A steryl ester from Lepidium sativum

A new steryl ester isolated from the aerial parts of Lepidium sativumfy1>cf1>, has been identified as stigmast-5-en-3,β27-diol 27-benzoate on the basis of spectral data analyses and chemical reactions.     

Structural changes in root and shoot ofBacopa monniera in response to salt stress

Various concentrations of salt (NaCI) were shown to have an influence on the differentiation of tissues in the root and stem ofBacopa monniera (L) Wettst. Higher concentrations induced drastic changes in roots grown on salt-supplemented media; epidermal and cortical cells experienced changes in shape, size, and orientation and/or were got disintegrated. A low concentration of salt induced a profuse development of root hairs which gradually disappeared at higher concentrations. Air spaces in the stem cortex were enlarged and xylem cell walls in the vascular ring were thickened.     

Exploring bacterial diversity via a curated and searchable snapshot of archived DNA sequences

The open sharing of genomic data provides an incredibly rich resource for the study of bacterial evolution and function and even anthropogenic activities such as the widespread use of antimicrobials. However, these data consist of genomes assembled with different tools and levels of quality checking, and of large volumes of completely unprocessed raw sequence data. In both cases, considerable computational effort is required before biological questions can be addressed. Here, we assembled and characterised 661,405 bacterial genomes retrieved from the European Nucleotide Archive (ENA) in November of 2018 using a uniform standardised approach. Of these, 311,006 did not previously have an assembly. We produced a searchable COmpact Bit-sliced Signature (COBS) index, facilitating the easy interrogation of the entire dataset for a specific sequence (e.g., gene, mutation, or plasmid). Additional MinHash and pp-sketch indices support genome-wide comparisons and estimations of genomic distance. Combined, this resource will allow data to be easily subset and searched, phylogenetic relationships between genomes to be quickly elucidated, and hypotheses rapidly generated and tested. We believe that this combination of uniform processing and variety of search/filter functionalities will make this a resource of very wide utility. In terms of diversity within the data, a breakdown of the 639,981 high-quality genomes emphasised the uneven species composition of the ENA/public databases, with just 20 of the total 2,336 species making up 90% of the genomes. The overrepresented species tend to be acute/common human pathogens, aligning with research priorities at different levels from individual interests to funding bodies and national and global public health agencies.

This study presents the first uniformly assembled, comprehensively described and searchable dataset of 661,405 bacterial genomes; this resource will empower more scientists to harness the multitude of data in public sequencing archives, but also reveals the biased composition of these archives, with 90% of the data originating from just 20 species.     

Design,synthesis and characterisation of affinity ligands for glycoproteins

The concepts of rational design and solid phase combinatorial chemistry were used to develop affinity adsorbents for glycoproteins. A detailed assessment of protein–carbohydrate interactions was used to identify key residues that determine monosaccharide specificity, which were subsequently exploited as the basis for the synthesis of a library of glycoprotein binding ligands. The ligands were synthesised using solid phase combinatorial chemistry and were assessed for their sugar‐binding ability with the glycoenzymes, glucose oxidase and RNase B. Partial and completely deglycosylated enzymes were used as controls. The triazine‐based ligand, histamine/tryptamine (8/10) was identified as a putative glycoprotein binding ligand, since it displayed particular affinity for glucose oxidase and other mannosylated glycoproteins. Experiments with deglycosylated control proteins, specific eluants and retardation in the presence of competing sugars strongly suggest that the ligand binds the carbohydrate moiety of glucose oxidase rather than the protein itself. Copyright © 1999 John Wiley & Sons, Ltd.     

Antioxidant and cytotoxic activity of bioactive phenolic metabolites isolated from the yeast-extract treated cell culture of apple

Buds of in vitro-grown shoots of two purple-fleshed potato genotypes were successfully cryopreserved by encapsulation-vitrification (Encap-vitri) and droplet-vitrification (Drop-vitri). Optimal time durations of exposure to PVS2 for shoot regrowth of cryopreserved buds were 5–7 h and 6 h for ‘E03-2677’ and for ‘Blue Congo’, respectively, in Encap-vitri, and 30–50 min and 40 min for the former and the latter, respectively, in Drop-vitri. Higher rates of shoot regrowth were obtained in 1.5–2.0 mm-buds than in 1.0–1.4 mm-ones in Encap-vitri for ‘E03-2677’ and ‘Blue Congo’, while opposite results were found in Drop-vitri. In ‘Blue Congo’, only apical shoot tips survived and developed into shoots, with one shoot produced in one cryopreserved bud in Encap-vitri and Drop-vitri. In ‘E03-2677’, survival and shoot regrowth patterns were similar to those of ‘Blue Congo’ in Encap-vitri. However, both apical and axillary shoot tips survived and developed into two shoots in one bud in Drop-vitri. In ‘E03-2677’, histological observations revealed only apical shoot tips survived following Encap-vitri, while both apical and axillary shoot tips survived following Drop-vitri. Vegetative growth in shoots regenerated from Encap-vitri and Drop-vitri after 3 weeks of post-thaw culture was significantly lower than that from control, but markedly increased after 6 months of post-thaw culture. In both ‘E03-2677’ and ‘Blue Congo’, number of microtubers per shoot, per vessel and ≥3 mm in diameter were significantly greater in shoots regenerated from Encap-vitri than in those from the control. Assessments by ISSR and RAPD of genetic stability did not find any polymorphic bands in regenerants recovered from Encap-vitri and Drop-vitri. To the best of our knowledge, this is the first report on cryopreservation of purple-fleshed potato by vitrification-based procedures. Results reported here would provide valuable basic and technical information on cryopreservation of purple-fleshed potato.     

