Chemical investigation of the dichloromethane extract of the aerial parts of Plectranthus scutellarioides led to the isolation and characterization of 10 diterpenoids with an abietane skeleton and one cembrane-type diterpenoid. Among them, six have not yet been described in the literature. Their structures were established by 1D and 2D NMR, UV and IR spectroscopy, and HRESIMS. The relative configuration was determined by Gauge-Independent Atomic Orbital NMR chemical shift calculations supported by the advanced statistical method DP4 plus and further confirmed by electronic circular dichroism. The isolated constituents were evaluated for their in vitro NF-κB inhibitory activity, as well as for their cytotoxic effects in human multiple myeloma cancer stem cells and RPMI 8226 tumor cell line. Coleon O, coleon G, lanugone K and 6-acetylfredericone B showed the highest inhibitory effect against NF-κB, displaying IC50 of 11.2, 11.0, 4.5 and 9.7 μM, respectively. Coleon O exhibited also a significant activity towards human multiple myeloma cancer stem cells and RPMI 8226 cells with IC50 of 9.2 and 8.4 μM, respectively.

中文翻译：

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来自 Plectranthus scutellarioides 的抗炎和抗增殖二萜类化合物

通过对 Plectranthus scutellarioides 地上部分二氯甲烷提取物的化学研究，分离和表征了 10 种具有松香烷骨架的二萜和一种 Cembrane 型二萜。其中，文献中尚未记载的有6种。它们的结构是通过一维和二维核磁共振、紫外和红外光谱以及 HRESIMS 确定的。相对构型是由先进的统计方法 DP4 plus 支持的与规范无关的原子轨道核磁共振化学位移计算确定的，并由电子圆二色性进一步证实。评估了分离的成分的体外 NF-κB 抑制活性，以及​​它们在人多发性骨髓瘤癌症干细胞和 RPMI 8226 肿瘤细胞系中的细胞毒性作用。科伦 O，科伦 G，lanugone K 和 6-acetylfredericone B 对 NF-κB 的抑制作用最高，IC50 分别为 11.2、11.0、4.5 和 9.7 μM。Coleon O 对人多发性骨髓瘤癌症干细胞和 RPMI 8226 细胞也表现出显着的活性，IC50 分别为 9.2 和 8.4 μM。