RESUMO
Objective: To investigate the mechanism of cytoskeletal recombination and migration inhibition induced by wangzaozin A, ent-kaurane diterpenoid, in A549 cells. Methods: The effects of wangzaozin A on cytotoxicity, cell morphology, cytoskeleton and protein expression as well as cell migration were detected in A549 cells by using MTT, microscope observation, Western blotting, immunofluorescence assay and scratch assay. Results: Wangzaozin A induced significant changes in cell morphology at 24, 48 and 72 h, including increased pseudopods, stretched pseudopods and flattened nucleus in A549 cells. Moreover, microtubules and keratin fibers networks in A549 cells also showed obvious rearrangement, which indicated the cytoskeleton had gone through a continuous recombination process. Further, wangzaozin A significantly increased the phosphorylation of extracellular regulated protein kinase (ERK), microtubule-associated protein 4 (MAP4), keratin 8 (K8) (P < 0.05, 0.01), while wangzaozin A-induced phosphorylation of MAP4 and K8 were suppressed in A549 cells treated with ERK inhibitors U0126 (P < 0.05, 0.01); Wangzaozin A inhibited the migration of A549 cells with a correlation between concentration and time. Conclusion: Wangzaozin A can upregulate the phosphorylation of MAP4 and K8 by activating ERK signaling pathway, which can significantly increase the dynamics of MTs and KFs, disturb the dynamic balance of the cytoskeleton, and inhibit the migration of A549 cells.
RESUMO
Objective To study the fragmentation pathways of five 7,20-cyclo-ent-kaurane diterpenoid compounds (rabdocoetsin B, megathyrin B, rabdocoetsin A, enanderianin N, and megathyrin A) in Isodon coetsa. Methods The samples were analyzed by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS2). According to the fragment in MS2 of five compounds, the possible fragmentation pathways of these diterpenoid compounds were inducted. Results In negative mode, the typical fragmentation pathways of these compounds in high-quality areas were mainly loss of substituents on C-1, C-7, and the oxygen bridge on C-20. The fragmentation pathways were different as a result of the difference of the substituents on C-1. The fragment, which in medium and low quality areas, suggested that fracture order of these compounds were A ring to B and then to C ring. Conclusion The study on fragmentation pathways contributed to the structural identification of 7,20-cyclo-ent-kaurane diterpenoid compounds.