ACYCLIC MONOTHERPENS Classification of essential oils and essential oil raw materials скачать в хорошем качестве

ACYCLIC MONOTHERPENS Classification of essential oils and essential oil raw materials

1. ACYCLIC MONOTHERPENS Classification of essential oils and essential oil raw materials 2. Essential oil raw materials and their essential oils can be divided into groups containing: 1) acyclic monoterpenes, 2) monocyclic monoterpenes, 3) bicyclic monoterpenes, 4) sesquiter foams, 5) aromatic compounds. 3. Acyclic (or aliphitic) monoterpenes can be considered as unsaturated fatty compounds with 3 double bonds. As an example, we can cite a compound that is quite common in essential oils - myrcene: 4. The most common oxygen derivatives of aliphatic terpenes are: from alcohols - geraniol, linalool, citronellol, and from aldehydes - citronellal and citral. Geraniol is a primary alcohol that has two double bonds, the location of which distinguishes between the alpha form (bonds at C1 and C6) and the beta form (C 2 and C6 bonds). Natural geraniol is always a mixture with a significant predominance of the beta form. 5. Citronellol is a primary alcohol with one unsaturated bond, which is also a mixture of alpha and beta forms with a predominance of the latter. Like geraniol, citronellol has a rose scent. 7. Monoterpene aliphitic alcohols are often found in the form of esters with various fatty acids (formic, acetic, butyric, isovaleric, etc.). 8. The structure of acyclic monoterpenes and their derivatives can equally be depicted in a "folded" form, outwardly resembling monocyclic terpenes, but with an open ring. 9. The biosynthesis of the simplest monoterpenes proceeds through mevalonic acid. Under the influence of the enzyme kinase and ATP, mevalonic acid is converted into 5-phosphomevalonic acid. When this ester interacts with coenzyme A, a new ester is obtained - 5-pyrophosphomevalonic acid. Then, isopentenyl pyrophosphate (or isopentenyl diphosphate) is formed, the main isoprenoid intermediate that underlies the biosynthesis of various groups of terpenoids, including acyclic terpenes. In particular, in the biosynthesis of acyclic terpenes, isopentenyl pyrophosphate is isomerized into dimethylallyl pyrophosphate, and the condensation of one molecule of the latter with one molecule of isopentenyl pyrophosphate (head-to-tail) leads to the formation of geranium pyrophosphate, and then free geraniol.