Three previously undescribed dihydronaphthalenones, 7-hydroxycatalponol, (4S)-3,4-dihydro-4-hydroxy-2-[(2R)-2,3-dihydroxy-3-methylbutylidene]naphthalen-1(2H)-one, and (6S)-5,6-dihydro-6-hydroxy-2,2-dimethyl-2H-benzo[h]chromen-4(3H)-one and one phthalide, (±)-3-(5-hydroxy-5-methyl-2-oxohex-3-en-1-yl)isobenzofuran-1(3H)-one, were isolated from the wood of Catalpa ovata G. Don (Bignoniaceae), together with six known compounds. The structures of the previously undescribed compounds were elucidated by interpretation of 1D and 2D NMR data. The absolute configurations of the dihydronaphthalenones were deduced by analysis of the ECD data and application of Mosher ester methodology. All isolates were investigated for their cytoprotective effects against hydrogen peroxide (H2O2)-induced oxidative damage in HepG2 cells. Moreover, the mRNA expression levels of antioxidant enzymes such as heme oxygenase-1 (HO-1) and NAD(P)H:quinine oxidoreductase 1 (NQO1) in HepG2 cells were examined by RT-PCR analysis. As a result, catalponol and epi-catalponol showed antioxidant activities via directly scavenging of intracellular ROS and inducing the antioxidant enzymes in vitro.

中文翻译：

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来自楸木木材的细胞保护性二氢萘酮

三种以前未描述的二氢萘酮、7-羟基邻苯二酚、(4S)-3,4-二氢-4-羟基-2-[(2R)-2,3-二羟基-3-甲基亚丁基]萘-1(2H)-one，和(6S)-5,6-dihydro-6-hydroxy-2,2-dimethyl-2H-benzo[h]chromen-4(3H)-one and one phthalide, (±)-3-(5-hydroxy-5) -methyl-2-oxohex-3-en-1-yl)isobenzofuran-1(3H)-one，与六种已知化合物一起从 Catalpa ovata G. Don（Bignoniaceae）的木材中分离出来。通过对 1D 和 2D NMR 数据的解释阐明了先前未描述的化合物的结构。二氢萘酮的绝对构型是通过分析 ECD 数据和应用 Mosher 酯方法推导出来的。研究了所有分离株对过氧化氢 (H2O2) 诱导的 HepG2 细胞氧化损伤的细胞保护作用。而且，通过RT-PCR分析检测HepG2细胞中抗氧化酶如血红素加氧酶-1（HO-1）和NAD（P）H：奎宁氧化还原酶1（NQO1）的mRNA表达水平。因此，梓醇和表苯二酚通过直接清除细胞内 ROS 并在体外诱导抗氧化酶而表现出抗氧化活性。