A comparative microbiological study of the essential oils from the genus Rosa L.

Manures, vermicompost, and chemical fertilizer impacts on the yield and volatile compounds of the damask rose (Rosa damascena Mill.) flower petals

Damask rose (Rosa damascena Mill.) is an economically important species in the Rosaceae family for rose oil and rose water production, obtained exclusively from freshly-gathered Damask rose flowers. Iran is famous for producing organic rose essential oil, mainly used in the perfume industry and for folk medicines due to its healing properties. Due to their high perishability, postharvest handling of the flowers prior to oil extraction are a key point in rose essential oil production. In this study, postharvest handling conditions of Damask rose flowers were evaluated for the effect on yield and quality of the extracted essential oils. Organically-grown flowers were stored under different conditions included packaging in polyethylene bags and immersing into water containers, and then held at 25 ± 2 °C or 4 ± 1 °C for 1, 2, or 3 days. Identification of the chemical composition of the essential oils was performed by GC and GC/MS. The results indicated that petal storage in water resulted in the highest essential oil content and quality, and storage in polyethylene bags resulted in the greatest loss, compared to those from unstored petals. The results provide a reference for interested groups such as producers and consumers who are concerned about Damask rose flower storage and subsequent oil extraction.

Damask rose of the Veselka variety is an important industrial rose variety used to obtain essential oil. It is widely used in modern cosmetology, perfumery, and aromatherapy. In addition, the essential oil of Damask rose has a whole spectrum of pharmacological properties. The scientific innovation of this research lies in its foundation on cultivating and acquiring planting materials of the Damask rose in vitro. This approach guarantees controlled conditions for plant growth, the production of robust seedlings, and an enhancement in the precision and credibility of the research outcomes. Moreover, the study has scientific novelty in that it explores to assess both the quantitative and qualitative constituents of the essential oil in the acquired plant material of the Damask rose. This assessment takes place within the context of cultivating regenerative plants in an outdoor environment. Such an approach acknowledges the potential distinctions in the oil's component composition acquired from plants propagated through this method in comparison to traditional vegetative reproduction. Lastly, the research has scientific novelty in investigating the potential antimicrobial properties of Damask rose essential oil, which could have significant practical implications in the development of new drugs and combatting infectious diseases. The purpose of the study was to establish the component composition of the essential oil of Rosa damascena Mill., which was grown in vitro, and to determine its antimicrobial effect. Methods. The object of the study was the essential oil of Damask rose of the Veselka variety, which was grown by the method of clonal micropropagation in vitro. The essential oil was extracted from fresh petals collected during dry weather conditions prior to sunrise by hydrodistillation. Determination of the qualitative composition and quantitative content of volatile substances was carried out by the GC-MS method using an Agilent 7890B chromatograph. Antimicrobial activity was studied in vitro using the disk diffusion method with reference test strains of microorganisms Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Candida albicans ATCC 885-653. Results. According to the results of the chromato-mass spectrometric study, 41 compounds (6 of which were in the isomeric state) were identified, which was belong to 13 different classes of chemicals. Dominant compounds among terpenoid substances were shown: geraniol – 30.96 %, citronellol – 27.08 %, alkanes: nonadecane – 17.29 %, and heneicosene – 5.46 %. It was established that the essential oil of Damask rose had a significant antimicrobial effect against strains of C. albicans and E. coli, the diameters of which growth retardation zones ranged from 32-35 mm and 20-23 mm, respectively. In studies with P. aeruginosa and S. aureus, the essential oil showed moderate antibacterial activity: the diameters of the growth retardation zone of these microorganisms ranged from 13 to 15 mm and 11 to 12 mm, respectively. Conclusion. For the first time, the qualitative composition and quantitative content of volatile substances in the essential oil extracted from the petals of Rosa damascena Mill., Veselka variety, cultivated through the clonal micropropagation in vitro, were explored by chromatography-mass spectrometry techniques. The results of the study of antimicrobial activity showed that the studied essential oil exhibits significant fungicidal effects against Candida microorganisms, along with moderate bactericidal effects on gram-negative (E. coli, P. aeruginosa) and gram-positive (S. Aureus) bacteria. These results highlight the potential of this essential oil for further investigation in the realm of developing novel medicines and herbal preparations. Further clinical studies are needed to assess this potential.

