Avance 3 600 ascend

Melting points were determined on a Yanaco MP-S3 apparatus. UV spectra were measured on a Shimadzu UV 240 spectrophotometer. A JASCO DIP–360 Digital polarimeter was used to measure the optical rotations in chloroform by using a 10-cm cell tube. The ¹H-NMR and 2D NMR spectra were recorded on a Bruker Avance III 600 Ascend spectrometer using the BBO probe, while ¹³C-NMR spectra were recorded on a Bruker Avance III 600 Ascend spectrometer operating at 125 MHz using CDCl₃ as a solvent. Chemical shifts were reported in δ (ppm), relative to SiMe₄ as internal standard, and coupling constants (J) were measured in Hz. The EI-MS and HREIMS were measured on the Jeol HX 110 mass spectrometer. Thin-layer chromatography (TLC) was performed on silica gel pre-coated plates (PF₂₅₄ 20 × 20, 0.25mm, Merck, Germany). Ceric sulfate in 10% H₂SO₄ spraying reagent was used for the staining of compounds on TLC. All reagents used were of analytical grades.