Fourier transform infrared (FTIR) and Raman spectroscopy are complementary techniques, typically called vibrational spectroscopy. Both techniques allow simple, rapid, non-destructive, specific, providing fingerprint spectra, and real-time analytical

Curculigo orchioides and C. latifolia 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 Curculigo 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 C. latifolia 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.

Guazuma ulmifolia is one of the common tropical plants that has long been used as a traditional medicine to reduce body weight as slimming herbs and to lower the cholesterol in the body. The leaves of G. ulmifolia contain phenolics compound such as flavonoids and tannin that contributes to its biological activities. In this research, we determined the content of total phenolics, flavonoids, tannins, antioxidant activity, and FTIR spectrum profile from four extracts of G. ulmifolia leaves. The extraction method used in this study was stepwise maceration with different solvents n-hexane, ethyl acetate, ethanol, and water. The content of total phenolics and flavonoids were found high in ethanol extract of G. ulmifolia leaves with 35.42 and 44.85 mg QE/g dry powder, respectively. The highest content of total tannins was obtained in ethyl acetate extract of G. ulmifolia leaves as 0.55%. Antioxidant activity from four extracts of G. ulmifolia leaves was measured using DPPH, CUPRAC, and reducing power method. The highest antioxidant activity for DPPH and CUPRAC method was obtained in ethyl acetate extract with the antioxidant capacity as 55.47 and 98.17 µmol trolox/g dry powder, respectively. While using reducing power assay gives the capacity 176.75 µmol trolox/g dry powder in the water extract. The pattern of FTIR spectra from four extracts of G. ulmifolia leaves gives the distinct characteristics of each spectrum profile. Principal component analysis using FTIR spectrum shows good clustering for each extract with 94% data variability (PC1= 77% and PC2 = 17%). It can be concluded that each extract of G. ulmifolia leaves gives a distinct phytochemical profile (phenolics content, flavonoids, tannins, and FTIR spectrum) that contributes to the antioxidant activity. This antioxidant activity mainly influenced by the concentration of phenolic compounds, which is known to have antioxidant properties.

A cataract is a condition that causes 17 million people to experience blindness and is the most significant cause of vision loss, around 47.9%. The formation of cataracts is linked to both the production of reactive oxygen species (ROS) and the reduction of endogenous antioxidants. ROS are highly reactive molecules produced by oxygen. Examples of ROS include peroxides, super-oxides, and hydroxyl radicals. ROS are produced in cellular responses to xenobiotics and bacterial invasion and during mitochondrial oxidative metabolism. Excessive ROS can trigger oxidative stress that initiates the progression of eye lens opacities. ROS and other free radicals are highly reactive molecules because their outer orbitals have one or more unpaired electrons and can be neutralized by electron-donating compounds, such as antioxidants. Examples of natural antioxidant compounds are vitamin C, vitamin E, and beta-carotene. Numerous studies have demonstrated that plants contain numerous antioxidant compounds that can be used as cataract preventatives or inhibitors. Natural antioxidant extracts for cataract therapy may be investigated further in light of these findings, which show that consuming a sufficient amount of antioxidant-rich plants is an excellent approach to cataract prevention. Several other natural compounds also prevent cataracts by inhibiting aldose reductase and preventing apoptosis of the eye lens.