Examining the Phytochemicals in Leaves of Pterocarpus Species in Nigeria

Abstract

Aim of study: The study carried out a phytochemical analysis for tannin, flavonoid, saponins, phenol, alkaloids, terpenoids and anti-nutrient compounds – Oxalate and phytate. Materials and method: These were carried out on powdered leaf methanolic extract of five endemic Pterocarpus species viz; P. osun, P. mildbraedii, P. soyauxii, P. erinaceus and P. santaloides using standard procedure. Main results: Both qualitative and quantitative analysis indicated that the leaves sample contained similar phytochemical/secondary metabolites with variation in mean concentration value (mg/100g); Tannins (1.06 - 2.89 mg/100g); flavonoid (2.17-5.46 mg/100g); saponins (2.78¬¬-9.38 mg/100g), phenol (1.13-2.56 mg/100g), Alkaloids (3.06-6.28 mg/100g), Terpenoids (1.32-2.46 mg/100g); Oxalate (0.34-1.14 mg/100g) and Phytate (0.16-0.46 mg/100g). These differed significantly (p≥0.05) amongst the examined taxa. Research highlights: The highest concentration of saponins, phenol, tannin and phytate was found in leaves of P. mildbraedii while P. erinaceus contained the highest concentration of flavonoid, alkaloid and oxalate. However, terpenoid was found highest in leaves of P. soyauxii. Generally, the studied Pterocarpus species contained low level of anti-nutrient compound making them safe for consumption. Thus, the study revealed the rich phytochemical content in leaves of this genus to justify their ethnobotanical usage for leafy vegetable and ethnomedicine. Furthermore, findings provided additional information in support of the taxonomic placement and classification of members of the genus on the basis of their phytochemistry.