2-Amino-5-substituted-1,3,4-oxadiazole as chemosensor for Ni(II) ion detection: antifungal,antioxidant, DNA binding,and molecular docking studies

An oxadiazole derivative 2 was prepared by condensation reaction through cyclization of semicarbazone in the presence of bromine; the structural confirmation was supported by ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy, Fourier transform-infrared spectroscopy, and liquid chromatography-mass spectrometry. Its sensing ability towards Ni²⁺ ion was examined showing a binding constant of 1.04 × 10⁵ compared with other suitable metal cations (Ca²⁺, Co²⁺, Cr³⁺, Ag⁺, Pb²⁺, Fe³⁺, Mg²⁺, and K⁺) using ultraviolet–visible (UV–vis) and fluorescence spectroscopic studies. The minimum concentration of Ni²⁺ ions and limit of detection was found to be 9.4 μM. A job's plot gave the binding stoichiometry ratio of oxadiazole derivative 2 vs Ni²⁺ ions as 2:1. Furthermore, the intercalative binding mode of oxadiazole derivative 2 with calf thymus DNA was supported by ultraviolet–visible (UV–vis) and fluorescent light, viscosity, cyclic voltammetry, time-resolved fluorescence, and circular dichroism measurements. The molecular docking result gave the binding score for oxadiazole derivative 2 as −6.5 kcal/mol, which further confirmed the intercalative interaction. In addition, the antifungal activity of oxadiazole derivative 2 was also screened against several fungal strains (C. albicans, C. glabrata, and C. tropicalis) by broth dilution and disc diffusion methods. In antioxidant studies, the oxadiazole derivative 2 showed potential scavenging activity against 2,2-diphenyl-1-picrylhydrazyl and H₂O₂ free radicals.     

Fungal Biodiversity Mediates the Effects of Drying on Freshwater Ecosystem Functioning

Ecosystems - Investigating the influence of biodiversity on ecosystem functioning over environmental gradients is needed to anticipate ecosystem responses to global change. However, our...     

Hexose monophosphate shunt,the role of its metabolites and associated disorders: A review

The hexose monophosphate (HMP) shunt acts as an essential component of cellular metabolism in maintaining carbon homeostasis. The HMP shunt comprises two phases viz. oxidative and nonoxidative, which provide different intermediates for the synthesis of biomolecules like nucleotides, DNA, RNA, amino acids, and so forth; reducing molecules for anabolism and detoxifying the reactive oxygen species during oxidative stress. The HMP shunt is significantly important in the liver, adipose tissue, erythrocytes, adrenal glands, lactating mammary glands and testes. We have researched the articles related to the HMP pathway, its metabolites and disorders related to its metabolic abnormalities. The literature for this paper was taken typically from a personal database, the Cochrane database of systemic reviews, PubMed publications, biochemistry textbooks, and electronic journals uptil date on the hexose monophosphate shunt. The HMP shunt is a tightly controlled metabolic pathway, which is also interconnected with other metabolic pathways in the body like glycolysis, gluconeogenesis, and glucuronic acid depending upon the metabolic needs of the body and depending upon the biochemical demand. The HMP shunt plays a significant role in NADPH₂ formation and in pentose sugars that are biosynthetic precursors of nucleic acids and amino acids. Cells can be protected from highly reactive oxygen species by NADPH ₂. Deficiency in the hexose monophosphate pathway is linked to numerous disorders. Furthermore, it was also reported that this metabolic pathway could act as a therapeutic target to treat different types of cancers, so treatments at the molecular level could be planned by limiting the synthesis of biomolecules required for proliferating cells provided by the HMP shunt, hence, more experiments still could be carried out to find additional discoveries.     

Modulation of auxin signalling through DIAGETROPICA and ENTIRE differentially affects tomato plant growth via changes in photosynthetic and mitochondrial metabolism

