Identification of geographical origin of Lignosus samples using Fourier transform infrared and two-dimensional infrared correlation spectroscopy

• Published in: Journal of molecular structure 2014-07, Vol.1069, p.188-195
• Main Authors: Choong, Yew-Keong, Xu, Chang-Hua, Lan, Jin, Chen, Xiang-Dong, Jamal, Jamia Azdina
• Format: Article
• Language: English
• Subjects: 2DIR correlation spectroscopy; Correlation; Fourier transforms; FTIR; Infrared; Infrared spectroscopy; Lignosus spp. geographical origin; Mushrooms; Origins; Spectroscopy; Vibration
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2014.04.001

•A good example in analysing incomplete sample using 2DIR spectroscopy.•Sample (M26/08) origin determined by comparing with authenticated sample (M49/07, M23/08).•Spectrum of M26/08 at 1260–950cm−1 was 99.4% similar to M23/08.•M26/08 and M23/08 were more closely related than M49/07.•2DIR correlation technique increases resolution and simplifies overlapping bands. Lignosus spp. is a medicinal mushroom that has been used as a folk remedy for ‘clearing heat’, eliminating phlegm, ‘moistening the lungs’ and as an anti-breast cancer agent. The objective of this study was to identify the active chemical constituents of the mushroom limited number of sample by using Fourier transform infrared (FTIR) and two-dimensional correlation Fourier transform infrared spectroscopy (2DIR). The sample M26/08 was purchased from a Chinese medicine shop in Kuala Lumpur, while M49/07 and M23/08 were collected from Semenyih and Kuala Lipis respectively. The three samples have strong absorption peaks corresponding to the stretching vibration of conjugated carbonyl CO group. Both fresh sample M49/07 and M23/08 showed an identical peak of 1655cm−1, whereby M26/08 contained stretching vibration of 1648cm−1. The peaks from 1260cm−1 onwards were assignation of carbohydrate content including saccharides. Spectrum of M26/08 showed region from 1260cm−1 to 950cm−1 which was 99.4% similar to M23/08. The chemical constitutes of M26/08 and M23/08 were closely correlated (r=0.97), whereas the correlation coefficient of M26/08 and M49/07 was 0.94. The use of second derivative and 2DIR spectroscopy enhanced the distinct differences to a more significant level. Although the geographical origin of M26/08 was unknown, its origin was determined by comparing with M49/07 and M23/08. The visual and colorful 2DIR spectra provided dynamic structural information of the chemical components analyzed and demonstrated a powerful and useful approach using the spectroscopy of different samples.