Three new biflavones, apigenin-(3′,8″)-chrysin (1), (2S)-2,3-Dihydroametoflavone 5,4′-dimethyl ether (2), and (2S)-5″,7″-Dihydroxy-2″-phenoxychromonyl-(4′″,3′)-naringenin (3), together with seven known biflavones (4–10) were isolated from the 75% EtOH extract of Selaginella doederleinii. The structures of new compounds were established by application of spectroscopic methods, including 1D and 2D NMR, HRMS, and CD measurements. In addition, all new compounds were evaluated for their cytotoxic potential against three human cancer cell lines A549, MCF-7, and SMMC-7721 in vitro. Compound 2 exhibited potent cytotoxic activity with IC₅₀ values ranging from 6.35 to 10.18 μM.

A new neolignan, selamoellenin A (1), was isolated from the whole plants of Selaginella moellendorffii Hieron. The structure was elucidated on the basis of comprehensive spectroscopic methods (1D/2D NMR and HRMS). Compound 1 was evaluated for its protective effect against high glucose-induced human umbilical vein endothelial cells (HUVECs) damage in vitro.

Four new biflavonoids (1–4) were isolated from Selaginella doederleinii together with a known biflavonoid derivative (5). Their structures contained a rare linker of individual flavones to each other by direct C-3-O-C-4′′′ bonds, and were elucidated by extensive spectroscopic data, including HRESIMS, NMR and ECD data. All isolates significantly inhibited the proliferation of NSCLC cells (IC₅₀ = 2.3–8.4 μM) with low toxicity to non-cancer MRC-5 cells, superior to the clinically used drug DDP. Furthermore, the most active compound 3 suppressed XIAP and survivin expression, promoted upregulation of caspase-3/cleaved-caspase-3, as well as induced cell apoptosis and cycle arrest in A549 cells. Together, our findings suggest that 3 may be worth studying further for intervention of NSCLC.

Two new lignans, noreucol A (1) and (+)-epicycloolivil (2), along with seven known compounds (3–9) were isolated from the aqueous extract of Eucommia ulmoides Oliver. Compound 1 was a new norlignan and 2 was an epimer at C-7 of (+)-cycloolivil (3). Their structures were elucidated by spectroscopic methods, and the absolute configurations of new compounds were determined by conformational analysis and DFT theoretic electronic circular dichroism spectra calculations. In addition, the neuroprotective activity of compounds 1–3 against glutamate-induced HT-22 cells injury were evaluated, and only compound 1 exhibited moderate effect at the concentrations ranging from 10 ∼ 50 μM.