Complementing classical drug discovery, phytochemicals act on multiple pharmacological targets, especially in botanical extracts, where they form complex bioactive mixtures. The reductionist approach used in bioactivity-guided fractionation to identify single bioactive phytochemicals is inadequate for capturing the full therapeutic potential of the (bio)chemical interactions present in such complex mixtures. This study used a DESIGNER (Deplete and Enrich Select Ingredients to Generate Normalized Extract Resources) approach to selectively remove the known bioactives, 4'-O-methyldavidigenin (1; 4,2'-dihydroxy-4'-methoxydihydrochalcone, syn. DMC-1) and its isomer 4-O-methyldavidigenin (2; syn. DMC-2), from the mixture of phytochemicals in an ethanol extract from Artemisia dracunculus to determine to what degree the more abundant 2 accounts for the established antidiabetic effect of the A. dracunculus extract. Using an otherwise chemically intact "knock-out extract" depleted in 2 and its regioisomer, 1, in vitro and in vivo outcomes confirmed that 2 (and likely 1) acts as major bioactive(s) that enhance(s) insulin signaling in skeletal muscle, but also revealed that 2 does not account for the breadth of detectable biological activity of the extract. This is the first report of generating, at a sufficiently large preparative scale, a "knock-out extract" used as a pharmacological tool for in vitro and in vivo studies to dissect the biological impact of a designated bioactive in a complex phytochemical mixture.

中文翻译：

---

DESIGNER方法可帮助了解青蒿（俄罗斯龙蒿）的降血糖生物活性原理。

作为经典药物发现的补充，植物化学物质可作用于多种药理学目标，尤其是在植物提取物中，它们在其中形成复杂的生物活性混合物。用于生物活性指导的分级分离以鉴定单一生物活性植物化学物质的还原论方法不足以捕获此类复杂混合物中存在的（生物）化学相互作用的全部治疗潜力。这项研究使用了DESIGNER（消耗大量和丰富的精选成分来生成标准化提取物资源）方法，以选择性去除已知的生物活性物质4'-O-甲基达维己二酸（1； 4,2'-二羟基-4'-甲氧基二氢查尔酮，同为DMC- 1）及其异构体4-O-甲基davidigenin（2;合成DMC-2），从龙蒿的乙醇提取物中提取的植物化学物质混合物中的含量，以确定更丰富的2在多大程度上解释了龙蒿提取物已确立的抗糖尿病作用。使用以2耗尽的化学上完整的“敲除提取物”及其区域异构体1，在体外和体内的结果证实2（很可能是1）是主要的生物活性物质，可增强骨骼中的胰岛素信号传导。肌肉，但还表明2不能解释提取物可检测到的生物活性的广度。这是第一个以足够大的制备规模产生“敲除提取物”的报告，该提取物用作药理学工具，用于体外和体内研究，以分析指定生物活性剂在复杂植物化学混合物中的生物学影响。