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Polyprenols and triterpenoids from leaves of Alcea nudiflora were studied for the first time. It was shown that the principal components of the unsaponified fraction were polyprenols, sterols, a phytol, and tocopherols. The composition of the polyprenols from Alcea nudiflora was established. Minor components of polyprenols with chain lengths 8, 9, and 14 isoprene units were observed for the first time in plants of the genus Alcea. A total of 28 terpene components of the unsaponified fraction, 26 of which were not previously observed in this species, were determined by GC-MS.Plants of the family Malvaceae are exceptional among leafy plants because of their high content of polyprenols (PPs), which are chemotaxonomic markers [1][2][3][4][5][6]. Such plants also have a characteristically high content of cyclopropane acids, which are practically not observed in plants of other families [7].Alcea nudiflora belongs to this family, is widely distributed, and is common in the plant cover of the whole Tian-Shan (Chatkal, Kuramin, Ugam, Pskom, etc. ranges) and Pamir-Alai (Alai, Turkestan, Nuratau, Zarafshan, etc. ranges) [8-10]. However, neutral triterpenoids and bioactive PPs from this plant are insufficiently studied [11].Various qualitative and quantitative analytical methods for PPs and dolichols from plant material have been reported. However, each of them has certain shortcomings. Thus, comparison of HPLC analyses of an extract and a chromatographic standard concentrate of PPs does not consider seasonal cycles of the component ratio in plant material according to vegetation periods. Furthermore, PPs and dolichols in certain plant species are present as esters of aliphatic acids that are unsuitable for HPLC analysis [12,13]. HPLC with refractive-index detection also has shortcomings. Normalization to the total peak area in the chromatogram does not consider differences in the extinction or refraction.PMR analysis of polyisoprenoid concentrates also has several shortcomings. A PMR spectrum of a PP sample is a superposition of resonances of similar structural fragments. The regular structure of the PPs produces total resonances that are stronger than those of impurities. This leads to a substantial overestimation of the quantitative characteristics of the studied PP fraction. Solanesol can be cited as an example [14].Use of densitometry of thin-layer chromatograms compared with a standard [15] also usually causes substantial overestimation of quantitative results because accompanying mono-, sesqui-, and diterpene alcohols overlap the spot for the PP fraction. Thus, borneol, cis-abienol, isoabienol, dehydroabietinol, and other alcohols that enhanced the intensity of the PP spot were present as impurities in the total fraction during a study of PPs from conifers [16,17]. Bisabolol was isolated from essential oil of cotton buds [18]. The chromatographic mobility of total extracted compounds depends on the chain length of the PPs in them and their form (as alcohols or esters). Therefore it is practically impossible to choose...
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Neutral substances, carbohydrates, and microelements from the aerial part of Silene viridiflora in addition to the protein content and its amino-acid composition were determined.The literature indicates that the genus Silene (Caryophyllaceae) has the highest content of ecdysteroids [1][2][3][4][5][6][7][8]. The maximum amount of phytoecdysteroids in the aerial part of plants of the genus Silene L. accumulates during budding and flowering [9]. The aerial part of S. viridiflora L. (budding phase) is a promising source of phytoecdysteroids for practical application.We carried out a comprehensive investigation of the chemical composition of the principal classes of natural compounds in S. viridiflora (ripening phase) collected in Tashkent at the experimental plot of the S. Yu. Yunosov ICPS of the ASRU [10].Fresh raw material was dried in the shade at 20-25°C to a residual moisture content of 2.7%. Ground leaves and roots were extracted with (C 2 H 5 ) 2 O, CHCl 3 , C 2 H 5 OH, and CH 3 OH to isolate the extracable substances (ES). The ES content in the leaves was 4.2, 3.8, 12.6, and 17.3% whereas the values in the roots were 2.4, 3.2, 6.0, and 13.1%, respectively. TLC of the neutral part identified [11] the following compounds: sitosterol, stigmasterol, polyisoprenoids, and α-tocopherol, the contents of which were 0.08, 0.02, 0.01, and 0.005% of the air-dried mass (ADM) of plant material.Proteins were extracted under alkaline conditions by borate buffer (0.2 M, pH 9.0) as before [12]. The protein content was determined by the Kjeldahl method [13]. The protein yield was 5.88 wt. %.The amino-acid composition of the isolated protein was determined after acid hydrolysis on an amino-acid analyzer. A total of 17 amino acids was observed in the hydrolysate. Table 1 lists the results. The quantitative determination of amino acids in the protein hydrolysate from S. viridiflora showed that the protein contained essential amino acids -histidine, isoleucine, leucine, lysine, phenylalanine, methionine, threonine, valine, and arginine.The content of organic acids was determined as before [14]. It made up 8.32% calculated as malic acid in the absolute dry raw material.Remaining raw material was boiled with alcohol (80°) to determine the sugars soluble in alcohol (SSA). SSA extracts were purified with lead acetate (10%) and Na 2 SO 4 . Purified SSA solutions were evaporated to dryness. Paper chromatography (PC) (system 1) detected the following sugars that were characteristic of all plant organs: galactose, glucose, arabinose, and rhamnose in various ratios. Water-soluble polysaccharides (WSPS-1 and WSPS-2) were extracted by treating the raw material with water at room temperature and on a water bath at 70°C. Pectinic substances (PS) were obtained using oxalic-acid solution (0.5%). Table 2 gives the percent content of carbohydates and shows that the amount of free sugars is highest in leaves. WSPS-1 accumlated in roots; PS, in stems.Solutions of WSPS-1 and WSPS-2 were condensed and precipitated with alcohol (1:3). Dried samples were...
