Myrcenol is a rare acyclic monoterpenoid alcohol primarily valued in fragrance chemistry. It serves as a key intermediate in the formulation of synthetic rose, lilac, and citrus accords, while also exhibiting mild antimicrobial activity, mainly attributed to membrane disruption mechanisms.

Chemical Properties

Myrcenol (2-methyl-6-methylideneoct-7-en-2-ol; molecular formula C₁₀H₁₈O; molecular weight 154.25 g/mol) is a colorless and mobile liquid. It presents a boiling point of approximately 195–200°C at 15 mmHg, a density ranging from 0.870 to 0.880 g/cm³, and a refractive index (nD20) between 1.470 and 1.475. Structurally, it is characterized by a tertiary allylic alcohol bearing both an exocyclic methylene group (C6=CH₂) and a terminal vinyl group (C7=C8).

Highly lipophilic (logP ≈ 3.5), myrcenol undergoes hydrogenation to yield dihydromyrcenol, a compound widely used for its floral-musk odor profile. It can also be oxidized to myrcenals or subjected to acid-catalyzed cyclization reactions leading to linalool and terpineol isomers. Industrial synthesis typically involves hydroamination of myrcene followed by palladium-catalyzed deamination.

Biosynthetic Occurrence

Myrcenol occurs naturally at low concentrations (approximately 0.1–1%) in various biological sources, including lemongrass, hop essential oils, and certain marine algae such as Basella species. Its biosynthesis originates from myrcene through allylic hydroxylation, mediated by cytochrome P450 or P450-like monooxygenases.

Advances in microbial engineering have enabled the heterologous production of myrcenol in organisms such as Rhodococcus and Pseudomonas expressing myrcene hydroxylases, achieving titers in the range of 50–200 mg/L. In plants, myrcenol also functions as a volatile metabolite involved in signaling pathways associated with wound response.