1st generation 1,2,3-triazole based dendrimers with arylmethyl Meldrum's acid surface groups - synthesis and radical scavenging activity.

Substituted Meldrum's acids are known as carbon centred antioxidants. Herein a series of 11 dendrimeric antioxidants with either a phenol-type, carboxylic acid or aliphatic alcohol core are synthesised. The dendrons are attached through a 1,4-disubstituted 1,2,3-triazole linker. The compounds are synthesised in a divergent approach through the Huisgen reaction, followed by the Knoevenagel condensation with Meldrum's acid and double bond reduction. Additionally, a telescoped Huisgen reaction without isolation of the azide intermediate is presented. The obtained dendrimers display considerable DPPH radical scavenging activity (Inh100 = 68-88%). The antiradical activity for these compounds is remarkably higher than for such widely used antioxidants as ascorbic acid (DPPH test: Inh100 = 14%) and BHT (DPPH test: Inh100 = 16%). The antiradical activity slightly varies depending on the solvent. Some of the compounds have even demonstrated higher antiradical activity in less polar solvents, thus indicating the HAT mechanism as favourable for these compounds.