A full set of 8,4′-oxy-8′-phenylneolignan stereoisomers from Sophora tonkinensis and their absolute configurations by TDDFT

• Published in: Phytochemistry (Oxford) 2022-05, Vol.197, p.113135-113135, Article 113135
• Main Authors: He, Hao-Ke, Li, Xin, Yang, Sheng-Li, Tian, Meng-Yin, Zhang, Qian-Ru, Zhang, Ning, Hou, Qi, Lin, Ming-Bao, Wang, Su-Juan
• Format: Article
• Language: English
• Subjects: 8,4′-oxy-8′-phenylneolignan; Animals; Anti-inflammatory; Conformer filtering; ECD calculation; Fabaceae; Mice; Molecular Structure; Nitric Oxide; Plant Roots - chemistry; Rhizome; Sophora - chemistry; Sophoratonkinensis Gagnep; Stereoisomerism
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2022.113135

A full set of 8,4′-oxy-8′-phenylneolignans with four chiral carbons, named (+)/(−)-leptolepisols D1‒D2 and (+)/(−)-sophorols A‒F, were isolated from the roots and rhizomes of Sophora tonkinensis Gagnep., including 14 previously undescribed stereoisomers, along with 2 known leptolepisol D diastereomers. Their planar structures and relative configurations were elucidated by detailed spectroscopic analysis (HRESIMS and NMR). Based on a highly accurate conformer filtering protocol at low computational cost, the absolute configurations of full set 8,4′-oxy-8′-phenylneolignans were completely assigned by TDDFT calculations of ECD spectra for the first time. Furthermore, (+)/(−)-sophorol A, (−)-sophorol B, and (−)-sophorol E could moderately suppress the lipopolysaccharide-induced nitric oxide production in murine macrophages at 10 μM, with inhibitory ratios of 48.4–52.9%. A full set of 8,4′-oxy-8′-phenylneolignans with four chiral carbons were isolated from Sophora tonkinensis Gagnep. Four compounds could suppress the LPS-induced NO production in murine macrophages. [Display omitted] •Sixteen 8,4′-oxy-8′-phenylneolignans were isolated, 14 of which were undescribed.•The absolute configurations of 8,4′-oxy-8′-phenylneolignans were assigned by TDDFT.•An accurate conformer filtering protocol at low cost for flexible molecules was used.•Four isomers exhibited moderately anti-inflammatory activities.