A new megastigmane from Kalanchoe tubiflora (Harvey) Hamet

- One new megastigmane were isolated and characterized from Kalanchoe tubiflora.
- Ten known compounds were also isolated from Kalanchoe tubiflora.
- Structures of these isolates were elucidated by spectroscopic methods.
- Compounds 1-4, 6, 9, and 11 possessed nitric oxide inhibitory activity.

One new megastigmane, (6S,7R,8R,9S)-6-oxaspiro-7,8-dihydroxymegastigman-4-en-3-one (1) (tubiflorone, 1), and ten known compounds were isolated and characterized from the EtOH extract of Kalanchoe tubiflora (Harvey) Hamet. Structures of these isolates were assigned based on spectroscopic analyses that included 1D and 2D NMR techniques, such as HMQC, HMBC, and NOESY. The anti-inflammatory activities of selected isolated compounds (1-6 and 9-11) were evaluated as inhibitory activities against lipopolysaccharide (LPS) induced nitric oxide (NO) production in RAW264.7 cell lines. Compounds 1-4, 6, 9, and 11 possessed nitric oxide inhibitory activity with IC50 values ranging from 15.1 ± 0.9 to 98.9 ± 1.3 μM.

One new megastigmane, (6S,7R,8R,9S)-6-oxaspiro-7,8-dihydroxy megastigman-4-en-3-one (tubiflorone, 1), and ten known compounds (2-11) were isolated and characterized from the EtOH extract of Kalanchoe tubiflora (Harvey) Hamet. Compounds 1-4, 6, 9, and 11 possessed nitric oxide inhibitory activity with IC50 values ranging from 15.1 ± 0.9 to 98.9 ± 1.3 μM.