Yang Yingbo, Gu Lihua, Xiao Ying, Liu Qing, Hu Haijun, Wang Zhengtao, Chen Kaixian
The MOE Key Laboratory of Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
The MOE Key Laboratory of Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China; Department of Pharmacy, Changzheng Hospital, Second Military Medical University, Shanghai, China.
PLoS One. 2015 Feb 6;10(2):e0116922. doi: 10.1371/journal.pone.0116922. eCollection 2015.
Alpha-glucosidase inhibitors currently form an important basis for developing novel drugs for diabetes treatment. In our preliminary tests, the ethyl acetate fraction of Phlomis tuberosa extracts showed significant α-glucosidase inhibitory activity (IC₅₀ = 100 μg/mL). In the present study, a combined method using Sepbox chromatography and thin-layer chromatography (TLC) bioautography was developed to probe α-glucosidase inhibitors further. The ethyl acetate fraction of P. tuberosa extracts was separated into 150 individual subfractions within 20 h using Sepbox chromatography. Then, under the guidance of TLC bioautography, 20 compounds were successfully isolated from these fractions, including four new diterpenoids [14-hydroxyabieta-8,11,13-triene-11-carbaldehyde-18-oic-12-carboxy-13-(1-hydroxy-1-methylethyl)-lactone (1), 14-hydroxyabieta-8,11,13-triene-17-oic-12-carboxy-13-(1-hydroxy-1-methylethyl)-lactone (2), 14,16-dihydroxyabieta-8,11,13-triene-15,17-dioic acid (3), and phlomisol (15,16-eposy-8,13(16),14-labdatrien-19-ol) (4)], and 16 known compounds. Activity estimation indicated that 15 compounds showed more potent α-glucosidase inhibitory effects (with IC50 values in the range 0.067-1.203 mM) than the positive control, acarbose (IC50 = 3.72 ± 0.113 mM). This is the first report of separation of α-glucosidase inhibitors from P. tuberosa.
α-葡萄糖苷酶抑制剂目前是开发新型糖尿病治疗药物的重要基础。在我们的初步试验中，糙苏提取物的乙酸乙酯部分显示出显著的α-葡萄糖苷酶抑制活性（IC₅₀ = 100 μg/mL）。在本研究中，开发了一种结合Sepbox色谱法和薄层色谱（TLC）生物自显影的方法，以进一步探究α-葡萄糖苷酶抑制剂。使用Sepbox色谱法在20小时内将糙苏提取物的乙酸乙酯部分分离成150个单独的亚组分。然后，在TLC生物自显影的指导下，从这些组分中成功分离出20种化合物，包括四种新的二萜类化合物[14-羟基枞-8,11,13-三烯-11-甲醛-18-酸-12-羧基-13-(1-羟基-1-甲基乙基)-内酯（1）、14-羟基枞-8,11,13-三烯-17-酸-12-羧基-13-(1-羟基-1-甲基乙基)-内酯（2）、14,16-二羟基枞-8,11,13-三烯-15,17-二酸（3）和糙苏醇（15,16-环氧-8,13(16),14-赖百当三烯-19-醇）（4）]以及16种已知化合物。活性评估表明，15种化合物显示出比阳性对照阿卡波糖（IC50 = 3.72 ± 0.113 mM）更强的α-葡萄糖苷酶抑制作用（IC50值在0.067 - 1.203 mM范围内）。这是首次从糙苏中分离出α-葡萄糖苷酶抑制剂的报道。
