%0 Journal Article
%T Chemical Constituents from Ethyl Acetate Extract of <i>Graptophyllum</i> <i>glandulosum</i> Turrill and New Semi-Synthetic Derivative with Antimicrobial Activities
%A Cyrille Ngoufack Tagousop
%A Donald L&#233
%A onel Feugap Tsamo
%A Arnaud Joseph Nguetse Dongmo
%A Dominique Harakat
%A Laurence Voutquenne-Nazabadioko
%A Jean-de-Dieu Tamokou
%A David Ngnokam
%J Advances in Biological Chemistry
%P 18-30
%@ 2162-2191
%D 2025
%I Scientific Research Publishing
%R 10.4236/abc.2025.151002
%X From the ethyl acetate extract of the medicinal plant <i>Graptophyllum</i> <i>glandulosum</i> Turrill, five known compounds: Lupeol (<b>1</b>), Oleanolic acid (<b>2</b>), Chrysoeriol (<b>3</b>), <i>N</i>-methyl-isonicotinamide (<b>4</b>) and <i>&#946;</i>-sitosterol 3-<i>O</i>-<i>&#946;</i>-<i>D</i>-glucopyranoside (<b>5</b>) were isolated. In addition, oxidation reactions carried out on lupeol (<b>1</b>) yielded two semi-synthetic compounds, including a previously unreported: (20<i>R</i>)-formyloxy-29-<i>nor-</i>lupan-3-one (<b>1b</b>) and one other well-known Lupenone (<b>1a</b>). The structures of natural and semi-synthetic compounds were determined by analysis of 1D-(<sup>1</sup>H, <sup>13</sup>C), 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 (<b>1</b>) as well as semi-synthetic derivatives (<b>1a</b> and <b>1b</b>) using broth microdilution method showed that compound <b>1b</b> was the most active (16 &#8804; MIC &#8804; 32 &#956;g/mL) against <i>Escherichia coli</i>, <i>Staphylococcus aureus</i> and <i>Candida albicans</i> compared to the starting material <b>1</b> (16 &#8804; MIC &#8804; 64 &#956;g/mL) and derivative <b>1a</b> (32 &#8804; MIC &#8804; 64 &#956;g/mL).
%K <i>Graptophyllum</i> <i>glandulosum</i> Turrill
%K Lupeol
%K Oxidation Reaction
%K Antimicrobial Activities
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=140640