8,4'-Oxyneolignane glucosides from an aqueous extract of "ban lan gen" (Isatis indigotica root) and their absolute configurations

Lingjie Meng; Qinglan Guo; Yufeng Liu; Jiangong Shi

doi:10.1016/j.apsb.2017.09.006

8,4'-Oxyneolignane glucosides from an aqueous extract of "ban lan gen" (Isatis indigotica root) and their absolute configurations

Acta Pharm Sin B. 2017 Nov;7(6):638-646. doi: 10.1016/j.apsb.2017.09.006. Epub 2017 Oct 18.

Authors

Lingjie Meng¹, Qinglan Guo¹, Yufeng Liu¹, Jiangong Shi¹

Affiliation

¹ State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.

Abstract

Three pairs of glycosidic 8,4'-oxyneolignane diastereoisomers, named isatioxyneolignosides A-F (1-6), were isolated from an aqueous extract of Isatis indigotica roots. Their structures and absolute configurations were elucidated by comprehensive spectroscopic data analysis and enzyme hydrolysis. The validity of Δδ_C8-C7 values to distinguish threo and erythro aryl glycerol units and Cotton effects at 235±5 nm to determine absolute configurations at C-8 in 1-6 and their aglycones (1a-6a) are discussed.

Keywords: 8,4′-Oxyneolignane; Absolute configuration; Cotton effect; Cruciferae; Isatioxyneolignosides A−F; Isatis indigotica; Threo/erythro Isomers; ΔδC8-C7 value.