human and rat liver microsomes with a half-life of 1.1 and 2.2 h, respectively, suggesting that TTBP-TAZ is a potential precursor of 2,4,6-TBP. In contrast, 2,4,6-TBP was not formed as a result of biotransformation of TBBPA, BTBPE, and DBDPE in both human and rat liver microsomes. We applied suspect and target screening to explore the metabolic pathways of TTBP-TAZ and identified 2,4,6-TBP as a major metabolite of TTBP-TAZ accounting for 87% of all formed metabolites. These in vitro results were further tested by an in vivo experiment in which 2,4,6-TBP was detected in the rat blood and liver at concentrations of 270 ± 110 and 50 ± 14 μg/g lipid weight, respectively, after being exposed to 250 mg/kg body weight/day of TTBP-TAZ for a week. The hepatic mRNA expression demonstrated that TTBP-TAZ significantly activates the aryl hydrocarbon receptor (AhR) and promotes fatty degeneration (18 and 28-fold change compared to control, respectively) in rats.