A small-angle X-ray scattering study of the structure of lysozyme-sodium dodecyl sulfate complexes

The structure of lysozyme-sodium dodecyl sulfate (SDS) complexes in solution is studied using small-angle X-ray scattering (SAXS). The SAXS data cannot be explained by the necklace and bead model for unfolded polypeptide chain interspersed with surfactant micelles. For the protein and surfactant concentrations used in the study, there is only marginal growth of SDS micelles as they complex with the protein. Being a small and rather rigid protein, lysozyme can penetrate the micellar core which is occupied by flexible and disordered paraffin chains and also the shell occupied by the hydrated head groups. A partially embedded swollen micellar model seems appropriate and describes well the scattering data. The SAXS intensity profiles are analyzed by considering the change in the electron scattering length density of the micellar core and shell due to complexation with protein and treating the intermicellar interaction using rescaled mean spherical approximation (RMSA) for charged spheres.     

Effect of hydrocarbons and other parameters on hydrocarbon-utilizing Pichia angusta MTCC-225

Pichia angusta MTCC-225, a catalase-positive yeast that utilizes methanol and lighter hydrocarbons, is the subject of this investigation. An orthogonal experimental design L₁₆ was used to investigate the effects of methanol, a gas mixture, zero air, temperature, agitation, and salts solution on hydrocarbon utilizing P. angusta. QUALITEK-4 Software was used for automatic design and analysis of the experimental results. Among the various parameters tested, agitation contributed the highest influence (56.5%). Zero air, methanol concentration, and gas mixture showed a moderate influence on the growth of P. angusta. Methanol concentration and gas mixture showed a 10.91 and 10.12% influence, respectively, on yeast growth. Zero air played an important role, with a 15.19% influence on the utilization of hydrocarbon.     

Quartz crystal microbalance genosensor for sequence specific detection of attomolar DNA targets

A mass sensitive quartz crystal microbalance (QCM) based genosensor has been developed using breast cancer 1 (BRCA1) gene as a model gene. We modified the traditional sandwich assay by conjugating reporter probe DNA (DNA-r) with an assembly of gold nanoparticles leading to an increased mass on the surface, which enhanced the sensitivity to few orders of magnitude. The unique cleavage function of endonuclease is used for achieving the selectivity to complementary DNA over mismatched DNA. With this combination, the sensor exhibited excellent sensitivity with a detection limit of 10 aM BRCA1 gene and it showed good selectivity for even single base mismatch DNA targets. This ultrasensitive and cost-effective DNA detection protocol can be extended to the direct analysis of any non-amplified genomic DNA.     

Copolymers from Castor Oil Prepolymers (COP). 4. Copolymerization of Methyl Methacrylate with COP

The copolymerization of castor oil prepolymer (COP) with methyl methacrylate (MMA) has been accomplished at 75°C using a free radical initiator. The monomer reactivity ratios of MMA (r₁) and COP (r₂) were determined to be r₁ = 3.04 and r₂ = 0.605. With an increasing concentration of COP in the binary mixture, copolymers with decreasing molecular weight were obtained. The copolymers obtained were powdery substances soluble in many organic solvents.     

Brauhenefloroside E and F; acylated flavonol glycosides from Stocksia brauhica Linn

Two new acylated flavonol glycosides, 3‐O‐{[2‐O‐β‐D ‐glucopyranosyl]‐3‐[O‐β‐D ‐glucopyranosyl]‐4‐[(6‐O‐p‐coumaroyl)‐O‐β‐D ‐glucopyranosyl]}‐α‐L ‐rhamnopyranosyl‐kaempferol 7‐O‐α‐L ‐rhamnopyranoside and 3‐O‐{2‐[(6‐O‐p‐coumaroyl)‐O‐β‐D ‐glucopyranosyl]‐3‐[O‐β‐D ‐glucopyranosyl]‐4‐[(6‐O‐p‐coumaroyl)‐O‐β‐D ‐glucopyranosyl]}‐α‐L ‐rhamnopyranosyl‐kaempferol 7‐O‐α‐L ‐rhamnopyranoside, trivially named as brauhenefloroside E (1) and F (2), respectively, were isolated from the fruits of Stocksia brauhica and their structures were elucidated using spectroscopic methods, including 2D NMR experiments. Copyright © 2010 John Wiley & Sons, Ltd.     

New Secondary Metabolites from Asphodelus tenuifolius

Asphorins A and B ( 1 and 2 , resp.), two new triterpene glycosides, have been isolated along with a new chromone, 3 , from the AcOEt subfraction of the MeOH extract of the whole plant of Asphodelus tenuifolius. Their structures were elucidated by spectral analysis including 2D‐NMR spectroscopic experiments.     

Design,synthesis, and biological evaluation of novel benzimidazole derivatives and their interaction with calf thymus DNA and synergistic effects with clinical drugs

A series of new benzimidazole derivatives was synthesized and characterized by IR,1H NMR,13C NMR,MS,and HRMS spectra.All the new compounds were screened for their antimicrobial activities in vitro by a twofold serial dilution technique.The bioactive evaluation showed that 3,5-bis(trifluoromethyl)phenyl benzimidazoles were comparably or even more strongly antibacterial and antifungal than the reference drugs Chloromycin,Norfloxacin,and Fluconazole.The combination of2,4-difluorobenzyl benzimidazole derivative 5l and its hydrochloride 7 respectively with the antibacterials Chloromycin,Norfloxacin,and the antifungal Fluconazole was more sensitive to methicillin-resistant MRSA and Fluconazole-insensitive A.flavus.In addition,the interaction of compound 5l with calf thymus DNA demonstrated that this compound could effectively intercalate into DNA to form a compound 5l-DNA complex that might block DNA replication and thereby exert good antimicrobial activity.     

Concise and Simple Synthesis of M1 Allosteric Agonist TBPB

A concise and simple synthesis of M₁ allosteric agonist 1-(1′-(2-methylbenzyl)-1,4′-bipiperidin-4-yl)-1H-benzo[d]imidazol-2(3H)-one (TBPB) using economical and commercially available orthophenylenediamine (O-PDA) and Boc piperidone has been described. The disclosed scheme allows synthesizing more analogs that were otherwise difficult to prepare with the original method.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Simple Method for the Preparation of Symmetrical Alkyl and Aryl Disulfides with Alkyl Sulfonyl Halides in Nitrogenous Base

In the present study, the reaction of thiols with alkyl sulfonyl halides was carried out in a nitrogenous base to compare the reactivity of ‐SH with that of ‐OH, which, however, led to the formation of disulfides. The reaction achieved as a result offers the use of an inexpensive reagent, quantitative yields of the product, and simplicity for the formation of the S‐S bond.