Rosewood, linalool from

Sampaio Lde F, Maia JG, de Parijos AM, de Souza RZ, Barata LE (2012) Linalool from rosewood (Aniba rosaeodora Ducke) oil inhibits adenylate cyclase in the retina, contributing to understanding its biological activity. Phytother Res 26(l) 73-77... 

Bois de Rose. Bois de rose oil is obtained by steam distillation of wood chips from South American rosewood trees, Aniba rosaeodora. The tree, a wild evergreen, grows mainly in the Amazon basin. The oil is used as obtained in perfumery for its sweet, woody-floral odor and as a source of linalool [78-70-6] (3), which it contains to the extent of 70%. Linalool distilled from bois de rose oil is also used directly in perfumery and for conversion to esters, eg, the acetate (1). 

Production. In the 1950s nearly all linalool used in perfumery was isolated from essential oils, particularly from rosewood oil. Currently, this method is used only in countries where oils with a high linalool content are available and where the importation of linalool is restricted. 

Isolation from Essential Oils. Linalool can be isolated by fractional distillation of essential oils, for example, rosewood oil, Shiu oil, and coriander oil, of which Brazilian rosewood oil is probably the most important. 

Linalool (3,7-dimethyl-l,6-octadien-3-ol) (62) occurs as one of its enantiomers in many essential oils, where it is often the main component. (/ )-(-)-Linalool for example occurs at a concentration of 80-85% in Ho oils from Cinnamomum camphora rosewood oil contains ca 80%. (S)-(+)-Linalool makes up 60-70% of coriander oil [26]. 

Terpenoid alcohols appeared early in the history of synthetic perfumery because several were readily available from inexpensive essential oils. Alpha-terpineol, citronellol and linalool shown in Figure 7 are important constituents of pine stump oil, citro-nella oil and rosewood oil, respectively. The fourth material listed, hydroxycitronellal, is a hydroxy aldehyde which perhaps has a questionable place in this discussion. It is included because it is one of the most important fragrance chemicals used today. "Hydroxy" is almost a perfume unto itself. Its soft flowery, linden blossom odor blends very well in many floral perfumes. 

Rosewood oil, Brazilian (Bois de rose oil) is obtained by steam distillation of wood from Aniba rosaeodora A. Ducke var. amazonica A. Ducke and/or A. parvi-fora Meissner Mez. (Lauraceae). It is an almost colorless to pale yellow liquid with a characteristic, sweet odor, reminiscent of linalool, its main constituent [743, 743a],... 

Linalool (3.17) occurs even more widely than geraniol. The richest source is Ho leaf oil which can contain over 95% linalool. Rosewood contains 80-85% and freesia about 80% linalool. It also occurs at levels around 50% in lavender and in herbs such as coriander and basil. Citrus leaves and flowers also contain significant amounts of linalool. However, it takes its name from the oil of linaloe wood, of which it accounts for about 30%. 

The sources of the aforementioned key substances fall into three main categories natural extracts, turpentine, and petrochemicals. The balance depends on economics and also on the product in question. For example, while about 10% of geraniol is sourced from natural extracts, it is only about 1% in the case of linalool. Natural grades of geraniol are obtained from the oils of citronella, geranium, and palmarosa (including the variants jamrosa and dhanrosa). Citronella is also used as a source of citronellal. Ho, rosewood, and linaloe were used as sources of linalool, but conservation and economic factors have reduced these sources of supply very considerably. Similarly, citral was once extracted from L. cubeba but overharvesting has resulted in loss of that source. 

A typical example is the hydroformylation of linalool, a monoterpenoid allyhc alcohol with a pleasant lily odor. It is a key building block for the synthesis of various vitamins and fragrances, such as vitamin A, vitamin E, citral, citronel-lol, and phnol (see Scheme 6.44). Linalool is found in the essential oils of several plants, for example, Brazihan rosewood and Chinese Ho leaf oils, but mostly it is produced industrially from a-pinene or from the petrochemically derived source 6-methylhept-5-en-2-one (Hoflimann-La Roche Process) [144]. 

Linalool (23) is more properly spelt linalool and pronounced with two distinct o sounds, the first long and the second short. This gives an indication of one of its principal sources, Linaloe oil, the essential oil of the Indian tree Bursera delpechiana, which contains levels of 30% linalool and 45-50% of its acetate. However, it is common practice nowadays to omit the diaeresis and even to speU the name with a single letter o. Other synonyms include linalyl alcohol, Licareol (extract from rosewood), and Coriandrol (extract from coriander). It occurs very widely in nature. The richest source is Ho leaf oil from China and Taiwan, which typically contains >90% linalool and levels as high as 97.5%, have been reported (150). Rosewood oil will typically contain 75-85% linalool and it is a major component of many flower (e.g., 80% in Ifeesia and 75% in honeysuckle) and herb (e.g., 65-80% in coriander) oils. Linalyl acetate is also a frequently encountered component of plant oils. Oils in which it plays a particularly important organoleptic role, include lavender ( 50%) and citrus leaf oils (also 50%). 

Namral linalool is extracted mainly from three species. The largest is Brazilian rosewood of which 100-150 tpa is produced. In recent years, there has been some concern about the endangering of the rosewood species by overharvesting and consequently about the sustainability of production of the oil. About 10 tpa is produced from Chinese and Taiwanese Ho leaf. Production from Linaloe oil is only a few tpa in India (151). Minor sources of natural linalool include shin and coriander oils (82). In the past, it was also extracted from lavender and bergamot. 

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