Aromatic diglycosides from Sophora tonkinensis and a multi-step conformer filtering procedure for TDDFT calculation of flexible glycoside

Abstract

Three previously undescribed aromatic diglycosides (1, 5, and 8) and six known analogs (2–4, 6, 7, and 9) were isolated from the roots and rhizomes of Sophora tonkinensis Gagnep. Their structures were elucidated by detailed spectroscopic analysis. The absolute configuration of compound 8 was determined by comparing the experimental and TDDFT calculated ECD spectra of 8 and aglycone 8a. Furthermore, a multistep conformer filtering procedure for TDDFT calculation of flexible glycoside was proposed, which afforded high accuracy with acceptable computing cost in determining the absolute configuration of glycosides using quantum calculated ECD.

Graphical Abstract

Keywords:

• Sophora tonkinensis
• aromatic glycosides
• calculated ECD

Acknowledgments

Thanks Mr. Feng Chen and Mr. Runben Chen for the modification of the Python scripts.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was financially supported by the National Natural Science Foundation of China [NSFC, 22177134] and the CAMS Innovation Fund for Medical Sciences [CIFMS 2021-I2M-1–028].