Targeting PDGF receptor inhibitors: synthesis and biological evaluation of oleanolic acid analogs

The computer-aided design was used to simulate the docking of PDGF receptor with known active compounds, and the active groups that can bind to key sites were identified by analyzing the key amino acid residue fragments that exerted active effects on the target proteins. The natural product oleanolic acid was used as the parent, and the active group was introduced into the 2-position, and the C-28 carboxyl group was esterified and amidated. A series of oleanolic acid analogues targeting PDGF receptor inhibitors were designed and synthesized. Their structures were confirmed by MS and NMR. Through MTT assay, SGC-7901 and A549 cells were selected for preliminary in vitro anti-tumor activity screening. PDGF receptor protein inhibition test was performed on I₃ and Ⅱ₅ by FPIA. The activity tests showed that I₃ and Ⅱ₅, compared with the positive control drug, had stronger inhibition. FPIA test showed that Ⅱ₅ and PDGF receptor protein had good binding ability. The newly synthesized oleanolic acid analogues have significantly higher antitumor activity than the parent compound and deserve further study.