1. Academic Validation
  2. Bioassay-guided isolation of constituents of Piper sarmentosum using a mitochondrial transmembrane potential assay

Bioassay-guided isolation of constituents of Piper sarmentosum using a mitochondrial transmembrane potential assay

  • J Nat Prod. 2011 Oct 28;74(10):2193-9. doi: 10.1021/np200557e.
Li Pan 1 Susan Matthew Daniel D Lantvit Xiaoli Zhang Tran Ngoc Ninh Heebyung Chai Esperanza J Carcache de Blanco Djaja D Soejarto Steven M Swanson A Douglas Kinghorn
Affiliations

Affiliation

  • 1 Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, Center for Biostatistics, The Ohio State University, Columbus, Ohio 43210, United States.
Abstract

Bioassay-guided fractionation was conducted on a chloroform-soluble extract of the aerial parts of Piper sarmentosum collected in Vietnam, monitored by a mitochondrial transmembrane potential assay using HT-29 human colon Cancer cells. This led to the isolation of four new C-benzylated dihydroflavones, sarmentosumins A-D (1-4), as well as 14 known compounds. The structures of the new compounds were elucidated on the basis of spectroscopic data interpretation. Among these compounds, 1-4 as well as five known C-benzylated dihydroflavones (5-9) and a piperamide, pipercallosine (11), were found to induce Apoptosis in HT-29 cells by moderately reducing the mitochondrial transmembrane potential (ΔΨm), with ED50 values ranging from 1.6 to 13.6 μM. Furthermore, 7-methoxydichamanetin (8) and pinocembrin (10) exhibited Proteasome inhibitory activities in a human 20S Proteasome bioassay with IC50 values of 3.45±0.18 and 2.87±0.26 μM, respectively. This is the first time that C-benzylated dihydroflavones have been reported to demonstrate an apoptotic effect associated with disruption of the mitochondrial transmembrane potential.

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