CD spectra were recorded with a Biologic MOS-450 spectrometer using MeOH as solvent.
The sample I (Em/Ag/MeOH) contained the drug adsorbed on AgNPs surface using MeOH as solvent.
The catalytic structure exhibited promising activity using MeOH as solvent and as the unique source of acetalization.
It is noteworthy that purification of compounds 156 on silica gel column chromatography using MeOH as eluent led to the formation of methylphosphate byproduct 157.
The HPLC analysis was carried out on an Agilent 1200 HPLC system (Agilent Techonologies, Santa Clara, CA, USA), combined with Prodigy ODS (2) column of 250 × 4.6 mm i.d., 5 μ (Phenomenex, Torrance,CA, USA), and guard column of 7.5 × 3.2 mm i.d.. Gradient elution was applied, using MeOH (solvent A) and water (solvent B) as mobile phase components.
Chemical shifts are reported in parts per million (ppm) using MeOH solvent peaks as an internal reference (referenced to 3.34 ppm (1H) and 49.5 ppm (13C)).
The residue was purified by silica gel column chromatography (petrol/EtOAc, 10 1 and HPLC with a Waters XBridge C-18 column (5 μm, 10 × 250 mm) using MeOH-H2O 95:5) MeOH-H2O 95o yield 6[9] (tR = 9.876 min, 23 mg, 0.0530 mmol) asd 7(tR = 11.955 min, 17 mg, 0.0368 mmol).
H and C NMR spectra of the isolated pure compounds were recorded with a Bruker AV 600 instrument, using MeOH-d4 or DMSO-d6 as a solvent.
High-resolution mass spectra were recorded on an LC-Mass (Agilent technologies 6530 Accurate-Mass QTOF LC/MC), using MeOH-Water (40:60) as the eluent.
The residual fraction (190.98 g) of the crude extract of P. fulva stem bark was fractionated on a chromatographic column HP 20 (70×8.5 cm) using MeOH-H2O (1:0 → 0 1 v/v) as eluting system followed by acetone.
