The Journal of Phytopharmacology 2025; 14(3):180-187 DOI:10.31254/phyto.2025.14309

Research Article

Phytochemical analyses of extracts of the Peltophorum pterocarpum root bark and their anti-tyrosinase activities

Fatogun Oluwayomi Patrick¹ , Muluh Emmanuel Khan² , Abdullahi Shehu¹ , Ekundayo Timi Areh³

Fatogun Oluwayomi Patrick,Muluh Emmanuel Khan,Abdullahi Shehu,Ekundayo Timi Areh

1. Department of Chemistry, Federal University Lokoja, Kogi State, Nigeria
2. Department of Chemistry, Federal University Lokoja, Kogi State, Nigeria
3. Department of Chemistry, Confluence University of Science and Technology, Osara, Kogi State, Nigeria

*Author to whom correspondence should be addressed.

Received: 31st May, 2025 / Accepted: 10th July, 2025 / Published : 31st July, 2025

Abstract

Background: Hyperpigmentation and other melanin-related disorders have driven interest in natural tyrosinase inhibitors. Peltophorum pterocarpum, a medicinal plant traditionally used for various ailments, presents potential for dermatological applications. However, scientific studies validating its anti-tyrosinase activity remain limited. Objective: This study aimed to investigate the phytochemical constituents of the chloroform extract of Peltophorum pterocarpum root bark and evaluate its anti-tyrosinase potential, thereby supporting its ethnopharmacological relevance. Materials and Methods: A total of 800 g of Peltophorum pterocarpum root bark was collected, defatted with n-hexane, and extracted using methanol. The methanol extract was partitioned with chloroform and water. The chloroform extract was subjected to phytochemical screening and analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). The anti-tyrosinase activity was evaluated in vitro using the dopachrome method, with L-DOPA as the substrate and kojic acid as a standard reference inhibitor. Results: Preliminary phytochemical analysis revealed the presence of flavonoids, alkaloids, tannins, cardiac glycosides, and saponins in both chloroform and aqueous extracts. GC-MS profiling of the chloroform extract identified thirty-three (33) bioactive compounds, comprising 98.88% of the total extract. Major constituents included n-hexadecanoic acid (17.13%), 2-methoxy-4-vinylphenol (11.20%), phytol (5.65%), and various methyl esters of fatty acids. The chloroform extract exhibited significant anti-tyrosinase activity with an IC?? value of 2.35 ± 1.07 µg/mL, which was closely comparable to kojic acid (IC?? = 2.84 ± 0.38 µg/mL) and more potent than the aqueous extract (IC?? = 3.52 ± 1.19 µg/mL). Conclusion: The chloroform extract of Peltophorum pterocarpum root bark contains a rich profile of phytochemicals with strong tyrosinase inhibitory activity. These findings support its potential application in managing hyperpigmentation and related skin conditions. The results also provide a scientific basis for the traditional use of this plant in dermatological therapy and natural cosmetic formulation.