This chapter reviews the theoretical background for continuum models of solvation, recent advances in their implementation, and illustrative examples of their use. Continuum models are the most efficient way to include condensed-phase effects into quantum mechanical calculations, and this is typically accomplished by the using self-consistent reaction field (SCRF) approach for the electrostatic...

Four new compounds have been synthesized as potential inhibitors of dihydroorotase from Escherichia coli. NMR spectroscopy was used to show that 4,6-dioxo-piperidine-2(S)-carboxylic acid (3), exists in solution as a mixture of the hydrate (7), enol (8), and enolate (9) tautomeric forms. This compound was found to be a competitive inhibitor versus dihydroorotate and thio-dihydroorotate at pH val...

We investigate possible mutations in the genetic code induced by cisplatin with an approach combining molecular dynamics (MD) and hybrid quantum mechanics/molecular mechanics (QM/MM) calculations. Specifically, the impact of platination on the natural tautomeric equilibrium in guanine-cytosine (GC) base pairs is assessed to disclose the possible role played by non-canonical forms in anti-tumour...

Bis-dehydroxycurcumin tert-butyl ester (K2T23) is a derivative of the natural spice curcumin. Curcumin is widely studied for its multiple therapeutic properties, including photosensitized cytotoxicity. However, the full exploitation of curcumin phototoxic potential is hindered by the extreme instability of its excited state, caused by very efficient non radiative decay by means of transfer of t...

In the ground electronic state, the first two (1 and 2) of the compounds investigated--9-(methoxyamino)acridine (1), 9-hydrazinoacridine (2), N-(2-chloroethyl)acridin-9-amine (3) and N-(5-methylpyridin-2-yl)acridin-9-amine (4)--exist principally in the imino tautomeric form, while the other two (3 and 4) can coexist as amino and imino tautomers in solvents of various polarities and abilities to...

Natural abundance *‘C NMR (at 67.9 MHz) is used to study the nonprotonated aromatic carbons of bovine pancreatic ribonuclease A. The CY resonances of the 4 histidines are identified and assigned to specific residues. The effect of pH on the chemical shifts of these resonances yields information about the tautomeric state of the imidazole form of each histidine residue. Only His-119 exists predo...

The title compound, C18H11BrF3NO2, crystallizes in the phenol-imine tautomeric form, with a strong intra-molecular O-H⋯N hydrogen bond. The dihedral angle between the naphthalene ring system and the benzene ring is 28.54 (10)°.