Two 8-O-4′-type neolignan epimers erythro-guaiacylglycerol-β-coniferyl aldehyde ether (1) and threo-guaiacylglycerol-β-coniferyl aldehyde ether (2) were isolated from the stems of Picrasma quassioides. Further chiral separation gave two pairs of enantiomers 1a/1b and 2a/2b. The cytotoxicity assay against hepatocellular carcinoma Hep3B and HepG2 cells was evaluated by MTT assay. The results showed that 1b (IC₅₀ = 45.56 μM) and 2b (IC₅₀ = 39.02 μM) had more cytotoxic effect than its enantiomers 1a (IC₅₀ = 82.66 μM) and 2a (IC₅₀ = 67.97 μM) in Hep3B cells, respectively. Moreover, 1b and 2b could induce more apoptotic cells as well as higher reactive oxygen species (ROS) generation than 1a and 2a at 50 μM. In addition, a further study on the phosphoinositide 3-kinase (PI3K)/AKT and mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathways was investigated. The results revealed that all compounds had no significant effect on PI3K/AKT pathway, however, 1b and 2b attenuated the relative levels of p-MEK and p-ERK when compared with 1a and 2a. Taken together, the absolute configurations of guaiacylglycerol-β-coniferyl aldehyde ether had an impact on the inhibitory effect on Hep3B cells. The inactivation of MEK/ERK signaling pathway might contribute to apoptosis induction and ROS generation in 1b- and 2b-treated cells.

从拟南芥（Picrasma quassioides）的茎中分离出两个8 - O -4'-型新木脂糖差向异构体赤-愈创甘油基甘油-β-松柏基醛醚（1）和苏-愈创甘油基-β-松柏基醛醚（2）。进一步的手性分离得到了两对对映体1a / 1b和2a / 2b。通过MTT分析评估针对肝细胞癌Hep3B和HepG2细胞的细胞毒性分析。结果显示1b（IC ₅₀  = 45.56μM）和2b（IC ₅₀ 在Hep3B细胞中， α= 39.02μM） 比其对映异构体1a（IC ₅₀ = 82.66μM）和2a（IC ₅₀ = 67.97μM ）具有更大的细胞毒性作用。此外，在50μM下，1b和2b可以比1a和2a诱导更多的凋亡细胞以及更高的活性氧（ROS）生成。此外，对磷酸肌醇3-激酶（PI3K）/ AKT和有丝分裂原激活的蛋白激酶激酶（MEK）/细胞外信号调节激酶（ERK）信号通路进行了进一步的研究。结果表明，所有化合物对PI3K / AKT途径均无显着影响，但是1b和2b与1a和2a相比，p-MEK和p-ERK的相对水平降低。总之，愈创木脂甘油-β-松柏基醛醚的绝对构型对Hep3B细胞的抑制作用有影响。MEK / ERK信号通路的失活可能有助于1b和2b处理细胞的凋亡诱导和ROS的产生。