Agronomic interventions for the improvement of essential oil content and composition of damask rose (Rosa damascena Mill.) under western Himalayas

The aim of the research was to improve the quality of medicinal plants by developing new varieties of Salvia sclarea, Lavandula angustifolia and Origanum vulgare. Plant material included 50 heterotic hybrids, 62 inbred lines, 8 varieties derived from hybrids with constant heterosis of S. sclarea; 9 varieties, derived from F1 hybrids of L. angustifolia; 7 varieties of O. vulgare ssp. vulgare, 15 varieties of O. vulgare ssp. hirtum. Early, medium, late inbred lines of S. sclarea were developed; low (0.458-0.700%), medium (0.701-1.000%), high (0.101-1.350%), very high (0.351-1.958 %) essential oil content. S. sclarea hybrids are characterized by their high essential oil content. Resistant to biotic and abiotic factors ‘Ambriela’ variety was developed. Productivity: 26.9t/ha raw material; essential oil content 1.175-1.185% (dry matter), essential oil production, 104.1 kg/ha. Resistant to biotic, abiotic factors varieties of L. angustifolia have been derived from F1 hybrids with the effect of heterosis. The L. angustifolia variety ‘Favoare’ has an essential oil content of 5.154% (dry matter), major components: linalyl acetate, 38.2%; linalool, 39.2%, inflorescence production, 7.4 t/ha, essential oil production, 155.2 kg/ha; ‘Svetlana’, late variety are distinctively by essential oil content 5.157% (dry matter), major components: linalyl acetate: 44,406%, linalool, 37,250%; inflorescence harvest: 7.7 t/ha; essential oil production, 179.2 kg/ha. The O. vulgare ssp. hirtum ‘Savoare’ variety was selected with production of raw matter, 8.9 t/ha; pharmaceutical herba production, 1.88 t/ha; essential oil production, 138 kg/ha; essential oil content, 3.877% (dry matter), major components: carvacrol, 83.917%. The O. vulgare ssp. vulgare ‘Panacea’ variety was developed with production of raw matter of 7.8 t/ha; essential oil production: 8.35 kg/ha. Essential oil content: 0.267% (dry matter). Major essential oil components: germacrene, 31.13%.

The chemical compositions of essential oil from nine distinct genotypes of Iranian Rosa damascena (Fars1, Fars2, Tehran, Mazandaran, Gilan, East Azar, Ardabi, Kermanshah and Qom) were determined following gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS) analysis. The main essential oil components identified in the different genotypes were citronellol, geraniol, neral, linalool and nonadecane. The relative percentage of citronellol was highest in Fars1 (42.2%) and Gilan (40.3%) genotypes and lowest in the Qom (2.2%) and East Azar (0.6%) genotypes, while in Mazandaran, Ardabil and Kermanshah genotypes citronellol was not detected. The highest content of geraniol was detected in the essential oil of the Kermanshah genotype (37.5%); however, in the Fars1, Fars2, Tehran, Gilan, East Azar, Kermanshah and Qom genotypes this component was not detected. Linalool was detected in the essential oil of all genotypes, and the highest amount of this component was in Fars2 (39.2%). Hydrocarbons had the highest contribution to the essential oil of the East Azar genotype. The major hydrocarbons identified in all genotypes were nonadecane (10.7 to 51.2%), heneicosane (3.7 to 18%), eicosane (0.8 to 6.2%) and tricosane (0.5 to 2.4%). Key words: Rosa damascena, essential oil, genotypes.

The intraspecies variability of essential oil (EO) compounds in the Oregano plants ( Origanum vulgare L.) was studied. To this end, total content of EO, as well as the composition and content of EO compounds were analyzed in the samples of three varieties and six clones of Oregano plants obtained in the course of breeding, and which were distinguished by some morphological characteristics (height and form of plant, flowers coloring). Application of gas-liquid chromatography with mass spectrometric detector (GC-MS) allowed determining in the samples of Oregano EO 120 individual compounds, 60 of which were identified. The major compounds were terpinene-4-ol (16,4%), β-caryophyllene (12,4%), germacrene-D (9,7%), caryophyllene oxide (8,2%), spathulenol (7,7%), α-cadinol (6,0%), γ-terpinen (2,9%), α-cadinol (2,8%), α-humulene (2,2%), δ-cadinene (1,9%) и α-terpineol (1,7%). They account for 71,9 % of total content of EO. Analysis of GC-MS data by the methods of multivariate statistics show that the studied clones (varieties) of Oregano plants are divided on the two groups with high and low EO content. Compounds that were mainly responsible for the differences of these two groups in the EO content were determined. It is assumed the existence of a positive relationship between high EO content and compact, dwarf form of Oregano plants.

