Infrared spectroscopy of proteins.

Tetrathiafulvalenes, oligoacenenes, and their buckminsterfullerene derivatives: the brick and mortar of organic electronics.

Salts and cocrystals are multicomponent crystals that can be distinguished by the location of the proton between an acid and a base. At the salt end of the spectrum proton transfer is complete, and on the opposite end proton transfer is absent in cocrystals. However, for acid−base complexes with similar pKa values, the extent of proton transfer in the solid state is not predictable and a continuum exists between the two extremes. For these systems, both the ΔpKa value (pKa of base − pKa of acid) and the crystalline environment determine the extent of proton transfer. A total of 20 complexes containing theophylline and guest molecules with ΔpKa values less than 3 have been prepared, resulting in 13 cocrystals, five salts, and two complexes with mixed ionization states based on IR spectroscopy and single-crystal diffraction data. We propose modifications to the ΔpKa rule for selecting salt screen counterions that focus on the discovery of solid forms with useful physical properties rather than an arbitrary ...

http://pubs.acs.org/doi/pdf/10.1021/mp0601345

The Salt−Cocrystal Continuum: The Influence of Crystal Structure on Ionization State

Schiff bases: A short review of their antimicrobial activities

Hydrogen bonds are a key feature of chemical structure and reactivity. Recently there has been much interest in a special class of hydrogen bonds called "strong" or "low-barrier" and characterized by great strength, short distances, a low or vanishing barrier to hydrogen transfer, and distinctive features in the NMR spectrum. Although the energy of an ordinary hydrogen bond is ca 5 kcal mol-1, the strength of these hydrogen bonds may be > or = 10 kcal mol-1. The properties of these hydrogen bonds have been investigated by many experimental techniques, as well as by calculation and by correlations among those properties. Although it has been proposed that strong, short, low-barrier hydrogen bonds are important in enzymatic reactions, it is concluded that the evidence for them in small molecules and in biomolecules is inconclusive.

Strong hydrogen bonds in chemistry and biology

Biological Properties of Schiff Bases and Azo Derivatives of Phenols

Polyether ionophores represent a large group of natural, biologically active substances produced by Streptomyces spp. They are lipid soluble and able to transport metal cations across cell membranes. Several of polyether ionophores are widely used as growth promoters in veterinary. Polyether antibiotics show a broad spectrum of bioactivity ranging from antibacterial, antifungal, antiparasitic, antiviral, and tumour cell cytotoxicity. Recently, it has been shown that some of these compounds are able to selectively kill cancer stem cells and multidrug-resistant cancer cells. Thus, they are recognized as new potential anticancer drugs. The biological activity of polyether ionophores is strictly connected with their molecular structure; therefore, the purpose of this paper is to present an overview of their formula, molecular structure, and properties.

/pdf/structures-and-properties-of-naturally-occurring-polyether-4wlbawjle1.pdf

Structures and properties of naturally occurring polyether antibiotics.

Synthesis, cytotoxicity and antibacterial activity of new esters of polyether antibiotic – salinomycin

A proton pathway with large proton polarizability and the proton pumping mechanism in bacteriorhodopsin — Fourier transform difference spectra of photoproducts of bacteriorhodopsin and of its pentademethyl analogue

Bogumil Brzezinski

Papers

Biological Properties of Schiff Bases and Azo Derivatives of Phenols

Structures and properties of naturally occurring polyether antibiotics.

Synthesis, cytotoxicity and antibacterial activity of new esters of polyether antibiotic – salinomycin

A proton pathway with large proton polarizability and the proton pumping mechanism in bacteriorhodopsin — Fourier transform difference spectra of photoproducts of bacteriorhodopsin and of its pentademethyl analogue

Antiproliferative activity of salinomycin and its derivatives.