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Herba Polonica
|
1994
|
tom 40
|
nr 3
118-124
The state of research over flavonoid compounds in genus Rosa L. has been presented. The need for further research as well as the necessity and purposefulness of using detailed taxonomie descriptions of the plants in phytochemical research of this genus have been pointed out.
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The oil content and fatty acids profile of a number of Polish wild species of rose fruits were examined by GC. The total fatty acid contents ranged from 6.5% to 12.9% of dry mass in fruits. The composition of oils was similar in the investigated species. 17 components were identified. An average composition was estimated as follows: linoleic acid (44.4-55.7%), a-linolenic acid (18.6-31.4%), oleic acid (13.5-20.3%), palmitic acid (2.3-3.3%), stearic acid (1-2.5%), octadecenoic acid (0.38-0.72%), eicosenoic acid (0.3-0.7%), eicosadienoic acid (0-0.16%), erucic acid (0.03-0.17%) and minor fatty acids. The results indicate that rose fruits are a rich source of unsaturated fatty acids, especially in R. rubiginosa, R. rugosa and R. dumalis. There were statistically significant (p<0.05) differences in fatty acid compositions of some species. Fatty acids were suggested to have a potential chemotaxonomic value in this genus.
The aim of this examination was optimization of flavonols' detection method in plant's extracts. The leaves of Rosa canina L. and Rosa damascena Mill, were chosen as the experi­mental material, due to their rich content of flavonols. In the study, optimization and comparison of extraction, hydrolysis and purification processes of samples predesti­nated to HPLC analysis of flavonol aglycones were performed. The most optimal method to detect flavonols in examined material was their direct hydrolysis with 1.2 N HCL dur­ing 1 h connected with its extraction with 50% methanol and then purification of the sample by SPE before HPLC examination. The comparison and evaluation of two elaborated methods of hydrolyzate purification from neutral compounds, which are liquid-liquid extraction (LLE) with ethyl acetate and solid phase extraction (SPE) in RP-18 microcolumns, were carried out. 78% recovery of standard quercetin during LLE and 98.8% recovery of standard quercetin during filtering and elution of hydrolyzate with methanol through octadecyl microcolumns in SPE method were observed. These results showed that SPE is better then LLE during superior sample purification procedure.
The aim of this examination was optimization of flavonols’ detection method in plant’s extracts. In the first stage of the research the analysis of standard aglycones mixture stability in different hydrolysis conditions was performed. It was shown, among others, that most of the flavonols aglycones presented high durability during heating with acid. Moreover, the significant impact of acidity of environment of the reaction (acid’s kind and concentration) on the height and surface area of analyzed compounds was observed. These facts indicate the necessity of using in quantitative analysis solutions of standards of pH similar to pH of analyzed hydrolyzates. Also the possibility of obtaining incorrect results while using sulfuric acid as hydrolytic medium of the examined extracts was shown.
W zielu Epilobium angustifolium i Epilobium parviflorum metodami spektrofotometrycznymi określono w przeliczeniu na suchą masę całkowitą zawartość polifenoli wolnych (9,1%; 8,7%) oraz po hydrolizie kwasowej (17,9%; 13,5%) i zasadowej (9,7%; 9,0%), ilość o-dihydroksyfenoli (3,1%; 2,1%) oraz sumy triterpenów i steroli (4,2%; 4,7%). Zawartość flawonoidów oznaczona metodą Christa-Müllera wynosi w zielu E. angustifolium 6,6%, a w E. parviflorum 5,9%, natomiast metodą Hagedorna-Neu'a odpowiednio 4,4% oraz 3,0%. W zielu E. angustifolium określono metodą wagową ogólną zawartość steroli jako 0,1331 g w 100 g surowca. Metodą RP-HPLC określono zawartość aglikonów flawonoidowych po hydrolizie kwasowej w tym surowcu: 0,42% kwercetyny, 0,37% kemferolu, 0,32% mirycetyny.
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