Javed Iqbal

Multistimuli-Responsive Benzothiadiazole-Cored Phenylene Vinylene Derivative with Nanoassembly Properties

A trifluoromethyl-substituted benzothiadiazole-cored phenylene vinylene fluorophore (1) was synthesized and displayed piezo- and vapochromism and thermo-induced fluorescence variation in solid phase. Grinding could disrupt the crystalline compound 1 with orange emission into amorphous compound 1 with green emission, and heating treatment could change the amorphous compound 1 into crystalline compound 1. Ultraviolet-visible (UV-vis) absorption spectra, (13)C nuclear magnetic resonance (NMR), and powder X-ray diffraction (PXRD) characterizations demonstrated that crystalline and amorphous compound 1 possess different molecular packing. A differential scanning calorimetry (DSC) measurement revealed that the emission switching was due to the exchange between the thermodynamic-stable crystalline and metastable amorphous states. The ground sample exhibited vapochromic fluorescence property. Furthermore, compound 1 showed interesting supramolecular assembly characteristics in solution. Slowly cooling the hot N,N-dimethylformamide (DMF) solution of compound 1 resulted in the formation of orange fluorescent fibers, whereas sonication treatment of the cooling solution led to the generation of organic molecular gel. The field emission scanning electronic microscope (FESEM) and fluorescent microscopy images revealed smooth nano- or microfiber and network morphology properties. The PXRD spectra confirmed that these nano- or microstructures had a similar molecular-packing model with the crystalline state of compound 1. Slow evaporation of the toluene solution of compound 1 could produce green emissive microrods, which exhibited interesting thermo-induced fluorescence variation.

Evaluation of the hypoglycaemic effect of Achyranthes aspera in normal and alloxan-diabetic rabbits

Blood glucose levels of normal and alloxan diabetic rabbits were determined after oral administration of various doses of Achyranthes aspera powdered whole plant and certain aqueous and methanolic extracts. Oral administration of 2, 3 and 4 g/kg of A. aspera powder produced a significant dose-related hypoglycaemic effect in normal as well as in diabetic rabbits. The water and methanol extracts also decreased blood glucose levels in normal and alloxan diabetic rabbits. A 7-day acute toxicity study in rabbits did not reveal any adverse or side effects of this folk medicine at dosages up to 8 g/kg orally. It is possible that the plant could act by providing certain necessary elements like calcium, zinc, magnesium, manganese and copper to the beta-cells.

Marine bioactive peptides: Types, structures, and physiological functions

ABSTRACT Oceans are considered one of the richest sources of bioactive compounds. The extraction and utilization of marine peptides have attracted attention owing to their potential health benefits. They can be used in different functional and nutraceutical foods due to their antihypertensive, antioxidant, and antimicrobial properties. These bioactive peptides can be extracted from sponges, ascidians, seaweeds, and mollusks and reportedly have pharmacological properties. The objectives of this article are to provide an overview on the sources of marine bioactive peptides, a brief description of their extraction methods, and their biological activities and potential applications in functional foods and pharmaceuticals.

Theoretical study of the non linear optical properties of alkali metal (Li, Na, K) doped aluminum nitride nanocages

The effect of alkali metal (Li, Na, and K) doping in aluminum nitride (Al12N12) nanocages is studied through density functional theory (DFT) methods. Six new stable compounds of M@Al12N11 and M@Al11N12 are designed theoretically where alkali metal replaces an atom (Al/N) of a nanocage. The stability of the doped nano-cages is evaluated through binding energy calculations. Doping alkali atom M (M = Li, Na, K) into a nanocage significantly reduces the band gap (HOMO–LUMO gap). Polarizability and first hyperpolarizability are calculated using long range separated methods to evaluate the non-linear optical (NLO) properties of these doped systems. The hyperpolarizability of MAl12N11 nanocages is much higher than that of M@Al11N12 nanocages. The higher hyperpolarizability of M@Al12N11 nanocages is believed to arise from participation of excess diffuse electrons, revealed from PDOS.

Enantiodivergent routes to (+) and (−)-novioses from (−)-pantolactone

Noviose, a rare sugar moiety present in many biologically interesting molecules such as novobiocin and tiacumicin was obtained through formal synthesis in (+)- and (−)-forms starting from commercially available (−)-pantolactone in an enantiodivergent manner.

Appraisal of gene action for indeterminate growth in mungbean [Vigna radiata (L.) Wilczek].

In order to investigate the inheritance pattern of indeterminate growth in Vigna radiata, various related traits were studied. The techniques used for the purpose were generation mean and variance analyses. Narrow sense heritability estimates were also computed. Four out of fifty greengram accessions were selected during preliminary screen trial based on DDd2 and DDh2 values. Two cross combinations were made by utilizing four parents. Generation variance analysis demonstrated the engagement of additive and environmental components, with the pre-pondrance of additive gene action. Narrow sense heritability estimates (>67%) also supported the same. In generation mean analysis both cross combinations manifested non-allelic epistatic digenic interactions for the investigated traits except for plant height at first flower initiation and for seed yield per plant in one cross combination, where only additive and dominance components were important. For pyramiding the additive genes favoring determinate plant growth, higher harvest index and simultaneously purging the genes promoting twining growth habit escorted with low seed yield, any modified breeding scheme which could serve the said purpose may be opted.

