Aiming at providing an efficient and versatile method for the diversity-oriented decoration and ligation of fullerenes, we report the first C derivatization strategy based on isocyanide-multicomponent reactions (I-MCRs). The approach comprises the use of Passerini and Ugi reactions for assembling pseudo-peptidic scaffolds (i.e., N-alkylated and depsipeptides, peptoids) on carboxylic acid-functionalized fullerenes. The method showed wide substrate scope for the oxo and isocyanide components, albeit the Ugi reaction proved efficient only for aromatic amines. The approach was successfully employed for the ligation of oligopeptides and polyethyleneglycol chains (PEG) to C , as well as for the construction of bis-antennary as well as PEG-tethered dimeric fullerenes. The quantum yields for the formation of O was remarkable for the selected compounds analyzed.

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Herein, a new Ugi multicomponent reaction strategy is described to enhance activity and solubility of the chemotherapeutic drug chlorambucil through its conjugation to poly(amidoamine) (PAMAM-NH2) dendrimers with the simultaneous introduction of lipidic (i-Pr) and cationic (–NH2) or anionic (–COOH) groups. Standard viability assays were used to evaluate the anticancer potential of the water-soluble dendrimers against PC-3 prostate and HT-29 colon cancer cell lines, as well as non-cancerous mouse NIH3T3 fibroblasts. It could be demonstrated that the anticancer activity against PC-3 cells was considerably improved when both chlorambucil and –NH2 (cationic) groups were present on the dendrimer surface (1b). Additionally, this dendrimer showed activity only against the prostate cancer cells (PC-3), while it did not affect colon cancer cells and fibroblasts significantly. The cationic chlorambucil-dendrimer 1b blocks PC-3 cells in the G2/M phase and induces caspase independent apoptosis.

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Triterpenes and phytosterols are classes of natural compounds widespread in plants possessing a great number of pharmacological activities. In our continued search for new compounds from natural sources with pharmacological potential, we prepared a series of novel stigmasterol and ursolic acid (UA) derivatives by coupling with L-proline, L-cysteine and L-glutamic acid. Unlike stigmasterol, the eight derivatives obtained showed good inhibitory capacity against acetylcholinesterase (AChE) or prolyl oligopeptidase (POP). Among these derivatives, we highlight 3 and 5 with IC50 values of 99.0 ± 8.8 and 97.5 ± 5.0 µM against AChE, respectively, and derivative 8 with a POP IC50 value of 75.7 ± 6.3 µM. The ursolic acid derivative 19 was the most promising compound of its class, with IC50 against AChE of 98.3 ± 7.7 µM. These results demonstrate that simple structural modifications on triterpenes and phytosterols can enhance their performance as enzymatic inhibitors.