Tagousop, C.N., Tamokou, J., Feugap, L.D.T., Harakat, D., Voutquenne-Nazabadioko, L. and Ngnokam, D. (2021) New Hemisynthetic Oleanane Saponin with Antimicrobial Activities. Advances in Biological Chemistry, 11, 1-11.
https://doi.org/10.4236/abc.2021.111001

has been cited by the following article:

• TITLE: Chemical Constituents from Ethyl Acetate Extract of Graptophyllum glandulosum Turrill and New Semi-Synthetic Derivative with Antimicrobial Activities

  AUTHORS: Cyrille Ngoufack Tagousop, Donald Léonel Feugap Tsamo, Arnaud Joseph Nguetse Dongmo, Dominique Harakat, Laurence Voutquenne-Nazabadioko, Jean-de-Dieu Tamokou, David Ngnokam

  KEYWORDS: Graptophyllum glandulosum Turrill, Lupeol, Oxidation Reaction, Antimicrobial Activities

  JOURNAL NAME: Advances in Biological Chemistry, Vol.15 No.1, February 18, 2025

  ABSTRACT: From the ethyl acetate extract of the medicinal plant Graptophyllum glandulosum Turrill, five known compounds: Lupeol (1), Oleanolic acid (2), Chrysoeriol (3), N-methyl-isonicotinamide (4) and β-sitosterol 3-O-β-D-glucopyranoside (5) were isolated. In addition, oxidation reactions carried out on lupeol (1) yielded two semi-synthetic compounds, including a previously unreported: (20R)-formyloxy-29-nor-lupan-3-one (1b) and one other well-known Lupenone (1a). The structures of natural and semi-synthetic compounds were determined by analysis of 1D-(1H, 13C), 2D-(COSY, HSQC and HMBC) NMR data in conjunction with mass spectrometry (TOFESIMS and HR-TOFESIMS) and by comparison with the reported data. The evaluation of antimicrobial activities of substrate (1) as well as semi-synthetic derivatives (1a and 1b) using broth microdilution method showed that compound 1b was the most active (16 ≤ MIC ≤ 32 μg/mL) against Escherichia coli, Staphylococcus aureus and Candida albicans compared to the starting material 1 (16 ≤ MIC ≤ 64 μg/mL) and derivative 1a (32 ≤ MIC ≤ 64 μg/mL).