Zhou B N, Bahler B D, Hofmann G A, Mattern M R, Johnson R K, Kingston D G
Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0212, USA.
J Nat Prod. 1998 Nov;61(11):1410-2. doi: 10.1021/np980147s.
In a continuation of our search for potential tumor inhibitors from plants, it was found that the CH2Cl2-MeOH (1:1) extracts from Digitalis purpurea and Penstemon linarioides both showed PKCalpha-inhibitory bioactivity. Bioassay-directed fractionation of the extract from D. purpurea yielded the new, weakly active phenylethanoid glycoside 2-(3-hydroxy-4-methoxy-phenyl)-ethyl-O-(alpha-L-rhamnosyl)-(1-->3) -O- (alpha-L-rhamnosyl)-(1-->6)-4-O-E-feruloyl-beta-D-glucopy ran oside (1) together with the four known compounds calceolarioside A (2), calceolarioside B (3), forsythiaside (4), and plantainoside D (5). The extract from P. linarioides yielded the three known glycosides leucosceptoside A (6), acteoside (7), and poliumoside (8), together with the iridoid plantarenaloside (9). All of the isolated compounds, except compound 9, showed inhibitory activity against PKCalpha with IC50 values (in microM) of 125 (1), 0.6 (2), 4.6 (3), 1.9 (4), 14.8 (5), 19.0 (6), 9.3 (7), and 24.4 (8).
在我们持续从植物中寻找潜在肿瘤抑制剂的过程中，发现毛地黄和柳穿鱼的二氯甲烷 - 甲醇（1:1）提取物均显示出蛋白激酶Cα（PKCalpha）抑制生物活性。对毛地黄提取物进行生物活性导向的分离，得到了新的、活性较弱的苯乙醇苷2-(3-羟基-4-甲氧基苯基)-乙基 - O-(α-L-鼠李糖基)-(1→3)-O-(α-L-鼠李糖基)-(1→6)-4-O-E-阿魏酰基-β-D-吡喃葡萄糖苷（1）以及四种已知化合物大车前苷A（2）、大车前苷B（3）、连翘酯苷（4）和车前糖苷D（5）。柳穿鱼提取物得到了三种已知糖苷白花败酱苷A（6）、洋丁香酚苷（7）和绵毛旋覆花苷（8），以及环烯醚萜类植物肾苷（9）。除化合物9外，所有分离出的化合物均对PKCalpha显示出抑制活性，其半数抑制浓度（IC50值，单位为μM）分别为125（1）、0.6（2）、4.6（3）、1.9（4）、14.8（5）、19.0（6）、9.3（7）和24.4（8）。
