Three cyclodipeptides [cyclo(L-Pro-L-Leu), 1; cyclo(L-Pro-L-Val), 2; and cyclo(L-Pro-L-Phe), 3] were isolated from Pseudomonas fluorescens IB-MR-66e. The structures were established by spectral means and corroborated by synthesis. The antidiabetic potential of compounds 1–3 was explored in vivo, in vitro and in silico. The three peptides showed important inhibitory activity against the α-glucosidase enzyme. Further analysis in vivo using a sucrose tolerance test corroborated that compounds 1 and 3 (1–30 mg kg⁻¹) significantly reduced the postprandial state. Peptide 1 (1–30 mg kg⁻¹) also reduced the postprandial peak after a glucose challenge and exhibited significant hypoglycemia during an insulin tolerance test; thus, its antidiabetic action involved also an improvement of insulin utilization not related to Akt phosphorylation nor to an increment in mitochondrial bioenergetics nor insulin secretion.

A novel series of (Z)-2-(hydroxy(aryl)methylene)-2,3-dihydro-1H-indanone derivatives were designed, synthesized and evaluated as cytotoxic agents against six cancer cell lines. In vitro studies showed that most of the molecules exhibited significant activity and selectivity towards the U-251 glioblastoma cell line, especially compounds 1 and 4, which were shown to have a lower IC₅₀ value than that of temozolomide (TMZ) and promoted apoptosis in these cells. The compounds were also shown to be metal chelators, particularly iron chelators (Fe²⁺, Fe⁰ and Fe³⁺) that form iron(III) complexes, an important anticancer property. Compounds 8a and 1b, in particular, formed complexes with an IC₅₀ value markedly lower than that of TMZ and showed pro-apoptotic activity. Basic structure–activity relationship analysis indicated that the skeleton base of 1-indanone and the aryl group are coplanar, and that the electron-donating methoxy moiety was responsible for the selective cytotoxic response.