Variation in essential oil composition of Hypericum scabrum L. and H. scabroides N. Robson & Poulter (Hypericaceae) aerial parts during its phenological cycle

Abstract

The quantitative and qualitative variations of the essential oils from the aerial parts of Hypericum scabrum L. and H. scabroides N. Robson & Poulter from Turkey were examined. Plant materials were harvested at different phenological stages (i.e. vegetative, flowering and fruiting stages) of the life cycle of both Hypericum species. Analysis by GC and GC—MS of the essential oils enabled us to identify 67 of the whole components. The main components were nonane, alpha-pinene, beta-pinene, beta-myrcene, d—limonene and germacrene—D in H. scabrum oil and, as additional, sabinene, delta 3-carene were found as the main constituents in H. scabroides. However, monoterpenoids composition and partly sesquiterpenoids levels varied with the phenological cycle and the number of compounds detected increased during ontogenesis in particular at fruiting stage in both Hypericum species.

Résumé

Les variations quantitatives et qualitatives des huiles essentielles des parties aériennes de Hypericum scabrum L. et H. scabroides N. Robson & Poulter de Turquie sont étudiées. Le matériel végétal fut récolté à divers stades phénologiques de ces deux taxons. Les analyses par GC et GC—MS ont permis d'identifier 67 composés majeurs, les principaux étant: nonane, alpha-pinène, beta-pinène, beta-myrcène, d-limonène et germacrene—D chez H. scabrum; en outre, des sabinène et delta 3-carène furent trouvés chez H. scabroides. Cependant, la composition en monoterpénoïdes et partiellement en sesquiter- pénoïdes varie au cours du cycle phénologique et le nombre de composés détectés augmente durant l'ontogénèse, en particulier au stade fruit, chez les deux espèces.

Key words:

• Hypericum scabrum
• H. scabroides
• Hypericaceae
• essential oils
• phenological cycle

Mots clés:

• Hypericum scabrum
• H. scabroides
• Hypericaceae
• huiles essentielles
• cycle phénologique