C-Glucosylated malonitrile as a key intermediate towards carbohydrate-based glycogen phosphorylase inhibitors

Glycogen utilization involves glycogen phosphorylase, an enzyme which appears to be a potential target for the regulation of glycaemia, as the liver isoform is a major player for hepatic glucose output. A single C-glucosylated malonitrile allowed for the synthesis of three glucose-based derivatives namely bis-oxadiazoles, bis-amides and a C-glucosylated tetrahydropyrimidin-2-one. When evaluated as glycogen phosphorylase inhibitors, two of the synthesized compounds displayed inhibition in the sub-millimolar range. In silico studies revealed that only one out of the bis-amides obtained and the C-glucosylated tetrahydropyrimidin-2-one may bind at the catalytic site.     

Expression and activity of paraoxonase 1 in human cataractous lens tissue

Paraoxonase 1 (PON1) is a high-density lipoprotein-associated enzyme that is believed to be involved in the protection against oxidative stress. There is evidence that paraoxonase activity is reduced in patients with diabetes and cataract. In the current study, we analyzed mRNA expression of PON1 as well as other members of the paraoxonase family, PON2 and PON3, in human cataractous lens samples. Our results indicate that only PON1 is expressed at the gene and protein levels in human lens tissues. We quantified MDA levels and measured PON1 (paraoxonase/arylesterase) enzymatic activities in subjects suffering from cataract due to aging and diabetes. Decreased PON1 activity was more pronounced in diabetic patients (p  <  0.001) compared to senile subjects, which may be due to glycation and increased oxidative insult. To examine the structural alterations that occur in response to glycation, we constructed a three-dimensional model of PON1 and its glycated variant. Glycation at Lys70 and Lys75 is predicted to cause hindrance in binding of substrate to the active site of the enzyme.     

Probing for missing links in the binary and ternary V(V)-citrate-(H2O2) systems: Synthetic efforts and in vitro insulin mimetic activity studies

In a pH-specific fashion, V₂O₅ and citric acid in the absence and presence of H₂O₂ reacted and afforded, in the presence of NaOH and (CH₆N₃)₂CO₃, two new dinuclear V(V) binary non-peroxo (CH₆N₃)₆[V₂O₄(C₆H₄O₇)₂] · 2H₂O (1) and ternary peroxo (CH₆N₃)₄[V₂O₂(Ο₂)₂(C₆H₅O₇)₂] · 6Η₂Ο (2) species, respectively. Complexes 1 and 2 were further characterized by elemental analysis, UV/Vis, FT-IR, NMR (solution and solid state Cross Polarization-Magic Angle Spinning (CP-MAS)) and Raman spectroscopies, cyclic voltammetry, and X-ray crystallography. Both 1 and 2 are members of the family of dinuclear V(V)-citrate species bearing citrate with a distinct coordination mode and degree of deprotonation, with 2 being the missing link in the family of pH-structural variants of the ternary V(V)-peroxo-citrate system. Given that 1 and 2 possess distinct structural features, relevant binary V(III), V(IV) and V(V), and ternary V(V) species bearing O- and N-containing ligands were tested in in vitro cell cultures to assess their cellular toxicity and insulin mimetic capacity. The results project a clear profile for all species tested, earmarking the importance of vanadium oxidation state and its ligand environment in influencing further binary and ternary interactions of vanadium arising with variable mass cellular targets, ultimately leading to a specific (non)toxic phenotype and glucose uptake ability.     

