Dihydrophenanthro[b]furan derivatives from the tubers of Bletilla striata

Abstract

Two pairs of new dihydrophenanthro[b]furan enantiomers blephebibnols G–H (1–2), one new dihydrophenanthro[b]furan derivative blephebibnol I (3), along with four known analogues (4–7), were isolated from the tubers of Bletilla striata. Their structures including the absolute configurations were determined by the combination of spectroscopic data analysis, ECD and NMR calculations. Compounds 1a, 1b, and 2b showed inhibition of NO production in LPS-stimulated BV-2 cells, with IC₅₀ values ranging from 4.11 to 14.65 μM. Further mechanistic study revealed that 1a suppressed the phosphorylation of p65 subunit to regulate the NF-κB signaling pathway. In addition, some compounds displayed selective cytotoxic activities against HCT-116, HepG2, A549, or HGC27 cancer cell lines with IC₅₀ values ranging from 0.1 to 8.23 μM.

Keywords:

• Orchidaceae
• Bletilla striata
• dihydrophenanthro[b]furan derivatives
• anti-neuroinflammatory activity
• NF-κB signaling pathway
• cytotoxic activity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China under Grant (No. 81903488).