Current Organic Chemistry - Volume 16, Issue 12, 2012

Imprinting of macromolecule such as proteins with molecular imprinting technique remains challenge because of their bulkiness, structural complexity and sensitivity of denaturation. The purpose of this study was to synthesize a Lys-MIP film on the surface of the MWNTs by surface molecular imprinting technique, and subsequently selectively recognized and purified Lys from egg white. The Lys-MIP film was prepared using AAm as functional monomer, MBA as cross-linker, APS and TEMED as initiator under the optimized conditions. The polymer was characterized by TEM, FT-IR, TGA, and BET, as well. The equilibrium adsorption experiments and dynamic adsorption experiments were carried out to determine the binding capacity and the equilibrium time. The results showed that adsorption capacity of the Lys-MIP film was 20.89 mg g-1 at 0.50 mg mL-1, and adsorption capacity was 15.37 mg g-1 for the NIP. 82.10% of binging was obtained within 30 min and the adsorption equilibrium was achieved within 300 min. The selectivity adsorption experiments showed the Lys-MIP film had higher affinity and capacity for Lys than that for the competitive proteins, such as Cyt C, Mb, Hb and BSA. The relative selectivity coefficients for Lys/Cyt C, Lys/Mb, Lys/Hb, and Lys/BSA were 1.30, 1.30, 3.12 and 2.82, respectively. Purification experiment of Lys from egg white showed that adsorption capacity of the Lys-MIP film was 1.86 times more than that of the NIP. All these results proved that Lys-MIP film possessed high adsorption capacity and excellent selectivity. This material has great potential for separation of Lys in real samples.

Conjugated polyelectrolytes (CPEs) have attracted much attention as an emerging sensory material because of their meritorious signal amplification, convenient optical detection, readily tunable properties, and easy fabrication. This review paper summarizes the advances in synthesis of conjugated polyelectrolytes (such as polyfluorene, poly(para-phenylene ethynylene), poly(para-phenylene), poly(para-phenylene vinylene) and polythiophene, etc.) and their application in biomolecule detection. Additionally, new strategies to modify and optimize CPEs properties for specific applications are provided.

Molecular iodine has acquired an important role in organic synthesis due to its unique and powerful feature to catalyze organic transformations on account of its mild Lewis acidic character. The current review enlightens the versatile nature of the catalyst for numerous organic strategies including the synthesis of various heterocyclic compounds, iodination, protection- deprotection of functional groups etc.

The specific rates of solvolysis of chloromethyl phenyl sulfide [(phenylthio)methyl chloride] and its p-chloro-derivative have been determined at 0.0 oC in a wide range of hydroxylic solvents, including several containing a fluroalcohol. Treatment in terms of a two-term Grunwald-Winstein equation, incorporating terms based on solvent ionizing power (YCl) and solvent nucleophilicity (NT) suggest a mechanism similar to that for the solvolyses of tert-butyl chloride, involving in the rate-determining step a nucleophilic solvation of the incipient carbocation in an ionization process. A previous suggestion, that a third-term governed by the aromatic ring parameter (I) is required, is shown both for the new and for the previously studied related substrates to be an artifact, resulting from an appreciable degree of multicollinearity between I values and a linear combination of NT and YCl values.

Cembrane-type diterpenoids are a large and structurally varied group of natural products isolated from both terrestrial and marine organisms. The present paper reviews all the metabolites of cembrane diterpenes, reported up to 2010. The natural products discussed in this review can be divided into several different structural families featuring a variety of ring sizes and oxidation patterns. The currently known biological activities will be presented as well.

A new and efficient methodology for the Clauson-Kaas synthesis of N-aryl pyrroles, employing CeCl3.7H2O as catalyst, was developed. The transformation was performed in acetonitrile under reflux, using conventional heating and microwave irradiation. Employing NH4SCN/Oxiall as a new thiocyanating system for the so obtained N-aryl pyrroles, the synthesis 1-aryl-2-thiocyanato-1Hpyrroles was also successfully accomplished. The latter served as starting materials for the high-yielding NaBH4-mediated preparation of 1,2-bis(1-(aryl)-1H-pyrrol-2-yl)disulfides and the phase transfer-mediated synthesis of 1-aryl-2-(trichloromethylthio)-1H-pyrroles.

Methodology of a selection and environmental economy in nitration reaction of aromatics will be rather attractive to replace traditional sulfonitric acid process in industry. The cross-linked pillared clays originated from a natural bentonite show an obviously selective catalysis in nitration reaction of alkylbenzenes by respectively using nitric acid and a nitrogen dioxide/molecular oxygen system when compared with Kyodai-nitration. Several hydroxyl-aluminum cross-linked bentonites (Al-CLB, NH4Al-CLB, HAl-CLB, LaAl- CLB) were prepared in various conditions from a natural bentonite with polymeric cationic complexes of aluminum as pillars or crosslinkers. When they were applied in the nitration of weakly activated aromatic substrates, a para-preferential nitration is achieved.