TY  - EJOU
AU  - Nga, Liliane 
AU  - Ndiwe, Benoit 
AU  - Biwolé, Achille Bernard 
AU  - Pizzi, Antonio 
AU  - Biwole, Jean Jalin Eyinga 
AU  - Mfomo, Joseph Zobo 

TI  - Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF)-Mass Spectrometry and <sup>13</sup>C-NMR-Identified New Compounds in <i>Paraberlinia bifoliolata (Ekop-Beli)</i> Bark Tannins
T2  - Journal of Renewable Materials

PY  - 2024
VL  - 12
IS  - 3
SN  - 2164-6341

AB  - Extracts of plant origin, particularly tannins, are attracting growing interest for the sustainable development of materials in the industrial sector. The discovery of new tannins is therefore necessary. The aim of this work was to contribute to the understanding of the properties of <i>Paraberlinia bifoliolata</i> tannin by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectroscopy MALDI-TOF/MS and Carbon 13 Nuclear Magnetic Resonance (<sup>13</sup>C NMR). The chemical composition of tannin extracted from <i>Paraberlinia bifoliolata</i> bark was determined, as was the mechanical strength of the resin hardened with <i>Acacia nilotica</i> extracts. Yield by successive water extraction was 35%. MALDI-TOF/MS analysis revealed the presence of three new compounds in this tannin, previously unknown in this family of extracts. These are 3-hydroxyproline acid, N-methyl-4-hydroxypipecolic acid and N-methyl-5-dihydroxypipecolic acid. The identification of the above molecules means that this tannin can be used for industrial applications, as a resin in the manufacture of particleboard and in the formulation of green corrosion inhibitors. This information is reinforced by <sup>13</sup>C NMR spectrometry, which indicates the presence of several polyflavonoid units, confirming the condensed nature of the tannin. Thermomechanical analysis of the resin formed by the purified tannin of <i>Paraberlinia bifoliolata</i> to which a vegetal biohardener has been added provided a Modulus of Elasticity (MOE) value of 4840 MPa at 150°C, confirming its possible use as a binder resin in the manufacture of wood panels as well as for the formulation of a corrosion inhibitor.
KW  - Tannin; <i>Paraberlinia bifoliolata</i>; Central African wood species; MALDI-TOF/MS; <sup>13</sup>C NMR; bark extracts; thermomechanical behaviour; wood-binder

DO  - 10.32604/jrm.2023.046568