Two new eudesmane derivatives from Verbesina virginica

<正>Two new eudesmane derivatives were isolated from the leaves and flowers of Verbesina virginica,along with the known 6-O-β-E -p-coumaroyl-4α-hydroxyeudesmane(1).Their structures were determined as 6-O-β-Z-p-coumaroyl-4α-hydroxyeudesmane(2) and 6-O-α-E-p-coumaroyl-1β-4α-dihydroxyeudesmane(3) by spectroscopic methods.     

Effect of Pr-Ca substitution on the transport and magnetic behavior of LaMnO3 perovskite

The effect of simultaneous substitution of a fluctuating cation and a divalent cation in LaMnO₃ perovskite modifies the properties of the material to exhibit large valence colossal magnetoresistance (CMR) effect. A good example of these properties is (La_1−2x Pr _x Ca _x )MnO₃ (LPCMO) type CMR material. In this communication it is reported that, with the increase in x (for x=0.1, 0.15, 0.2), the T _c varies between 100 and 120 K with improvisation in metal-insulator transition. Interestingly, resistance increases with x from few hundred ohms to few kilo ohms with corresponding decrease in the unit cell volume. The results of the studies using X-ray diffraction (XRD), electrical resistivity, magnetoresistance and ac susceptibility measurements on LPCMO samples for understanding the structural, transport and magnetic properties are discussed in detail.     

PRESSURE-VELOCITY EQUILIBRIUM HYDRODYNAMIC MODELS

This article describes mathematical models for phase separated mixtures of materials that are in pressure and velocity equilibrium but not necessarily temperature equilibrium. General conditions for constitutive models for such mixtures that exhibit a single mixture sound speed are discussed and specific examples are described.     

Molecularly imprinted hydrogels for sustained release of sunitinib in breast cancer therapy

The present work reports on the synthesis of a molecularly imprinted polymer (MIP) based on methacrylic acid and ethylene glycol dimethacrylate for sunitinib delivery. Sunitinib (SUT) is a tyrosine kinase inhibitor used in many cancer diseases. Like the majority of the anticancer drugs, SUT suffers of a low bioavailability, and at the same time, it is characterized by a narrow therapeutic window. In order to reduce drug systemic toxicity, we synthesized a MIP‐based drug delivery system for SUT‐controlled release. MIP was obtained by bulk polymerization through the so‐called noncovalent approach. Rebinding experiments were performed to evaluate the success of the imprinting process and the ability of MIP to bind in a specific and selective fashion the template molecule. Resulting data showed that sunitinib rebinding percentage was 70%, while nonimprinted polymer (NIP) rebinding percentage was 46%. A not significant difference was observed between MIP and NIP in semaxanib binding experiments. Moreover, the drug release profiles were studied for both MIP and NIP. A sustained release was observed from sunitinib‐loaded MIP during 24 hours, reaching 58% after 6 hours and 76% at the end‐point. NIP, on the contrary, released almost 90% of the loaded drug within 6 hours. Furthermore, the drug carrier was tested in vitro against MCF‐7 cells, in which the cytotoxic effect of sunitinib released from MIP reached the maximum after 72 hours, while NIP completed its effect within 48 hours. These results demonstrated that molecularly imprinted polymers are suitable systems for SUT release.     

Efficient and simple synthesis of 6-aryl-1,4-dimethyl-9H-carbazoles

A synthetic method for the preparation of 6-aryl-1,4-dimethyl-9H-carbazoles involving a palladium catalyzed coupling reaction of 1,4-dimethyl-9H-carbazole-6-boronic acids and (hetero)aryl halides is described.     

Synthesis of beta‐proline like derivatives and their evaluation as sodium channel blockers

A simple and convenient procedure for the preparation of beta‐proline like derivatives in their racemic and optically active forms has been reported. The compounds have been screened for their potential activity as sodium channel blockers.