The accumulation dynamics of polyprenols in leaves of 1-, 2-, and 3-year-old Althaea armeniaca growing in Tashkent were studied according to vegetative phase. Optimal conditions for isolating the polyprenols were determined. It has been shown that the content of polyprenols was highest during fruiting in the second year of growth.
UDC 631.523A method has been developed for isolating polyprenolsfrom the leaves of cotton plants of lines L-463, L-501, and L-4. The influence of an undecaprenol on the level of biosynthesis of the proteins of the nuclei of cotton seedlings has been studied in vivo and in vitro. It has been found that they double the level of biosynthesis nuclear proteins when the seeds are first wetted in a O. 1% solution.Polyprenols, which belong to the class of natural polyisoprenoids, are distributed in the green parts of many plants. They have the general formula H-(CH2-C(CH 3) = CH-CH2)n-OH, where the number of isoprenoid residues (n) varies from one plant family to another (for example, n = 11-13 for the cotton plant).In the leaves of various species of trees polyprenol is found in the form of esters with acetic acid [1] and with higher fatty acids [2]. Plants of different families have different compositions of their polyprenols: in broad-leaved species of trees the number of isoprene units in the molecular chain ranges from 6 to 12 [3, 41 and in conifers from 10 to 20 [1, 5]. The amount of polyprenols varies according to the phase of development of the leaves, from 0.08% (in June) to 1.25% (in September).The interest in polyprenols that has arisen in recent years is due mainly to the important role that they play as lipophilic precursors of sugars in the biosynthesis of bacterial polysaccharides and glycoproteins [7]. We have recently discovered a capacity of polyprenols for opening the Ca 2+ channels of bilayer membranes [8].The synthesis of polyprenols is a multistage process [4, 5]. The finding of new natural sources will open up prospects for the creation from them of drugs and other agents with a high penetrating capacity --for example, plant-protecting agents with improved membrane properties.It must be mentioned that the biological function of endogenous polyprenols still remains unclear, although reviews have appeared both on their synthesis [9] and on their biological activity [10].In the present paper we give results on the isolation of polyprenols from the leaves of cotton plants of lines L-463, L-501, and L-4, in which their level amounts to 1-3% of the air-dry mass, and also on the influence of undecaprenol on the biochemical reactions of cotton seedling nuclei.Undecaprenol predominated in all the cotton plant lines (Table 1). The undecaprenol:dodecaprenol ratio was 2:1 for L-501 and L-4 and almost 3:1 for L-463.From the leaves of an L-4 cotton plant we succeeded in isolating undecaprenol with a purity greater than 98 %, as was confirmed by the results of physical methods of analysis. Its mass spectrum included the peaks of the molecular ion with m/z 766 (C55H900) and fragments with m/z 748 (M + -H20) and 698 (M + -68).The following signals were observed in the PMR spectrum: two singlets at 1.62 and 1.54 ppm from cis-and transmethyl groups in a ratio of 2:1, a multiplet in the 1.90-2.05 ppm region with its center at 1.96 ppm from the methylene groups of the isoprenoid chain, a doublet with its center at 3....
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