6530 qtof spectrometer

Diethyl malonate, 2-hydroxy-1-naphthaldehyde, pyridin-2-ylmethanamine, 1-(3-dimethylaminopropyl)-3-ethylcarbodimide hydrochloride (EDCI) and 4-(dimethylamino) pyridine (DMAP) were purchased from Aladdin reagent Co. (Shanghai, China). Metal ions (nitrate salts), biothiols and amino acids were obtained from Sinopharm Chemical Reagent Co., Ltd. (China). Slow qualitative filter paper (Φ 9 cm) was purchased from commercial source. Unless otherwise stated, solvents and reagents were of analytical grade from commercial suppliers and were used without further purification. Deionized water was used throughout.
¹H nuclear magnetic resonance (NMR) and ¹³C NMR spectra were recorded with an AVANCE600MHZ spectrometer (BRUKER) with chemical shifts reported as ppm (in CDCl₃, TMS as internal standard). Coupling constants (J values) are reported in hertz. API mass spectra were recorded on an Agilent 6530 QTOF spectrometer. Absorption spectra were recorded with a Perkin Elmer Lambda 900 ultraviolet/visible/near-infrared (UV/VIS/NIR) spectrophotometer (USA). Fluorescence spectra were measured with Perkin Elmer LS55 luminescence spectrometer (USA). All pH measurements were made with an OHAUS Starter 3100/f meter (USA).

All starting materials and reagents were obtained from commercial suppliers as follows: All reducing sugars were purchased from Shanghai Yuanye Bio-Technology Co., Ltd. (Shanghai, China). Oleanolic acid was purchased from Nanjing jingzhu Bio-Technology Co., Ltd. (Nanjing, China). Methoxylamine hydrochloride (CH₃ONH₂·HCl), sodium cyanoborohydride (NaCNBH₃), 4-dimethylaminopyridine (DMAP), N,N-diisopropylethylamine (DIPEA) were purchased from Shanghai Saen Chemical Technology Co., Ltd. (Shanghai, China). Reaction progress was monitored by analytical TLC on 0.50 mm Silica Gel 60 F254 plates (Qingdao Ocean Chemical Factory, Qingdao, Shandong, China) and observed by spraying with 10% ethanol sulfate solution. ¹H- and ¹³C-NMR spectra were obtained on an AV-400 or AV-500 spectrometer (Bruker, Germany). The chemical shifts of ¹H and ¹³C were referenced to TMS (for CDCl₃) or (for C₅D₅N). Multiplicities was represented by s (singlet), d (doublet), t (triplet), q (quartet) and m (multiplet). Chemical shift assignments for anomeric mixtures, where possible, are noted as α or β with the atom responsible for the shift. Mass spectrometric data were recorded on a 6530 QTOF spectrometer (Agilent, Santa Clara, CA, USA) using electrospray ionization.

Unless otherwise stated, all reagents
were purchased from commercial sources and used without further purification.
The solvents used were of laboratory grade, with ether referring to
diethyl ether. 0.1 M Ammonium hydroxide/ethylenediaminetetraacetic
acid (NH₄OH/EDTA) solution for washing out copper salts
from alkyne/azide coupling reactions was made up by mixing 30 g of
EDTA with 900 mL of water and 100 mL of NH₄OH.
¹H and ¹³C NMR spectra were recorded on Bruker 400,
500, and 600 Avance NMR spectrometers at 298 K. Chemical shifts (δ)
are reported in parts per million (ppm) and referenced to residual
solvent peaks (CDCl₃: ¹H δ 7.26 ppm, ¹³C δ 77.16 ppm; CD₃CN: ¹H δ
1.94 ppm, ¹³C δ 118.26, 1.32 ppm). Coupling constants
(J) are reported in hertz (Hz). Standard abbreviations
indicating multiplicity were used as follows: m = multiplet, q = quartet,
t = triplet, dt = double of triplet, d = doublet, dd = double doublet,
s = singlet. IR spectra were recorded on a Bruker α FT-IR spectrometer
with an attached α-P measurement module. Electrospray mass spectra
(HRMS-ESI) were collected on a Bruker microTOF-Q or Agilent 6530 QTOF
spectrometer. UV–visible absorption spectra were recorded on
an Agilent Cary-60 spectrophotometer utilizing quartz cuvettes of
10 mm path length. Photoluminescence spectra were recorded on a Horiba
Fluoromax-4 spectrophotometer at 77 K in an EtOH/MeOH glassing mixture.