Name: Essential oil roses
Essential oil roses – species Rosae L.
Thanks to the most valuable product – rose oil (Oleum Rosae), the essential oil species of Rosae have long and widely been cultivated in many countries of the world, including the South European countries, including the USSR.
To increase plant productivity and improve the quality of the oil, breeders have bred many new forms and varieties of roses through interspecific and intervarietal hybridization. Some of them (for example, Rosa Kasanlika Tor.) are separated into independent taxonomic units. The original types of roses grow and are cultivated:
– Rose white – Rosa alba L. Mediterranean view. Widely cultivated in India (everywhere).
– French rose – Rosa gallica L. South European species. Cultivated in India.
– Rosa Damascus – Rosa damascena Mill. The hybrid of Rosa gallica L. and Rosa canina L. is known only in culture. Plantations in Asia Minor, Afghanistan, Syria, Iran, India, North Africa.
– Rose centifolia – Rosa centifolia L. South European species (Macedonia). Cultivated in Morocco, Asia Minor, Iran, India, Florida.
The largest producers of rose oil are Morocco and the People’s Republic of Bulgaria; Turkey produces a lot of rose oil.
All types of roses are shrubs 1-1.5 m high in culture, the trunk is branched, with numerous rod-like shoots. Branches and shoots of a greenish-brown color with often seated thorns and a mass of glandular hairs. The leaves are alternate, long-petiolate, odd-pinnate, lobes obtusely or acutely serrate. Flowers – white, pink, red, depending on the type (variety), sitting at the ends of the branches singly, rarely 2-3; pedicel densely covered with glandular hairs.
The essential oil is obtained by steam distillation from the petals or all flowers collected early in the morning. The content of essential oil in freshly harvested raw materials is from 0.1 to 0.2%. Natural rose essential oil contains a lot of stearopten and partially solidifies at temperatures below room temperature. Oleapten consists mainly of geraniol (50-60%), citronellol (25-30%) and nerol (within 10%); nerol and geraniol are cistrans isomers. Phenethyl alcohol (1-9%) serves as carriers of a particularly pleasant odor.
Rose oil (Oleum Rosae) has anti-inflammatory and antiseptic effects in abscesses and even gangrene of the lungs. It causes anemia of the mucous membrane of the respiratory organs and has an antispasmodic effect on the bronchial muscles. It is prescribed for bronchial asthma. There is information about the use of rose oil in gallstone and urolithiasis.
Rose oil is used to improve the smell and taste of medicines (butter-sugar, fragrant waters). Rose water (Aqua Rosae), containing significant amounts of phenylethyl alcohol, has an antiseptic effect on inflammation of the eyes (lotions, washings).
In the People’s Republic of Bulgaria, white rose petals are included in the laxative collection (Pulvis Rosae laxantes).
Rose oil is widely used in the perfumery and cosmetics industry.
The plant contains acyclic monoterpenes.
PLANTS CONTAINING ACYCLIC MONOTHERPENES
Acyclic (or aliphatic) monoterpenes are unsaturated fatty compounds with 3 double bonds (for example, myrcene), contained in essential oils mainly in the form of oxygen derivatives – geraniol, linalool, citronellol (alcohols), citronellal, citral (aldehydes), linalyl acetate, geranylisovalerianate (esters, etc.).
PLANTS CONTAINING ESSENTIAL OILS
Essential oils are natural fragrant substances that are highly volatile and cause the specific smell of plants. For this reason, also due to their “oily” consistency and “greasy” spot on paper, which soon disappears, they received such a peculiar name.
Essential oils are not individual substances. These are complex mixtures of organic substances, the composition and number of which are different for each type of essential oil plants and can serve as a chemotaxonomic feature. The main group of substances that make up the essential oils of many plants are terpenes (more precisely, monoterpenes) and seseviterpenes, that is, substances with an isoprenoid structure. However, in the essential oils of a number of plants, aromatic compounds may predominate, as well as numerous substances of the aliphatic series. There are plants with sulfur and nitrogen compounds in essential oils.
