Suberic acid

For cytotoxicity measurements, cells were plated at a density of 5000 cells/well in a 96-well plate and grown for 24 h. Cells were then exposed to vehicle (dimethyl sulfoxide, DMSO; Sigma-Aldrich, St. Louis, MO, USA) control or 12.5–400 uM suberic acid (Sigma-Aldrich), and incubated for an additional 24 h. Cell viability was determined using the cell proliferation reagent water-soluble tetrazolium salt (WST-8; Sigma-Aldrich), as recommended by the manufacturer.

Methanol and deionized water of LC-MS grade was purchased from Sigma-Aldrich (St. Louis, MO, USA). Formic acid (extra pure grade) was purchased from Duksan (Seoul, Korea). Analytical grade reference compounds, l-acetylcarnitine, azelaic acid, ophthalmic acid, uric acid, suberic acid, ε-(γ-glutamyl)-lysine, and pimelic acid, were purchased from Sigma-Aldrich and Toronto Research Chemicals (Toronto, ON, Canada). Deionized water for sample preparation was obtained using Milli-Q (Merck, Darmstadt, Germany).

Isotactic PP (Ecolen HZ42Q) with melt flow index equal to 18 g/10 min, tensile strength equal to 33 MPa, and melting point of 168–171 °C was obtained from Hellenic Petroleum S.A., Thessaloniki, Greece. A masterbatch (Bondyram^® 1001) with PP grafted with maleic anhydride (PP-g-MA), with MA content of 1%, melt flow index equal to 100 g/10 min, and melting point of 160 °C, obtained from Polyram Plastic Industries Ltd., Gilboa, Israel, was used as a compatibilizer. Wollastonite in the form of needle-like particles (NYAD M9000) with aspect ratio equal to 3 (9 μm length to 3 μm diameter) was kindly supplied by Imerys Minerals Ltd., Paris, France.
Two different organic solvents were used, namely, Ethanol and carbon tetrachloride, for the modification procedure of wollastonite. Ethanol was purchased from Honeywell, Charlotte, NC, USA (purity ≥ 99.8%), while carbon tetrachloride was purchased from Fluka Chemie AG, Buchs, Switzerland (purity > 99.5%).
Myristic, malonic, glutaric, pimelic, and suberic acid were purchased from Sigma-Aldrich, St. Louis, MO, USA, while maleic acid was purchased from Alfa Aesar, Haverhill, MA, USA. Potassium bromide (KBr, >99.5%) was purchased from Chem-Lab, Zedelgem, Belgium and was dried at 170 °C for 3 h prior to use. All other chemicals were used as received (unless otherwise noted).