Newly Isolated Lactic Acid Bacteria with Probiotic Features for Potential Application in Food Industry

Five newly isolated lactic acid bacteria were identified as Weissella cibaria, Enterococcus faecium, and three different strains of Lactobacillus plantarum by 16S rRNA sequencing. Essential probiotic requirements of these isolates such as tolerance to phenol, low pH, high sodium chloride, and bile salt concentration were checked. Efficiency in adherence to mucin and hydrophobicity of the bacterial cell were also evaluated by in vitro studies. Antimicrobial activities against some pathogens were tried, and the sensitivity of these strains against 25 different antibiotics was also checked. Further studies revealed Weissella and Enterococcus as substantial producers of folic acid. Folate is involved as a cofactor in many metabolic reactions, and it has to be an essential component in the human diet. The folate level in the fermented samples was determined by microbiological assay using Lactobacillus casei NCIM 2364 as indicator strain. The three strains of L. plantarum showed significant inhibitory activity against various fungi that commonly contaminate food stuffs indicating their potential as a biopreservative of food material.     

New anthracene based Schiff base ligands appended Cu(II) complexes: Theoretical study,DNA binding and cleavage activities

New anthracene based Schiff base ligands L ¹ and H( L ² ), their Cu(II) complexes [Cu( L ¹ )Cl₂] ( 1 ) and [Cu( L ² )Cl] ( 2 ) , (where L ¹  = N¹,N²‐bis(anthracene‐9‐methylene)benzene‐1,2‐diamine, L ²  = (2Z,4E)‐4‐(2‐(anthracen‐9‐ylmethyleneamino)phenylimino)pent‐2‐en‐2‐ol) have been prepared and characterized by elemental analysis, NMR, FAB‐mass, EPR, FT‐IR, UV–Vis and cyclic voltammetry. The electronic structures and geometrical parameters of complexes 1 and 2 were analyzed by the theoretical B3LYP/DFT method. The interaction of these complexes 1 and 2 with CT‐DNA has been explored by using absorption, cyclic voltammetric and CD spectral studies. From the electronic absorption spectral studies, it was found that the DNA binding constants of complexes 1 and 2 are 8.7 × 10³ and 7.0 × 10⁴ M^?1, respectively. From electrochemical studies, the ratio of DNA binding constants K₊/K₂₊ for 2 has been estimated to be >1. The high binding constant values, K₊/K₂₊ ratios more than unity and positive shift of voltammetric E_1/2 value on titration with DNA for complex 2 suggest that they bind more avidly with DNA than complex 1 . The inability to affect the conformational changes of DNA in the CD spectrum is the definite evidences of electrostatic binding by the complex 1 . It can be assumed that it is the bulky anthracene unit which sterically inhibits these complexes 1 and 2 from intercalation and thereby remains in the groove or electrostatic. The complex 2 hardly cleaves supercoiled pUC18 plasmid DNA in the presence of hydrogen peroxide. The results suggest that complex 2 bind to DNA through minor groove binding.     

A non‐covalent functionalization of copper tetraphenylporphyrin/chemically reduced graphene oxide nanocomposite for the selective determination of dopamine

A non‐covalent functionalization based on a copper tetraphenylporphyrin/chemically reduced graphene oxide (Cu‐TPP/CRGO) nanocomposite is demonstrated for selective determination of dopamine (DA) in pharmaceutical and biological samples. A homogeneous electron‐rich environment can be created on the graphene surface by Cu‐TPP due to the π–π non‐covalent stacking interaction. The synthesized Cu‐TPP/CRGO nanocomposite was characterized using scanning electron microscopy NMR, ultraviolet–visible and electrochemical impedance spectroscopies. The electrocatalytic activity of DA was evaluated using cyclic voltammetry and differential pulse voltammetry. The oxidation peak current (I_pa) of DA increased linearly with increasing concentration of DA in the range 2–200 μM. The detection limit was calculated as 0.76 μM with a high sensitivity of 2.46 μA μM^?1 cm ^{? 2}. The practicality of the proposed DA sensor was evaluated in DA hydrochloride injection, human urine and saliva, and showed satisfactory recovery results for the detection of DA. In addition, the Cu‐TPP/CRGO nanocomposite‐modified electrode showed excellent stability, repeatability and reproducibility towards the detection of DA. Copyright © 2015 John Wiley & Sons, Ltd.     

