Chemical profiling of Dracocephalum moldavica L. essential oils under varied fertilization regimes and storage durations of dried herb implications for phytochemical yield

Abstract

Dracocephalum moldavica L., commonly known as Dragonhead, is an herbaceous aromatic plant whose essential oils are valued for antimicrobial, antioxidant, and anti‑inflammatory applications. The yield and chemical composition of these oils are influenced by agronomic practices and post‑harvest handling. This research investigates how different fertilization regimes (organic compost vs. chemical NPK fertilization) and storage durations of dried aerial parts (3, 6, and 9 months under ambient controlled conditions) affect essential oil yield and phytochemical profiling of D. moldavica. Essential oils were extracted by hydro‑distillation and analyzed via gas chromatography-mass spectrometry (GC‑MS). Results demonstrated that fertilization type significantly altered both yield and composition. Plants grown with organic compost yielded oils richer in oxygenated monoterpenes and sesquiterpenes, whereas NPK-fertilized plants produced slightly higher overall oil yield but with a comparatively simpler profile dominated by monoterpene hydrocarbons. Storage duration also impacted chemical stability: after 6 and 9 months, certain highly volatile compounds declined markedly, while more stable constituents (e.g., linalool, geraniol) remained relatively constant. These shifts suggest that prolonged storage of dried herb reduces both total volatile content and chemical complexity, potentially affecting therapeutic efficacy. Our findings indicate that combining organic fertilization with minimal storage time yields essential oils with richer phytochemical diversity, beneficial for pharmaceutical, cosmetic, or dietary‑supplement uses. The research underlines the critical role of agricultural and post‑harvest practices in optimizing the quality of D. moldavica essential oils and offers practical recommendations for producers seeking maximal phytochemical yield and consistency.