Identification of bioactive ingredients of heath forest’s sedges species as potential natural poison

Heath forests, also called kerangas forests, have a different composition and structure compared to the adjoining dipterocarp forests. They are found throughout the tropic regions and grow well in nutrient-poor sandy soil. Hence, there is a need to carry out a comprehensive analysis of the constituent composition of the plant species growing in these forests as it would help the researchers to determine the complete potential of every species. In this study, the researchers have attempted to analyze the functional groups of the compounds present in the various sedge plant species present in the heath forests, such as Lepironia articulata, Dapsilanthus disjunctus and Eleocharis ochrostachys. For this purpose, they used the FT-IR analysis technique for determining the functional groups at absorbance values ranging between 400 and 4000 cm-1. Then, they identified the phenolic compounds and individual phenolic acids with the help of a High-Performance Liquid Chromatography technique coupled with the photo Diode Array Detector (HPLC-DAD). In the past, the sedges were recognized for their valuable traditional properties as they contained several bioactive compounds. In this paper, the researchers extracted the water-soluble compounds from the sedge species using an alkaline technique, where they used sodium hydroxide (NaOH) for extraction of bioactive compounds for 12h in the oven at 60°C, followed by an acidic treatment using hydrochloric acid (HCl, pH 2). Thereafter, they re-extracted the supernatant using different types of solvents. The results of these experiments indicated that the sedge species contained 5 major functional groups, i.e., aliphatic ethers (1050-1150 cmˉ¹), alcohols (1200 cmˉ¹), aromatic hydrocarbon (1700-2000 cmˉ¹), aliphatic ketones (1705-1725 cmˉ¹) and aliphatic hydrocarbons (2950-2975 cmˉ¹). The researchers characterized the phenolic compounds present in the sedge species based on their retention time and then compared the UV data with the different standards that were used. It was noted that Lepironia articulata contained the maximal Total Phenolic Content (984.63 ± 5.96 μg GAE/g DW) out of all the sedge species that were studied. Also, trans-p-Coumaric acid was seen to be the main phenolic compound in Eleocharis ochrostachys (645.75 μg/g dw) whereas Vanillic acid was the main phenolic compound present in Dapsilanthus disjunctus (138.72 μg/g dw) and Lepironia articulata (114.72 μg/g dw). The results indicated that Caffeic acid, Ferulic acid, 4-Hydroxybenzoic acid, Vanillic acid and trans-p-Coumaric acid were present in high concentrations in the sedge species. Out of these compounds, trans-p-Coumaric was the main phenolic compound that was present in the sedge plant extracts. In this study, the researchers have described the uses of the FT-IR and HPLC analyses and also attempted to garner the interest of the researchers in the field of natural plant analysis