State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences , Kunming 650201, People's Republic of China.
Guilin Normal College , Guilin 541001, People's Republic of China.
J Nat Prod. 2018 Feb 23;81(2):227-235. doi: 10.1021/acs.jnatprod.7b00150. Epub 2018 Jan 17.
Investigation of the 95% EtOH extract of stems of Dendrobium findlayanum afforded four new seco-dendrobines, findlayines A-D (1-4); two known dendrobines, dendrobine (5) and 2-hydroxydendrobine (6); and four new phenolic compounds, dendrofindlaphenols A-C (7, 9, and 10) and 6″-de-O-methyldendrofindlaphenol A (8). Compounds 1 and 2 are the first seco-dendrobines possessing a seven-membered lactam moiety, with 3 and 4 derived from the oxidative cleavage of the C-2-C-3 bond of dendrobine. The structures were established using spectroscopic methods and by comparison with literature data. The absolute configurations of 1-4 were confirmed via single-crystal X-ray diffraction data. Cytotoxic activity assays against HL-60, SMMC-7721, A-549, MCF-7, and SW480 human cancer cell lines revealed IC values ranging from 2.3 to 5.3 μM for compound 7, from 19.4 to 34.4 μM for 8, and from 49.4 to 96.8 μg/mL for the EtOAc extract. An assay of the inhibition of NO production with RAW 264.7 cells indicated that 8 had an IC value of 21.4 μM, and the EtOAc extract, 10.5 μg/mL. The EtOAc extract possessed DPPH radical scavenging activity of 69.93% at 100 μg/mL.
对金钗石斛茎的 95%乙醇提取物进行研究，得到了四个新的铁皮石斛素类似物，分别为 findlayines A-D（1-4）；两个已知的铁皮石斛素，铁皮石斛素（5）和 2-羟基铁皮石斛素（6）；以及四个新的酚类化合物，dendrofindlaphenols A-C（7、9 和 10）和 6″-去-O-甲基金钗石斛素 A（8）。化合物 1 和 2 是第一个具有七元内酰胺部分的铁皮石斛素类似物，3 和 4 是由铁皮石斛素的 C-2-C-3 键氧化裂解而来。结构通过光谱方法和与文献数据的比较来确定。通过单晶 X 射线衍射数据确定了 1-4 的绝对构型。对 HL-60、SMMC-7721、A-549、MCF-7 和 SW480 人癌细胞系的细胞毒性活性测定表明，化合物 7 的 IC 值范围为 2.3-5.3 μM，8 的 IC 值范围为 19.4-34.4 μM，乙酸乙酯提取物的 IC 值范围为 49.4-96.8 μg/mL。用 RAW 264.7 细胞测定对 NO 产生的抑制作用表明，8 的 IC 值为 21.4 μM，乙酸乙酯提取物为 10.5 μg/mL。乙酸乙酯提取物在 100 μg/mL 时具有 69.93%的 DPPH 自由基清除活性。
