Comparison of chemical compositions in wood and bark of Persian silk tree (Albizia julibrissin Durazz.)

Abstract

ABSTRACT This research was conducted to identify and compare the chemical compositions in Persian silk tree (Albizia julibrissin Durazz.) from different parts of wood and bark, using Fourier Transform Infrared (FTIR) Spectroscopy, gas and liquid chromatography coupled to mass spectrometry (GC-MS, LC-MS), and elemental analysis. FTIR analysis showed significant differences in the chemical structure of bark and wood at peaks that belong to the cellulose and hemicelluloses. According to the results, the C-O-C asymmetric stretch vibration in cellulose and hemicelluloses peak of Persian silk tree was lower in the bark and ѵC=O in quinone or p-quinone peak was higher in the bark. The results of GC-MS showed 12 chemical constituents in the bark and 43 in the wood, respectively. Among these, hexadecanoic acid and inositol were in common. According to the LC-MS analyses, bark samples were rich in lignan compositions and triterpenoid saponins, whereas wood was poor in these compositions. Altogether 61 compositions have been tentatively identified and described from bark and wood tissues; many of them were identified for the first time. Energy-dispersive X-ray (EDX) spectrometry illustrated that the bark contained iron and aluminium, sodium, phosphorus, sulphur and chlorine, while these elements did not exist in wood.