Volatile Constituents of Four Hypericum Species Native to Greece

The genus Hypericum (Hypericaceae), comprising approximately 500 taxa classified into 22 sections, has remained largely unexplored in terms of its chemical composition, with existing studies on a limited number of species revealing significant chemical polymorphism. This study investigates the volatile profiles of four Hypericum species (H. rumeliacum subsp. apollinis, H. vesiculosum, H. delphicum, and H. olympicum) through GC-MS analysis. Hypericum rumeliacum subsp. apollinis, collected from Mt. Parnassos, exhibited a high abundance of sesquiterpenes hydrocarbons (32.5%) and oxygenated sesquiterpenes (29.7%). Hypericum vesiculosum collected from Mt. Chelmos was rich in oxygenated monoterpenes (33.5%), followed by benzyl derivatives (25.9%). Hypericum delphicum and H. olympicum, collected from the island of Evvia, showed a predominance of alkanes (35.8%) and oxygenated sesquiterpenes (31.9%) in H. delphicum and sesquiterpenes hydrocarbons (41.2%) and oxygenated sesquiterpenes (29.9%) in H. olympicum. Our findings provide new data on the volatile profile of H. vesiculosum and enhance existing information on other species, highlighting notable chemical diversity within the genus Hypericum.