Vanillylacetone

ELACs in monolayer cultures were treated with a combination of 2.5 ng/mL IL-1β and 2 ng/mL OSM or 0.5 μg/mL LPS for 2 h [60 ]. Following this, they were treated with drugs, including diacerein (2.5–10 μM; TRB Chemidica, Italy), dexamethasone (5–20 nM; Sigma-Aldrich, U.S.A.), indomethacin (2.5–10 μM; Sigma-Aldrich, U.S.A.), and etoricoxib (2.5–10 μM; Zuelling, Philippines) or with natural bioactive compounds (Sigma-Aldrich, U.S.A.), including sesamin (0.25–1 μM), andrographolide (1.25–5 μM), and vanillylacetone (20–80 μM), for 24 h. The cells were then harvested to investigate the expression of MMP3 and MMP13 by real-time RT-PCR, and the culture media were analyzed for protein levels of MMP-3 and MMP-13.

A mixture of solid support proline–proline dipeptide (30 mol%), Vanillylacetone (1 mmol; Sigma Aldrich, St. Louis, MI, USA), and thiophene 3-carbaldehyde (1.2 mmol; Sigma Aldrich, USA) in anhydrous DMF (5 cm³; Sigma Aldrich, USA) under inert conditions (nitrogen gas) was stirred at 80 °C for 8 h. The reaction progress was monitored using thin-layer chromatography (TLC, Silica gel 60 F₂₅₄, Merck, St. Louis, MI, USA). After the reaction, the mixture was diluted with cold water and filtered to separate the catalyst. The reaction mixture was then extracted with diethyl ether and removed under reduced pressure. The residue was separated using column chromatography (Silica gel 100–200 mesh, Merck, Rahway, NJ, USA) with a hexane–ethyl acetate mixture to afford pure compounds. The filtered catalyst was reused after drying. All the solvents and reagents were of analytical grade and obtained from Merck. The STCs were characterised using ¹H, ¹³C nuclear magnetic resonance (NMR; JOEL 400 MHz) and CHN analysis (Thermo Scientific, Waltham, MA, USA). The synthetic scheme is shown in Figure 2.