A facile and green strategy for the synthesis of Au, Ag and Au-Ag alloy nanoparticles using aerial parts of R. hypocrateriformis extract and their biological evaluation.

A facile and green strategy is reported here to synthesize gold (Au), silver (Ag) and gold-silver (Au-Ag) alloy nanoparticles (NPs) through bio-reduction reactions of aqueous corresponding metal precursors mediated by extracts of aerial parts of R. hypocrateriformis, which act as both reducing and stabilizing agents, under microwave irradiation. UV-vis spectrophotometer, XRD, FT-IR, FESEM/TEM, TGA and EDAX analysis were used to characterize the obtained NPs. The formation of NPs is evident from their surface plasmon resonance peak observed at λmax=∼550, 450 and 500nm for Au, Ag and Au-Ag alloy NPs respectively. XRD pattern revealed that fcc structure, while FT-IR spectra signify the presence of phytochemicals adsorbed on NPs. Such a biofunctionalized NPs were characterized by their weight loss, 30% due to thermal degradation of plant phytochemicals observed in TG analysis. The spherical shape of Au, Ag and Au-Ag alloy NPs (∼10-50nm) is observed by FE-SEM/TEM images. EDAX analysis confirms the expected elemental composition. Moreover, these NPs showed enhanced antimicrobial, antioxidant, and anticancer activities, though it is more pronounced for Au-Ag alloy NPs, which is due to the combining effect of phytochemicals, Au and Ag metals. Thus, the biosynthesized NPs could be applied as effective growth inhibitors for various biomedical applications.

Solvent-free, microwave assisted Knoevenagel condensation of novel 2,5-disubstituted indole analogues and their biological evaluation.

A rapid, efficient and environmental benign methodology for the preparation of 2,5-disubstituted indole analogues is developed. 2,5-Disubstituted indole-3-carboxaldehydes (1a-c) undergo Knoevenagel condensation with barbiturates (2 &4), thiazolidine-2,4-dione (6) and 3-methyl-1H-pyrazol-5(4H)-one (8) in solvent-free, NH(4)OAc catalyzed, microwave assisted reaction. Structures of the products thus obtained were confirmed by their m.p, Elemental analysis, IR, (1)H NMR, (13)C NMR and Mass spectral data. The in vitro antioxidant and cytotoxic activities against three tumor cell lines were evaluated and discussed in terms of their structural differences. Among the screened compounds 9b, 9c, 7b and 5b exhibited excellent antioxidant activity. Compounds 9b, 9c and 7b have shown strong cytotoxicity among the compounds tested.

Synthesis, antioxidant and DNA cleavage activities of novel indole derivatives.

A new series of novel indole derivatives containing barbitone moiety (5a-i) are synthesized by simple and efficient condensation of chalcones (3a-i) with barbituric acid (4). The synthesized compounds are screened for their antioxidant (free radical scavenging, total antioxidant capacity and ferric reducing antioxidant power) and DNA cleavage activities were evaluated. Among the synthesized compounds (5a), (5d) and (5g) exhibited excellent antioxidant activity and all the tested compounds in the series have exhibited promising DNA cleavage activities. The structures of the synthesized compounds are assigned on the basis of elemental analysis, IR, (1)H NMR, (13)C NMR and mass spectral data.

Potential transition state phosphoramidate inhibitors of beta-tubulin as antifilarial agents.

Transition state phosphoramidate inhibitors of beta-tubulin were designed as potential antifilarial agents. The reaction of 2-aminobenzimidazole with diisopropyl phosphite and carbon tetrachloride at a low temperature gave the unexpected 1-diisopropoxyphosphoryl-2-aminobenzimidazole, which on heating gave the novel benzimidazole derivative, 2-(diisopropoxyphosphoryl)aminobenzimidazole. Both products were fully characterized and the synthetic procedure to both compounds was optimized. The procedure was used to prepare the related 5-benzoyl-2-(diisopropoxyphosphoryl)aminobenzimidazole and 5-benzoyl-2-(diethoxyphosphoryl)aminobenzimidazole (1d). In a preliminary trial against Brugia pahangi compound 1d was found to have no antifilarial activity. This lack of activity may be attributed to its extreme insolubility and thus low bioavailability. The synthesis of analogous, more soluble, phosphorothioate-substituted benzimidazoles using the same methods may yield compounds with greater antifilarial activity.