UV absorbers for cellulosic apparels: A computational and experimental study

Two triazine based Ultra Violet (UV) absorbers Sulfuric acid mono-(2-{4-[4-chloro-6-(4-{4-chloro-6-[4-(2-sulfooxy-ethanesulfonyl)-phenylamino]-[1,3,5] triazin-2-ylamino-phenylamino)-[1,3,5]triazin-2-ylamino]-benzenesulfonyl}-ethyl) ester (1a) and 4-{4-chloro-6-[4-(2-sulfooxy-ethanesulfonyl)-phenylamino]-[1,3,5] triazin-2-ylamino}-2-[4-chloro-6-(2-sulfooxy-ethanesulfonyl)-[1,3,5]triazin-2-ylamino]-benzenesulfonic acid (2a) with different substituents were designed computationally. The influence of different substituents on the electrochemical properties and UV spectra of the absorbers was investigated. The presence of electron deficient unit in 1a to the molecular core significantly reduces the LUMO levels and energy gap. The designed absorbers were synthesized via condensation reaction and characterized by UV-Vis, FT-IR, MS studies. The performance of synthesized compounds as UV absorbers and their fastness properties were assessed by finishing the cotton fabric through exhaust method at different concentration and results appeared in good range.

The substitution effect of heterocyclic rings to tune the optical and nonlinear optical properties of hybrid chalcones: A comparative study

The present study spotlights the hybrid chalcone derivatives consisting of coumarin moieties conjugated systematically with different heterocyclic rings. The heterocyclic rings including bifuran, bicyclopentane, bipyrrole and bithiophenes groups are used to design compounds 1, 2, 3 and 4, respectively. Different density functional theory (DFT) methods are used for optimization of designed compounds. The M06 functional shows reasonably good accuracy for calculations of geometrical and absorption spectra as compared with other methods and/or available experimental data. The calculated average third-order NLO polarizabilities (γ) for compounds 1, 2, 3 and 4 are found to be 526.22u202f×u202f10-36, 675.40u202f×u202f10-36, 939.58u202f×u202f10-36 and 1109.30u202f×u202f10-36xa0esu., respectively, at M06/6-311G** level of theory. The γ amplitudes of compounds 1, 2, 3 and 4 are reasonably enhanced, which are about 25, 27, 30 and 32 times larger to the γ amplitude of para nitroaniline (a prototype NLO molecule) at same M06/6-311G** level of theory. Furthermore, we highlight the structure-property relationship using TD-DFT calculations for absorption and emission spectra, frontier molecular orbitals and molecular electrostatic potential maps. Thus, the present study will evoke the interest of scientific community to develop the above title materials for efficient NLO applications.

Design and Analysis of Self-Healing Tree-Based Hybrid Spectral Amplitude Coding OCDMA System

This paper presents an efficient tree-based hybrid spectral amplitude coding optical code division multiple access (SAC-OCDMA) system that is able to provide high capacity transmission along with fault detection and restoration throughout the passive optical network (PON). Enhanced multidiagonal (EMD) code is adapted to elevate system’s performance, which negates multiple access interference and associated phase induced intensity noise through efficient two-matrix structure. Moreover, system connection availability is enhanced through an efficient protection architecture with tree and star-ring topology at the feeder and distribution level, respectively. The proposed hybrid architecture aims to provide seamless transmission of information at minimum cost. Mathematical model based on Gaussian approximation is developed to analyze performance of the proposed setup, followed by simulation analysis for validation. It is observed that the proposed system supports 64 subscribers, operating at the data rates of 2.5 and above. Moreover, survivability and cost analysis in comparison with existing schemes show that the proposed tree-based hybrid SAC-OCDMA system provides the required redundancy at minimum cost of infrastructure and operation.

Synthesis, crystal structure and biological activity of a cobalt(II) complex of N,N,N′,N′-tetrakis(2-hydroxypropyl) ethylenediamine

AbstractnThe synthesis, crystal structure and biological properties of [Co(edtp)Cl)]·NO3·H2O are described, where edtp is N,N,N′,N′-tetrakis(2-hydroxypropyl) ethylenediamine. The Co2+ ion is coordinated by the N,N′,O,O′,O″-pentadentate edtp ligand and a chloride to generate a distorted CoClN2O3 octahedron. The complex exhibits moderate antithrombolytic activity (38xa0% screened by hemolytic assay) against clots developed by bovine blood and negligible cytotoxicity (5xa0%) against bovine erythrocytes. Conversely, very high bacterial biofilm inhibition (90xa0%) was recorded against both Gram-positive and Gram-negative bacterial species.