The first synthesis of (+)- and (-)-akolactone A is described by using Pd-catalyzed carbonylation. A comparison of the optical rotation of both enantiomers of akolactone A and the natural compound suggests that the absolute configuration at the 4-position of akolactone A is R.

The right-handed helical fraction H(L) in a D,L-copolypeptide chain is evaluated by a simple probability theory for each L-fraction, p. The curves of optical rotation at a single wavelength against p for poly(gamma-benzyl-D,L-glutamate) and D,L-copolyleucine of a series of different D:L ratios in several positive helix-solvents are calculated with a modified semi-empirical Moffitt equation. Fro...

The title ergosterol compound, C(28)H(44)O(4)·H(2)O, is composed of four fused rings (three six-membered and one five-membered) and a side chain. It is a derivative of ergosterol and was isolated from a marine-derived halotolerant fungus, Cladosporium cladosporioides PXP-49. In the crystal, mol-ecules are assembled by classical O-H⋯O hydrogen bonds, forming a two-dimensional network, with base ...

SUMITOMO KAGAKU 2012 In this paper, the author will introduce biocatalysts that can be used in the synthesis of optically active alcohols, which are important key compounds because they are intermediates for pharmaceuticals and agricultural chemicals, and in particular, he will introduce the development of techniques for asymmetric reduction enzymes and catalysts. In addition, a work on the eng...

Polarimetry has been used to detect the occurrence of configurational changes accompanying denaturation in various proteins (Jirgensons, 1950, 1951, 1952; Kauzmann el al., 1953; Yang and Foster, 1954; Linderstrf~mLang and Schellman, 1954). However, because of the present incomplete knowledge of protein structure, no concrete proposals have yet been made connecting observed rotational values and...

Chlorophylls are a fundamental class of tetrapyrroles and function as the central reaction center, accessory and photoprotective pigments in photosynthesis. Their unique individual photochemical properties are a consequence of the tetrapyrrole macrocycle, the structural chemistry and coordination behavior of the phytochlorin system, and specific substituent pattern. They achieve their full pote...

Light-driven transcription, replication and enzyme catalysis are critically dependent upon a delicate transfer between molecular and supramolecular chirality. Chemists have well realized the impressive stereospecificity over many thermally accessible cycloaddition with chiral catalysts, but making light work in the enantiomer control of diarylethene photocyclization has proved to be more challe...

A shape phase transition is demonstrated to occur in W by applying the Projected Shell Model, which goes beyond the usual mean-field approximation. Rotation alignment of neutrons in the high-j, i13/2 orbital drives the yrast sequence of the system, changing suddenly from prolate to oblate shape at angular momentum 10~. We propose observables to test the picture.

Polarimetry has been used to detect the occurrence of configurational changes accompanying denaturation in various proteins (Jirgensons, 1950, 1951, 1952; Kauzmann el al., 1953; Yang and Foster, 1954; Linderstrf~mLang and Schellman, 1954). However, because of the present incomplete knowledge of protein structure, no concrete proposals have yet been made connecting observed rotational values and...

Radiative corrections to the polarizability tensor of isotropic particles are fundamental to understand the energy balance between absorption and scattering processes. Equivalent radiative corrections for anisotropic particles are not well known. Assuming that the polarization within the particle is uniform, we derived a closed-form expression for the polarizability tensor which includes radiat...