Kadsindutalignans A–C: three new dibenzocyclooctadiene lignans from Kasura induta A.C.Sm. and their nitric oxide production inhibitory activities

Abstract

Phytochemical study on the methanol extract of the stems and leaves of Kadsura induta led to the isolation of six dibenzocyclooctadiene lignans, including three new compounds named kadsindutalignans A–C (1–3), and three known ones, heteroclitalignan B (4), kadsuphilin C (5) and kadsulignan E (6). Their structures were elucidated based on extensive spectroscopic analyses, including HRESIMS, 1D- (¹H NMR and ¹³C NMR), 2D-NMR (HSQC, HMBC, ¹H-¹H COSY and NOESY), and experimental circular dichroism (CD) spectra. All the isolates inhibited NO production in LPS-activated RAW264.7 cells with IC₅₀ values in the range from 5.67 ± 0.54 µM to 38.19 ± 2.03 µM, compared to that of the positive control of N^G-monomethyl-L-arginine acetate (L-NMMA) with an IC₅₀ value of 8.90 ± 0.48 µM. Interestingly, the new compound 2 showed potential inhibition of NO production with an IC₅₀ value of 5.67 ± 0.54 µM, which was higher than that of the positive control.

Graphical Abstract

Keywords:

• Kadsura induta
• Schisandraceae
• kadsindutalignan A
• kadsindutalignan B
• kadsindutalignan C
• nitric oxide inhibitor

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This research was supported by Vietnam National Foundation for Science and Technology (NAFOSTED) under grant number 104.01-2020.22. The authors would like to thank Dr Nguyen Van Thanh, Institute of Ecology and Biological Resources, VAST, for the plant identification.