Reconciliation of size-density bivariate distributions over a separating node

Data reconciliation considers the restoration of mass balance among the noise prone measured data by way of component adjustments for the various particle size or particle density classes or assays over the separating node. In this paper, the method of Lagrange multipliers has been extended to balance bivariate feed and product size-density distributions of coal particles split from a settling column. The settling suspension in the column was split into two product fractions at 40% height from the bottom after a minute settling of homogenized suspension at start. Reconciliation of data assists to estimate solid flow split of particles to the settled stream as well as helps to calculate the profiles of partition curves of the marginal particle size or particle density distributions. In general, Lagrange multiplier method with uniform weighting of its components may not guarantee a smooth partition surface and thus the reconciled data needs further refinement to establish the nature of the surface. In order to overcome this difficulty, a simple alternative method of reconciling bivariate size-density data using partition surface concept is explored in this paper.     

Synthesis of cytotoxic cyanobactin,Wewakazole B

We report herein the synthesis of cytotoxic cyanobactin, Wewakazole B through an efficient solution-phase approach. The key steps of the synthesis are the macrocyclic lactamization of linear dodecapeptide and construction of two hexapeptides with three different substituted oxazole rings.     

Structure, self-assembly, and dual role of a beta-defensin-like peptide from the Chinese soft-shelled turtle eggshell matrix

Biomineral matrix formation and molecular recognition are two important processes associated with eggshell biomineralization. To understand these two processes, a major intracrystalline peptide, pelovaterin, was isolated from turtle (Pelodiscus sinensis) eggshell and its tertiary and quaternary structures were established. The global fold of pelovaterin is similar to that of human beta-defensins but has a large hydrophobic core and a short hydrophilic N-terminal segment, which is not preserved in defensins. Pelovaterin exhibits strong antimicrobial activity against two pathogenic gram-negative bacteria, Pseudomonas aeruginosa and Proteus vulgaris, and stabilizes a thin film of metastable vaterite. We show that pelovaterin self-aggregates in the form of micellar nanospheres and the aggregation in solution is entropy-driven. It is suggested that the micellar aggregation of pelovaterin is responsible for the induction and stabilization of the metastable phase by altering the interfacial energy. The results demonstrate the adaptability of an extracellular matrix protein to perform multiple tasks: polymorph discrimination and protection of the contents of the egg against bacterial invasion.     

Study of Regiochemical Trends During the Synthesis of Furan and 5‐(p‐chlorophenyl)Furan Containing Novel Spiropyrrolidine Library Through 1,3‐dipolar Cycloaddition Reactions

A new class of functionalized furan and 5‐(p‐chlorophenyl)furan containing spiropyrrolidines has been synthesized in moderate to excellent yields by the one‐pot, three‐component 1,3‐dipolar cycloaddition reaction of in situ generated azomethine ylides with various furan/aryl furan‐substituted chalcones as dipolarophiles. The effect of electron deficient substituents at the fifth position of the furan ring in the chalcone on the regiochemistry of the cycloaddition formed was studied. The structures of the newly synthesized cycloaddicts were proved by analytical and spectral data.     

Targeting EGFR Overexpression at the Surface of Colorectal Cancer Cells by Exploiting Amidated BODIPY-Peptide Conjugates

Three BODIPY-peptide conjugates designed to target the epidermal growth factor receptor (EGFR) at the extracellular domain were synthesized, and their specificity for binding to EGFR was investigated. Peptide sequences containing seven amino acids, GLARLLT ( 2) and KLARLLT ( 4 ), and 13 amino acids, GYHWYGYTPQNVI ( 3 ), were conjugated to carboxyl BODIPY dye ( 1 ) by amide bond formation in up to 73% yields. The BODIPY-peptide conjugates and their “parent” peptides were determined to bind to EGFR experimentally using SPR analysis and were further investigated using computational methods (AutoDock). Results of SPR, competitive binding and docking studies propose that conjugate 6 including the GYHWYGYTPQNVI sequence binds to EGFR more effectively than conjugates 5 and 7 , bearing the smaller peptide sequences. Findings in human carcinoma HEp2 cells overexpressing EGFR showed nontoxic behavior in the presence of activated light (1.5 J cm⁻²) and in the absence of light for all BODIPYs. Furthermore, conjugate 6 showed about five-fold higher accumulation within HEp2 cells compared with conjugates 5 and 7 , localizing preferentially in the cell ER and lysosomes. Our findings suggest that BODIPY-peptide conjugate 6 is a promising contrast agent for detection of colorectal cancer and potentially other EGFR-overexpressing cancers.     

Molecular Targeting of Epidermal Growth Factor Receptor (EGFR) and Vascular Endothelial Growth Factor Receptor (VEGFR)

Epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor (VEGFR) are two extensively studied membrane-bound receptor tyrosine kinase proteins that are frequently overexpressed in many cancers. As a result, these receptor families constitute attractive targets for imaging and therapeutic applications in the detection and treatment of cancer. This review explores the dynamic structure and structure-function relationships of these two growth factor receptors and their significance as it relates to theranostics of cancer, followed by some of the common inhibition modalities frequently employed to target EGFR and VEGFR, such as tyrosine kinase inhibitors (TKIs), antibodies, nanobodies, and peptides. A summary of the recent advances in molecular imaging techniques, including positron emission tomography (PET), single-photon emission computerized tomography (SPECT), computed tomography (CT), magnetic resonance imaging (MRI), and optical imaging (OI), and in particular, near-IR fluorescence imaging using tetrapyrrolic-based fluorophores, concludes this review.