Synthesis of Amino Acid-Derived 1,2,3-Triazoles: Development of a Nontrivial Fluorescent Sensor in Solution for the Enantioselective Sensing of a Carbohydrate and Bovine Serum Albumin Interaction.

A series of amino acid-derived 1,2,3-triazoles presenting the amino acid and the aromatic moieties connected by a triazole-4-carboxylate spacer is discussed in this work. These compounds were achieved in good yields by organocatalytic enamine-azide [3 + 2] cycloadditions. One of the molecules obtained, bearing a 7-chloroquinoline moiety, was photoactive in the UV-violet region and was successfully employed as a probe for substrate-specific enantiomeric sensing using d-(-)-arabinose and l-(+)-arabinose. The potential application as a fluorescent probe to detect protein in phosphate buffer solution was also explored using as model bovine serum albumin (BSA). The studied compounds presented both suppression and association behavior in the presence of BSA. In addition, theoretical calculations were performed at levels ωB97XD/cc-pVDZ and PBE1PBE/6-311+G(d,p) together with the polarizable continuum model to understand the interaction of the molecules with the enantiomers.

Stereoselective Arylation of Amino Aldehydes: Overriding Natural Substrate Control through Chelation.

The chelation-controlled arylation reaction of chiral, enantiopure acyclic α-amino aldehydes enabled by a B/Zn exchange reaction between arylboronic acids and Et2Zn is reported. The presence of dibenzyl substituents at the nitrogen plays a key role in the stereochemical outcome of the reaction, and chelation is favored over the natural tendency of this type of substrate to undergo Felkin-Anh controlled additions with organomagnesium and organolithium reagents.

Bromelain-Functionalized Multiple-Wall Lipid-Core Nanocapsules: Formulation, Chemical Structure and Antiproliferative Effect Against Human Breast Cancer Cells (MCF-7).

PURPOSE: This study was conducted a promising approach to surface functionalization developed for lipid-core nanocapsules and the merit to pursue new strategies to treat solid tumors. METHODS: Bromelain-functionalized multiple-wall lipid-core nanocapsules (Bro-MLNC-Zn) were produced by self-assembling following three steps of interfacial reactions. Physicochemical and structural characteristics, in vitro proteolytic activity (casein substrate) and antiproliferative activity (breast cancer cells, MCF-7) were determined. RESULTS: Bro-MLNC-Zn had z-average diameter of 135 nm and zeta potential of +23 mV. The complex is formed by a Zn-N chemical bond and a chelate with hydroxyl and carboxyl groups. Bromelain complexed at the nanocapsule surface maintained its proteolytic activity and showed anti-proliferative effect against human breast cancer cells (MCF-7) (72.6 ± 1.2% at 1.250 µg mL-1 and 65.5 ± 5.5% at 0.625 µg mL-1). Comparing Bro-MLNC-Zn and bromelain solution, the former needed a dose 160-folds lower than the latter for a similar effect. Tripan blue dye assay corroborated the results. CONCLUSIONS: The surface functionalization approach produced an innovative formulation having a much higher anti-proliferative effect than the bromelain solution, even though both in vitro proteolytic activity were similar, opening up a great opportunity for further studies in nanomedicine.