A series of novel quinazoline analogs with a variety of cysteine-targeting warheads (electrophiles) were designed and synthesized based on ARS-1620 as covalent KRAS G12C inhibitors. Among them, compounds LLK10 and LLK14 exhibited similar or better antiproliferative activity than ARS-1620. LLK10 was used for subsequent biological studies due to the higher selectivity towards KRAS G12C-mutated cells than LLK14. LLK10 maintained the mechanism of action by forming a covalent bond with KRAS G12C protein, thus decreasing the level of phosphorylated Mek and Erk, and leading to tumor cell apoptosis. In addition, LLK10 was able to suppress the formation of H358 tumor colonies. Molecular modeling study indicated that LLK10 binds with high affinity to the SWII binding site in KRAS G12C and overlaps well with ARS-1620. The high binding affinity of LLK10 was further confirmed by the isothermal titration calorimetry (ITC) assay in which LLK10 exhibited a K_D of 115 nM for binding to KRAS G12C. These results suggest that the novel covalent inhibitors of KRAS G12C with different warheads deserve further investigation as potential anticancer agents.

基于 ARS-1620 作为共价 KRAS G12C 抑制剂，设计并合成了一系列具有多种半胱氨酸靶向弹头（亲电试剂）的新型喹唑啉类似物。其中，化合物LLK10和LLK14表现出与ARS-1620相似或更好的抗增殖活性。LLK10用于随后的生物学研究，由于朝比KRAS G12C突变细胞的选择性更高LLK14。LLK10通过与KRAS G12C蛋白形成共价键维持作用机制，从而降低磷酸化的Mek和Erk水平，导致肿瘤细胞凋亡。此外，LLK10能够抑制 H358 肿瘤集落的形成。分子建模研究表明，LLK10与 KRAS G12C 中的 SWII 结合位点以高亲和力结合，并与 ARS-1620 重叠良好。等温滴定量热法 (ITC) 测定进一步证实了LLK10的高结合亲和力，其中LLK10与 KRAS G12C 结合的 K _D为 115 nM。这些结果表明，具有不同弹头的新型 KRAS G12C 共价抑制剂作为潜在的抗癌剂值得进一步研究。