Varian vns500 spectrometer

Optical rotation was recorded on a JASCO P-2100 polarimeter. NMR spectra were recorded on an Agilent Varian VNS500 spectrometer. Chemical shifts (ppm) were referenced to residual solvent peaks (δ_H 3.31 and δ_C 49.0 for CD₃OD). Positive-mode ESITOFMS was obtained on a JEOL JMS-T100LP AccuTOF LC-plus 4G spectrometer using a sample dissolved in MeOH.

Optical rotation was recorded on a JASCO P-2100 polarimeter (Jasco Co., Tokyo, Japan). UV spectrum was recorded on a Shimadzu UV-1280 spectrophotometer (Shimadzu Co., Kyoto, Japan). ECD spectrum was recorded on a JASCO J-725 spectropolarimeter. IR spectrum was recorded on a Shimadzu IR affinity-1 spectrometer. NMR spectra were recorded on an Agilent Varian VNS500 spectrometer (Agilent Technologies, Santa Clara, CA, USA). Chemical shifts (ppm) were referenced to the residual solvent peaks (δ_H 3.31 and δ_C 49.0 for CD₃OD). Negative-mode ESITOFMS was obtained on a JEOL JMS-T100LP AccuTOF LC-plus 4 G spectrometer using a sample dissolved in MeOH (Jeol Ltd., Tokyo, Japan). For LC-MS/MS analysis, Quattro Premier XE (Waters Co., Milford, MA, USA) system was used. Optical densities were measured using a microplate reader (ARVO MX 1420 multilabel counter, Perkin Elmer).