HPLC and FT-IR Analyses of Nigerian Alligator Pepper (Aframomum melegueta) Methanol Seed Extract

Abstract

Traditional knowledge had been established to successfully preserve and restore biodiversity across the continent since it accommodates indigenous herbalism. Traditional medicine had been adopted in Nigeria prior to the colonialism era. The study examined the phytochemical constituents in methanolic seed extract of alligator pepper (Aframomum melegueta) grown in Nigeria by Fourier Transform Infrared Spectrophotometer (FT-IR) and High Performance Liquid Chromatography (HPLC) analyses. Aframomum melegueta seeds were extracted with 70% methanol at room temperature for 48 h. The functional groups in aqueous methanolic seed extract were determined using FT-IR spectroscopic method while the bioactive compounds were determined using HPLC. The FT-IR result established the presence of N-H, C=N, C=C, C-O and O-H functional groups in the methanolic extract. The HPLC analysis of the methanolic extract identified ten compounds. The major components were farnesyl (37.11%), lycopene (34.15%), dihydrocapsiacin (9.55%), capsaicin (8.40%) and delphenidin (7.91%). Other compounds present in the extract at low levels were phytoene (0.74%), β-lonone (0.57%), limonene (0.56%), 6-methoxymellen (0.56%) and trans-beta-ocimene (0.45%). In essence, this study established the ethnobotanical use of Aframomum melegueta as functional food ingredient.