Lecanicillium and Verticillium species from Indonesia and Japan including three new species

Forty-six Lecanicillium strains and one Verticillium strain were isolated from subterranean and epiphytic arthropods, soil, and other sources collected in Indonesia and Japan. These strains were identified as nine Lecanicillium and one Verticillium species including six undescribed species based on light microscopy and the sequences of the ITS-1 and ITS-2 regions including 5.8S ribosomal DNA. Four of the ten species (L. araneicola, L. kalimantanense, Lecanicillium sp. 4, and V. indonesiacum) were recovered from Indonesia, five of the ten (L. attenuatum, L. fusisporum, L. psalliotae, Lecanicillium sp. 1, and Lecanicillium sp. 3) were from Japan, and L. saksenae was from both countries. In this article, new species (L. araneicola, L. kalimantanense, and V. indonesiacum) and a new combination (L. saksenae) are proposed from the fungi isolated from epiphytic and subterranean arthropods collected in East Kalimantan.     

A strategy for mitigating avian colibacillosis disease using plant growth promoting rhizobacteria and green synthesized zinc oxide nanoparticles

Avian colibacillosis caused by the zoonotic pathogen Escherichia coli is a common bacterial infection that causes major losses in the poultry sector. Extracts of different medicinal plants and antibiotics have been used against poultry bacterial pathogens. However, overuse of antibiotics and extracts against pathogenic strains leads to the proliferation of multi-drug resistant bacteria. Due to their environmentally friendly nature, nanotechnology and beneficial bacterial strains can be used as effective strategies against poultry infections. Green synthesis of zinc oxide nanoparticles (ZnO-NPs) from Eucalyptus globulus leaves was carried out in this study. Their characterization was done by UV–vis spectroscopy, X-ray diffraction (XRD), and Fourier transmission infrared spectroscopy (FT-IR) which confirmed their synthesis, structure, and size. In vitro, antimicrobial activities of plant leaf extract, ZnO-NPs, and plant growth-promoting rhizobacteria (PGPR) were checked against E. coli using well diffusion as well as disc diffusion method. Results proved that the antimicrobial activity of ZnO-NPs and PGPR strains was more enhanced when compared to eucalyptus leaf extract at 36 h. The maximum relative inhibition shown by ZnO-NPs, PGPR strains and eucalyptus leaf extracts was 88%, 67% and 58%, respectively. The effectiveness of ZnO-NPs was also increased with an increase in particle dose and treatment time. The 90 mg/ml of ZnO-NPs was more effective. PGPR strains from all over the tested strains, Pseudomonas sp. (HY8N) exhibited a strong antagonism against the E. coli strain as compared to other PGPR strains used in this study. However, combined application of PGPR (Pseudomonas sp. (HY8N)) and ZnO-NPs augment antagonistic effects and showed maximum 69% antagonism. The study intends to investigate the binding affinity of ZnO-NPs with the suitable receptor of the bacterial pathogen by in silico methods. The binding site conformations showed that the ligand ZnO binds with conserved binding site of penicillin-binding protein 6 (PBP 6) receptor. According to the interactions, ZnO-NPs form the same interaction pattern with respect to other reported ligands, hence it can play a significant role in the inhibition of PBP 6. This research also found that combining ZnO-NPs with Pseudomonas sp. (HY8N) was a novel and effective technique for treating pathogenic bacteria, including multidrug-resistant bacteria.     

An effector-targeted protease contributes to defense against Phytophthora infestans and is under diversifying selection in natural hosts

Since the leaf apoplast is a primary habitat for many plant pathogens, apoplastic proteins are potent, ancient targets for apoplastic effectors secreted by plant pathogens. So far, however, only a few apoplastic effector targets have been identified and characterized. Here, we discovered that the papain-like cysteine protease C14 is a new common target of EPIC1 and EPIC2B, two apoplastic, cystatin-like proteins secreted by the potato (Solanum tuberosum) late blight pathogen Phytophthora infestans. C14 is a secreted protease of tomato (Solanum lycopersicum) and potato typified by a carboxyl-terminal granulin domain. The EPIC-C14 interaction occurs at a wide pH range and is stronger than the previously described interactions of EPICs with tomato defense proteases PIP1 and RCR3. The selectivity of the EPICs is also different when compared with the AVR2 effector of the fungal tomato pathogen Cladosporium fulvum, which targets PIP1 and RCR3, and only at apoplastic pH. Importantly, silencing of C14 increased susceptibility to P. infestans, demonstrating that this protease plays a role in pathogen defense. Although C14 is under conservative selection in tomato, it is under diversifying selection in wild potato species (Solanum demissum, Solanum verrucosum, and Solanum stoliniferum) that are the natural hosts of P. infestans. These data reveal a novel effector target in the apoplast that contributes to immunity and is under diversifying selection, but only in the natural host of the pathogen.     

