Ap 300 digital

Optical rotations were measured on an Atago AP-300 digital polarimeter with a 1 dm microcell and a sodium lamp (589 nm). NMR data were recorded on a Bruker DRX-600 spectrometer at 300 K (Bruker BioSpinGmBH, Rheinstetten, Germany) equipped with a Bruker 5 mm TCI Cryoprobe at 300 K. All 2D NMR spectra were acquired from MeOH-d4 (99.95%, Sigma-Aldrich, Milano, Italy), and standard pulse-sequences and phase cycling were used for the DQF-COSY, HSQC, and HMBC spectra. The NMR data were processed using TOPSPIN 3.2 software (Bruker Biospin, Rheinstetten, Germany). HRESIMS data were obtained on a Q Exactive Plus mass spectrometer, Orbitrap-based FT-MS system, equipped with an ESI source (Thermo Fischer Scientific Inc., Bremen, Germany). Column chromatography was performed over Sephadex LH-20 (Pharmacia). RP-HPLC separations were carried out using a Shimadzu LC-8A series pumping-system equipped with a Shimadzu RID-10A refractive index detector and Shimadzu injector (Shimadzu Corporation, Kyoto, Japan) on a C 18 μ-Bondapak column (30 mm × 7.8 mm, 10 µm, Waters-Milford, Milford, MA, USA). TLC separations were conducted using silica gel 60 F 254 (0.20 mm thickness) plates (Merck, Germany) and Ce(SO₄)₂/H₂SO₄ as spray reagent (Sigma-Aldrich, Milano, Italy).

Optical rotations were measured by an Atago AP-300 digital polarimeter with a 1 dm microcell and sodium lamp (589 nm). NMR experiments were recorded on a Bruker Digital Receiver uniX 600 spectrometer at 300 K (Bruker BioSpin, Germany), revealing the spectra for methanol-d4 and CDCl₃. HRESIMS data were obtained by using the positive ion modes on an Linear trap quadrupole LTQ Orbitrap XL mass spectrometer (Thermo Fisher Scientific). Quantitative data were acquired using an API6500 Q-Trap (ABSciex Foster City, CA, USA) apparatus.