Origanum vulgare subsp. hirtum (Link) Ietswaart is an essential oil rich plant traditionally used as oregano. Based on the interest of the essential oil producing sector, in 2000 we have started a breeding program of O. vulgare subsp. hirtum. Plant material for our breeding work consists of 6 progeny. Individual evaluation of the plant material was carried out in 2008-2009 with the primary aim of finding mother plants with appropriate morphological features, high essential oil content (> 7%) and with carvacrol as the main essential oil component. Among the survey of morphological characteristics special attention was given to glandular hair density in order to test the usability of it as a morphological marker for screening progeny for high essential oil content. The characteristics of the progeny can be described with high variability ensuring the possibility of a good selection base. Evaluating the morphology, essential oil content and constitution of the individuals, 20 plants were selected on the grounds of their high (7-8.6%) essential oil content, high ratio (70-93%) of carvacrol in the essential oil and typical morphological features of O. vulgare subsp. hirtum. From the results of glandular hair density it can be stated that the correlation between glandular hair density of the upper, middle and lower leaves either on vegetative or generative shoots and essential oil content was never strong enough (correlation coefficient < or = 0.5) to use it exclusively as a morphological marker for individual selection.

Chemical analysis of Iranian Rosa damascena essential oil, concrete, and absolute oil under different bio-climatic conditions

This study was conducted in order to determine the effect of different storage temperatures (0 o C and 3 o C) and durations (7, 14, 21 and 28 days) on oil yield and essential oil components of oil rose (Rosa damascena Mill.). In this study, the rose oils were obtained by hydro-distillation in Clevenger-type apparatus and the components in the rose oil were analyzed by GC-MS. It was determined that the effect of storage temperatures on oil content wasn’ t significant whereas the effect of storage duration was significant (p�0.01). The highest essential oil content was obtained at 0.043% from the petals distilled immediately after the harvest while the lowest oil content was obtained at 0.022% from the petals stored at both temperatures for 28 days, respectively. The rate of citronellol, one of the main components of rose oil, was 25.34% in the petals distilled immediately whereas it varied from 41.07 to 72.52% in the petals stored at 0 o C and 3 o C for 28 days. The rates of nerol and geraniol in the petals distilled immediately were 14.30% and 33.02%, respectively whereas they are 2.68%, the trace amount, and range between 0.43 and 6.74% in the stored petals, respectively. The rates of hexadecane, nonadecane, eicosane and methyl eugenol in the petals distilled immediately were determined to be lower than those of the stored petals. The optimal results in terms of its oil content and components were obtained from the rose petals distilled immediately after the harvest as well as from the petals stored at 0 o C for 7 days.

In the present study, we investigated the irrigation of L. angustifolia plants and drying temperatures on the yield of dry leaves and lavender essential oil. Plants were irrigated using an on-surface system with drip lines. Plants without additional irrigation were the control object. Each dose of water consisted of 15 mm. The total amount of water used for irrigation in 2016 and 2017 was 90 L·m−2. The plant raw material was dried using two methods: in natural conditions and convectively. Natural drying was performed in a shaded room at a temperature of 20–22 °C for five days. The convective drying process was carried out in a drying oven in a stream of air at 35 °C, flowing parallel to the layer being dried at 0.5 m·s−1. Under the influence of irrigation, there was an increase in the yield of fresh and airdried leaves and a higher content of essential oil (EO) than in the cultivation without irrigation. The EO obtained from irrigated plants was characterized by higher contents of caryophyllene oxide (9.08%), linalool (7.87%), and β-caryophyllene (4.58%). In nonirrigated crops, α-muurolol (19.67%), linalyl acetate (15.76%), borneol (13.90%), γ-cadinene (8.66%), camphor (2.55%) had a higher percentage in the EO. After drying under natural conditions, the airdried herb yield and leaf yield of lavender were higher by 25% and 17%, respectively, as compared to the raw material dried at 30 °C. Higher drying temperatures (30 °C) increased the EO by 18% on average and total phenolic acid (TPA) by 50%. The plant material dried at 30 °C, with a larger amount of TPA, showed higher antioxidant activity (AA) in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) tests. Linalyl acetate (15.76%) and linalool (7.87%) were predominant in the EO extracted from the oven-dried herb. Drying under natural conditions resulted in a decreased content of linalyl acetate (0.89%), β-caryophyllene (0.11%), linalool (1.17%), and camphor (1.80%) in comparison with thermal drying. Linalool, linalyl acetate, and β-caryophyllene had a higher percentage in the EO extracted from the raw material obtained from irrigated and oven-dried plants, whereas camphor was found to have a larger percentage in the case of the EO from nonirrigated plants. Our study reveals that there are prospects for the practical use of irrigation in lavender cultivation and of the raw material preservation method in order to modify the EO content and chemical composition.

