SELECTIVE CLEAVAGE OF N-t-BUTOXYCARBONYL PROTECTING GROUP

Abstract

The selective cleavage of BOC-peptide-OBut was investigated by the use of 85% formic acid, and it was found that BOC-peptide-OBut gave H-peptide-OBut in good yield by this procedure. This method was also applied to investigation of the selectivity of di-t-butyl esters of dibasic amino acids and N-deprotection of peptides containing these amino acids.

Coarse-grained depletion potentials for anisotropic colloids: Application to lock-and-key systems

“…We refer to the indented particles as lock particles, since the spherical keys fit within the indentation, leading to lock-and-key binding. Compared with the interaction between spherical particles, this binding is strong, due to the complementary shapes of the lock and key particles 8,16,23,37,38 . We refer to both the indented particles and the keys as colloidal particles, to distinguish them from the depletant.…”

Theoretical study of solvent-mediated Ising-like systems: One-dimensional version

“…When the solutes are sufficiently separated, μ SO L is given by Nμ 1 (μ 1 is the solvation free energy of the solute). Since μ 1 is the solvation free energy of the one solute with computationally available size, it can be calculated by 3D integral equation theory [8][9][10][11][12][13][14], a statistical-mechanical theory for fluids (see Supplemental Material [15]).…”

“…Solvation free energy of the two separated solutes (μ 2 P or μ 2 A ) can be calculated using 3D integral equation theory [8][9][10][11][12][13][14] by regarding the separated solutes as the one solute [10] as long as the solutes are not extremely large (i.e., the one solute is computationally available size). Substituting Eq.…”

“…In addition, their amplitudes decay into zero as d 2 increases (i.e., the directional correlation vanishes). These behaviors derive from oscillatory fluctuation of Δμ PA (=μ 2 P −μ 2 A ), and it is similar to a distribution function of a solvent [8,9,19,20] and solvent-mediated potential of mean force between two arbitrary solutes [7][8][9][10][11][12][13][14]21].…”

“…Although we do not explain in detail here, our theoretical treatment can be readily extended to a non-rigid-body system. For examples, Lennard-Jones fluid can be used as the solvent by re-employing 3D integral equation theory [7][8][9][10][11][12][13][14], and water (aqueous solution) can be introduced by employing 3D-reference interaction site model [25] or theory of energy representation [26][27][28]. Therefore, effects of solvophobicity (hydrophobicity) and solvophilicit y (hydrophilicity) on a SI system can be studied.…”