Analysis of plasticizer influence in Poly(vinyl acetate)/Poly(vinylidene fluoride) polymer blend electrolyte

Gel polymer electrolyte based on poly(vinyl acetate) and poly(vinylidene fluoride) was prepared by solvent casting technique, in which the addition of plasticizers improves the conductivity of polymer membranes. The blend polymer electrolyte containing propylene carbonate (PC) exhibits the highest conductivity of 0.922?×?10^?2 S cm^?1 at room temperature because of the higher dielectric constant as compared to other plasticizers used in the present study. Material characterizations were done with the help of SEM and FT-IR techniques. The activation energy values were computed from ‘log σ?1/T’ Arrhenius plots.     

A new biflavone glycoside from flowers of <Emphasis Type="Italic">Asystasia gangetica</Emphasis>

The yellow parts of the flowers of Asystasia gangetica were extracted with 85% methanol under reflux. The alcoholic extract was concentrated in vacuo and the aqueous extract was fractionated with solvents of increasing polarity. The ethyl acetate fraction yielded a yellow solid, which was characterized as apigenin 7-O-glucosyl(3′ → 6″)luteolin 7″-O-glucoside using UV, ¹H, ¹H–¹H COSY, ¹³C NMR, and mass spectral studies.     

A technique for embedding efpi fiber optic strain sensors in concrete

Experimental Techniques -     

Synthesis of peptide–cellulose conjugate mediated by a soluble cellulose derivative having β-Ala esters (II): conjugates with O-phospho-l-serine-containing peptides

A synthetic route is described here for novel peptide-cellulose conjugates containing O-phospho-l-serine. First, Boc-Ser(PO₃Ph₂) and the related dipeptides, Boc-Ser(PO₃Ph₂)-Asp(OBzl) and Boc-Asp(OBzl)-Ser(PO₃Ph₂), were synthesized by adopting the phosphoryl-protection strategy. The condensation reaction between the α-carboxyl group of the protected Boc-Ser(PO₃Ph₂) and the β-amino groups of β-Ala-Cellulose using isobutyl chloroformate and N-methylmorpholine yielded the product conjugate, N ^β -[Boc-Ser(PO₃Ph₂)]-β-Ala-Cellulose. The degree of substitution of Boc-Ser(PO₃Ph₂) towards the β-amino groups of β-Ala-Cellulose was estimated as DS ^N  = 0.75 (maximum, 1.0). Similar reactions between β-Ala-Cellulose and two kinds of protected dipeptides, Boc-Asp(OBzl)-Ser(PO₃Ph₂) and Boc-Ser(PO₃Ph₂)-Asp(OBzl), gave the corresponding conjugates, and the DS ^N was estimated to be 0.95 and 0.69, respectively. The phenyl, benzyl, and Boc groups were removed in one-pot using the Pt₂O catalyst in 50 % trifluoroacetic acid/acetic acid. The ³¹P-NMR and UV–Visible spectra indicated the complete deprotection without any observable elimination of the phosphorylated peptides.     

Control of Spoilage Fungi by Protective Lactic Acid Bacteria Displaying Probiotic Properties

Thirty-six lactic acid bacteria belong to Lactococcus, Lactobacillus, Enterococcus, and Pediococcus were isolated, and the spectrum of antifungal activity was verified against Fusarium oxysporum (KACC 42109), Aspergillus niger (KACC 42589), Fusarium moniliforme (KACC 08141), Penicillium chrysogenum (NII 08137), and the yeast Candida albicans (MTCC 3017). Three isolates, identified as Pediococcus pentosaceus (TG2), Lactobacillus casei (DY2), and Lactococcus (BSN) were selected further, and their antifungal compounds were identified by ESI-MS and HPLC analysis as a range of carboxylic acids along with some unidentified, higher molecular weight compounds. An attempt to check out the shelf life extension of wheat bread without fungal spoilage was performed by fermenting the dough with the Lactococcus isolate. Apart from growth in low pH and tolerance to bile salts, probiotic potential of these three isolates was further substantiated by in vitro screening methods that include transit tolerance to the conditions in the upper human gastrointestinal tract and bacterial adhesion capacity to human intestinal cell lines.     

The reaction of 4-methoxybenzylmagnesium chloride with aldehydes. The formation of 4-exomethylenecyclohexenones

The reaction of 4-methoxybenzylmagnesium chloride with aldehydes provides good yields of 4-exomethylenecyclohexenones.