Chemical Composition and Ursolic Acid Quantification in Plumeria Rubra along the Syrian Coast

Plumeria rubra is an ornamental plant cultivated in several countries, including Syria. This plant is also used in traditional Indian medicine to treat diarrhea, asthma, bronchitis, and cough. This study aims to investigate the active components in the flower oil and quantify ursolic acid in different parts of P. rubra found along the Syrian coast. Samples were collected from various parts of P. rubra plants along the Syrian coast. Flower oil was extracted and analyzed using gas chromatography-mass spectrometry (GC-MS). Ursolic acid was detected and quantified in the methanolic extracts of different plant parts using high-performance thin-layer chromatography (HPTLC). Then, free radical scavenging was determined in the leaves’ methanolic extract. The results revealed the presence of 30 compounds in the flower essential oil, with the highest percentage belonging to Nerolidalol at 14.11%, followed by Linalol at 13.86% and Geraniol at 10.24%. The study showed the presence of ursolic acid in leaves (0.029%), but the flowers and stem bark were not detected. In interaction with diphenyl picryl hydroxyl, the inhibitory concentrations of half of free radicals were 300µg/mL. These findings contribute to understanding the chemical characteristics of P. rubra and potential medical uses.