Iidentifying the Peel Essential Oil Constituents in Three Lemon Cultivars Using GC-MS

Abstract This study was conducted at the College of Agriculture and Marshes, University of Thi-Qar, Department of Horticulture and Landscape design, in Thi Qar Governorate during the 2024-2025 season. The aim of the study was to identify the medically active compounds in the essential oil extracted from the peels of three lemon cultivars: the local sour lemon ( Citrus limon ), rough lemon, and Eureka lemon ( Citrus limon ‘Eureka’). The results revealed the presence of medically active compounds in the peel oil extracts, the most prominent of which was 3-Carene, with relative abundances of 4.21% in the local lemon, 3.56% in rough lemon, and 2.77% in Eureka lemon. The compound D-Limonene was also abundant, with relative concentrations of 29.97%, 14.00%, and 6.17% in the local, Eureka, and rough lemon cultivars, respectively. Linalool was also identified, with the highest relative abundance in the Eureka cultivar (2.76%), followed by the local lemon (1.62%) and rough lemon (1.15%). Additionally, Geraniol was detected at 2.41% in Eureka, 1.73% in rough lemon, and 1.55% in local lemon. The compound Oleic Acid was found at relative abundances of 2.19% in Eureka, 1.73% in rough lemon, and 0.49% in local lemon. The present study revealed that the peel oil extracts of the three lemon cultivars consist of a diverse array of secondary metabolites and medically active compounds, as well as novel substances that could be isolated, evaluated, and validated for their medical and biological activities, thereby offering potential use as plant-based therapeutic agents.