Simple and rapid biosynthesis of stable silver nanoparticles using dried leaves of Catharanthus roseus. Linn. G. Donn and its anti microbial activity.

Nanoparticles have been used to alter and improve the pharmacokinetic and pharmacodynamic properties of various types of drug molecules. The plant extracts are eco-friendly, economical and cost effective for synthesis of large scale of nanoparticles. In this paper we represent the synthesis of silver nanoparticles (AgNPs) from room dried leaves of Vinca rosea. The AgNPs were characterized by UV-vis spectroscopy. The AgNPs are crystalline in nature, were determined from scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX), X-ray diffraction patterns (XRD), and also the size of the NPs was calculated by using Hariba Nanoparticle analyzer and the stability was calculated by using the Zetapotential. The nanoparticles obtained from leaf extracts were of size 27±2 and 30±2 respectively and Zetapotential of AgNPs was found to be -63.1 mV, so it indicates the dispersion and stability. The synthesized AgNPs have very good antimicrobial activity.

Synthesis, spectral characterization and biological activities of Mn(II) and Co(II) complexes with benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone.

Mn(II) and Co(II) complexes of benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone have been synthesized and characterized by the investigations of electronic and EPR spectra and X-ray diffraction. Based on the spectral studies, an octahedral geometry is assigned for the Mn(II) and Co(II) complexes. X-ray powder diffraction studies reveal that Mn(II) and Co(II) complexes have triclinic crystal lattices. The unit cell parameters of the Mn(II) complex are a=11.0469 Å, b=6.2096 Å, c=7.4145 Å, α=90.646°, ß=95.127°, γ=104.776°, V=489.7 Å(3) and those of Co(II) complex are a=9.3236 Å, b=10.2410 Å, c=7.8326 Å, α=90.694°, ß=99.694°, γ=100.476°, V=724.2 Å(3). When the free ligand and its metal complexes are subjected to antibacterial activity, the metal complexes are proved to be more active than the ligand. However with regard to in vitro antioxidant activity, the ligand exhibits greater antioxidant activity than its metal(II) complexes.

Extractive spectrophotometric determination of trace amounts of cadmium(II) in medicinal leaves and environmental samples using benzildithiosemicarbazone (BDTSC).

A new thiosemicarbazone, benzildithiosemicarbazone (BDTSC), is proposed as a sensitive and selective analytical reagent for extractive spectrophotometric determination of Cd(II). BDTSC reacts with cadmium(II) to give a yellow-colored complex in ammonium chloride-ammonium hydroxide buffer of pH 10.5, which is easily extracted into isoamylalcohol with 1:1 composition having a maximum absorbance at wavelength 360 nm. The molar absorptivity and Sandell's sensitivity are found to be 0.196 x 10(4)dm3 mol(-1)cm(-1) and 0.008 microg cm(-2) of Cd(II), respectively. The instability constant of the method has been calculated by Asmus' method as 5.05 x 10(-5) (which is in close agreement with the value obtained by Edmonds and Birnbaum's method) at room temperature. The interfering effect of various cations and anions has also been studied. The method has been successfully applied for the determination of Cd(II) in several standard reference materials as well as environmental samples, medicinal leaves and leafy vegetables.