Alkaline treatment method was used to ext ract collagen. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and circular dichroism (CD) spectra revealed that the alkali-soluble pigskin collagen (ASPC) retained the polypeptide chains and triple helix conformat ion. The amino acid profiles showed no major deviation from the characteristic collagen composition. Both of the denat...

Two optically active N-acetyldopamine dimers together with four phenolic monomers were isolated from the crude drug "Zentai," a cast-off shell of the cicada of Cryptotympana sp. (Cicadidae). The former two were 2-(3',4'-dihydroxyphenyl)-1,4-benzodioxane derivatives carrying substituents at the 3 and 6 (or 7) positions, which are known to be components of sclerotized insect cuticles. Their struc...

The absolute configuration and solution-state conformers of three peperomin-type secolignans isolated from Peperomia blanda (Piperaceae) are unambiguously determined by using vibrational circular dichroism (VCD) spectroscopy associated with density functional theory (DFT) calculations. Advantages of VCD over the electronic form of CD for the analysis of diastereomers are also discussed. This wo...

The absolute configuration of three 4-aryl-3, 4-dihydro-2(1H)-pyrimidones (Biginelli compounds, DHPMs) was established by comparison of the typical circular dichroism (CD) spectra of individual enantiomers with reference samples of known absolute configuration. The enantiomers were obtained by semipreparative separation of racemic mixtures on a Chiralcel OD-H chiral stationary phase. The method...

Abbreviations: CD: circular dichroism CLEC: cross linked enzyme crystals DDC: double dimer constructs ESI: electrospray ionization HOBT: hydroxybenzotriazole HPLC: high performance liquid hromatography KCS: kinetically controlled synthesis MALDI: matrix-assisted laser desorption ionization MAP: multiple antigen peptide system MS: mass spectrometry NMR: nuclear magnetic resonance SPS: solution p...

A two-stranded alpha-helical coiled coil was prepared having a Cys 4 metal-binding site within its hydrophobic interior. The addition of Cd2+ results in the incorporation of 2 equiv of metal ion, which is accompanied by a conformational change of the peptide, as observed by circular dichroism (CD) spectroscopy. Isothermal titration calorimetry (ITC) shows that the addition of Cd2+ is accompanie...

Two phenylethanoid glycosides, acteoside and forsythoside B, were first isolated from the traditional Chinese herb Callicarpa peii H.T. Chang. The interaction between the two phenylethanoid glycosides and bovine serum albumin (BSA) was investigated by fluorescence, UV-vis absorbance and circular dichroism (CD). The results showed that the quenching mechanism in the drug-BSA binary systems was a...

The circular dichroism data on 17 adenine nucleosides show that the 260- and 207-mmu absorption systems of the adenine chromophore each contain at least two electronic transitions. The CD maxima are commonly found at around 260, 220, and 200 mmu, and occasionally at 240 mmu. Solvent studies suggest that these CD bands arise from pi-pi(*) transitions. A weak absorption band that obeys the McConn...

the L2,3 x-ray fluorescence spectra of magnetized Fe and CO excited by circularly polarized synchrotron radiation exhibit magnetic circular dichroism. The results are compared to the energy resolved spin polarized densities of states given by first-principles calculations.

Two macrotricyclic ligands composed of two face-to-face octadentate metal chelates were synthesized. These cage-shaped disodium complexes had special recognition ability for various counter anions. Specific chiral dicarboxylates bound to the complexes within the cavity and exhibited chirality induction properties. For instance, N-Boc-Asp dianion strongly induced circular dichroism (CD) signals,...