Neuraminidase (NA) is a glycoside hydrolase that has been proposed as a potential therapeutic target for influenza. Thus, the identification of compounds that modulate NA activity could be of great therapeutic importance. The aim of this study is to develop a drug discovery tool for the identification of novel modulators of NA from both compound libraries and natural plant extracts. NA was immobilized onto the surface of magnetic beads and the inherent catalytic activity of NA-functionalized magnetic beads was characterized. Based on the enzymatic activity (hydrolysis ratio), the inhibitory activities of 12 compounds from plant secondary metabolites were screened, and the desired anti-NA activities of flavonoids were certified. Ligand fishing with the immobilized enzyme was optimized using an artificial test mixture consisting of oseltamivir, lycorine and matrine prior to carrying out the proof-of-concept experiment with the crude extract of Flos Lonicerae. The combination of ligand fishing and HPLC-MS/MS identified luteolin-7-O-β-D-glucoside, luteolin, 3,5-di-O-caffeoylquinic acid and 3,4-di-O-caffeoylquinic acid as neuraminidase inhibitory ligands in Flos Lonicerae. This is the first report on the use of neuraminidase functionalized magnetic beads for the identification of active ligands from a botanical matrix, and it sets the basis for the de novo identification of NA modulators from complex biological mixtures.

神经氨酸酶（NA）是一种糖苷水解酶，已被提议作为流感的潜在治疗靶标。因此，鉴定调节NA活性的化合物可能具有极大的治疗重要性。这项研究的目的是开发一种药物发现工具，用于从化合物文库和天然植物提取物中鉴定出NA的新型调节剂。将NA固定在磁珠的表面上，并表征了NA官能化磁珠的固有催化活性。基于酶促活性（水解率），筛选了植物次生代谢产物中12种化合物的抑制活性，并确定了所需的类黄酮抗NA活性。使用由奥司他韦，金银花。配体钓鱼和HPLC-MS / MS鉴定木犀草素-7-的组合Ô -β-d葡糖苷，木犀草素，3,5-二- ö -caffeoylquinic酸和3,4-二- ö -caffeoylquinic酸作为神经氨酸酶抑制金银花中的配体。这是有关神经氨酸酶功能化磁珠用于从植物基质中鉴定活性配体的首次报道，它为从复杂生物混合物中从头鉴定NA调节剂奠定了基础。