Enoyl-(ACYL-Carrier-Protein) Reductase Inhibitory Components From Taraxacum

The fatty acid is an important component of the cell membrane. So the fatty acid synthesis is necessary in bacterial body. The study aimed to discovery active ingredients and mechanism of inhibit enoyl-(acyl-carrier-protein) reductase from dandelion in Changbai Mountain.Dandelion is a commonly used Chinese medicine of detoxification around the country wild. For the treatment of breast carbuncle, furuncle swollen poison, scrofula, conjunctival congestion, sore throat, damp heat jaundice and hot shower acerbity pain and so on. Modern pharmacological studies have shown that, The dandelion with antioxidant, antibacterial, antitumor and anti-inflammatory effect. Most pharmacological studies are dandelion crude extracts for the study. In order to further study its antibacterial active ingredients, This experiment by streptococcus mutans track purification has bacteriostatic activity of the monomer compounds in dandelion, Provide a theoretical basis for the the dandelion pharmacological research and clinical applications, this study made systemic research with dandelion whitch was collected from Helong, Jilin.This experiment on the dandelion aerial part and underground part separately in50%ethanol reflux extraction, then extract was extracted with petroleum ether and ethyl acetate. Staphylococcus aureus and streptococcus mutans for each component screening in vitro bacteriostasis experiment. Determine the dandelion antibacterial activity effective parts is petroleum ether and ethyl acetate parts.The ground part of petroleum ether layer as the strongest active site.Using silicagel column chromatography, gel column chromatography and HPLC separation method and by streptococcus mutans track separation and purification of petroleum ether and ethyl acetate extraction, aerial part and underground part of petroleum ether layer separation wasn’t getting the monomer compounds with antimicrobial activity, The above-ground part of the ethyl acetate layer was separated to give2having antibacterial activity of the monomer compound. From the aerial parts of petroleum ether layer was separated to obtain a compound. Application spectrum technique (1H-NMR,13C-NMR,1H-1H COSY, GC-MS, etc.) and various chemical methods identified its structure. Linolenic acid (Ⅰ) and linoleic acid (II) respectively. Structural modifications of compounds I and II:will compound I and compound II respectively with H2SO4/CH3OH react get compounds linoleic acid methyl ester (IV) and linolenic acid methyl ester (V). Compounds Ⅳ and V structures were confirmed by’H-NMR.The minimum bacteriostatic concentration (MIC) values of staphylococcus aureus, escherichia coli, streptococcus mutans, bacillus subtilis,etc was test with a two-fold serial dilution method. Which compounds Ⅰ and Ⅱ on staphylococcus aureus, MIC value is128μg/mL and64μg/mL, streptococcus mutans MIC value is16μg/mL and16μg/mL, bacillus subtilis MIC values is4μg/mL and4μg/mL, Compound Ⅱ also has antibacterial activity of methicillin-resistant Staphylococcus aureus and quinolone-resistant Staphylococcus aureus, MIC value is64μg/mL. But compound Ⅲ, compound IV and V had no activity of the above strains.The experimental test compound Ⅰ to V bacterial fatty acid synthase (Fab) inhibitory activity, the result compounds Ⅰ and Ⅱ on the FabI IC50(uM) value were30.2and75.2, the other three compounds were not showed an inhibitory effect on FabI. Compound I to the compound V showed no inhibitory activity of FabK and FabG. In straight-chain fatty acids, carboxyl groups is the antibacterial action of necessity, and its antimicrobial activity was associated with fatty acid unsaturation.