Two novel seco-polycyclic polyprenylated acylphloroglucinols(PPAPs),hyperbenzones A(1)and B(2),were isolated from the roots of Hypericum beanii,together with one known biosynthetic congener 3.Compound 1 incorporates a...Two novel seco-polycyclic polyprenylated acylphloroglucinols(PPAPs),hyperbenzones A(1)and B(2),were isolated from the roots of Hypericum beanii,together with one known biosynthetic congener 3.Compound 1 incorporates a 6/5/5 ring system with an unprecedented spiro[bicyclo[3.3.0]octane-3,1'-cyclohexane]-2,2'-dione motif.The structures of 1 and 2 were determined by a combination of high resolution electrospray ionization mass spectroscopy(HRESIMS),nuclear magnetic resonance(NMR)spectroscopic analyses,gage-independent atomic orbital(GIAO)NMR chemical shift calculation with DP4+analyses,electronic circular dichroism(ECD)calculation,and X-ray diffraction analysis.A 1,2-seco retroClaisen rearrangement from a bicyclo[3.3.1]nonane PPAP precursor and following chemodivergent radical cascade cyclizations are proposed as the key steps in the biosynthetic pathway to yield compounds 1 and2.Biological investigations indicated that compounds 1 and 3 could decrease intracellular lipid accumulation in a palmitic acid-induced nonalcoholic steatohepatitis(NASH)cell model.展开更多
基金supported by the National Natural Science Foundation of China(Nos.31900287 and 81773886)the 111 Project from Ministry of Education of China and the State Administration of Foreign Export Affairs of China(No.B18056)Special fund from the Central Committee for guiding local scientific and technological development of Shenzhen(No.2021Szvup161)。
文摘Two novel seco-polycyclic polyprenylated acylphloroglucinols(PPAPs),hyperbenzones A(1)and B(2),were isolated from the roots of Hypericum beanii,together with one known biosynthetic congener 3.Compound 1 incorporates a 6/5/5 ring system with an unprecedented spiro[bicyclo[3.3.0]octane-3,1'-cyclohexane]-2,2'-dione motif.The structures of 1 and 2 were determined by a combination of high resolution electrospray ionization mass spectroscopy(HRESIMS),nuclear magnetic resonance(NMR)spectroscopic analyses,gage-independent atomic orbital(GIAO)NMR chemical shift calculation with DP4+analyses,electronic circular dichroism(ECD)calculation,and X-ray diffraction analysis.A 1,2-seco retroClaisen rearrangement from a bicyclo[3.3.1]nonane PPAP precursor and following chemodivergent radical cascade cyclizations are proposed as the key steps in the biosynthetic pathway to yield compounds 1 and2.Biological investigations indicated that compounds 1 and 3 could decrease intracellular lipid accumulation in a palmitic acid-induced nonalcoholic steatohepatitis(NASH)cell model.
