Sesquiterpenes cubebs

Pinene or camphene, dipentene sesquiterpenes, cubeb camphor —... 

Cubeb camphor, CuHjgO, is a sesquiterpene alcohol which is found in oil of cuhebs, especially in old samples of the oil. It is laevo-rotatory, melts at 68° to 70°, and boils at 248° with decomposition. Nothing is known of its constitution. 

Cadinene is a trivial name of a number of isomers which occur in a wide variety of essential oils e.g. cubeb oil. Actually, it is derived from the Cade juniper Juniperus oxycedrus L.). The cadalane (4-isopropyl-1,6-dimethyldecahydro-naphthalene) carbon skeleton is the base. Prominent stereochemical isomers are a-cadinene 79, y-cadinene 80 and d-cadinene 81 (Structure 4.23). This group is also known as naphthalene-type sesquiterpenes. 

Cubebae fructus Cubeb, Java pepper Piper cubeba L. Piperaceae L5% 2.5% cubebin i0%-18% essential oil tricyclic sesquiterpene alcohols 1,4-cineol, terpineol-4, cadinol, cadinene Fig. 6... 

Sesquiterpenes, C15H24, were discovered in oils of cloves, calamus, cas-carilla, patchouli and cubebs by Gladstone. They were studied particularly by F. W. Semmler, professor in Greifswald and Breslau, who also worked on fenchone, and by Ruzicka. Wallach s suggestion that they are built up from three isoprene units (1887) is true for most of them. 

Cadinene an optically active sesquiterpene found in the essential oils of juniper, cedar, cade and cubebs. Together with its isomers and their hydroxyl derivatives (cadinols), C. is representative of the car-dinanes, which are the best known and most widespread sesquiterpenes. Cadinanes are also known as cadalene precursors because they can be dehydrogenated to cadalene (4-isopropyl-l,6-dimethylnaphtha-lene). For formula and biosynthesis, see Sesquiterpenes. 

The chemistry of this oil is in need of further elucidation, as it is -clear that thei-e are several constituents present which have, so far, escaped identification. The terpene dipentene is present, and probably small quantities of pinene or camphene cadinene is present, as well as a second sesquiterpene not yet identified. There is also present, especially in the oil distilled from old fruit, which has doubtless become partially oxidised, a small amount of the so-called cubeb-camphor. This b y, C H gOH, appears to be a crystalline sesquiterpene alcohol derived from the sesquiterpenes (or one of them) by oxidation. From a mixture of ether and alcohol it crystallises in rhombs, melting at 65 and is laevo-rotatory. It boils at 248 , with decomposition. The nature of the blue oil found in the higher fractions is unknown. 

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