Análise proteômica de extratos de arilos de Strelitzia reginae

Abstract

Strelitzia reginae is an ornamental species known as the bird-of-paradise, whose seeds bear orange arils composed of long and dense filaments. These structures are notable for their vibrant coloration, associated with the presence of bilirubin, and for their potential as a source of bioactive compounds. Morpho-anatomical analysis showed oval black seeds with arils arranged radially from a point of insertion. Histologically, the cells exhibited well-defined walls and intense staining with Sudan III, confirming a high lipid content in the tissue. Scanning electron microscopy revealed flat, smooth, and intertwined fibers with a thicker and more compact base. Elemental analysis by EDS indicated a predominance of carbon (69.23% by weight) and oxygen (30.77%), consistent with cellulosic/lipidic structures, with no nitrogen detected. The extract obtained with SDS displayed an intense orange coloration and absorbance peaks at 300 nm and between 400–500 nm, suggesting the presence of proteins and pigments. Protein quantification revealed 2322.12 μg/mL in the crude extract and 839 μg/mL in the precipitate, corresponding to 36.1% recovery. In SDS-PAGE, all samples exhibited a single protein band (~11.74 kDa), suggesting high purity. Bilirubin analysis showed peaks at ~270 and ~450 nm, confirmed by thin-layer chromatography (Rf = 0.7333). It is concluded that the arils of S. reginae combine pigments (bilirubin) and low molecular weight proteins associated with high lipid concentration, features that support their potential for applications in the cosmetic, food, and pharmaceutical industries.