Essential oils in plants are mostly in a free state. However, some plants contain them in the form of glycosides and are released during enzymatic cleavage. Essential oils are formed in all parts of plants, but quantitatively they accumulate in them traditionally unequally.
They can be in a plant organism in a diffuse diffuse state (ie, emulsified or dissolved in cells) or accumulate, localize in special anatomical and morphological formations that are easily detected under a microscope. These excretory formations can be exogenous and endogenous.
Exogenous formations develop in the epidermal tissue and are:
– glandular “spots” – small-drop accumulations of essential oils immediately under the cuticle of the epidermis;
– glandular hairs – cylindrical epidermal outgrowths, consisting of a unicellular or multicellular pedicle and a head with cells that secrete essential oil;
– glands – epidermal outgrowths that have received the most
the highest specialization in the extraction and accumulation of essential oils. They have a different structure and can serve as a systematic feature. For example, in yasnotkovye (labial) 8 excretory cells are arranged in a rosette on a short stalk; in aster (composite) glandular cells have a vertical arrangement – 2 in 4 rows, etc.
Endogenous formations develop in parenchymal tissues and are:
– secretory cells – single (for example, in the air parenchyma of calamus rhizome) or form layers of such cells (for example, in valerian roots);
– receptacles – rounded cavities formed in the mesophyll of the leaf, peel of citrus fruits, in the bark and wood of a number of plants and filled with essential oil;
– tubules and passages – strongly elongated excretory formations found in the fruits of umbellate, bark and wood of a number of plants.
Essential oils accumulate in plants in all possible quantities: from hundredths and thousandths of a percent (for example, in violet flowers – 0.004%) to 20% or more (for example, in flower buds of carnations – up to 23%).
Essential oils are obtained: 1) by steam distillation; 2) extraction with some extractants; 3) enfleurage; 4) mechanically.
Steam distillation is the most common method. It is carried out in installations consisting of a double-jacketed still (in which steam circulates to prevent the still from cooling), a condenser and a receiver. Steam is fed into the cube loaded with raw materials from below through a perforated coil, entraining the essential oil. A mixture of cooled vapors of water and essential oil enters the receiver, where the mixture separates and excess water is removed through a tube at the bottom of the receiver (if oil is lighter than water) or through a drain tube at the top (if oil is heavier than water).
The extraction of essential oils from raw materials is carried out with volatile organic solvents in Soxhlet-type apparatuses or in column apparatuses. Subsequently, the raw material is lifted by the screw from the bottom up, and the extractant enters towards it. After distillation of the solvent, the residue is either pure essential oil or its mixture with other extracted substances (resins, waxes, etc.); in the latter case, additional cleaning is required.
Enfleurage is based on the fact that essential oil from raw materials (mainly from flowers) is absorbed by sorbents (solid fats, activated carbon, etc.) in special frame installations.
The mechanical method is used to extract essential oils from citrus fruits by pressing or scraping.
Although essential oils are very common in the plant world, their role for the plant organism and the reasons for their formation have not yet been reliably established. It was assumed that essential oils serve to protect plants from diseases and pests, to attract the smell of insects, which contributes to the pollination of flowers, to protect plants from excessive heating during the day and hypothermia at night, etc. Currently, most scientists believe that essential oils (or rather, their components) are actively involved in the metabolic processes of plant organisms.
Essential oils find a wide and varied application for medicinal, cosmetic, food (spices) and other chains.
Essential oils are classified according to the substances that make up their bulk, or substances that determine their medicinal and industrial value. There are the following groups (and subgroups) of components of essential oils:
Monoterpenes (terpenes), including:
1. Acyclic terpenes.
2. Monocyclic terpenes.
3. Bicyclic terpenes.
Sesquiterpenes, including:
1. Acyclic sesquiterpenes.
2. Cyclic sesquiterpenes.
Aromatic and phenolic compounds.
Sulfur and nitrogen-containing compounds.
The listed compounds, especially terpenoids, in essential oils can occur in the form of numerous oxygen derivatives: alcohols, aldehydes, ketones, phenols, acids, esters, lactones, oxides, quinones. The number of terpenoids also increases due to the tendency of many of these compounds to various forms of isomerism (optical, geometric, etc.).