Auxin modulates a range of plant developmental processes including embryogenesis, organogenesis, and shoot and root development. Recent studies have shown that plant hormones also strongly influence metabolic networks, which results in altered growth phenotypes. Modulating auxin signalling pathways may therefore provide an opportunity to alter crop performance. Here, we performed a detailed physiological and metabolic characterization of tomato (Solanum lycopersicum) mutants with either increased (entire) or reduced (diageotropica—dgt) auxin signalling to investigate the consequences of altered auxin signalling on photosynthesis, water use, and primary metabolism. We show that reduced auxin sensitivity in dgt led to anatomical and physiological modifications, including altered stomatal distribution along the leaf blade and reduced stomatal conductance, resulting in clear reductions in both photosynthesis and water loss in detached leaves. By contrast, plants with higher auxin sensitivity (entire) increased the photosynthetic capacity, as deduced by higher V_cmax and J_max coupled with reduced stomatal limitation. Remarkably, our results demonstrate that auxin‐sensitive mutants (dgt) are characterized by impairments in the usage of starch that led to lower growth, most likely associated with decreased respiration. Collectively, our findings suggest that mutations in different components of the auxin signalling pathway specifically modulate photosynthetic and respiratory processes.     

3-Monoterpenyl-2,4-dioxygenated quinoline alkaloids from the aerial parts of Halfordia kendack

The aerial parts of Halfordia kendack (Rutaceae) have yielded the known alkaloid trans-erioaustralasine ([rel]-1-acetoxymethyl-4.8'-epoxy-3-(1'beta,2'beta-epoxy-3'beta,4'alpha-para-menthyl-3'-yl)quinolin-2-one) together with four new alkaloids. The latter were characterised by spectroscopic methods as trans-deacetoxyerioaustralasine ([rel]-1-methyl-4.8'-epoxy-3-(1'beta,2'beta-epoxy-3'beta,4'alpha-para-menthyl-3'-yl)quinolin-2-one), trans-deacetoxyerioaustralasine hydrate ([rel]-1-methyl-4.8'-epoxy-3-(1'alpha,2'alpha-dihydroxy-3'beta,4'alpha-para-;menthyl-3'-yl)quinolin-2-one), trans-erioaustralasine hydrate ([rel]-1-acetoxymethyl-4.8'-epoxy-3-(1'alpha,2'alpha-dihydroxy-3'beta,4'alpha-para-menthyl-3'-yl)quinolin-2-one) and trans-1-epi-deacetoxyerioaustralasine hydrate ([rel]-1-acetoxymethyl-4.8'-epoxy-3-(1'beta,2'alpha-dihydroxy-3'beta,4'alpha-para-menthyl-3'-yl)quinolin-2-one).     

Possible involvement of a sperm-associated body in the process of fertilization in quail

The present paper describes a novel structure, termed the sperm-associated body, which is found both in the lumen at the oviductal infundibulum and in the vitelline membrane of the ovum in the quail Coturnix japonica. The fully developed sperm-associated body, which is about 100 microm long, consisted of two parts; a core of concentric-circular appearance and a cortex of needle-like projections. The outer surface of the body was coated with CaCO3. The body was always accompanied by spermatozoa. About 70 sperm-associated bodies were observed in a single ovum. Electron-microscopically, small numbers of holes were detected in the vitelline membranes of a fertile ovum, and the sperm-associated bodies were always present in these holes. Frequently observed in the vitelline membranes was a disk speculated to be a portion of the inner layer of the membrane partially affected by spermatozoa. However, neither sperm-associated bodies nor spermatozoa were observed there. It was suggested that the sperm-associated bodies assist fertile spermatozoa in binding the inner layer of the vitelline membrane and penetrating it.     

Revisiting the mouse mitochondrial DNA sequence

The existence of reliable mtDNA reference sequences for each species is of great relevance in a variety of fields, from phylogenetic and population genetics studies to pathogenetic determination of mtDNA variants in humans or in animal models of mtDNA-linked diseases. We present compelling evidence for the existence of sequencing errors on the current mouse mtDNA reference sequence. This includes the deletion of a full codon in two genes, the substitution of one amino acid on five occasions and also the involvement of tRNA and rRNA genes. The conclusions are supported by: (i) the re-sequencing of the original cell line used by Bibb and Clayton, the LA9 cell line, (ii) the sequencing of a second L-derivative clone (L929), and (iii) the comparison with 12 other mtDNA sequences from live mice, 10 of them maternally related with the mouse from which the L cells were generated. Two of the latest sequences are reported for the first time in this study (Balb/cJ and C57BL/6J). In addition, we found that both the LA9 and L929 mtDNAs also contain private clone polymorphic variants that, at least in the case of L929, promote functional impairment of the oxidative phosphorylation system. Conse quently, the mtDNA of the strain used for the mouse genome project (C57BL/6J) is proposed as the new standard for the mouse mtDNA sequence.