Homotropic negative allostery in alkali metal ion recognition by biscalix[4]arene-based receptor

A novel host which shows homotropic and negative allostery for alkali metal ion recognition is constructed by utilizing a biscalix[4]arene skeleton bearing biphenyls and ester moieties. As the ionic radius of the guest increases, recognition of the second guest is suppressed more effectively. A larger ion changes the structure of the first binding site more drastically to cause conformational change unfavorable for the guest binding of the second site.     

Jordan Algebras and Dual Affine Connections on Symmetric Cones

We study dually flat structures on symmetric cones associated with Jordan algebras. We give an interpretation of connections, a geometrical concept, in terms of Jordan algebras and show a relation between doubly autoparallel submanifolds and Jordan subalgebras.     

Biosynthesis of phytoecdysteroids in Ajuga hairy roots: clerosterol as a precursor of cyasterone, isocyasterone and 29-norcyasterone

Feeding studies of six ¹³C-labeled sterols, including clerosterol, to hairy roots of Ajugareptans var. atropurpurea have established that clerosterol is a precursor of three phytoecdysteroids, cyasterone, isocyasterone and 29-norcyasterone.     

Reaction of azolones with acetylene

Conclusions The reaction of 4,5-diphenylimidazol-2-, benzimidazol-2-, and indazol-3-ones with acetylene gave their N- and O-mono- and N,N- and N,O-divinyl derivatives.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1882–1885, August, 1988.     

Asymmetric reactions with cyclodextrins

Cyclodextrins have great potential for exploitation as a useful tool for asymmetric induction. Many kinds of asymmetric reaction have been achieved in the presence of cyclodextrin under various conditions such as the solid phase, heterogeneous suspension or homogeneous aqueous or organic solution. Complexation is essential for asymmetric induction. What is necessary to improve CDs for greater asymmetric induction?     

The hierarchical and social decision making procedure for bi-objective optimization problems by using the simple majority decision rule

Multi-objective optimization has been successfully applied to problems of industrial design, problems of quality control and production management, and problems of finance. The theme of these applications is how to choose the best solution for the decision makers out of a set of non-inferior solutions to a multi-objective optimization problem. For this purpose, an optimization model with hierarchical structure, whose lower problem is a multi-objective optimization problem and the upper problem is a preference optimization problem on a set of non-inferior solutions, must be constructed. This kind of hierarchical problems have been previously analyzed only with regard to linear programming problems by Benson[6]. In this paper, an algorithm is derived that provides a solution as a social choice, obtained by aggregating plural decision-makers' preferences. In the case of the simple majority rule, the bi-objective problem is transformed into an -parameter choice problem, and the golden section method is applied. The availability of the approach is demonstrated with the means of an illustrative example.Technische Universität BerlinFaculty of Science and Technology, Keio University     

Reactions of α-halo-α, β-unsaturated aldehydes with secondary amines

Reactions of 2-halo-2-alkenals R(R)C=CX-CHO with secondary amines R₂NH occur asipso-substitution of the halogen atom, along with fragmentation and condensation, yielding 1,2-diaminoethenes R₂NCH=CHNR₂, carbonyl compounds RC(O)R, 1,3-bis(amino)-2-haloolefins R(R)C(NR₂)CX=CHNR₂, and formamides R₂NCHO. The ratio between the competing reactions depends on the structure of the starting compounds and the experimental conditions.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp, 135–138, January, I996.     

Efficient photocleavage of DNA utilising water-soluble lipid membrane-incorporated [60]fullerenes prepared using a [60]fullerene exchange method

Various types of lipid membrane-incorporated C60 with high C60 concentrations can be prepared easily in several hours using the C60 exchange method and the photocleaving activity of cationic lipid membrane-incorporated C60 was appreciably higher than that of the C60.gamma-CDx complex.     

Perrottetins E,F, and G from Radula perrottetii (liverwort)--isolation,structure determination,and synthesis of perrottetin e

Perrottetin E, a cytotoxic bis(bibenzyl) ether, was isolated from $\text{Radula perrottetii}$ and its structure determined by spectroscopic methods and total synthesis. Perrottetins F and G were also isolated from the same source and fully characterized.     

Synthesis of 2-thiabicyclo[3.2.0]hept-3-enes by reaction of acetylene with sodium sulfide

The previously unknown2-thiabicyclo[2.3.0]hept-3-ene and exo- and endo-6-methyl-2-thiabicyclo[3.2.0]hept-3-enes were synthesized in one step from acetylene and sodium sulfide in aqueous dimethyl disulfoxide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7. pp. 895–899, July, 1976.