Antioxidant norbergenin derivatives from the leaves of Diospyros gilletii De Wild (Ebenaceae). (April 2020)

• Record Type: Journal Article
• Authors: Jouwa Tameye, Nathalie S.; Mvot Akak, Carine; Mouthé Happi, Gervais; Frese, Marcel; Stammler, Hans-Georg; Neumann, Beate; Ndjakou Lenta, Bruno; Sewald, Norbert; Nkengfack, Augustin E.
• Is Part Of: Phytochemistry letters. Volume 36(2020)
• Page Start: 63
• Page End: 67
• Publication Date: 2020-04
• Subjects: Diospyros gilletii -- Ebenaceae -- Norbergenin -- Antioxidant -- X-ray crystal structure; Botanical chemistry -- Periodicals; Chimie végétale -- Périodiques; 572.205
• DOI: 10.1016/j.phytol.2020.01.012
• Languages: English
• ISSNs: 1874-3900

Abstract

Graphical abstract: Highlights: Two new norbergenin derivatives were isolated from the leaves of Diospyros gilletii De Wild. Their structures were established based on spectrometric and spectroscopic techniques (HRMS and 1D/2D-NMR). The norbergenin derivatives exhibited antioxidant properties with IC50 values ranging from 8.2 μg/ml to 41.6 μg/ml. Abstract: Two new norbergenin derivatives, 4- O - p -hydroxybenzoylnorbergenin (1 ) and 11- O -( E )-cinnamoylnorbergenin (2 ), were isolated from the leaves of Diospyros gilletii De Wild along with nine known compounds, including norbergenin (3 ), 4- O -galloylnorbergenin (4 ), betulin (5 ), betulinic acid (6 ), lupeol (7 ), ursolic acid (8 ), corosolic acid (9 ), β-sitosterol (10 ) and quercitol (11 ). Their structures were elucidated from the analysis of their 1D and 2D 1 H and 13 C NMR spectral data in conjunction with mass spectrometry. Single-crystal X-ray diffraction technique unambiguously established the structure of compound (1 ). The antimicrobial properties of the eleven compounds isolated were investigated as well as the antioxidant activity of the norbergenin derivatives (1–4 ). The results obtained showed that none of those compounds displayed antimicrobial activity at 0.5 μg/ml whereas norbergenin derivatives exhibited noteworthy antioxidant property with IC50 values ranging from 8.2 μg/ml to 41.6 μg/ml.