Commemorating Two Centuries of Iodine Research: An Interdisciplinary Overview of Current Research

Abstract

Iodine was discovered as a novel element in 1811 during the Napoleonic Wars. To celebrate the bicentennial anniversary of this event we reflect on the history and highlight the many facets of iodine research that have evolved since its discovery. Iodine has an impact on many aspects of life on Earth as well as on human civilization. It is accumulated in high concentrations by marine algae, which are the origin of strong iodine fluxes into the coastal atmosphere which influence climatic processes, and dissolved iodine is considered a biophilic element in marine sediments. Iodine is central to thyroid function in vertebrates, with paramount implications for human health. Iodine can exist in a wide range of oxidation states and it features a diverse supramolecular chemistry. Iodine is amenable to several analytical techniques, and iodine compounds have found widespread use in organic synthesis. Elemental iodine is produced on an industrial scale and has found a wide range of applications in innovative materials, including semiconductors--in particular, in solar cells.

Biophysical Optimization of a Therapeutic Protein by Nonstandard Mutagenesis

“…We thus undertook to synthesize and characterize a derivative of a rapid-acting insulin analog in clinical use (Lys B28 , Pro B29 -insulin; lispro or KP-insulin, the active component of Humalog (Eli Lilly and Co.)) (16) in which an invariant tyrosine (Tyr B26 ) was substituted by 3-iodotyrosine (3-I-Tyr). Choice of this modification was motivated by the unique physicochemical properties of iodo-aromatic groups (17) as exploited in the evolution of thyroid hormones (18). Substitution of Tyr B26 by 3-I-Tyr was previously shown to preserve the function of insulin (19,20).…”

“…Its atomic radius (ϳ2 Å) relative to other atoms in a polypeptide (oxygen, nitrogen, carbon, and hydrogen), and indeed relative to smaller halogen atoms, confers unique properties derived from the average distance of its electrons from the nucleus. Unlike smaller halogens, the electronegativity of iodine is approximately equivalent to that of carbon (2.66 versus 2.55) because its electron density is spread over a larger volume; this spreading also imparts a higher polarization potential relative to smaller halogens (18). Together, these factors render 3-I-Tyr hydrophobic despite the inductive effect of the halogen leading to an electrostatic dipole moment (17).…”

Transmembrane anion transport mediated by halogen-bond donors

“…Halogen bonds form between nucleophilic acceptors, such as anions, and highly localized positive-charge density on halogen atoms appearing on the side opposite to the covalent bond [13][14][15][16][17][18][19][20][21][22] . They are most prominent with iodine atoms but occur, to a lesser extent, also with the less polarizable bromine, chlorine, and even fluorine (Fig.…”

Iodine-catalyzed Transformation of Aryl-substituted Alcohols Under Solvent-free and Highly Concentrated Reaction Conditions

“…[19][20][21] Mixtures of water with organic solvents have been employed to determine the geometry of the transition states, 22 with the hydrophobic effect attracting attention in studies of organic reactions in the presence of water. [23][24][25] In recent years, iodine 26,27 has emerged as remarkable catalyst exhibiting high water tolerance in diverse types of reactions. One of beneficial properties of iodine is its high affinity towards molecular oxygen as well as functional groups bearing at least one oxygen atom.…”