Akçura, Sevim2025-01-272025-01-2720230305-1978https://doi.org/10.1016/j.bse.2023.104712https://hdl.handle.net/20.500.12428/12705Pittosporum tobira L. (P. tobira) leaves were tested for essential oil and chemical composition monthly for 12 months. Leaves had 0.12–0.25% essential oil depending on the month. January, December, and February leaves had the most essential oil (0.25–0.23%). Low temperatures increased volatile oil content, while high temperatures decreased it. P. tobira leaf volatile oil had 45 components. Sesquiterpenes were the most abundant terpene group (34.93%), with the highest concentrations in May (38.75%) and the lowest in January (30.50%). Alkanes followed (22.1%). This group's highest values (23.81%) were again found in May. Oxygenated sesquiterpenes had the highest September values (21.32%). When analyzed separately, viridiflorol (13.34%), nonane (11.48%), undecane (9.99%), ?-pinene (6.59%), and ?-cubebene (6.02%) were the main components. The volatile oil of P. tobira leaves had the highest viridiflorol (18.64%) in October and the highest nonane (13.79%) in February and December. June had the highest ?-pinene (8.68%) and ?-cubebene (7.88%) ratios. Thus, Mediterranean-grown P. tobira leaves had different volatile oil and volatile components each month. This plant's leaves should be studied in months with the highest volatile components. © 2023eninfo:eu-repo/semantics/closedAccessBiplot; Leaf volatile oil; Monthly variation; Pittosporum tobira; Volatile componentsArticle11010.1016/j.bse.2023.1047122-s2.0-85169833633Q2