piperitenone and carvone

Essential oils from Greek Mentha species showed different chemical compositions for two populations of M. pulegium, characterized by piperitone and pulegone. Mentha spicata essential oil was characterized by endocyclic piperitenone epoxide, piperitone epoxide, and carvone. The bioactivities of these essential oils and their components have been tested against insect pests (Leptinotarsa decemlineata, Spodoptera littoralis and Myzus persicae), root-knot nematodes (Meloydogine javanica) and plants (Lactuca sativa, Lolium perenne, Solanum lycopersicum). The structure-activity relationships of these compounds have been studied including semi-synthetic endocyclic trans-carvone epoxide, exocyclic carvone epoxide, a new exocyclic piperitenone epoxide and trans-pulegone epoxide. Leptinotarsa decemlineata feeding was affected by piperitenone and piperitone epoxide. Spodoptera littoralis was affected by piperitone epoxide and pulegone. The strongest nematicidal agent was piperitenone epoxide, followed by piperitone epoxide, piperitenone and carvone. Germination of S. lycopersicum and L. perenne was significantly affected by piperitenone epoxide. This compound and carvone epoxide inhibited L. perenne root and leaf growth. Piperitenone epoxide also inhibited the root growth of S. lycopersicum. The presence of a C(1) epoxide resulted in strong antifeedant, nematicidal and phytotoxic compounds regardless of the C(4) substituent. New natural crop protectants could be developed through appropriate structural modifications in the p-menthane skeleton.

Topics: Animals; Cyclohexane Monoterpenes; Epoxy Compounds; Gas Chromatography-Mass Spectrometry; Germination; Mentha; Monoterpenes; Oils, Volatile; Plant Leaves; Plant Roots; Solanum lycopersicum; Spodoptera; Structure-Activity Relationship

In vitro plantlets and callus of M. longifolia were established and their volatile constituents characterized by GC-MS analysis of their headspaces (HSs) and essential oils (EOs). Significant quali-quantitative differences were found in the aromatic fingerprints in comparison with the M. longifolia parent plants. In fact, limonene and carvone were the main constituents in the EOs of the mother plants, while the aroma of the in vitro plant material were especially enriched in oxygenated terpenes. In particular, huge amounts of piperitenone and piperitenone oxide (75 %) were found for in vitro plantlets, while trans-carvone oxide (19 %) and trans-piperitone epoxide (9 %) were found in callus EO. However, the established in vitro plant material showed lack of pulegone and menthofurane, thus preserving an important feature observed in the volatile fingerprint of the parent plants. In fact, because of their well-known toxicity significant amounts of pulegone and menthofurane may compromise the safety using of mint essential oil. Therefore the in vitro M. longifolia plantlets and callus may be regarded as a potential source of a safe flavouring agent.

Topics: Cyclohexane Monoterpenes; Cyclohexenes; Flavoring Agents; Gas Chromatography-Mass Spectrometry; Limonene; Mentha; Monoterpenes; Odorants; Oils, Volatile; Plant Leaves; Plant Oils; Plant Stems; Seeds; Terpenes; Tissue Culture Techniques

Topics: Cyclohexane Monoterpenes; Ketones; Monoterpenes