Thiourea-Based Receptors for Anion Recognition and Signaling.

This work reports on two thiourea-based receptors with pyridine and amine units including 1-naphthyl () and 4-nytrophenyl () as signaling units. For both compounds, their affinity and signaling ability toward various anions of different geometry and basicity in DMSO were studied using UV-vis, fluorescence, and H NMR techniques. Anion recognition studies revealed that both and have, in general, high affinities toward basic anions.

Berberine as Source of Antiproliferative Hybrid Compounds: In Vitro Antiproliferative Activity and Quantitative Structure-activity Relationship.

Background: Despite advances for cancer treatment, it still remains a major worldwide public health problem. Compounds derived from natural sources are important alternatives to combat this mortal disease. Berberine is an isoquinoline alkaloid with a wide variety of pharmacological properties, including antiproliferative activity.

Synthesis, spectroscopic, physicochemical and structural characterization of tetrandrine-based macrocycles functionalized with acridine and anthracene groups: DNA binding and anti-proliferative activity.

In this work, we report on the synthesis of two new mono-alkylated tetrandrine derivatives with acridine and anthracene units, MAcT and MAnT. The compounds were fully characterized by physicochemical techniques and single-crystal X-ray diffraction analysis. In addition, both derivatives were studied as nucleotide receptors and double-stranded DNA binders in aqueous phosphate buffer at pH = 7.

Recognition of alpha-amino acid derivatives by N,N'-dibenzylated S,S-(+)-tetrandrine.

Complexation of free and N-acetylated alpha-amino acid anions (Gly, Ala, Phe) and some structurally related guests by a dicationic cyclophane-type N,N'-dibenzylated chiral derivative of a bisisoquinoline macrocyclic alkaloid S,S-(+)-tetrandrine (DBT) has been studied by (1)H-NMR titrations in D(2)O. In contrast to other macrocyclic hosts like cyclodextrins and calixarenes, DBT shows highest affinity and large enantioselectivity (K(S)/K(R) >/=10) toward smaller N-acetylalanine and binds larger phenylalanine derivatives more weakly and non-selectively. With 1,2,3,4-tetrahydroisoquinoline-3-carboxylate, a rigid analog of phenylalanine, binding again becomes enantioselective with K(S)/K(R)= 3.