Structural Elucidation of Bioactive Constituents of Justicia carnea Leaf Using Gas Chromatography-Mass Spectroscopy Technique

Abstract

Aims: This investigation focused on the bioactive constituents of Justicia carnea aqueous leaf extract using Gas Chromatography-Mass Spectroscopy (GC-MS) analysis. Study Design: Fresh leaves of Justicia carnea were collected from their natural habitat at Rumuogba, Obio/Akpor L. G. A. Rivers State. The plant materials were identified and authenticated by a plant taxonomist at the Department of Plant Science, University of Port Harcourt, Nigeria, Dr Ekeke Chimezie and given the Voucher number UPH/V/1448. Place and Duration of Study: The study was conducted in the Faculty of Sciences Laboratory, University of Port Harcourt, Choba, Rivers state, Nigeria. Between December 2024 to April 2025. Methodology: Fresh leaves of Justicia carnea were collected, washed thoroughly with water to remove any dirt or impurity and air dried at room temperature for 21 days. The dried leaves were then ground into a fine powder using a blender after which 1g of sample was weighed and transferred in a test tube and 15ml water and 10ml of 50% W/V potassium hydroxide was added. 0.4g of sample was weighed and transferred in a test tube and 15ml of water was added. The test tube was allowed to react in a water bath at 600C for 60mins. After the reaction time, the reaction product contained in the test tube was transferred to a separatory funnel for the GC-MS analyses of both phytochemicals and bioactive constituents. Results: Analysis of aqueous leaf extract of Justicia carnea revealed the presence of a cassette of phytochemicals that possess pharmacological benefits. Spartein, Epihedrine, Narigenin, Phytate, Kaempferol and Dihydrocytisine were observed as the most abundant secondary metabolites of J. carnea leaf aqueous extract. GC-MS analysis result showed 29 volatile bioactive compounds in the aqueous extract of Justicia carnea leaf. Among the identified compounds of aqueous extract of J. carnea were 1,2-Benzenedicarboxylic acid and Ethyltriethylene glycol, which has been reported to possess antioxidant, antimicrobial and positive anti-cancer activity. The compound Bis (2-ethylhexyl) phthalate, a member of the class of phthalates was identified in the extract. The compound is a plasticizer which play a role as a precursor of polyvinyl chloride. Bis(2-ethylhexyl) phthalate and its metabolites exhibit acute and chronic toxicities which includes endocrine disruption and testicular toxicity. Conclusion: The current investigation has identified significant bioactive compounds in the aqueous extract of Justicia carnea leaf. The presence of these phytochemical and bioactive compounds could be a pointer to its applicability as a safer alternative therapy in the management of diseases.