A phase 2a RTS,S/AS malaria vaccine trial, conducted previously at the Walter Reed Army Institute of Research, conferred sterile immunity against a primary challenge with infectious sporozoites in 40% of the 80 subjects enrolled in the study. The frequency of Plasmodium falciparum circumsporozoite protein (CSP)-specific CD4(+) T cells was significantly higher in protected subjects as compared t...

Readily available natural α-amino acids are one of nature's most attractive and versatile building blocks in synthesis of natural products and biomolecules. Peptides and N-heterocycles exhibit various biological and pharmaceutical functions. Conjugation of amino acids or peptides with N-heterocycles provides boundless potentiality for screening and discovery of diverse biologically active molec...

Two darts in the middle! This work reports double addition of propargylzinc reagents to nitriles (acylcyanohydrins and cyanocarbonates). methodology provides a straightforward access dipropargylic α,α-disubstituted hydroxyamides or N-Boc-protected amino alcohols which can be converted into functionalized pyridine derivatives after cobalt-catalyzed [2+2+2] cycloaddition reactions involving nitri...

A series of chiral N-phosphonyl protected α-alkenyl homoallylic primary amines were synthesized by asymmetric addition of allylmagnesium bromide Grignard reagent towards chiral α,β-unsaturated imines. Only 1,2-adduct was obtained for all the imines with good yields and excellent diastereoselectivities. The chiral auxiliary could be easily removed under simple conditions, giving free multiple fu...

α ,2-3- and α ,2-6-sialylated lactosaminide precursor structures obtained by various enzymatic procedures could be used for glycosylations employing triflic acid/N-iodosuccinimide. Easily accessible selectively protected lactoside derivatives served as acceptor disaccharides to give the corresponding human milk pentasaccharides in good yields. These were characterized by spectroscopic means in ...

We investigated the roles of gap junction communication and oxidative stress in modulating potentially lethal damage repair in human fibroblast cultures exposed to doses of α particles or γ rays that targeted all cells in the cultures. As expected, α particles were more effective than γ rays at inducing cell killing; further, holding γ-irradiated cells in the confluent state for several hours a...