COMPARATIVE ANALYSIS OF FREON EXTRACTS FROM LIME FLOWERS CROPPED IN 2016 AND 2017 YEARS

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COMPARATIVE ANALYSIS OF FREON EXTRACTS FROM LIME FLOWERS CROPPED IN 2016 AND 2017 YEARS

Journal Title: Annals of Mechnikov Institute - Year 2018, Vol 0, Issue 2

Abstract

Introduction. The article is devoted to gas-liquid-chromatography analysis of the freon extracts taken from lime flowers cropped in 2016 and 2017 years. It’s well-known that quantitative content of a sum of extractives or active substances (and even their structure) can vary con-siderably in plants depending on harvesting place (and, hence, soils), harvest time, and, especially, weather condi-tions. This is the main reasons for difficulties in standard-ization of herbal drugs. Often they are standardized by total extractives, for some plant species there are no tech-niques of quantitative analysis at all in pharmacopoeias, such an example is lime flowers. Recently, in 2007, 2008, 2009 we studied lipophilic fractions from lime flowers and found slight differences in their quantitative and qual-itative compositions. The main aim was to compare chemical composition of volatile compounds in lipophilic freon extracts from lime flowers considering that springs and beginning of summers in 2016 and 2017 was charac-terized by abnormal weather conditions. Materials and methods. The herbal raw materials were lime flowers cropped from linden Tilia cordata within Kharkiv region in 2016 and 2017, comminuted to particle size 0,5-2,0 mm. They were extracted with condensed difluoro-chloromethane (freon R22) in two parallel connected per-colators of the experimental equipment. The extraction was two-stage at raw material : extracting solvent ratio 1:8 on each stage under constant circulation of a liquid phase. The minimum pressure and temperature were 12 atm and +30°С accordingly, maximum ones – 17 atm and +45°С. Total exposure of the process took about 2 hours on each stage. The extracts were dissolved in methylene chloride to make 1,00 % solution which was entered into the front injector of gas-chromato-mass-spectrograph «Agilent Technology 6890» (USA) including two conse-quently connected columns: Agilent 19091S-433HP-5MS, filled with adsorbed 5 % Phenyl-Methyl-Silox, and Agilent 165-6626 USB369911A, and also mass selective detector 5973N. The oven was programmed as follows: equilibration time – 0.5 min, temperature – from 50°C to 250 °C with rate 4°C/min, then 30°C/min to 300 °C, max-imum temperature was 325°C, runtime – 51,667 min. Carrier gas was helium: in the first column the flow rate - 1 ml/min under 14,313 psi, and in the second one – 3,8 ml/min at initial pressure 3,8 psi, and in the outlet vacuum was provided. Transferring from gas-liquid chromato-graph (GLC) to mass spectrometer occurred at 230°С. The detector and evaporator temperature was supported at 150°С. Electron ionization was spent at 70 eV in range of masses from m/z 29 to 450. Identification of compounds was carried out by comparison of the acquired mass spec-tra with the data of existing libraries (about 500000 sub-stances). Pentadecane was used as the internal standard. Quantitative content of each substance expressed in per-centage of total assay weight of the sample was deter-mined by areas of corresponding peaks considering that 109 standard units of an area corresponded to 0,002 mg of a substance in the assay. Besides, relative percentage con-tent of each substance in the assays was calculated. All solvents and chemicals were of analytical grade. Chroma-tographic experiments were reproduced in triplicate. Re-sults and discussion. On the chromatograms of the difluorochloromethane extracts from lime flowers cropped in 2016 and 2017 on the territory of Kharkiv re-gion 80 and 68 volatile substances were found according-ly. Most of them have retention times more than 35 minutes. Samples of 2017 contained more volatile sub-stances with shorter retention times if compare with ex-tracts obtained from 2016 crop. Total yield of the freon extract in 2016 was 2,75 %, and in 2017 – 1,42 % recal-culated on dry weight of raw materials studied. Prevailing chemical groups of substances were aliphatic hydrocar-bons and fatty acids, also there were alcohols and terpe-noids in appreciable quantities. In the sample of 2016 total quantitative contents of aliphatic hydrocarbons, aro-matic alcohols and terpenoids were approximately 3 times more in comparison with 2017. At the same time, fatty acids, especially unsaturated, and also aldehydes and ke-tones were found to be much less, and esters were absent at all in 2016 samples. The freon extract of lime flowers cropped in 2016 consisted of 14 substances which relative content exceeded 1 % with total contain 78,7 % of the whole assay, where the dominating ones were: hexatri-acontane - 18,73 %, n-hexadecanoic acid - 12,75 %, lino-leic alcohol - 10,68 %, 1-pentadecene - 10,57 %. The fre-on extract of the raw material of 2017 crop included 13 substances with total contain 84,14 % of the whole assay weight from which the prevailing ones are: oleic, octade-canoic, hexadecanoic acids with concentrations 27,68 %, 15,02 % and 12,91 % respectively. Conclusions. The comparative analysis of the freon extracts from lime flowers cropped in 2016 and 2017 years using method of gas-liquid chromatography has been carried out. Basing on results of gas-liquid chromatography it has been estab-lished that the samples obtained from raw materials of 2016 and 2017 years considerably differ in their quantita-tive and qualitative characteristics of essential oil frac-tions: the studied samples contained 80 and 68 com-pounds accordingly, total percentage of dominating sub-stances was 78,66% and 84,14% of the assays weight respectively. Thus, weather conditions which can change dramatically in spring from year to year in Ukraine, espe-cially in its Northeast part, strongly influence accumula-tion of volatile compounds in lime flower.

Authors and Affiliations

D. V. , Demyanenko, A. A. , Sichkar, L. A. Karpenko

Keywords

difluorochoromethane extraction lime flow-er gas-liquid chromatography.

EP ID EP612795
DOI 10.5281/zenodo.1303973
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