Two Cu(II) complexes of triadimefon: crystal structure, antifungal activities and structure-activity relationship
NEW JOURNAL OF CHEMISTRY
Authors: Li, Jie; Xi, Teng; Yan, Biao; Yang, Mingyan; Song, Jirong; Ma, Haixia
Abstract
Two Cu(II) complexes, [CuL2Cl2(EtOH)] 1 and [CuL4(NO3)(2)]center dot 0.5H(2)O 2 (L = 1-(4-chlorophenoxy)-3,3-dimethyl-1-H(1,2,4-triazole-1-y)-2-butanone, triadimefon) have been synthesized and their structures were determined by single crystal X-ray diffraction (XRD). Crystal structural analysis shows that in complex 1, the copper cation lies on a crystallographic inversion center and is coordinated with two triazole groups, two chloride ligands and an ethanol molecule. In each unit cell, two pairs of adjacent [CuL2Cl2(EtOH)] molecules are linked by O-H center dot center dot center dot Cl hydrogen bonds to form a 2D plane. Complex 2 is octahedral with the metal cation bound to four triazole groups and two nitrate ligands. The geometry is elongated due to the more distant interactions between connecting nitrate O atoms and the Cu cation. The two complexes were screened for antifungal activities against five selected fungi using the mycelial growth rate method. The synergistic interactions between Cu2+ and triadimefon were also investigated by the Wadley approach, and the results reveal that the synergy levels for the ratio 1:4 of the molecular-level mixture of Cu2+ and triadimefon are better than that for the ratio 1:2. To better understand the structure-activity relationship, theoretical investigation of the electronic structure of the metal complexes has been carried out using density function theoretical (DFT) calculations. The results indicated that the Cu cation and the triazole originating from triadimefon are the active sites, and the decrease of the polarity of Cu2+ can contribute to the increased biocidal properties after complexation since it is responsible for the enhanced penetration of the metal complexes into the lipid membranes.
Grouping of histone deacetylase inhibitors and other toxicants disturbing neural crest migration by transcriptional profiling
NEUROTOXICOLOGY
Authors: Dreser, Nadine; Zimmer, Bastian; Dietz, Christian; Suegis, Elena; Pallocca, Giorgia; Nyffeler, Johanna; Meisig, Johannes; Bluethgen, Nils; Berthold, Michael R.; Waldmann, Tanja; Leist, Marcel
Abstract
Functional assays, such as the "migration inhibition of neural crest cells" (MINC) developmental toxicity test, can identify toxicants without requiring knowledge on their mode of action (MoA). Here, we were interested, whether (i) inhibition of migration by structurally diverse toxicants resulted in a unified signature of transcriptional changes; (ii) whether statistically-identified transcript patterns would inform on compound grouping even though individual genes were little regulated, and (iii) whether analysis of a small group of biologically-relevant transcripts would allow the grouping of compounds according to their MoA. We analyzed transcripts of 35 'migration genes' after treatment with 16 migration-inhibiting toxicants. Clustering, principal component analysis and correlation analyses of the data showed that mechanistically related compounds (e.g. histone deacetylase inhibitors (HDACi), PCBs) triggered similar transcriptional changes, but groups of structurally diverse toxicants largely differed in their transcriptional effects. Linear discriminant analysis (LDA) confirmed the specific clustering of HDACi across multiple separate experiments. Similarity of the signatures of the HDACi trichostatin A and suberoylanilide hydroxamic acid to the one of valproic acid (VPA), suggested that the latter compound acts as HDACi when impairing neural crest migration. In conclusion, the data suggest that (i) a given functional effect (e.g. inhibition of migration) can be associated with highly diverse signatures of transcript changes; (ii) statistically significant grouping of mechanistically-related compounds can be achieved on the basis of few genes with small regulations. Thus, incorporation of mechanistic markers in functional in vitro tests may support read-across procedures, also for structurally un-related compounds. (C) 2015 Elsevier Inc. All rights reserved.