A method for the production and characterization of fractionated libraries from Chinese herbal formulas

High-throughput screening (HTS) for pharmaceutical leads requires sufficient number of samples with vast chemical diversity. In this paper, we proposed Chinese herbal formulas as an attractive source for HTS and introduced a strategy for the production of high-quality fractionated libraries. An offline two-dimension liquid chromatography protocol was developed to separate medium- and low-polar extract (MLPE) of Chinese herbal formulas, which implemented the production of semi-purified mixture libraries. HPLC coupled with diode-array detector (DAD) and mass spectrum (MS) analysis was performed to obtain MS and UV spectrum of library components. The detected components were characterized by retention, molecular weight and UV absorbance assisted by WiseProcessor, a customer-developed software to automatically process analytical data. Based on the current understanding in pathophysiology and pharmacology, multiple cell-based bioassays were performed to screening the library samples. Through validation and dereplication process, bioactive compounds could be identified rapidly. The combination of off-line two-dimension liquid chromatography separation, HPLC-DAD-MS analysis and computer-aided data processing is reliable and efficient for the utilization of Chinese herbal formulas as valuable sources for HTS. As a demonstration, a library sample set was generated from Qi-Xue-Bing-Zhi Formula, an efficient Chinese herbal formula to treat atherosclerosis. Several bioactive compounds were quickly identified from this library through the screening and dereplication process.