Bioactive Compounds from the Roots of Strophioblachia fimbricalyx

Eight new compounds, fimbricalyxs B–D (1–3), fimbricalyxanhydrides A and B (4, 5), and fimbricalyxlactones A–C (6–8), together with three known compounds, trigonostemone (9), 3,6,9-trimethoxyphenanthropolone (10), and fimbricalyx A (11), were isolated from the roots of Strophioblachia fimbricalyx. The structures of the new compounds were elucidated on the basis of their spectroscopic data and, in the case of compounds 2, 4, and 7, confirmed by single-crystal X-ray crystallographic analysis. Compounds 1–4 and 8 were evaluated for their cytotoxicity (KB, MCF7, and NCI-H187 cancer cells) and antiplasmodial activity (Plasmodium falciparum, K1 multidrug-resistant strain). Fimbricalyx B (1) exhibited potent antiplasmodial activity with an IC50 value of 0.019 μM, while 4 was cytotoxic toward NCI-H187 cancer cells and showed antiplasmodial activities with IC50 values of 5.7 and 3.9 μM, respectively. In addition, the X-ray structure of 10 and the antiplasmodial activity of 11 are reported herein for the first time.本研究从棒萼棒果木（Strophioblachia fimbricalyx）的根部分离得到8个新化合物，包括fimbricalyxs B~D（1~3）、fimbricalyxanhydrides A与B（4、5）以及fimbricalyxlactones A~C（6~8），另获得3个已知化合物：三角果酮（trigonostemone，9）、3,6,9-三甲氧基菲酮（3,6,9-trimethoxyphenanthropolone，10）与fimbricalyx A（11）。所有新化合物的结构均通过光谱数据予以阐明，其中化合物2、4和7的结构经单晶X射线衍射分析得到确证。研究对化合物1~4及8开展了细胞毒性（针对KB、MCF7及NCI-H187癌细胞）与抗疟活性（针对恶性疟原虫（Plasmodium falciparum）K1多药耐药株）评价。结果显示，fimbricalyx B（1）具有强效抗疟活性，其半数抑制浓度（IC50）为0.019 μM；化合物4对NCI-H187癌细胞表现出细胞毒性，同时具备抗疟活性，对应IC50值分别为5.7 μM与3.9 μM。此外，本研究首次报道了化合物10的X射线晶体结构以及化合物11的抗疟活性。