Dendrocrepidamine, a novel octahydroindolizine alkaloid from the roots of Dendrobium crepidatum

Abstract

A novel octahydroindolizine alkaloid, named dendrocrepidamine (1) with an unusual 18,19,19′-cyclopropanone-dendrocrepine skeleton, was isolated from the ethanol extract of the roots of Dendrobium crepidatum, along with six known compounds (2–7). The structure of 1 was elucidated through HR-ESIMS, NMR spectroscopic data and computational calculations. All compounds were examined for their inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 cells with IC₅₀ values in the range of 3.04–54.89 µM. In vivo, crepidatin (6) (80, 40 and 10 mg/kg) showed a significant protective effect against LPS-induced acute lung injury (ALI) in mice.

Graphical Abstract

Keywords:

• Octahydroindolizine alkaloid
• bibenzyl
• Dendrobium crepidatum
• Orchidaceae
• acute lung injury

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the Ministry of Science and Technology of China under National Key R&D Program (2018YFC1707900), the National Natural Science Foundation (81803391), the Natural Science Foundation of Jiangsu (BK20180828), and the Natural Science Foundation Youth Program of Nanjing University of Chinese Medicine (NZY81803391).