Population genetics of apolipoproteins A-IV, E, and H, and the angiotensin converting enzyme (ACE): associations with lipids, and apolipoprotein levels in American Samoans

Distributions of alleles at three apolipoprotein loci (APO E, APO H, and APO A-IV) and an insertion/deletion (I/D) polymorphism at the angiotensin converting enzyme (ACE) locus among 274 American Samoans are described here. Genotypes at each locus are examined for associations with quantitative lipid (total cholesterol (total-c), LDL-cholesterol (LDL-c), HDL-cholesterol (HDL-c), and triglycerides) and apolipoprotein (APO AI, APO AII, APO E, and APO B) levels. Genotype frequencies at all four loci are in Hardy-Weinberg equilibrium. The most common APO A-IV genotype (1-1) was observed in 252 American Samoans (97%). The three most common APO E genotypes were 3-3 (47%), 3-4 (30%), and 2-3 (12%). The most frequent APO H genotype was 2-2 (86%). The most common ACE genotype (I/I) was observed in 75% of sampled individuals, and 23% were I/D heterozygotes. APO E genotypic variation was associated with total-c, HDL-c, LDL-c, and all four quantitative apolipoproteins (AI, AII, E, and B). APO A-IV genotypes were associated significantly with total cholesterol, LDL-c, and APO-B levels. APO H showed little association with any quantitative lipid or apolipoprotein. ACE D/D homozygotes had higher AII levels. ACE showed a consistent association with APO AII levels, with either APO A-IV or APO E as a covariate. The interaction term between ACE and APO E was also significantly associated with total-c and APO E levels, and the ACE genotype showed a significant main effect on APO AI levels in multivariate analyses.     

Integrating low water potential seed hydration with other treatments to improve cold tolerance

Matriconditioning improved the performance of pepper, tomato, sweet corn, snap bean, table beet, sugar beet and watermelon seeds in early field plantings at suboptimal temperatures (averaged over 10 d after planting) ranging from 12 to 18 °C. Reduction in the time to 50% (T(50)) emergence in conditioned seeds ranged from 0·6 d in watermelon to 3·3 d in pepper and improvement in emergence from 10% in sugar beet to 30% in table beet. Further improvement in emergence occurred by inclusion of pesticides and/or gibberellin during conditioning. A 4 d conditioning of pepper at 25 °C was superior to 7 d conditioning at 15 °C in seeds germinated at 15 °C on filter paper, but 15 °C conditioning was superior in improving percentage emergence in early field plantings. Tomato seeds conditioned at 15 or 25 °C performed equally well in the field. A 2 d conditioning was superior to 1 d conditioning in improving the performance of supersweet sweet corn cultivars grown in a growth chamber at 10/20 °C. The water uptake rate in the presence of Micro-Cel E during matriconditioning of sweet corn seeds was slower than when the seeds were exposed to the same amount of water in absence of the carrier. Electrolyte leakage was greater in supersweet 'Challenger' sweet corn seeds carrying the sh(2) gene compared to the sugary type sweet corn 'More', and in both cases matriconditioning reduced the leakage. Lettuce seeds matriconditioned for 24 h had higher 1-aminocyclopropane-l-carboxylic acid (ACC) content, developed greater ACC oxidase activity and performed better at 10 °C (germinated earlier and had higher percentage germination) than the untreated seeds. Matriconditioning appears to bring about beneficial physical, physiological and biochemical changes that seemingly improve embryo growth potential and tolerance to low temperatures.