Variation in chemical composition and biological activity of essential oils of medicinal plants may be observed due to the developmental stage of collected plant materials. In the present study, we compared the chemical compositions and antimicrobial activity of the essential oils from the aerial part of Thymus daenensis Celak. and Thymus fedtschenkoi Ronniger at different developmental stages. The highest essential oil content in both species was observed at the full flowering stage. The phenolic monoterpene thymol (71.9-73.9 %) and the monoterpene alcohol linalool (45.5-83.1 %) were the most abundant constituents at all phenological stages of T. daenensis and T. fedtschenkoi, respectively. All the essential oils possessed high antibacterial and antifungal activities against the microorganisms tested (Staphylococcus aureus, Bacillus cereus, Enterococcus faecium, Escherichia coli, Salmonella enteritidis, and Candida albicans), although of different degrees. The essential oils from T. fedtschenkoi appeared to be more active on almost all bacterial and fungal strains than that of T. daenensis (with MIC values of 1-16 mg/ml and 2-32 mg/ml, respectively). The effect of the plant phenological stage on the antimicrobial activity and constituents of T. fedtschenkoi essential oil was more pronounced than for T. daenensis. Interestingly, the antimicrobial effects of T. fedtschenkoi essential oil obtained at the seed set stage was noteworthy against all tested microorganisms, apart from the resistant E. faecium. Overall, this study highlighted the importance of the choice of the harvesting time to achieve the optimum of essential oil quality and quantity together with the antimicrobial activities, which are exploited in the pharmaceutical and food industries.

The effects of harvest date, fermentation duration and Tween 20 treatment on essential oil content and composition of industrial oil rose (Rosa damascena Mill.)

The effects of harvest date, fermentation duration and Tween 20 treatment on essential oil content and composition of industrial oil rose ( Rosa damascena Mill.)

The damask rose (Rosa damascena Mill.) is an ornamental–medicinal plant from the Rosaceae family, and its aromatic compounds and essential oils are applied globally in the food, cosmetic, and pharmaceutical industries. Due to its economic value, this research aimed to establish a protocol for an efficient, rapid, and cost-effective method for in vitro shoot multiplication and rooting of the R. damascena ‘Kashan’ and ‘Hervy Azerbaijan’ genotypes. Nodal segments (as primary explants) were cultured on the Murashige and Skoog (MS) medium with combinations of various plant growth regulators (PGRs) such as gibberellic acid (GA3), 6-benzylaminopurine (BAP), and indole-3-butyric acid (IBA), as well as a PGR-like substance, phloroglucinol (PG), vitamins such as ascorbic acid (AA), and activated carbon in the form of active charcoal (AC). For the establishment stage, 0.1 mg·L−1 PG, 0.2 mg·L−1 GA3, and 1 mg·L−1 BAP were added to the media. Secondary explants (nodal segments containing axillary buds produced from primary explants) were obtained after 30 days of in vitro culture and transferred to the proliferation media supplemented with different concentrations of BAP (0, 0.5, 1, 1.5, 2, and 2.5 mg·L−1) and GA3 (0, 0.1, 0.2, 0.4, 0.8, and 1 mg·L−1) together with 0.1 mg·L−1 PG and 20 mg·L−1 of AA. The rooting media were augmented with different concentrations of BAP and GA3 with 0.1 mg·L−1 of IBA, PG and 20 mg·L−1 of AA and AC. The results showed that the highest regeneration coefficient (4.29 and 4.28) and the largest number of leaves (23.33–24.33) were obtained in the explants grown on the medium supplemented with 2 mg·L−1 BAP and 0.4 mg·L−1 GA3 for the ‘Kashan’ and ‘Hervy Azerbaijan’ genotypes, respectively. Likewise, this PGR combination provided the shortest time until bud break (approximately 6.5 days) and root emergence (approximately 10 days) in both genotypes. The highest number of shoots (4.78 per explant) and roots (3.96) was achieved in this medium in the ‘Kashan’ rose. Stem and root lengths, as well as stem and root fresh and dry weights, were also analyzed. In most measured traits, the lowest values were found in the PGRs-free control medium. Rooted plantlets were transferred to pots filled with perlite and peat moss in a 2:1 proportion and were acclimatized to ambient greenhouse conditions with a mean 90.12% survival rate. This research contributes significantly to our understanding of Damask rose propagation and has practical implications for the cosmetic and ornamental plant industries. By offering insights into the manipulation of regeneration processes, our study opens up new possibilities for the effective production of high-quality plant material.