Asymmetric Michael reactions of α,α-disubstituted aldehydes with maleimides using a primary amine thiourea organocatalyst

Primary amine thiourea organocatalyst 8 was used to promote Michael additions of bulky α,α-disubstituted aldehydes, such as isobutyraldehyde with maleimides to afford the corresponding adducts in high to excellent yields and with up to 91% ee.     

Intricate Recognition of Glycolipid-Like Compounds by HIV-1 Envelope Proteins Evaluated with Surface Plasmon Resonance Imaging

Fusion of human immunodeficiency virus (HIV) to the cell membrane occurs by the specific binding of an envelope protein of HIV-1 (gp120 and gp160) and a glycosphingolipid of the cell membrane. In this study, quantitative and array-based affinity evaluation of gp120 and gp160 was performed by surface plasmon resonance (SPR) and the SPR imaging technique using a substrate immobilized with glycolipid-like compounds (Gb3, GM3, and Lac). Quantitative affinity evaluation showed that gp160 specifically bound to Gb3 and Lac compared with GM3, whereas gp120 showed lower binding affinity and specificity. Array-based evaluation showed that gp160 binds to Gb3 more favorably than Lac and GM3.     

Field theory for the function field of the quintic fermat curve

We study the structure of the function field K of the quintic Fermat curve F(5) in the following way: Let K m be a g-maximal rational subfield of K. Then the field extension K/K _m is obtained by the projection from F(5) to a line with a center p, ∈ F(5). By using this fact, we consider the field extension K/K m from several point of view.