Characterization of Functional Groups of Bioactive Compounds Extracted from Rhizophora apiculata Mangrove Fruit

Functional Groups of Bioactive Compounds in R. apiculata

Abstract

The mangrove fruit Rhizophora apiculata is known to contain various potential bioactive compounds, but information about the characterization of its chemical functional groups is still limited. This study aimed to identify the main functional groups in R. apiculata fruit extracts using Fourier Transform Infrared Spectroscopy (FTIR). The analysis was carried out using two types of extracts, namely ethanol extract and base–acid extract (NaOH + CH₃COOH), using a Bruker Alpha II ATR-based FTIR instrument in the range of 4,000–600 cm-1 with a resolution of 4 cm-1 and 32 scans. The FTIR spectrum of the ethanol extract showed dominant absorption bands of O–H (3100–2500 cm-1), C=O (1,725–1,700 cm-1), and C–O (1,320–1,211 cm-1) indicating the presence of carboxylic acids, esters, and ketones. In the base–acid extract, the spectrum profile became more complex with the detection of additional bands of N–H (3,360–3,100 cm-1) and amide II (1,570–1,515 cm-1), suggesting the presence of nitrogen-based compounds as well as the Si–O/Si–OH band (1,040–830 cm-1) from silica minerals. The differences in the spectral profiles indicate that the extraction method significantly affects the types of metabolites detected, with acid–base extracts being more effective at extracting polar compounds. These results reinforce the potential of R. apiculata fruit as a source of functional food materials rich in bioactive compounds, but further studies are still needed for definitive molecular identification.