The four diastereoisomers of cyclo(-Asp-Val-) were synthesized to compare with a proposed structure of cairomycin A. Their antimicrobial activities were determined against both Gram-positive and Gram-negative bacteria. The physico-chemical properties of the isomers were characterized by mp, 1H NMR, IR, FAB-MS, and solubility in solvents, which were different from those reported for cairomycin A.

Graphene's unique physical and chemical properties make it an attractive platform for use in micro- and nanoelectronic devices. However, electrostatically controlling the flow of electrons in graphene can be challenging as a result of Klein tunneling, where electrons normally incident to a one-dimensional potential barrier of height V are perfectly transmitted even as V → ∞. In this study, theo...

Silver nanoparticles (AgNPs) show different physical and chemical properties compared to their macroscale analogs. This is primarily due to their small size and, consequently, the exceptional surface area of these materials. Presently, advances in the synthesis, stabilization, and production of AgNPs have fostered a new generation of commercial products and intensified scientific investigation ...

Periodic density functional calculations are used to illustrate how the combination of strain and ligand effects modify the electronic and surface chemical properties of Ni, Pd, and Pt monolayers supported on other transition metals. Strain and the ligand effects are shown to change the width of the surface d band, which subsequently moves up or down in energy to maintain a constant band fillin...

The synthesis of the salt 3 and metallo-organic framework (MOF) [{(4,4(')-bipy)CoBr(2)}(n)] 4 by a range of solid state (mechanochemical and thermochemical) and solution methods is reported; they are isostructural with their respective chloride analogues 1 and 2. 3 and 4 can be interconverted by means of HBr elimination and absorption. Single phases of controlled composition and general formula...

Physical chemistry is the branch of chemistry that establishes and develops the principles of the subject in terms of the underlying concepts of physics and the language of mathematics. Its concepts are used to explain and interpret observations on the physical and chemical properties of matter. Physical chemistry is essential for developing and interpreting the techniques used to determine str...

Robert Rosen's concept of (M,R)-systems was a fundamental advance in our understanding of the essential nature of a living organism as a self-organizing system, one that is closed to efficient causation, synthesizing, and maintaining all of the catalysts necessary for sustained operation during the whole period of its lifetime. Although it is not difficult to construct a model metabolic system ...

Incorporating non-standard amino acids (NSAAs) into proteins enables new chemical properties, new structures, and new functions. In recent years, improvements in cell-free protein synthesis (CFPS) systems have opened the way to accurate and efficient incorporation of NSAAs into proteins. The driving force behind this development has been three-fold. First, a technical renaissance has enabled hi...

The syntheses and the structural, spectroscopic, and chemical properties of phosphirenes, phosphirene-transition metal complexes, and silirenes are discussed and compared. Close analogies are noted in the synthetic schemes and physico-chemical properties of the two types of three-membered rings.

The unique chemical properties of aryl trifluoromethyl sulfides (ArSCF3) have been known for over 60 years.[1] The capacity of SCF3 to act as a lipophilic electron-withdrawing group has resulted in the incorporation of ArSCF3 components into a number of pharmaceutical and agrochemical agents.[2] Unfortunately, direct access to this important class of compounds is complicated by a lack of effici...