Untargeted Metabolomics Analysis Using FTIR and UHPLC-Q-Orbitrap HRMS of Two <i>Curculigo</i> Species and Evaluation of their Antioxidant and α-Glucosidase Inhibitory Activities

• Main Authors: Abdul Halim Umar, Diah Ratnadewi, Mohamad Rafi, Yohana Caecilia Sulistyaningsih
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: Metabolites
• Subjects: antioxidant activity; α-glucosidase inhibitor; <i>Curculigo</i> spp.; FTIR; metabolomics; UHPLC-Q-Orbitrap HRMS
• Online Access: https://www.mdpi.com/2218-1989/11/1/42

<i>Curculigo orchioides </i>and <i>C. latifolia</i> have been used as traditional medicines such as antidiabetic and anticancer. This study measured the total phenolics and flavonoid contents as well as analyzed the functional groups and chemical compounds using Fourier-transform infrared (FTIR) spectra and UHPLC-Q-Orbitrap-HRMS profiling for the discrimination of plant parts, geographical origin, and compounds that presumably have a significant contribution as antioxidant and α-glucosidase inhibitors on both plants. The total phenolics and flavonoids contents in <i>Curculigo</i> species varied from 142.09 to 452.47 mg gallic acid equivalent (GAE/g) and from 0.82 to 5.44 mg quercetin equivalent (QE/g), respectively. The lowest IC₅₀ for antioxidant and α-glucosidase inhibitory activities is presented by <i>C. latifolia</i> from a higher altitude region. Principal component analysis (PCA) from FTIR and UHPLC-Q-Orbitrap-HRMS data could discriminate the plant parts and geographical origin. Partial least squares (PLS) analysis has identified several functional groups, such as O–H, C–H, C=O, C–C, C–O, and chemical compounds, unknown-185 and unknown-85, that are most likely to contribute to the antioxidant and α-glucosidase inhibitory activities.