A novel oxidative transformation of alcohols to nitriles: an efficient utility of azides as a nitrogen source

An efficient methodology to oxidize benzylic and cinnamyl alcohols to their corresponding nitriles in excellent yields has been developed. This methodology employs DDQ as an oxidant and TMSN(3) as a source of nitrogen in the presence of a catalytic amount of Cu(ClO(4))(2)·6H(2)O.     

A non-metal catalysed oxidation of primary azides to nitriles at ambient temperature

A novel non-metal catalyzed oxidation of organic azides to nitriles under solvent-free conditions is presented employing catalytic amounts of KI, and DABCO in aq. TBHP at room temperature. This non-metal catalyzed oxidation of azides provides good selectivity as double and triple bonds were not oxidized under the present reaction conditions.     

Detection and Confirmation of Alkaloids in Leaves of Justicia adhatoda and Bioinformatics Approach to Elicit Its Anti-tuberculosis Activity

The extraction and determination of alkaloids was performed and confirmed by phytochemical analysis. Six different quinazoline alkaloids (vasicoline, vasicolinone, vasicinone, vasicine, adhatodine and anisotine) were found in the leaf of Justicia adhatoda (J. adhatoda). The presence of the peaks obtained through HPLC indicated the diverse nature of alkaloid present in the leaf. The enzyme ??-ketoacyl-acyl-carrier protein synthase III that catalyses the initial step of fatty acid biosynthesis (FabH) via a type II fatty acid synthase has unique structural features and universal occurrence in Mycobacterium tuberculosis (M. tuberculosis). Thus, it was considered as a target for designing of anti-tuberculosis compounds. Docking simulations were conducted on the above alkaloids derived from J. adhatoda. The combination of docking/scoring provided interesting insights into the binding of different inhibitors and their activity. These results will be useful for designing inhibitors for M. tuberculosis and also will be a good starting point for natural plant-based pharmaceutical chemistry.     

Dual‐wavelength optical parametric oscillator using antiresonant ring interferometer

A novel technique for coupling of two resonant optical cavities using an antiresonant ring (ARR) interferometer is reported. By deploying two synchronously‐pumped femtosecond optical parametric oscillators (OPOs), it is shown that the use of an ARR can provide an intracavity common path for the two oscillating fields, but without gain coupling between the two nonlinear media. The new technique permits the generation of two signal (idler) wavelengths, which can be independently and arbitrarily varied across the OPO tuning range. The absence of gain coupling also enables unrestricted and uninterrupted tuning through wavelength degeneracy at any arbitrary point within the OPO tuning range. It is shown that signal wavelength pairs tunable across 1500–1580 nm, corresponding to a frequency separation from ∼ 10 THz down to exact degeneracy, can be generated from the coupled OPOs, limited only by the reflectivity of the available mirrors.     

Squaraine dyes for photodynamic therapy: study of their cytotoxicity and genotoxicity in bacteria and mammalian cells

Halogenated squaraine dyes are characterized by long wavelength absorption (>600 nm) and high triplet yields and therefore represent new types of photosensitizers that could be useful for photodynamic therapy. We have analyzed the cytotoxicity and genotoxicity of the bromo derivative 1, the iodo derivative 2 and the corresponding nonhalogenated dye 3 in the absence and presence of visible light. At concentrations of 1-2 microM, 1 and 2 reduced the cloning efficiency of AS52 Chinese hamster ovary cells to less than 1% under conditions that were well tolerated in the dark. Similarly, the proliferation of L5178Y mouse lymphoma cells was inhibited by photoexcited 1 and 2 with high selectivity. The squaraine 3 was much less efficient. Both 1 and 2 induced only few mutations in the gpt locus of the AS52 cells in the presence of light and were not mutagenic in the dark. No mutagenicity with and without irradiation was observed in Salmonella typhimurium TA100 and TA2638. However, both 1 and 2 plus light increased the frequency of micronuclei in AS52 cells. The results indicate that halogenated squaraines exhibit photobiological properties in vitro that are favorable for photodynamic therapeutical applications.     

Study of mixed complexes by polarography: cadmium-glycine-methionine and cadmium-glycine-ethylenediamine complexes

The mixed complexes of cadmium with glycine and methionine and glycine and ethylenediamine have been studied by polarography and the stability constants of the various species formed have been evaluated.