Novel flavonolignans from the roots of Indigofera stachyodes

• Published in: Fitoterapia Vol. 160; p. 105217
• Main Authors: Lou, Hua-Yong, Yi, Ping, Liu, Han-Fei, Wang, Huan, Fu, Jian, Li, Jin-Yu, Yang, Qi-Ping, Zhang, Shi-Lin, Hao, Xiao-Jiang, Pan, Wei-Dong
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.07.2022; Elsevier Science Ltd
• Subjects: Antioxidants; Bioassays; Chemical compounds; Circular dichroism; Dichroism; Electronic circular dichroism; Flavonolignans; Indigofera; Indigofera stachyodes; Isoflavanelignans; NMR; Nuclear magnetic resonance; Phenylpropanoids; Quantum chemistry; Roots; Scavenging; Indigofera stachyodes; Flavonolignans; Isoflavanelignans; Electronic circular dichroism
• ISSN: 0367-326X; 1873-6971
• DOI: 10.1016/j.fitote.2022.105217

Two pairs of new enantiomeric flavonolignans, ±stachyols A and B (±1 and ± 2), along with two novel isoflavanelignans, stachyols C and D (3 and 4) were isolated from the roots of Indigofera stachyodes. Their chemical structures and absolute configurations were determined using nuclear magnetic resonance and comparison of experimental and theoretical electronic circular dichroism (ECD) spectra, as well as quantum chemical calculations. Of those compounds, 1 and 2 represented the first examples of flavonolignans with 5-deoxyflavonoids adduct phenylpropanoids. Moreover, 3 and 4 possess an unprecedented skeleton with isoflavanes adduct phenylpropanoids. The antioxidant activity was evaluated for all compounds in terms of ABTS+ and DPPH bioassays. Compounds 3 and 4 exhibited significant radical-scavenging activity in the ABTS+ assay, with IC50 values of 15.15 and 5.83 μM, respectively. [Display omitted]