Lipids from Flowers and Leaves of Artemisia annua and Their Biological Activity

Abstract

Chemical, chromatographic, and spectral methods were used to show that the main components of the lipid extract of flowers and leaves are free and bound aliphatic and cyclic alcohols (sterols and triterpenols) and essential oil. It was shown that the lipid extract of Artemisia annua has a positive influence on skin metabolism and possesses anti-inflammatory activity.Key words: Artemisia annua, hydrocarbon extract, polar lipids, fatty acids, skin metabolism, anti-inflammatory activity.Artemisia annua L. (annual wormwood, Asteraceae) grows in Central Asia, Siberia, Europe, North Africa, and America [1]. The antimalarial preparation artemisinin is isolated from its aerial part [2]. Furthermore, annual wormwood is a source of essential oil, the content of which is highest during flowering, ~0.7% of the dry mass [3].The plant lipids are practically unstudied. Only the isolation and identification of four lipophilic components have been reported [4]. Data on the pharmacological properties of these lipids are also lacking.Neutral lipids were isolated from the air-dried flowers and leaves by hydrocarbon (bp 75-80°C) extraction. Then, polar lipids were extracted from the remaining pulp by CHCl 3 :CH 3 OH (2:1 by vol). The CHCl 3 :CH 3 OH extract was purified of nonlipid components by washing with aqueous CaCl 2 (0.05%). The yield of neutral lipids was 4.3% of the air-dried mass; of polar, 4.2%.The hydrocarbon extract was brown and thick and had a characteristic wormwood odor. The carotinoid content was 240 mg%. The acid number of the extract was 1.5 mg KOH.Essential oil was separated from the hydrocarbon extract by steam distillation. The yield was 13.0% of the extract mass and ~0.55% of the dry mass. We have previously reported the composition of the essential oil [5].The total substances remaining after removal of essential oil were extracted from the aqueous layer by diethylether. The ether was removed. The extracted substances were separated by column chromatography over silica gel into individual fractions, extracting them with hexane with a gradually increasing concentration of diethylether from 0 to 100%. Substances were identified by TLC on silica gel using solvent systems 1 and 2 and comparison with model samples of lipids and lipophilic components, qualitative reactions, GC, and mass spectrometry. The contents of the substances were determined gravimetrically (Table 1).It can be seen that paraffins and olefinic hydrocarbons dominate the extract. According to mass spectrometry, they include saturated components of the C 32 -C 20 series (m/z 450-282 [M] + ), monoenes C 38 -C 20 (m/z 532-280 [M] + ), dienes and trienes C 38 -C 28 (m/z 530-390, 528-388 [M] + ), tetraenes C 38 -C 27 (m/z 526-372 [M] + ), and pentaenes C 38 -C 30 (m/z 524-412 [M] + ).The fraction of esters of aliphatic and cyclic alcohols consisted according to mass spectrometry of a combination of saturated fatty acids of the series 24:0-10:0 and unsaturated 18:1, 18:2, and 18:3 with aliphatic alcohols of the series C 30 -C 16 , stigmasterol, β-sitos...

Screening of new solvents for artemisininextraction process using ab initio methodology

“…4% of the total lipid content, the major components being C 38 -C 20 saturated and unsaturated linear hydrocarbons. 46 In our own studies we identified 16 : 0 hexadecanoic (palmitic), 14 : 0 tetradecanoic (myristic) and 12 : 0 dodecanoic (lauric) acids as the main fatty acid compounds; dodecanoic acid was used in a representative simulation. The class of flavones is represented by casticin (23, ESI †), which is often found in A. annua extracts.…”

Comparative Assessment of Technologies for Extraction of Artemisinin

“…9 Recently, the lipid content of A. annua was analyzed and the medicinal effect of lipophilic extracts on the skin investigated. 14 Although there is already a limited commercial use of other than artemisinin compounds of the plant to produce cosmetics and flavorings, there is a significant scope to increase the commercial value of A. annua cultivation by more complete utilization of different biomolecules, i.e., the biorefinery concept. 15 The World Health Organization (WHO) estimated that they will require 120 million courses (adult equivalent) of artemisinin-based combination therapies (ACTs) in 2006, 16 although up to 500 million cases of malaria are reported to occur annually worldwide.…”

Importance of phytosterols and their determination in herbal medicines

“…β-sitosterol and stigmasterol are found in A. annua [14,15]. These compounds have intense antiviral effect [16] and antifungal properties [17].…”