Chemical constituents, the stereochemistry of 3-hydroxy furonaphthoquinones from the root bark of Newbouldia laevis Seem (Bignoniaceae), and screening against Onchocerca ochengi parasites

Autor: Salome Y. Ghansenyuy, Herve L. Ketsemen, Kenneth Oben Eyong, Gabriel N. Folefoc
Rok vydání: 2014
Předmět:
Zdroj: Medicinal Chemistry Research. 24:965-969
ISSN: 1554-8120
1054-2523
Popis: Through bioassay-guided fractionation, 13 compounds (1–13) were isolated from the CH2Cl2/MeOH (1:1) extracts of the root bark of Newbouldialeavis and characterized mainly by NMR and X-ray spectroscopy. Among these, nine quinone derivatives (1–7, 12–13), one triterpeniod (8), and three steroids (9–11) were isolated. The stereochemistry of 3-hydroxy furonaphthoquinones isolated from this plant has been established for the first time as (2S,3R) on the basis of single X-ray crystal structure analysis and show marked 3JH,H deviations from the Karplus curve from 1H-NMR spectral analysis. The fractions together with three of the isolated compounds namely lapachol, 2-acetyl-naphtho [2,3-b]furan-4,9-dione, and 2-(1-hydroxyethyl)-2-acetyl-naphtho[2,3-b]furan-4,9-dione were screened against Onchocercaochengi parasites. Lapachol and 2-(1-hydroxyethyl)-2-acetyl-naphtho[2,3-b]furan-4,9-dione showed 100 % inhibition at a concentration of 5 μg/mL after 5 days.
Databáze: OpenAIRE