Polyprenols and triterpenoids from leaves of Alcea nudiflora

Abstract

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...

Trace Element Analysis in Some Plants Species by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES)

“…The genera Alcea and Malvella are belong to Malvaceae family. Malvaceae family plants are exceptional among leafy plants due to their high content of polyprenols, which are chemotaxonomic markers (Matthaus et al, 2003;Khidyrova et al, 2012). Genus Alcea are represented by about 70 species worldwide, distributing in Mediterranean and Iran-Turanian phytogeographical region (Baytop, 1999;Turkoglu, 2000).…”

Aliphatic and Terpene Constituents of Alcea nudiflora Extracts

“…The compositions of normal and branched hydrocarbons were determined more fully than in previous publications [8]. Normal alkanols with 20 and 22 carbon chains were detected.…”

“…Fatty acids were methylated by diazomethane for GC-MS analysis; neutral ones, without derivatization. GC-MS spectra were recorded on a Hewlett Packard G 1800A instrument as described before [8,16]. Kovats indices KI were calculated as before [17].…”

“…A total of 19 neutral constituents were detected and identified for the first time in this plant. The content and composition of polyprenols were determined by HPLC on a Milikhrom-2 instrument with UV detection at 210 nm using a column (7.0 u 0.2 cm) with ProntoSil 120-5-C18 sorbent under the published conditions [8]. The polyprenol content in the unsaponified residue was 9.8% for MTBE and 2.59% for EtOH.…”

Experimental Evaluation of the Immunotropic Effect of the Polyprenols From Vitis Vinifera

“…Chromatographic purification of polyprenols. This was performed as described in [6]. The yield of polyprenolsis 5.12 g (2.56% of air-dry mass) with a content 97.8%.…”