Four new lignans obtained from the leaves of Schisandra cauliflora and their effect on skeletal muscle cell proliferation.

Plants of the Schisandra genus are commonly used in folk medicinal remedies. Some Schisandra species and their lignans have been reported to improve muscle strength. In the present study, four new lignans, named schisacaulins A-D, together with three previously described compounds ananonin B, alismoxide, and pregomisin were isolated from the leaves of S. cauliflora. Their chemical structures were determined by extensive analyses of HR-ESI-MS, NMR, and ECD spectra. Schisacaulin D and alismoxide significantly stimulated skeletal muscle cell proliferation by increasing the number of fused myotubes and expression of myosin heavy chain (MyHC) which may be good candidates for the treatment of sarcopenia.

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

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 NG-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.