胰脂肪酶(PL)是众所周知的预防和治疗肥胖的关键靶标。人羧酸酯酶1A(hCES1A)已成为治疗高脂血症的重要靶点。因此,基于PL和hCES1A的有效双靶点抑制剂的发现对于开发治疗相关代谢性疾病的药物具有巨大潜力。在这项研究中,收集了一系列天然三萜类化合物,并使用基于荧光的生化测定来测定这些三萜类化合物对PL和hCES1A的抑制作用。发现齐墩果酸(OA)和熊果酸(UA)对PL和hCES1A具有优异的抑制作用,和对hCES2A的高度选择性。随后,合成并评估了许多基于OA和UA骨架的化合物。这些化合物的结构-活性关系(SAR)分析表明,UA(化合物41)的C-3位点的乙酰基对于PL和hCES1A的抑制非常重要,IC50为0.75µM和0.014µM,分别。此外,具有OA的2-烯醇和3-缩酮部分的化合物39对PL和hCES1A也具有很强的抑制作用,IC50为2.13µM和0.055µM,分别。此外,化合物39和41对包括hCES2A在内的其他人类丝氨酸水解酶表现出良好的选择性,丁酰胆碱酯酶(BChE)和二肽基肽酶IV(DPP-IV)。抑制动力学和分子对接研究表明,化合物39和41均为有效的PL混合抑制剂,而hCES1A的竞争性抑制剂。进一步的研究表明,化合物39和41均可抑制小鼠前脂肪细胞诱导的脂肪细胞脂肪生成。总的来说,我们发现两种三萜衍生物对PL和hCES1A都有很强的抑制作用,它可以作为有前途的先导化合物,用于开发针对PL和hCES1A的更有效的双靶标抑制剂。
Pancreatic lipase (PL) is a well-known key target for the prevention and treatment of obesity. Human carboxylesterase 1A (hCES1A) has become an important target for the treatment of hyperlipidaemia. Thus, the discovery of potent dual-target inhibitors based on PL and hCES1A hold great potential for the development of remedies for treating related metabolic diseases. In this study, a series of natural triterpenoids were collected and the inhibitory effects of these triterpenoids on PL and hCES1A were determined using fluorescence-based biochemical assays. It was found that oleanolic acid (OA) and ursolic acid (UA) have the excellent inhibitory effects against PL and hCES1A, and highly selectivity over hCES2A. Subsequently, a number of compounds based on the OA and UA skeletons were synthesised and evaluated. Structure-activity relationship (SAR) analysis of these compounds revealed that the acetyl group at the C-3 site of UA (compound 41) was very essential for both PL and hCES1A inhibition, with IC50 of 0.75 µM and 0.014 µM, respectively. In addition, compound 39 with 2-enol and 3-ketal moiety of OA also has strong inhibitory effects against both PL and hCES1A, with IC50 of 2.13 µM and 0.055 µM, respectively. Furthermore, compound 39 and 41 exhibited good selectivity over other human serine hydrolases including hCES2A, butyrylcholinesterase (BChE) and dipeptidyl peptidase IV (DPP-IV). Inhibitory kinetics and molecular docking studies demonstrated that both compounds 39 and 41 were effective mixed inhibitors of PL, while competitive inhibitors of hCES1A. Further investigations demonstrated that both compounds 39 and 41 could inhibit adipocyte adipogenesis induced by mouse preadipocytes. Collectively, we found two triterpenoid derivatives with strong inhibitory ability on both PL and hCES1A, which can be served as promising lead compounds for the development of more potent dual-target inhibitors targeting on PL and hCES1A.