mass spectra were acquired from m/z 100 to 5000 inthe positive ion mode.Nuclear magnetic resonance spectrometry (NMR)The NMR spectra of compound 1, CP1 and CP2were recorded on a Bruker Advance AMX500 NMRspectrometer(Rheinstetten, Germany) at500.13MHz1 13( H)and125.75MHz( C),respectively....