Sophaloseedlines A—G: Diverse Matrine‐Based Alkaloids from Sophora alopecuroides with Potential Anti‐Hepatitis B Virus Activities

Main observation and conclusion Sophaloseedlines A—G (1—7), seven new matrine‐based alkaloids along with two known analogues, were isolated from the seeds of Sophora alopecuroides. The new structures were determined based on extensive spectroscopic data, electronic circular dichroism calculations, and X‐ray crystallography. Notably, sophaloseedline A (1) represents a novel rearranged 6(5→17)‐abeo‐matrine alkaloid featuring unprecedented highly constructed 7/6/5/6 tetracyclic fused ring skeleton. The hypothetical biosynthetic pathways for sophaloseedlines A—F were proposed based on co‐existing precursors. Additionally, all the isolated alkaloids were screened for their antiviral activities against hepatitis B virus, and new alkaloids 1 and 2 displayed more potent activities than those of matrine (a parent alkaloid of title plant) and positive control (lamivudine). Sophaloseedlines A‐G (1—7), seven new matrine‐based alkaloids along with two known analogues, were isolated from the seeds of Sophora alopecuroides. The new structures were determined based on extensive spectroscopic data, electronic circular dichroism calculations, and X‐ray crystallography. Notably, sophaloseedline A (1) represents a novel rearranged 6(5→17)‐abeo‐matrine alkaloid featuring unprecedented highly constructed 7/6/5/6 tetracyclic fused ring skeleton. The hypothetical biosynthetic pathways for sophaloseedlines A—F were proposed based on co‐existing precursors. Additionally, all the isolated alkaloids were screened for their antiviral activities against hepatitis B virus, and new alkaloids 1 and 2 displayed more potent activities than those of matrine (a parent alkaloid of title plant) and positive control (lamivudine).