Comparative analysis of polysaccharides of Rosa × damascena Mill. buds and flower petals

The aim. The aim of the work was a comparative study of polysaccharides of Rosa × damascena buds and flower petals after obtaining essential oils. Materials and methods. The water distillation technique was used to determine the essential oils (EO) content in buds and flower petals of R. × damascena. The content of water-soluble polysaccharides (WSPS) and pectins (PC) from buds and flower petals of R. ×damascena was obtained using the fractionation method after EO were isolated. Free and bound monosaccharides in WSPS from R. × damascena buds and flower petals were determined by gas chromatography-mass spectrometry (GC/MS) method. Agilent 6890N / 5973 inert gas chromato-mass spectrometric system (Agilent Technologies, USA) was used for the chromatographic separation with HP-5ms capillary column (30 m × 0.25 mm × 0.25 mm, Agilent Technologies, USA). The filtrates obtained after WSPS precipitation of buds and flower petals were analyzed by chemical reactions. Results. The results showed that the EO concentration in buds and flower petals of R. × damascena was 0.033 ± 0.005 % and 0.015 ± 0.002 %, respectively. The WSPS content was 10.33 ± 0.31 % in buds and 9.69 ± 0.25 % in flower petals. In addition, the PC content in buds was 4.35 ± 0.14 % and in flower petals 7.88 ± 0.15 %. GC/MS analysis revealed that WSPS from buds of R. × damascena composed of monosaccharides arabinose, fucose, mannose, glucose, galactose, and inositol. WSPS of R. damascena flower petals consist of arabinose, fucose, glucose, galactose, and inositol. Glucose is present in a higher amount. Analysis of the filtrate of buds and flower petals obtained after WSPS precipitation by chemical reactions shows the presence of flavonoids, tannins and triterpene saponins. Conclusions. The total content of WSPS in flower buds did not significantly exceed the content of these compounds in flower petals of R. × damascena. The PC content in flower buds was significantly lower (4.35±0.14 %) than in flower petals (7.88±0.15 %). It can be assumed that WSPS and PCS could be responsible for the high swelling index. The study of WSPS by GC/MS indicates the predominance of glucose and galactose in both types of raw materials, as well as differences in the qualitative and quantitative content of monosaccharides in the composition of WSPS of flower buds and flower petals. The study of the filtrate of flower buds and petals of R. × damascena, obtained after precipitating WSPS by chemical reactions, indicates the presence of phenolic compounds and triterpene saponins. The results obtained indicate the possibility of obtaining WSPS, PC, and an extract rich in phenolic compounds and triterpene saponins after extraction of EO from buds and flower petals of R. × damascena by hydrodistillation