1. Hyperbenzones A and B, two 1,2-seco and rearranged polycyclic polyprenylated acylphloroglucinols from Hypericum beanii
- Author
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Jun Luo, Wei-Jia Lu, Ling-Yi Kong, Yawei Li, Yanqiu Zhang, Wen-Jun Xu, and Shengtao Ye
- Subjects
chemistry.chemical_compound ,Circular dichroism ,chemistry ,Bicyclic molecule ,Hypericum beanii ,Stereochemistry ,Chemical shift ,Electrospray ionization ,General Chemistry ,Nonane ,Ring (chemistry) ,Mass spectrometry - Abstract
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-3,1ʹ-cyclohexane]-2,2ʹ-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, gauge-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 retro-Claisen 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 and 2. Biological investigations indicated that compounds 1 and 3 could decrease intracellular lipid accumulation in a palmitic acid-induced nonalcoholic steatohepatitis (NASH) cell model.
- Published
- 2022