Implications of molecular diversity of chitin and its derivatives

Chitin is a long unbranched polysaccharide, made up of β-1,4-linked N-acetylglucosamine which forms crystalline fiber-like structure. It is present in the fungal cell walls, insect and crustacean cuticles, nematode eggshells, and protozoa cyst. We provide a critical appraisal on the chemical modifications of chitin and its derivatives in the context of their improved efficacy in medical applications without any side effect. Recent advancement in nanobiotechnology has helped to synthesize several chitin derivatives having significant biological applications. Here, we discuss the molecular diversity of chitin and its applications in enzyme immobilization, wound healing, packaging material, controlled drug release, biomedical imaging, gene therapy, agriculture, biosensor, and cosmetics. Also, we highlighted chitin and its derivatives as an antioxidant, antimicrobial agent, anticoagulant material, food additive, and hypocholesterolemic agent. We envisage that chitin and chitosan-based nanomaterials with their potential applications would augment nanobiotechnology and biomedical industries.

     

Length–weight relationships of 21 fish species from the upland Ganga River Basin tributaries of Central Indian Himalaya

Length–weight relationships (LWRs) are described for 21 fish species belonging to six families from different tributaries of the upland Ganga Basin in India. LWRs for five selected species were unknown to FishBase and new maximum lengths are recorded for 13 species. These results will be useful for fishery research, management and conservation in these tributaries of the Ganga River basin.     

Foliar application of selenium increases fertility and grain yield in bread wheat under contrasting water availability regimes

The study was conducted to assess whether selenium (Se) application modulates fertility to alter grain yield in bread wheat grown under different moisture regimes. Seeds of wheat cultivar Millat-2011 were sown in the plots using a randomized complete block design with three replicates per treatment. After germination, the plants were exposed to six moisture regimes, viz. no irrigation after germination, irrigation at boot stage, irrigations at boot and grain-filling stages, irrigations at crown root, boot and grain-filling stages, irrigations at crown root, boot, heading and grain-filling stages and irrigations at crown root, stem elongation, boot, heading and grain-filling stages. At the heading stage, foliar spray of sodium selenate (0, 2 and 4 mg Se L^?1) was done. Withholding water at early growth stages significantly increased oxidative stress and decreased growth and grain yield. Irrespective of moisture regimes, foliar application of Se (2 mg L^?1) decreased oxidative stress, modulated photosynthetic pigments and fertility and increased grain yield in wheat. The Se-mediated increase in grain yield was attributed to the increase in chlorophyll and ascorbic acid contents and fertility coupled with decrease of oxidative stress under different moisture regimes. The results could be helpful to manage wheat production in the semi-arid environments.     

Rutin–Nickel Complex: Synthesis,Characterization, Antioxidant,DNA Binding,and DNA Cleavage Activities

The rutin–nickel (II) complex (RN) was synthesized and characterized by elemental analysis, UV–visible spectroscopy, IR, mass spectrometry, ¹H NMR, TG-DSC, SEM, and molar conductivity. The low molar conductivity value investigates the non-electrolyte nature of the complex. The elemental analysis and other physical and spectroscopic methods reveal the 1:2 stoichiometric ratio (metal/ligand) of the complex. An antioxidant study of rutin and its metal complex against DPPH radical showed that the complex has more radical scavenging activity than free rutin. The interaction of complex RN with DNA was determined using fluorescence spectra and agarose gel electrophoresis. The results showed that RN can intercalate moderately with DNA, quench a strong intercalator ethidium bromide (EB), and compete for the intercalative binding sites. The complex showed significant cleavage of pBR 322 DNA from supercoiled form (SC) to nicked circular form (NC), and these cleavage effects were dose-dependent. Moreover, the mechanism of DNA cleavage indicated that it was a hydrolytic cleavage pathway. These results revealed the potential nuclease activity of the complex to cleave DNA.