In this study, a successful synthesis of gold nanoparticles (AuNPs) using extract from the Carambola fruit was carried out. Remarkably fast reduction of Au3+ ions was observed when aqueous chloroauric acid was treated with star fruit powder at 60 ºC and this was obtained without the use of any stabilizing or reducing agents. The UV-visible, FT-IR, DLS, XRD, SEM and TEM were used to study the synthesized AuNPs. The FT-IR studies suggested that the phenolic group may have contributed to the reduction of Au3+. The DLS particle size analysis and TEM measurements revealed that AuNPs had a mean particle size of 10 nm and were nearly spherical in form. The crystalline character of AuNPs was established by TEM-SAED image and XRD analyses. Zeta potential measurements were used to analyze the stability of AuNPs. The synthesized AuNPs effectively scavenge free radicals such as DPPH, NO• and H2O2 with % inhibition values of 57.12, 58.75 and 60.23, respectively. The MTT assay of the anticancer activity demonstrated that the synthesized AuNPs worked effectively against MCF7 cell lines and are comparable to those of standard cancer drugs.

The nucleophilic reaction of 1H-triazole derivatives with piperidines under basic conditions is the essential step in the synthesis of a new series of dibenzyl N(2)-C-linked triazolyl piperidines. The triazole derivative was synthesized via the CuAAc reaction of 1-phenylprop-2-yn-1-ol (1a-b) with azidomethyl pivalate. Compound 3a-b underwent dehydroxylation and deprotection reactions using TFA, triethyl silane and 1 M NaOH respectively, yielding monobenzyl 1H-1,2,3-triazole (4a-b). The N(2)-piperidinyltriazoles (6a-j) were synthesized in significant amounts by nucleophilically reacting 1H-triazole derivatives (4a-b) with 4-mesyl-1-boc-piperidine (5) under basic conditions using sodium hydride, which further on acidic deprotection followed by benzylation reaction furnished dibenzyl N(2)-C-linked triazolyl piperidines (9a-j).