Chloroform d

Synthesis-grade solvents were employed
in all cases. Deuterated solvents acetonitrile-d₃ and chloroform-d were purchased from Euriso-top.
The diamine precursor A was obtained, as previously described.^{17 (link)} All other reagents were obtained from commercial
sources. All compounds are >96% pure by elemental analysis. Nuclear
magnetic resonance (NMR) spectra were recorded at 25 °C on a
Bruker AC 300E, Bruker AV 400, or Bruker AV 600 NMR spectrometer.
The corresponding deuterated solvent was used as an internal reference.
The solvents used were acetonitrile and DMSO, and their internal reference
was 1.94 and 2.50 ppm for ¹H spectra, respectively, and
1.32 and 39.52 ppm for ¹³C. Elemental analyses were performed
on a LECO’s CHNS-932 Elemental Analyzer. UV–vis spectroscopy
was carried out on a PerkinElmer Lambda 750 S spectrometer with operating
software. ESI mass (positive mode) analyses were carried out on an
HPLC/MS TOF 6220.

DMSO, Ko143, SN-38, Hoechst 33342, SDS, Crystal Violet solution, MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide], formic acid, HPLC-grade acetonitrile, and TPP^® tissue culture plates were purchased from Sigma-Aldrich/Merck (Darmstadt, Germany), and water was purified by deionization and 0.22 µm membrane filtration using a Millipore system (Billerica, MA, USA). Chloroform-d was purchased from Eurisotop (Gif-Sur-Yvette Cedex, France), and Roswell Park Memorial Institute (RPMI) 1640 GlutaMAX medium and foetal bovine serum (FBS) were purchased from Gibco (Gibco, Thermo Fisher Scientific, Waltham, MA, USA).

Deuterated water (D₂O) 99.97% D, methanol-D₄ 99.80% D, chloroform-D 99.80% D + 0.03% Tetramethylsilane (TMS), and 3-(trimethylsilyl)-propionic-2,2,3,3-d₄ acid sodium salt (TSP) were purchased from Euriso–Top (Saclay, France). Anhydrous sodium carbonate (Na₂CO₃), anhydrous potassium phosphate dibasic, anhydrous potassium phosphate monobasic and HPLC chemical standards (chlorogenic acid, caffeic acid, ferulic acid, gallic acid, and galacturonic acid) were purchased from Sigma–Aldrich (St. Louis, MO, USA). Methanol (HPLC-grade), chloroform (HPLC-grade), and glacial acetic acid were purchased from Carlo Erba Reagenti (Milan, Italy). Double-distilled water was obtained using a Millipore Milli-Q Plus water treatment system (Millipore Bedford Corp., Bedford, MA, USA).

Deuterated water (D₂O) 99.97% D, methanol-D4 99.80% D, chloroform-D 99.80% D + 0.03% tetramethylsilane (TMS), and 3-(trimethylsilyl)-propionic-2,2,3,3-d4 acid sodium salt (TSP) were purchased from Euriso–Top (Saclay, France). Anhydrous potassium phosphate dibasic (K₂HPO₄) and anhydrous potassium phosphate monobasic (KH₂PO₄) were purchased from Sigma–Aldrich (St. Louis, MO, USA). Methanol (HPLC-grade) and chloroform (HPLC-grade) were purchased from Carlo Erba Reagenti (Milan, Italy). Millipore grade water was purchased from Tito Menichelli S.r.l. (Rome, Italy).

Dichloromethane, ethanol, methanol, ethyl acetate, light petroleum, and m-chloroperbenzoic acid were purchased from Fisher Scientific (Geel, Belgium). The anhydrous magnesium sulfate was PanReac Applichem (Barcelona, Spain) products. Chloroform-d was produced by Eurisotop (Cambridge, England). Thin-layer chromatography (TLC) analyses were carried out on 0.25 mm thick, precoated silica plates (Merck Fertigplatten Kieselgel 60F254, Germany), and spots were visualized under UVlight. Chromatography on silica gel was carried out on Merck Kieselgel (230–240 mesh).

Dichloromethane, acetonitrile, ethyl acetate, light petroleum, 1,4-dioxane, 1-bromo-3-chloropropane, cesium carbonate, and m-chloroperbenzoic acid were purchased from Fisher Scientific (Geel, Belgium). The 1-Bromopropane, 3-bromopropan-1-ol and ethyl 4-bromobutanoate were from Sigma-Aldrich (St. Louis, MO, United States). The anhydrous magnesium sulphate and acetic anhydride were PanReac Applichem (Barcelona, Spain) products. Chloroform-d was produced by Eurisotop (Cambridge, England). Thin-layer chromatography (TLC) analyses were carried out on 0.25 mm-thick, precoated silica plates (Merck Fertigplatten Kieselgel 60F254, Germany), and spots were visualized under UV light. Chromatography on silica gel was carried out on Merck Kieselgel (230–240 mesh).