Correlation of FT-IR fingerprint and α-glucosidase inhibitory activity of Salak (Salacca zalacca) fruit extracts utilizing orthogonal partial least square

• Main Authors: Saleh, Mohammed S M, Siddiqui, Mohammad Jamshed Ahmad, Mat So'ad, Siti Zaiton, Roheem, Fatimah, Bes-Bes, Salima Saidi, Khatib, Alfi
• Format: Article
• Language: English; English; English
• Published: MDPI 2018
• Subjects: QD Chemistry
• Online Access: http://irep.iium.edu.my/64259/7/64259_Correlation%20of%20FT-IR%20fingerprint%20and%20%CE%B1-glucosidase%20inhibitory%20activity%20of%20Salak%20%28Salacca%20zalacca%29_article.pdf; http://irep.iium.edu.my/64259/13/64259_Correlation%20of%20FT-IR%20fingerprint%20and%20%CE%B1-glucosidase%20inhibitory%20activity%20of%20salak%20%28salacca%20zalacca%29%20fruit%20extracts%20utilizing%20orthogonal%20partial%20least%20square_WOS.pdf; http://irep.iium.edu.my/64259/18/64259_Correlation%20of%20FT-IR%20fingerprint%20and%20%CE%B1-glucosidase%20inhibitory%20activity%20of%20salak_SCOPUS.pdf; http://irep.iium.edu.my/64259/; http://www.mdpi.com/1420-3049/23/6/1434/htm

Salak fruit (Salacca zalacca), commonly known as snake fruit, is used indigenously as food and for medicinal applications in Southeast Asia. This study was conducted to evaluate the α-glucosidase inhibitory activity of salak fruit extracts in correlation to its Fourier transform infrared spectroscopy (FT-IR) fingerprint, utilizing orthogonal partial least square. This calibration model was applied to develop a rapid analytical method tool for quality control of this fruit. A total of 36 extracts prepared with different solvent ratios of ethanol–water (100, 80, 60, 40.20, 0% v/v) and their α-glucosidase inhibitory activities determined. The FT-IR spectra of ethanol–water extracts measured in the region of 400 and 4000 cm−1 at a resolution of 4 cm−1. Multivariate analysis with a combination of orthogonal partial least-squares (OPLS) algorithm was used to correlate the bioactivity of the samples with the FT-IR spectral data. The OPLS biplot model identified several functional groups (C–H, C=O, C–N, N–H, C–O, and C=C) which actively induced α-glucosidase inhibitory activity.