COMPONENT COMPOSITION OF ESSENTIAL OILS FROM LEAVES, INFLORESCENCES AND STEMS OF PEROVSKIA SCROPHULARIFOLIA GROWN IN UZBEKISTAN

Essential oils as secondary metabolites, promising sources of biologically active substances with pronounced antimicrobial, antifungal and antiviral effects, are of considerable interest for study and possible use in medicine, pharmaceuticals, and aromather-apy. We have studied the composition of the essential oil of an endemic species for the first time Perovskia scrophularifolia Bunge. (Lamiaceae = Labiatae). This species of plant is of considerable interest as a medicinal plant, which is widely used in folk medicine in Uzbekistan and neighboring countries. Studies of biologically active substances of this species did not concern the essential oil. During the period of mass flowering in the inflorescences of Perovskia scrophularifolia contains 0.65%, in leaves – 0.71% of essential oil. The stems of the plant contain essential oils in small quantities. The composition and content of the components of the studied samples were determined according to the data of gas chromatographic and chromate-mass-spectrometric analysis. 26 substances were identified in essential oils from leaves, 43 from inflorescences and 18 substances from stems. The main components of essential oils from leaves and inflorescences are 1,8-Cineol up to 19.3% and Isobornyl acetate – up to 15.9%. This species is a promising source of biologically active compounds with biological activity


Introduction
Perovskia scrophulariifolia Bunge.(Lamiaceae), perennial shrub, numerous stems up to 1-1.20 m tall, lignified at the base, leaves opposite, entire or pinnate, purple, pink, pale yellow or white flowers.This is an essential oil plant.Grows in mountainous and foothill areas (up to 1800 m above sea level) on rocky slopes, rocks, screes, dry riverbeds, often as a weed, rises to the mid-mountain belt of the mountains of Central Asia (Pamir-Alay, Tien Shan, Kashkadarya region), endemic [1,2].
Data on the possibility of obtaining preparations from the aerial part of Perovskia scrophulariifolia were actively studied in the 20th century, which is reflected in some works [3][4][5][6][7][8].The aqueous extract has been shown to be used in sunburn and scabies baths, and applied to the skin for various wounds, as a wound healing, skin disease, such as dermatitis.The decoction is also used to combat human intestinal parasites, antibacterial activity; ointment -as an antiprotozoal agent.Grass was used to dye silk and cotton pink, good honey plant and perganos (or ambrosia -pergsha source), and food for goats and sheep [5][6][7][9][10][11][12].

Materials and methods
The material was collected in natural habitats at the point of the Pamir-Alay, Gissar Range, 1469 m above sea level, in places of natural growth of plants during the period of mass flowering of plants.To obtain essential oil, 5-10 individuals were taken (each time at least 200 g of raw materials), divided by organs: leaves, flowers and stems.The essential oil was distilled off at least 5 times, then all samples of the obtained essential oil were combined, dried with calcined and anhydrous sodium sulphate.Herbarium samples collected in places of natural growth are stored in the private herbarium of Kh.Dzhumaev (Department of Botany, Termez Pedagogical University, Uzbekistan).
Essential oils from leaves, stems and inflorescences of Perovskia scrophulariifolia growing in the vicinity (Baysuntau, Pamir-Alai mountains) were obtained by hydrodistillation.In the period of mass flowering, inflorescences of plants contain an average 0.65% (from 0.59 till 0.71), leaves -contain an average 0.71% (from 0.68 till 0.73) of essential oil of the wet weight.The stems of the plant contain essential oils in a small amount (trace) contains an average of about ~0.1%.The bulk (up to 90% of the total amount) of the essential oil is collected 30 minutes after the start of boiling water in the flask.The production of essential oil was continued until the moment when there was no noticeable addition of essential oil in the receiver for 20 minutes.The resulting essential oils were yellow in color (from slightly colored to fairly intense color), with a specific, characteristic pungent odor.
The composition and content of the components of the studied samples were determined according to the data of gas chromatographic and chromate-mass-spectrometric analysis.Components were identified by mass spectra and RI values.Mass spectra were recorded on an LKB 2091 chromate-mass spectrometer (Sweden) using a packed glass column 1.8 m × 2 mm with 3% polydimethylsiloxane elastomer SE-30 on Chromosorb W (80-100 mesh) in the temperature programming mode from 50 to 200 °C at a rate of 5 °C/min.Evaporator temperature 200 °C, separator 220 °C, ion source 250 °C.Carrier gas helium, flow rate 25 ml/min.For mass spectrometric identification, the base (version 2017 and its predecessors) was used.Quantitative analysis of the essential oil, as in the works [13][14][15], was carried out on a Biochrome-1 chromatograph with a flame ionization detector using a 50 m × glass capillary column.0.25 mm with polydimethylsiloxane stationary phase OV-101 (phase film thickness 0.25 mm) in the temperature programming mode from 50 to 200 °C at a speed of 5 °C/min.The temperature of the evaporator is 200 °C, the detector is 220 °C.Carrier gas helium, linear velocity in the column 18 cm/s.The sample volume was 0.5 μl, the division of the carrier gas flow at sample dosing was 1 : 15.To determine the retention indices, a mixture of reference n-alkanes С6-С18 was added to the samples; linear-logarithmic indices were calculated using the QBasic program.For identification by RI values, the NIST database was used [16].
Even if the essential oils from the leaves, inflorescences and stems of the plant contain the same substances, nevertheless, each of them has its own unique composition.

Discussion of the results
An analysis of published works over the past few years (since 2000, and especially the last 5-10 years) shows that there is a search for a comparison of different plant species of different families (Pinaceae, Myrtaceae, Apiaceae (Umbelliferae), Asteraceae (Compositae), and of course Lamiaceae), the essential oils of which will provide antimicrobial, antibacterial, antifungal, antiviral activity.And also, a lot of work is devoted to the study of individual components of essential oils, which also show antibacterial, antifungal and antiviral activities, but also exhibit other properties that are valuable for medical use [17][18][19][20][21][22][23][24][25][26].
Perovskia scrophulariifolia is not widespread species, therefore, in order to ensure the production of essential oils from this plant, it is necessary to carry out work on introducing it into the culture.Work out the cultivation technology, agricultural technology and evaluate how the accumulation of essential oil in the leaves and inflorescences of the plant will change, and what will happen to the component composition.
Quantitative content (in%) of individual components in essential oils from leaves, inflorescences and stems of Perovskia scrophulariifolia (mass flowering phase) The presence of biologically active components in the composition of essential oils of P. scrophulariifolia should be assumed that it will have a pronounced abiotic effect on various types of microorganisms.This may open up prospects for the use of essential oils in the fight against pandemics.

Conclusion
The essential oil of Perovskia scrophulariifolia has a pleasant smell, contains active components that will exhibit biological activity, therefore, they can be used in medicine and aromatherapy [27][28][29].These essential oils may also be of significant interest in the fight against phytophages, given that these essential oils are not toxic to humans, but may exhibit a repellant and/or insecticidal effect [30][31][32][33][34][35][36].
As our studies have shown, leaves, inflorescences and stems of Perovskia scrophulariifolia contain a significant amount from 5 to 20% of the total number of identified components) 1,8-Cineol, Limonene, Camphor, Isoborneol (Borneol), Isobornyl acetate, trans-Caryophyllene, Santalen (Kalaren), β-Santalene (α-Humulene) this gives us reason to believe that the assessment of the biological activity of both these essential oils and its individual components will show a high abiotic activity.This allows us to conclude that it is necessary to develop technologies for the plantation cultivation of P. scrophulariifolia in Uzbekistan as a promising essential oil plant.