Construction And Antitumor Activity Evaluation Of Novel Biaryl Compound Library

Biaryl skeletons are widely found in natural products and drugs,and the construction of biaryl-based characteristic small molecule compound library can provide high-quality lead compounds for innovative drug discovery.Our group carried out systematic methodological researches on the biaryl skeleton,and constructed a unique and diverse small molecule compound library combining with subsequent functional modification.Through subsequent high-throughput screening,structure-based drug design,structural modification,structure-activity relationship research and evaluation of the biological mechanism in vitro and in vivo,we discovered a series of highly active and highly selective epidermal growth factor receptor（EGFR）and P-glycoprotein（P-gp,also known as ABCB1）inhibitors with independent intellectual property rights,which provides the original lead compounds for the development of novel anti-tumor targeted drugs.The detail research contents are shown as follows:（1）We used cheap and readily available chloropyrimidine and electron-rich arenes as substrates,Br?nsted acid bis（trifluoromethane sulfonimide）（Tf₂NH）as catalyst,and efficiently achieved the non-metal catalyzed C-H arylation in hexafluoroisopropanol（HIFP）solvent.This synthetic method has mild reaction conditions,do not require transition metal catalysis,and is well-tolerated with a variety of functional groups such as halogen,alkyl,methoxy,hydroxyl,and cyan etc.Using this method,we obtained a series of biaryl small molecule compounds with novel structures in moderate to excellent yields（up to 99%）.（2）We used benzonitrile and arylboronic acid as substrates,Pd（OAc）₂ as catalyst,and realized the‘on water’multi-component cascade cyclization reaction.This synthetic strategy efficiently constructs a C-C bond,a C-N bond and a quinazoline ring system through a one-step reaction.This synthetic method has mild reaction conditions,uses water as the green solvent,do not require inert gas protection and is well-tolerated with a variety of functional groups such as halogen,alkyl,hydroxyl,and nitro etc.Using this method,we obtained a series of 4-arylquinazoline derivatives in moderate to excellent yields（up to 98%）.Based on this method,we have achieved the synthesis of highly active PI3Kδinhibitor,confirming the practicality of this method and providing a new alternative synthetic strategy for the synthesis of other 4-arylquinazoline drugs.（3）We used diarylacetylene and aromatic aldehyde as substrates,Cu（OTf）₂ as catalyst,under the synergistic catalysis of iodine,achieved the radical cascade cyclization of diarylacetylene.This synthetic strategy efficiently constructs three C-X bonds（X=C,N,O）and two ring systems through a one-step reaction.This synthetic method has mild reaction conditions and short reaction time,do not require inert gas protection,and is well-tolerated with a variety of functional groups such as halogen,alkyl,hydroxyl,aldehyde etc.Using this method,we obtained 2-arylquinoline-fused biaryls（7 new skeletons,66 compounds）in moderate to excellent yields（up to 86%）.（4）We found the lead compound YS-67(IC₅₀=1.3 n M)with the EGFR inhibitory activity through screening of our in-house biaryl compound library and extensive structure-activity relationship studies.Compound YS-67 could selectively inhibit EGFR[WT](IC₅₀=5.4 n M),EGFR[d746-750](IC₅₀=10.3 n M),and EGFR[L858R](IC₅₀=1.3 n M),and has good anti-proliferative effect on various tumor cells.In addition,compound YS-67 could dose-dependently and reversibly inhibit EGF-induced phosphorylation of EGFR and downstream signaling factor AKT in tumor cells.Compound YS-67 could induce apoptosis of tumor cells through arresting cells in G0/G1 phase.In vivo experiments showed that compound YS-67could dose-dependently inhibit the growth of A431 xenograft tumor with good tolerance.（5）We found the lead compound YS-370(IC₅₀=2 n M,RF=1130)with the ABCB1 inhibitory activity through screening of our in-house biaryl compound library and extensive structure-activity relationship studies,which is 145-fold stronger than verapamil(IC₅₀=0.29μM).Through molecular docking analysis,we found compound YS-370 has a unique biaryl ring system that can be stably localized in the hydrophobic pocket through multiple interactions.Studies have shown that compound YS-370 does not change the expression and location of ABCB1 in SW620/AD300 cells,but increases the accumulation of paclitaxel in cells by inhibiting the efflux function of ABCB1 to achieve anti-tumor effects.ATPase activity assay and CYP3A4 activity assay demonstrated that compound YS-370 is a safe and effective ABCB1 substrate competitive inhibitor.In vivo experiments showed that compound YS-370 could inhibit the growth of SW620/AD300 xenograft tumor in a dose-dependent manner with good tolerance.In conclusion,we have developed a Br?nsted acid-catalyzed C-H arylation,a‘on water’palladium-catalyzed cascade cyclization and a copper-catalyzed intramolecular radical cascade cyclization in this dissertation,and synthesized a total of 220structurally diverse biaryls.Through screening of our in-house biaryl compound library and structure-activity relationship studies,the lead compound YS-67 with EGFR inhibitory activity(IC₅₀=1.3 n M)and the lead compound YS-370 with ABCB1 inhibitory activity(IC₅₀=2 n M,RF=1130)were successfully discovered.And the biological mechanism studies of the related compounds in vitro and in vivo have also been completed.This study not only provides a new option for the synthesis of biaryls,but also enriches the structural diversity of the drug molecule compound library.Simultaneously,the discovery of lead compounds YS-67 and YS-370provides the structural basis for the development of safe,effective and selective EGFR inhibitors and ABCB1 resistance reversal agents,which is of great significance.