Zhi-Ying Weng

6,7-seco-ent-kaurane diterpenoids from Isodon sculponeatus with cytotoxic activity.

Six new 6,7‐seco‐ent‐kaurane diterpenoids, sculponeatins N–S (1–6, resp.), together with eleven known analogues, 7–17, were isolated from the aerial parts of Isodon sculponeatus. The structures of compounds 1–6 were elucidated by spectroscopic methods including extensive 1D‐ and 2D‐NMR experiments, as well as HR‐ESI‐MS analysis. All diterpenoids obtained were assayed for their cytotoxic activity against K562 and HepG2 human tumor cell lines. Among them, compound 1 showed the most significant cytotoxicity with the IC50 values of 0.21 and 0.29 μM, respectively. The structure–activity relationships are discussed.

Bioactive Nortriterpenoids from Schisandra grandiflora

Three new nortriterpenoids, schigrandilactones A-C (1-3), along with eight known compounds, were isolated from an organic solvent extract of Schisandra grandiflora. Compounds 1 and 2 feature a spirocyclic moiety in their structures, and compound 3 was characterized with a new oxygenated pattern. The relative configurations of 1 and 3 were determined through single-crystal X-ray experiments. In addition, compounds 1 and 2 displayed cytotoxic activity against two human cancer cell lines, and compound 3 showed anti-HIV-1 inhibition in infected C8166 cells.

Three new ent-kauranoids from isodon phyllostachys

Three new ent-kaurane diterpenoids, phyllostacins C-E (1-3), together with six known analogues, oridonin (4), ponicidin (5), effusanin A (6), rabdotemin E (7), rabdoternin F (8), and macrocalyxoformin E (9), were isolated from the aerial parts of Isodon phyllostachys. The structures of compounds (1-3) were determined on the basis of spectroscopic methods including extensive ID and 2D NMR analysis. All compounds were evaluated for their inhibitory activity against K562, HL60 and HepG2 (hepatoma) cell lines.

Cytotoxic ent-kaurane diterpenoids from Isodon henryi.

Chromatographic fractionation of the extract of Isodon henryi resulted in the isolation of seven new ENT-kaurane diterpenoids, named minheryins A-G (1-7), together with the six known ENT-kaurane diterpenoids leukamenin F (8), excisoidesin (9), leukamenin E (10), wangzaozin A (11), pseurata A (12), and racemosin A (13), which were elucidated by spectroscopic analysis. Compounds 7-13 were tested for their cytotoxicity against K562 and HepG2 cell lines, and they all exhibited significant activities with IC50 values<0.50 microg/mL. Isolates 1-5 were evaluated against the K562 cell line, and only 3 showed weak activity.