An efficient total synthesis of sulfobacin A

A short and efficient enantioselective synthesis of sulfobacin A has been achieved using the Sharpless asymmetric dihydroxylation and the regiospecific nucleophilic opening of a cyclic sulfate as the key steps.     

Enantioselective synthesis of tarchonanthuslactone via iterative hydrolytic kinetic resolution

A short and practical enantioselective synthesis of tarchonanthuslactone has been achieved in high diastereomeric excess using iterative Jacobsen’s hydrolytic kinetic resolution and ring closing metathesis as the key steps.     

Environmentally benign process for the synthesis of N-formyl amino acid esters

Several amino acid ester hydrochlorides were reacted with ammonium formate to give N-formyl amino acid esters in good yields.     

Tryptophan–water interaction in Monellin: Hydration patterns from molecular dynamics simulation

Femtosecond spectroscopy carried out earlier on Monellin and some other systems has given insights into the hydration dynamics of the proteins. In the present work, molecular dynamics simulations have been performed on Monellin to study the hydration dynamics. A method has been described to follow up the molecular events of the protein–water interactions in detail. The time constants of the survival correlation function match well with the reported experimental values. This validates the procedure, adapted here for Monellin, to investigate the hydration dynamics in general.     

A novel bioassay for screening and quantification of taxanes

We report a novel method for screening and quantifying tubulin-binding antimitotic agents that promote microtubule formation. The method is based on the shift in the peak of the fluorescence emission difference spectrum of tubulin complexed to metal free tetrakis(4-carboxyphenyl)porphyrin (TCPP) in the presence of antimitotic agents. Taxol (paclitaxel), an anti-tumor drug approved for the treatment of a variety of cancers, caused the appearance of a new fluorescence peak at 645 nm at concentrations as low as 125 nM, the intensity of which was a function of the paclitaxel concentration. Cephalomannine caused the induction of a new fluorescence peak at 651 nm only above 1 muM. Baccatin did not induce the appearance of any new peak within detectable operating measurement conditions. These observations are in accordance with the biological activities/cytotoxicities of these compounds. Accordingly, it is proposed that the new method can be used for high throughput screening of antimitotic compounds.     

Solution-processed electrochemical synthesis of ZnFe2O4 photoanode for photoelectrochemical water splitting

Journal of Solid State Electrochemistry - Herein, we report the synthesis of ZnO nanorod films onto FTO (fluorine-doped tin oxide) substrates using the solution-processed electrodeposition method....     

A Synthetic Strategy for Novel Organothiophosphates Incorporating a Pyridine Ring

Eight novel amidothiophosphates have been successfully achieved using cycloiminium salts of pyridine as the starting material. Phosphorylation was done using phosphorus trichloride, and the resulting functionalized iminohalophosphines in situ were further oxidized and substituted through sulfur and a suitable secondary amine (alkyl, alicyclic, and aryl). The reactions were carried out in a dry nitrogen atmosphere. The synthesized products were characterized using different spectroscopic techniques (¹H and ³¹P NMR). The pyridine nucleus incorporating a phosphoryl group is highly bioactive. Hence, the synthesized organothiophosphates should be potential pesticidal molecules.     

Modeling of a control induced system for product formation in enzyme kinetics

Double substrate enzyme kinetics has a leading role for product quantification and optimization in different chemical and biochemical sectors. Mathematical approach for controlling these reactions in different stages by suitable parameters adds a new dimension in this interdisciplinary field of research. Applying control theoretic approach in the reversible backward stages of double substrate enzymatic model, time economization with regard to product formation is significant. In this article, we formulate a double substrate mathematical model of enzymatic dynamical reaction system with control measures with a view to observe the effect of changes of these measures with respect to the concentration of substrates, enzyme, complexes and finally product. Here, Pontryagin Minimum Principle is used for observing the effect of control measures in the system dynamics with the help of Hamiltonian. We compare the relevant numerical solutions for the substrates, enzyme, complexes and product concentration profile for a specified time interval with respect to control factors.     

Carbon Nanotubes-Based Label-Free Affinity Sensors for Environmental Monitoring

Nanostructures, such as nanowires, nanobelts, nanosprings, and nanotubes, are receiving growing interest as transducer elements of bio/chemical sensors as they provide high sensitivity, multiplexing, small size, and portability. Single-walled carbon nanotubes (SWNTs) are one such class of nanostructure materials that exhibit superior sensing behavior due to its large-surface carbon atoms that are highly responsive to surface adsorption events. Further, their compatibility with modern microfabrication technologies and facile functionalization with molecular recognition elements make them promising candidates for bio/chemical sensors applications. Here, we review recent results on nanosensors based on SWNTs modified with biological receptors such as aptamers, antibodies, and binding proteins, to develop highly sensitive, selective, rapid, and cost-effective label-free chemiresistor/field-effect transistor nanobiosensors for applications in environmental monitoring.