Ethylenediaminium di(4-nitrophenolate): a third order NLO material for optical limiting applications

Single crystals of ethylenediaminium di(4-nitrophenolate) [EDA4NP] were grown by slow evaporation solution growth technique using ethanol as solvent at constant temperature. It crystallizes in monoclinic centrosymmetric space group C2/c with cell dimension a=11.326Ǻ, b=7.264Ǻ, c=20.036Ǻ; β=93.55°. Fourier Transform Infra Red (FT-IR) spectrum was recorded to identify various functional groups present in EDA4NP. Nuclear Magnetic Resonance (NMR) spectral studies were performed to confirm the functional groups. Thermogravimetric analysis and differential thermal analysis showed that the compound melts at 142.9°C. The material possesses a wide optical transparency window in the visible and near IR region (500-1200nm). The nonlinear refractive index, nonlinear absorption coefficient and third-order nonlinear susceptibility of EDA4NP were estimated to be n2=5.46×10(-8)cm(2)W(-1), β=0.65×10(-3)cmW(-1) and χ((3))=2.96×10(-6)esu respectively. The limiting behavior observed with the sample is attributed mainly to nonlinear refraction.

Analytical characterization and structure elucidation of metabolites from Aspergillus ochraceus MP2 fungi

OBJECTIVE

To isolate and characterize the bioactive secondary metabolites from Aspergillus ochraceus (A. ochraceus) MP2 fungi.

METHODS

The anti bacterial activity of marine sponge derived fungi A. ochraceus MP2 was thoroughly investigated against antagonistic human pathogens. The optimum inhibitory concentration of the fungi in the elite solvent was also determined. The promising extracts that showed good antimicrobial activity were subjected to further analytical separation to get individual distinct metabolites and the eluants were further identified by GC MS instrumental analysis. The molecular characterization of the elite fungal strains were done by isolating their genomic DNA and amplify the internal transcribed spacer (ITS) region of 5.8s rRNA using specific ITS primer. The novelty of the strain was proved by homology search tools and elite sequences was submitted to GENBANK.

RESULTS

Three bioactive compounds were characterized to reveal their identity, chemical formula and structure. The first elutant was identified asα- Campholene aldehyde with chemical formula C10 H16 O and molecular weight 152 Da. The second elutant was identified as Lucenin-2 and chemical formula C27 H30 O16 and molecular weight 610 Da. The third elutant was identified as 6-Ethyloct- 3-yl- 2- ethylhexyl ester with Chemical formula C26 H42 O4 with molecular weight 418 Da.

CONCLUSIONS

The isolated compounds showed significant antimicrobial activity against potential human pathogens. Microbial secondary metabolites represent a large source of compounds endowed with ingenious structures and potent biological activities.

Pharmacological investigation and spectral characterization of bioactive compounds from crude extracts of sting ray, Dasyatis jenkinsii (Annandale, 1909)

AIM

Dasyatis jenkinsii is used traditionally to treat inflammatory complaints and arthritis by the fisherman community and local population. The present study was designed to scientifically investigate the traditional practice through the analgesic, anti-inflammatory, and organ toxicity studies and characterization of bioactive compounds of crude extracts of D. jenkinsii.

METHOD

Solvent extract of homogenized fresh fish was prepared using petroleum ether and diethyl ether. The chemical and spectral analyses of extracts were carried out using FT-IR and GC-MS. Analgesic and anti-inflammatory activities were assessed by hot plate, tail clip, and carrageenan induced rat paw edema methods. The organ toxicity of each extract was assessed on brain, liver, and kidney of mice.

RESULTS

The IR spectrum indicated the presence of aromatic and aliphatic compounds. GC-MS analysis revealed the presence of 1-(4-carboxy)phenylnona-2, 5-diene and 3-hydroxymono-glyceryl hydrogen phthalate in the petroleum ether extract and carboxyl serine, dihydrotryptophan, and indolyl carboxylic acid in the diethyl ether extract. Both extracts showed significant analgesic and anti-inflammatory effects in all the methods tested. The vital organs of the test animals were not affected by the crude extracts significantly.

CONCLUSIONS

The presence of biologically active compounds in the crude extracts with analgesic and anti-inflammatory properties justifies the traditional knowledge and paves the way for isolation of these compounds for further experimentation.

Anticancer and antimicrobial activity of mangrove derived fungi Hypocrea lixii VB1

AIM

Mangrove is one of the oldest living tree species and its leaves are among the most extensively studied botanicals in use today. Scientific research throughout the world has found evidence to support the fact that its foliar extracts have great potential against human microbial pathogens. This study highlights the isolation of foliar fungi from Rhizophora mucronata, Avicenna officialis and Avicenna marina.

METHOD

It was isolated in Sabouroud's Dextrose Agar and mass cultivation was done in Sabouroud's Dextrose broth.

RESULTS

The ethyl acetate extract showed maximum antibacterial activity which inturn checked for different concentration against bacterial pathogens and anticancer activity for Hep2 and MCF7 cell line in vitro. The DNA was isolated from the fungi and the ITS region of 5.8 s RNA was sequenced and assigned to new species as they are separated from the type strains phylogenetic neighbors by sequence similarities.

CONCLUSION

This preliminary screening of fungal endophytes revealed their potential to yield potent bioactive compounds for drug discovery programmes.

Genetic diversity in three populations of Avicennia marina along the eastcoast of India by RAPD markers

Genetic diversity was analysed in three populations of the mangrove species, Avicennia marina by using random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). Ten random decamer primers were used to score the diversity from three locations of eastcoast of India: Parangipettai (Tamil Nadu), Kakkinada (Andhra Pradesh) and Sundarbans (West Bengal). These primers produced 388 scorable DNA fragments, of which 252 (64.98%) were polymorphic, 182 (46.90%) were monomorphic, and 14 (3.61%) were unique. RAPD banding patterns displayed variations between and within the populations, while, there was no morphological variation.

Anomalous coulomb drag in electron-hole bilayers

We report Coulomb drag measurements on GaAs-AlGaAs electron-hole bilayers. The two layers are separated by a 10 or 25 nm barrier. Below T approximately 1 K we find two features that a Fermi-liquid picture cannot explain. First, the drag on the hole layer shows an upturn, which may be followed by a downturn. Second, the effect is either absent or much weaker in the electron layer, even though the measurements are within the linear response regime. Correlated phases have been anticipated in these, but surprisingly, the experimental results appear to contradict Onsager's reciprocity theorem.