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

• Published in: Acta pharmaceutica Sinica. B Vol. 7; no. 6; pp. 638 - 646
• Main Authors: Meng, Lingjie, Guo, Qinglan, Liu, Yufeng, Shi, Jiangong
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier 01-11-2017
• Subjects: 8,4′-Oxyneolignane; Absolute configuration; Cotton effect; Cruciferae; Isatioxyneolignosides A−F; Isatis indigotica; Original; Threo/erythro Isomers; ΔδC8-C7 value; Cotton effect; Threo/erythro Isomers; Cruciferae; Isatis indigotica; ΔδC8-C7 value; 8,4′-Oxyneolignane; Absolute configuration; Isatioxyneolignosides A−F
• ISSN: 2211-3835; 2211-3843
• DOI: 10.1016/j.apsb.2017.09.006

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 ΔδC8-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.