Am 500 instrument

The IR spectral studies for both free diosmin and its metal complex were performed in solid state as pressed KBr pellets using a Perkin-Elmer FT-IR spectrophotometer (400–4000 cm¹). Jeol Gc-mate mass spectrometer was used to obtain the mass spectrum of the complex. The ¹H NMR and ¹³C NMR of diosmin as well as its complex were obtained at 300 MHz and 500 MHz, respectively, using a Bruker AM-500 instrument. The spectral analysis data were recorded without any modification for instrumental characteristics.

NMR spectra were recorded on a Bruker AM500 instrument (¹H NMR at 500 MHz, ¹³C NMR at 125 MHz; Bruker, Karlsruhe, Germany), and tetramethylsilane was used as the internal standard. Chemical shifts are reported in p.p.m. (parts per million) and coupling constants (J) in Hz. Ultra‐performance liquid chromatography (UPLC) was performed using an ACQUITY UPLC™ system (Waters Corporation, Milford, MA, USA) equipped with a binary solvent delivery manager, a photodiode array (PDA). HRESIMS was performed on a Waters Q‐Tof Premier™ Mass Spectrometer equipped with an electrospray interface (Waters Corporation). Separations were conducted on an Armen Spot Prep II 250 medium‐pressure liquid chromatograph (MPLC) and on a PLC 2020 prep/high‐performance liquid chromatograph (prep‐HPLC; Gilson, Inc., Middleton, WI, USA) using an appropriately sized reversed‐phase silica gel column purchased from Waters. All solvents used for column chromatography were of analytical grade (SK Chemicals Co. Ltd., Seongnam, Korea), and all solvents used for HPLC were of HPLC grade (SK Chemicals Co., Ltd.). NMR solvents were purchased from Cambridge Isotope Laboratories Inc. (Andover, MA, USA).