Agilent 400 dd2 spectrometer

All the solvents used in
the reactions are commercially available superdry solvents (Energy
Chemical). The silica gel with a mesh of 200–300 was obtained
from Shanghai Titan Scientific General-Reagent (Shanghai, China).
The eluents were also produced by General-Reagent. The ¹H NMR and ¹³C NMR spectra were recorded at room temperature
using an Agilent 400 DD2 spectrometer (California, USA). The HRMS
was measured using Thermo Scientific Q Exactive Orbitrap Mass Spectrometers
(Massachusetts, USA). All other chemicals were analytical grade.
Fetal bovine serum (FBS) was purchased from AusGeneX (Molendinar,
Australia), RPMI 1640 medium (with penicillin and streptomycin) was
obtained from KeyGEN BioTECH (NanJing, China), trypsin EDTA (0.25%)
was purchased from Gibco Invitrogen (Grand Island, USA), and cellular-grade
DMSO was from Beijing Solarbio Science & Technology Co., Ltd.
(Beijing, China).

All chemicals reagents were of analytical grade and
applied without
treatment. Double-distilled water was applied for all tests. The NMR
tests were performed on an Agilent-400 DD2 spectrometer (Agilent,
Palo Alto, CA) in DMSO-d₆ with tetramethylsilane
(TMS) as the internal standard. The chemical shifts (δ) were
expressed in units of parts per million (ppm) relative to TMS. High-resolution
mass spectrometry (HR-MS) experiments were conducted on a time-of-flight
Micromass LCT Premier XE spectrometer (McKinley Scientific, Sparta
Township, NJ). Fluorescence spectra were recorded on a Cary Eclipse
spectrophotometer (Agilent, Palo Alto, CA). UV–vis absorption
spectra were recorded on a TU-1901 UV–vis spectrophotometer
(PuXi Science and Technology Development Co. Ltd., Beijing, China).
IR spectra were recorded on a Vary 1000 FT-IR spectrophotometer (Varian,
Palo Alto, CA). Fluorescence images of the cells were obtained by
an Olympus IX73+DP73 inverted microscope. Small-animal living imaging
was performed on IVIS Lumina LT Series III instrument (Caliper Life
Sciences, Hopkinton, MA). Additional experiment procedures are found
in the Supporting Information.