Abstract
Using various chromatographic separations, six glycoside derivatives (1–6), including one new ent-labdane glucoside named cayratioside (1), were isolated from the methanol extract of Cayratia geniculata stems and leaves. Their structures were elucidated by detailed analysis of the 1D, 2D NMR, and HRESIQTOF mass spectra. The inhibitory effect of 1–6 on LPS-induced NO production in RAW264.7 cells was also evaluated. Among isolated compounds, 1 exhibited moderate activity with an IC50 value of 59.65 ± 1.85 µM.
Acknowledgements
The authors are grateful to the Institute of Chemistry, VAST for recording of the NMR spectra, Prof. Do Thi Thao, Institute of Biotechnology, VAST for assessment of the biological activity, and Dr. Bui Huu Tai, Institute of Marine Biochemistry, VAST for obtaining of the CD and HR-QTOF mass spectra.
Disclosure statement
No potential conflict of interest was reported by the authors.
Supporting information
Structures of compounds of 1–6, 1D- and 2D-NMR and HR ESI QTOF mass spectra for the new compound 1.